Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Chromosome Banding: Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.X Chromosome: The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.Chromosome Aberrations: Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.Genes, Plant: The functional hereditary units of PLANTS.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Sex Chromosomes: The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Chromosomes, Human, Pair 1: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Chromosomes, Human: Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosome Segregation: The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.Chromosomes, Human, Pair 7: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 11: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Chromosomes, Human, Pair 17: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Plant Shoots: New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.Chromosomes, Human, Pair 6: A specific pair GROUP C CHROMSOMES of the human chromosome classification.Chromosome Deletion: Actual loss of portion of a chromosome.Chromosomes, Human, Pair 9: A specific pair of GROUP C CHROMSOMES of the human chromosome classification.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Chromosomes, Human, Pair 21: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosomes, Fungal: Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosomes, Human, 6-12 and X: The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Chromosomes, Human, Pair 2: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Chromosomes, Human, Pair 16: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosome Pairing: The alignment of CHROMOSOMES at homologous sequences.Chromosomes, Human, Pair 22: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosomes, Mammalian: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.Chromosomes, Human, Pair 13: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Plant Development: Processes orchestrated or driven by a plethora of genes, plant hormones, and inherent biological timing mechanisms facilitated by secondary molecules, which result in the systematic transformation of plants and plant parts, from one stage of maturity to another.Chromosomes, Human, Pair 4: A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 10: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Y: The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.Chromosomes, Human, Pair 8: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 19: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Chromosome Disorders: Clinical conditions caused by an abnormal chromosome constitution in which there is extra or missing chromosome material (either a whole chromosome or a chromosome segment). (from Thompson et al., Genetics in Medicine, 5th ed, p429)Chromosomes, Human, X: The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.Chromosomes, Human, 1-3: The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.Chromosome Painting: A technique for visualizing CHROMOSOME ABERRATIONS using fluorescently labeled DNA probes which are hybridized to chromosomal DNA. Multiple fluorochromes may be attached to the probes. Upon hybridization, this produces a multicolored, or painted, effect with a unique color at each site of hybridization. This technique may also be used to identify cross-species homology by labeling probes from one species for hybridization with chromosomes from another species.Chromosomes, Human, Pair 12: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 5: One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).Plants, Toxic: Plants or plant parts which are harmful to man or other animals.Chromosomes, Human, Pair 15: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Plant Cells: Basic functional unit of plants.Karyotyping: Mapping of the KARYOTYPE of a cell.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 18: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Chromosomes, Human, 16-18: The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.Chromosomes, Human, Pair 20: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Chromosomes, Artificial, Yeast: Chromosomes in which fragments of exogenous DNA ranging in length up to several hundred kilobase pairs have been cloned into yeast through ligation to vector sequences. These artificial chromosomes are used extensively in molecular biology for the construction of comprehensive genomic libraries of higher organisms.Plant Stems: Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Chromosomes, Human, 13-15: The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.Chromosome Breakage: A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.Chromosomes, Human, 21-22 and Y: The short, acrocentric human chromosomes, called group G in the human chromosome classification. This group consists of chromosome pairs 21 and 22 and the Y chromosome.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Ring Chromosomes: Aberrant chromosomes with no ends, i.e., circular.Chromosome Inversion: An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.Chromosome Positioning: The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.Chromosomes, Human, 4-5: The large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.Plants, Edible: An organism of the vegetable kingdom suitable by nature for use as a food, especially by human beings. Not all parts of any given plant are edible but all parts of edible plants have been known to figure as raw or cooked food: leaves, roots, tubers, stems, seeds, buds, fruits, and flowers. The most commonly edible parts of plants are FRUIT, usually sweet, fleshy, and succulent. Most edible plants are commonly cultivated for their nutritional value and are referred to as VEGETABLES.Plant Structures: The parts of plants, including SEEDS.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.X Chromosome Inactivation: A dosage compensation process occurring at an early embryonic stage in mammalian development whereby, at random, one X CHROMOSOME of the pair is repressed in the somatic cells of females.Centromere: The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.Plant Growth Regulators: Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Meiosis: A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.Chromosomes, Insect: Structures within the CELL NUCLEUS of insect cells containing DNA.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.Hybrid Cells: Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.Chromosome Structures: Structures which are contained in or part of CHROMOSOMES.Chromosomes, Human, 19-20: The short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Aneuploidy: The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).Metaphase: The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.Plant Immunity: The inherent or induced capacity of plants to withstand or ward off biological attack by pathogens.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Microsatellite Repeats: A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).Lod Score: The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."Pedigree: The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Plant Epidermis: A thin layer of cells forming the outer integument of seed plants and ferns. (Random House Unabridged Dictionary, 2d ed)Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Plant Stomata: Closable openings in the epidermis of plants on the underside of leaves. They allow the exchange of gases between the internal tissues of the plant and the outside atmosphere.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)Trisomy: The possession of a third chromosome of any one type in an otherwise diploid cell.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Nondisjunction, Genetic: The failure of homologous CHROMOSOMES or CHROMATIDS to segregate during MITOSIS or MEIOSIS with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none.Kinetochores: Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.Telomere: A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.Chromosomes, Artificial, Human: DNA constructs that are composed of, at least, all elements, such as a REPLICATION ORIGIN; TELOMERE; and CENTROMERE, required for successful replication, propagation to and maintainance in progeny human cells. In addition, they are constructed to carry other sequences for analysis or gene transfer.Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Chromosome Walking: A technique with which an unknown region of a chromosome can be explored. It is generally used to isolate a locus of interest for which no probe is available but that is known to be linked to a gene which has been identified and cloned. A fragment containing a known gene is selected and used as a probe to identify other overlapping fragments which contain the same gene. The nucleotide sequences of these fragments can then be characterized. This process continues for the length of the chromosome.Chromosomal Proteins, Non-Histone: Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Genetic Variation: Genotypic differences observed among individuals in a population.Spindle Apparatus: A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.Chromosomal Instability: An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.Lycopersicon esculentum: A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.Polyploidy: The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.Triticum: A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Flowers: The reproductive organs of plants.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Chromosome Fragility: Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.DNA, Satellite: Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.Chromosome Duplication: An aberration in which an extra chromosome or a chromosomal segment is made.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Plant Poisoning: Poisoning by the ingestion of plants or its leaves, berries, roots or stalks. The manifestations in both humans and animals vary in severity from mild to life threatening. In animals, especially domestic animals, it is usually the result of ingesting moldy or fermented forage.DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Plant Transpiration: The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Plant Tumors: A localized proliferation of plant tissue forming a swelling or outgrowth, commonly with a characteristic shape and unlike any organ of the normal plant. Plant tumors or galls usually form in response to the action of a pathogen or a pest. (Holliday, P., A Dictionary of Plant Pathology, 1989, p330)DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Chromatids: Either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. The chromatids are held together at the centromere. Sister chromatids are derived from the same chromosome. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Mosaicism: The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.Gene Dosage: The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.Plant Components, Aerial: The above-ground plant without the roots.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Abnormalities, MultipleDNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.DNA Replication: The process by which a DNA molecule is duplicated.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Polytene Chromosomes: Extra large CHROMOSOMES, each consisting of many identical copies of a chromosome lying next to each other in parallel.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Prophase: The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.Interphase: The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Seedling: Very young plant after GERMINATION of SEEDS.Transformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Cosmids: Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.Polymorphism, Restriction Fragment Length: Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.Plant Preparations: Material prepared from plants.Chromatin: The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Loss of Heterozygosity: The loss of one allele at a specific locus, caused by a deletion mutation; or loss of a chromosome from a chromosome pair, resulting in abnormal HEMIZYGOSITY. It is detected when heterozygous markers for a locus appear monomorphic because one of the ALLELES was deleted.Cytogenetic Analysis: Examination of CHROMOSOMES to diagnose, classify, screen for, or manage genetic diseases and abnormalities. Following preparation of the sample, KARYOTYPING is performed and/or the specific chromosomes are analyzed.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Cytogenetics: A subdiscipline of genetics which deals with the cytological and molecular analysis of the CHROMOSOMES, and location of the GENES on chromosomes, and the movements of chromosomes during the CELL CYCLE.Sequence Tagged Sites: Short tracts of DNA sequence that are used as landmarks in GENOME mapping. In most instances, 200 to 500 base pairs of sequence define a Sequence Tagged Site (STS) that is operationally unique in the human genome (i.e., can be specifically detected by the polymerase chain reaction in the presence of all other genomic sequences). The overwhelming advantage of STSs over mapping landmarks defined in other ways is that the means of testing for the presence of a particular STS can be completely described as information in a database.Power Plants: Units that convert some other form of energy into electrical energy.Karyotype: The full set of CHROMOSOMES presented as a systematized array of METAPHASE chromosomes from a photomicrograph of a single CELL NUCLEUS arranged in pairs in descending order of size and according to the position of the CENTROMERE. (From Stedman, 25th ed)Gene Rearrangement: The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.Hordeum: A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Fabaceae: The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.Bacterial Proteins: Proteins found in any species of bacterium.Herbivory: The act of feeding on plants by animals.Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.Chromosome Fragile Sites: Specific loci that show up during KARYOTYPING as a gap (an uncondensed stretch in closer views) on a CHROMATID arm after culturing cells under specific conditions. These sites are associated with an increase in CHROMOSOME FRAGILITY. They are classified as common or rare, and by the specific culture conditions under which they develop. Fragile site loci are named by the letters "FRA" followed by a designation for the specific chromosome, and a letter which refers to which fragile site of that chromosome (e.g. FRAXA refers to fragile site A on the X chromosome. It is a rare, folic acid-sensitive fragile site associated with FRAGILE X SYNDROME.)Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Genes, Bacterial: The functional hereditary units of BACTERIA.Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Ploidies: The degree of replication of the chromosome set in the karyotype.Sex Chromosome Disorders: Clinical conditions caused by an abnormal sex chromosome constitution (SEX CHROMOSOME ABERRATIONS), in which there is extra or missing sex chromosome material (either a whole chromosome or a chromosome segment).Genes, X-Linked: Genes that are located on the X CHROMOSOME.Biomass: Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.Monosomy: The condition in which one chromosome of a pair is missing. In a normally diploid cell it is represented symbolically as 2N-1.Haploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.Spermatocytes: Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.Cell Line: Established cell cultures that have the potential to propagate indefinitely.

A new FISH protocol with increased sensitivity for physical mapping with short probes in plants. (1/1662)

Fluorescence in situ hybridization (FISH) is a well-established technique used for the detection of specific DNA regions, that has been applied to interphase nuclei, pachytene and metaphase chromosomes as well as to extended DNA fibres. This technique allows the physical mapping of specific DNA sequences both on individual chromosomes and extended fibres. A new FISH protocol is described here that enhances the sensitivity of the method. Probes for small unique DNA sequences of less than 2 kb give high signal-to-noise ratio with this method, and can be visualized easily by means of conventional fluorescence microscopy.  (+info)

Quantitative trait loci for component physiological traits determining salt tolerance in rice. (2/1662)

Rice (Oryza sativa) is sensitive to salinity, which affects one-fifth of irrigated land worldwide. Reducing sodium and chloride uptake into rice while maintaining potassium uptake are characteristics that would aid growth under saline conditions. We describe genetic determinants of the net quantity of ions transported to the shoot, clearly distinguishing between quantitative trait loci (QTL) for the quantity of ions in a shoot and for those that affect the concentration of an ion in the shoot. The latter coincide with QTL for vegetative growth (vigor) and their interpretation is therefore ambiguous. We distinguished those QTL that are independent of vigor and thus directly indicate quantitative variation in the underlying mechanisms of ion uptake. These QTL independently govern sodium uptake, potassium uptake, and sodium:potassium selectivity. The QTL for sodium and potassium uptake are on different linkage groups (chromosomes). This is consistent with the independent inheritance of sodium and potassium uptake in the mapping population and with the mechanistically different uptake pathways for sodium and potassium in rice under saline conditions (apoplastic leakage and membrane transport, respectively). We report the chromosomal location of ion transport and selectivity traits that are compatible with agronomic needs and we indicate markers to assist selection in a breeding program. Based upon knowledge of the underlying mechanisms of ion uptake in rice, we argue that QTL for sodium transport are likely to act through the control of root development, whereas QTL for potassium uptake are likely to act through the structure or regulation of membrane-sited transport components.  (+info)

The Arabidopsis eer1 mutant has enhanced ethylene responses in the hypocotyl and stem. (3/1662)

By screening for enhanced ethylene-response (eer) mutants in Arabidopsis, we isolated a novel recessive mutant, eer1, which displays increased ethylene sensitivity in the hypocotyl and stem. Dark-grown eer1 seedlings have short and thick hypocotyls even in the absence of added ethylene. This phenotype is suppressed, however, by the ethylene biosynthesis inhibitor 1-aminoethoxyvinyl-glycine. Following ethylene treatment, the dark-grown eer1 hypocotyl response is greatly exaggerated in comparison with the wild type, indicating that the eer1 phenotype is not simply due to ethylene overproduction. eer1 seedlings have significantly elevated levels of basic-chitinase expression, suggesting that eer1 may be highly sensitive to low levels of endogenous ethylene. Adult eer1 plants display exaggerated ethylene-dependent stem thickening, which is an ethylene response previously unreported in Arabidopsis. eer1 also has enhanced responsiveness to the ethylene agonists propylene and 2,5-norbornadiene. The eer1 phenotype is completely suppressed by the ethylene-insensitive mutation etr1-1, and is additive with the constitutive ethylene-response mutation ctr1-3. Our findings suggest that the wild-type EER1 product acts to oppose ethylene responses in the hypocotyl and stem.  (+info)

The molecular genetic linkage map of the model legume Medicago truncatula: an essential tool for comparative legume genomics and the isolation of agronomically important genes. (4/1662)

BACKGROUND: The legume Medicago truncatula has emerged as a model plant for the molecular and genetic dissection of various plant processes involved in rhizobial, mycorrhizal and pathogenic plant-microbe interactions. Aiming to develop essential tools for such genetic approaches, we have established the first genetic map of this species. Two parental homozygous lines were selected from the cultivar Jemalong and from the Algerian natural population (DZA315) on the basis of their molecular and phenotypic polymorphism. RESULTS: An F2 segregating population of 124 individuals between these two lines was obtained using an efficient manual crossing technique established for M. truncatula and was used to construct a genetic map. This map spans 1225 cM (average 470 kb/cM) and comprises 289 markers including RAPD, AFLP, known genes and isoenzymes arranged in 8 linkage groups (2n = 16). Markers are uniformly distributed throughout the map and segregation distortion is limited to only 3 linkage groups. By mapping a number of common markers, the eight linkage groups are shown to be homologous to those of diploid alfalfa (M. sativa), implying a good level of macrosynteny between the two genomes. Using this M. truncatula map and the derived F3 populations, we were able to map the Mtsym6 symbiotic gene on linkage group 8 and the SPC gene, responsible for the direction of pod coiling, on linkage group 7. CONCLUSIONS: These results demonstrate that Medicago truncatula is amenable to diploid genetic analysis and they open the way to map-based cloning of symbiotic or other agronomically-important genes using this model plant.  (+info)

The molecular characterization of maize B chromosome specific AFLPs. (5/1662)

The origin and evolution of B chromosomes could be explained by the specific DNA sequence on them. But the specific sequences known were quite limited. To investigate maize B chromosome sqicific DNA sequeces, maize genomes with and without B chromosomes were analyzed by AFLP. Only 5 markers were found specific to genomes with B chromosomes among about 2000 AFLP markers. Southern hybridization and sequence analysis revealed that only the sequence of M8-2D was a B chromosome specific sequence. This sequence contained the telomeric repeat unit AGG  (+info)

Maize tertiary trisomic stocks derived from B-A translocations. (6/1662)

Reciprocal translocations between supernumerary B chromosomes and the basic complement of A chromosomes in maize have resulted in a powerful set of tools to manipulate the dosage of chromosomal segments. From 15 B-A reciprocal translocation stocks that have the B-A chromosome genetically marked we have developed tertiary trisomic stocks. Tertiary trisomics are 2n + 1 aneuploids where the extra chromosome is a translocation element, in this case a B-A chromosome. Whereas B-A translocations produce aneuploidy in the sperm, the tertiary trisomic plant efficiently transmits hyperploid gametes maternally. Because the B-A tertiary trisomic stocks and the B-A translocation stocks from which they were derived are introgressed into the W22 inbred line, the effects of maternally and paternally transmitted trisomic B-A chromosomes can be compared. Data are presented on both the male and female transmission rates of the B-A chromosomes in the tertiary trisomic stocks.  (+info)

Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis. (7/1662)

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1.  (+info)

A molecular cytogenetic map of sorghum chromosome 1. Fluorescence in situ hybridization analysis with mapped bacterial artificial chromosomes. (8/1662)

We used structural genomic resources for Sorghum bicolor (L.) Moench to target and develop multiple molecular cytogenetic probes that would provide extensive coverage for a specific chromosome of sorghum. Bacterial artificial chromosome (BAC) clones containing molecular markers mapped across sorghum linkage group A were labeled as probes for fluorescence in situ hybridization (FISH). Signals from single-, dual-, and multiprobe BAC-FISH to spreads of mitotic chromosomes and pachytene bivalents were associated with the largest sorghum chromosome, which bears the nucleolus organizing region (NOR). The order of individual BAC-FISH loci along the chromosome was fully concordant to that of marker loci along the linkage map. In addition, the order of several tightly linked molecular markers was clarified by FISH analysis. The FISH results indicate that markers from the linkage map positions 0.0-81.8 cM reside in the short arm of chromosome 1 whereas markers from 81.8-242.9 cM are located in the long arm of chromosome 1. The centromere and NOR were located in a large heterochromatic region that spans approximately 60% of chromosome 1. In contrast, this region represents only 0.7% of the total genetic map distance of this chromosome. Variation in recombination frequency among euchromatic chromosomal regions also was apparent. The integrated data underscore the value of cytological data, because minor errors and uncertainties in linkage maps can involve huge physical regions. The successful development of multiprobe FISH cocktails suggests that it is feasible to develop chromosome-specific "paints" from genomic resources rather than flow sorting or microdissection and that when applied to pachytene chromatin, such cocktails provide an especially powerful framework for mapping. Such a molecular cytogenetic infrastructure would be inherently cross-linked with other genomic tools and thereby establish a cytogenomics system with extensive utility in development and application of genomic resources, cloning, transgene localization, development of plant "chromonomics," germplasm introgression, and marker-assisted breeding. In combination with previously reported work, the results indicate that a sorghum cytogenomics system would be partially applicable to other gramineous genera.  (+info)

  • Dilkes said future research would focus on chromosome imbalances in crop plants such as corn and trying to understand how the excess or deficiency of a gene leads to a particular phenotypic characteristic. (
  • These limitations stimulated the development of a chromosome-based vector system suitable for transferring large genes, gene complexes, and/or multiple genes together with regulatory elements for safe, controlled, and persistent expression, avoiding rearrangements that are often linked with insertion events. (
  • This elegant in vivo approach was an important step toward constructing a gene delivery system based on engineered human chromosomes ( Lim and Farr, 2004 ). (
  • The leaf rust resistance gene in RL6077 is phenotypically similar to Lr34 which is located on chromosome 7D. (
  • It was previously hypothesized that the gene in RL6077 could be Lr34 translocated to another chromosome. (
  • Since no other known Lr genes exist on chromosome 4DL, the APR gene in RL6077 has been assigned the name Lr67 . (
  • Dyck PL (1987) The association of a gene for leaf rust resistance with the chromosome 7D suppressor of stem rust resistance in common wheat. (
  • To accelerate gene isolation from plants by positional cloning, vector systems suitable for both chromosome walking and genetic complementation are highly desirable. (
  • Furthermore, it has the cis sequences required for Agrobacterium -mediated gene transfer into plants. (
  • Molecular genetic approaches have been applied to analysis and cloning of plant genes, particularly those involved in complex biological processes such as developmental regulation and gene expression cascades ( 1 , 2 ). (
  • This gene, PDA1, encodes a specific cytochrome P450 that confers resistance to pisatin, an antibiotic produced by pea plants. (
  • This suggests that the short arm of barley chromosome 6 carries the dwarf bunt resistance gene(s). (
  • The finding is only one of many insights revealed by the long-awaited cannabis genome map detailing gene arrangement on the chromosomes, published November 8, 2018, in the journal Genome Research . (
  • Drs. Hughes, Page, and van Bakel first got together in 2011 when they released the first draft of the cannabis genome, which was too fragmented to reveal gene position on chromosomes at the time. (
  • The results indicate that trisomy 5 disrupts gene expression throughout the genome and supports the production and/or retention of truncated copies of chromosome 5. (
  • One level, the folding and positioning of chromosomes inside the nucleus, has only recently been recognised as playing an important role in gene expression. (
  • In this PhD project, you will employ state-of-the-art molecular techniques including chromosome conformation capture (Hi-C), high-resolution microscopy and CRISPR/Cas9 gene editing technology. (
  • Our overarching long-term goal is to uncover novel principles in plant gene regulation and to identify novel targets for plant breeding against pests and for improved plant health. (
  • Through horizontal chromosome transfer (HCT) to a non-pathogenic strain, we also show that the accessory chromosome containing the SIX gene homologs is indeed a pathogenicity chromosome for cucurbit infection. (
  • The genome of Fo is typically divided into a set of eleven 'core' chromosomes, with sequences generally conserved in all Fusarium species, and responsible for housekeeping, and one or several transposon-rich and gene-poor 'accessory' chromosomes 13 . (
  • The terms chromosome and gene were used long before biologists really understood what these structures were. (
  • The Watson and Crick discovery made it possible to express biological concepts (such as the gene) and structures (such as the chromosome) in concrete chemical terms. (
  • Furthermore, alignments between thefive grass proto-chromosomes and the recently identified seveneudicot proto-chromosomes indicated that additional very activeepisodes of genome rearrangements and gene mobility occurredduring angiosperm evolution. (
  • Incontrast to mammals, paleogenomics has been poorly investigatedin plants as angiosperm species have undergone serial wholegenome or segmental duplications, diploidization, small-scale re-arrangements (translocations, gene conversions), and gene copyingevents that make comparative studies between and within themonocotyledon (mainly grasses) and eudicot families very chal-lenging. (
  • In addition, B. xylophilus possesses a unique complement of plant cell wall modifying proteins acquired by horizontal gene transfer, underscoring the impact of this process on the evolution of plant parasitism by nematodes. (
  • For example, chromosomal recombination can result in the loss of a gene on one chromosome and the gain of an extra copy on the sister chromosome. (
  • Gene duplication can involve not only whole genes, but also parts of genes, several genes, parts of a chromosome, or even entire chromosomes. (
  • Rice chromosome 1 is (G + C)-rich, especially in its coding regions, and is characterized by several gene families that are dispersed or arranged in tandem repeats. (
  • Therefore, we concluded that the symbiotic genes have integrated into the chromosome after horizontal gene transfer from a different strain. (
  • So, scientists have to transform many plants, and hope that at least one individual didn't have the transgene interrupt a native gene. (
  • But in addition to proteins involved with packaging, chromosomes are associated with proteins involved with DNA replication, DNA repair, and gene expression. (
  • Here we review the occurrence and role of repetitive DNA in Y chromosome evolution in various species with a focus on dioecious plants. (
  • The grass family is the fourth largest family of flowering plants (approximately 10,000 species) and includes wheat ( Triticum spp. (
  • Both Aegilops species had higher proportions of β-glucan compared to arabinoxylan (AX) than wheat lines, and elevated β-glucan content was also observed in wheat chromosome addition lines 5U, 7U, and 7M. (
  • In order to modulate H3 phosphorylation, root meristems of different plant species were treated with the protein phosphatase inhibitor cantharidin or with ice-water. (
  • Some species of Genlisea possess ultrasmall nuclear genomes, the smallest known among angiosperms, and some have been found to have chromosomes of diminutive size, which may explain why chromosome numbers and karyotypes are not known for the majority of species of the genus. (
  • Chromosome segment substitution lines (CSSLs) are powerful QTL mapping populations that have been used to elucidate the molecular basis of interesting traits of wild species. (
  • Studies on newly resynthesized Brassica napus and recently formed polyploids of Tragopogon suggest that genomic changes occur rapidly following allopolyploidization in some plant species ( 12 - 14 ). (
  • Many plant species, including important crops like wheat, are polyploids that carry more than two sets of genetically related chromosomes capable of meiotic pairing. (
  • Other ant species have more chromosomes. (
  • This species can have more B chromosomes than A chromosomes at times, but 2n=4. (
  • Broccoli , cabbage, kale , kohlrabi , brussels sprouts , and cauliflower are all the same species and have the same chromosome number. (
  • Although some contradictory cases have been reported, the large homogeneity of the chromosome number 2n = 22 is now known for 135 (33.5%) distinct species among genus Eucalyptus . (
  • All species in the genus Phaseolus have the same chromosome number, including common bean ( P. vulgaris ), runner bean ( P. coccineus ), tepary bean ( P. acutifolius ) and lima bean ( P. lunatus ). (
  • produces two counts for Chenopodium (the literature carries counts for at least 30 species of the genus) Anybody know of any other sources of plant chromosome count info on line? (
  • Few plant species are dioecious and only a small fraction of these species are known to have sex chromosomes. (
  • However, chromosome microdissection requires sophisticated equipment and is difficult to apply to species with cytologically indistinguishable sex chromosomes. (
  • The 18-year-long project revealed that linking fragments of restored longleaf pine savanna by a natural passageway boosted the number of plant species by 14 percent in those patches by the end of the experiment. (
  • Researchers from Trinity College Dublin have uncovered the evolutionary mechanisms that have caused increases or decreases in the numbers of chromosomes in a group of yeast species during the last 100-150 million years. (
  • The researchers show that, in yeasts, chromosome complement has decreased in all except one notable event, a whole genome duplication an event that doubled the complement of an ancestor of several of the species from 8 chromosomes to 16. (
  • The focus of this job will be on data analysis and writing up, as extensive genomic and transcriptomic resources have already been generated for several species with relatively young sex chromosomes. (
  • We designed a plasmid vector that can be combined with a bacterial artificial chromosome (BAC) clone containing centromeric DNA sequences from a target plant species. (
  • Several different techniques have been developed to assemble AC constructs in mammalian and plant species. (
  • This results in a DNA molecule containing a large centromeric DNA fragment capped with telomeric DNA from the targeted animal or plant species. (
  • If one compares the pace of primateevolution of 90 million years (233 species) to 60 million years of thePoaceae (10,000 species), change in chromosome structure throughspeciation has accelerated significantly in plants. (
  • The rice species Oryza sativa is considered to be a model plant because of its small genome size, extensive genetic map, relative ease of transformation and synteny with other cereal crops. (
  • Many dioecious plants have sex chromosomes that are cytologically heteromorphic, but about half of species lack cytological differences between males and females and are thus homomorphic. (
  • The first dense molecular maps of B. humidicola provide strong support for cytogenetic evidence indicating a base chromosome number of six in this species. (
  • The article concludes with a abstract of the technical challenges nonetheless remaining for synchrotron-based laborious X-ray plant science analysis, notably these referring to subcellular stage analysis. (
  • Cobb J, Cargile B, Handel MA (1999) Acquisition of Competence to condense metaphase I chromosomes during spermatogenesis. (
  • For analysis of metaphase chromosomes, any tissue containing dividing cells can be used: Root tips from young seedlings, from newly grown roots at the edge of plant pots or hydroponic culture are all suitable. (
  • It is very important not to expose seedlings, roots and plants during germination and metaphase-arrest to chemicals and fumes, particularly fixatives (e.g. in a cold room also used for chemical storage) and to use clean labware with tight lids (disposable plastic is ideal), clean forceps, and distilled water. (
  • Treating material for too long in arresting agents, particularly colchicine, results in over-condensation of the metaphase chromosomes which might be desirable for counting chromosomes, but not for in situ hybridization where spatial resolution along chromosomes is wanted. (
  • We also discussed the possible connections between evolution and epigenetic alterations in chromosome structure and repatterning, such as heterochromatin formation, centromere function, and epigenetic-associated transposable element inactivation. (
  • To circumvent the necessity of de novo centromere formation, modification of existing chromosomes to generate a chromosome-based vector can be achieved by at least two different routes. (
  • The Ph1 locus in wheat was proposed to ensure homologous pairing by controlling the specificity of centromere associations that precede chromosome pairing. (
  • This technique uses the natural centromere sequence of an organism to build an entirely new chromosome that would be passed on to successive generations. (
  • Therefore, we developed a transformation-competent artificial chromosome (TAC) vector, pYLTAC7, that can accept and maintain large genomic DNA fragments stably in both Escherichia coli and Agrobacterium tumefaciens . (
  • Plant transformation-competent vectors, such as the cosmid vector pOCA18 ( 8 ) and the λ-phage vector λTI2 ( 9 ), have been developed for construction of genomic libraries with inserts of 5-25 kb that are used for genetic complementation of mutants. (
  • Our analysis reveals the complex genomic changes that can occur in aneuploids and underscores the importance of using multiple experimental approaches to investigate how chromosome numerical changes condition abnormal phenotypes and progressive genome instability. (
  • A detailed structural organization of two closely located 5S rDNA-tagged genomic regions on the 5BS chromosome of bread wheat has been established. (
  • The genomic consequences of polyploidy have been extensively studied, but the mechanisms for chromosome stability and diploidization in polyploids remain largely unknown. (
  • Polyploidy (i.e., whole genomic duplication) has played a significant role in the evolutionary history of all eukaryotes ( 1 ), and particularly in flowering plants ( 2 ). (
  • We are looking for a postdoctoral researcher to work on an evolutionary genomic project focused on sex-chromosome evolution in plants. (
  • Bursaphelenchus xylophilus is the nematode responsible for a devastating epidemic of pine wilt disease in Asia and Europe, and represents a recent, independent origin of plant parasitism in nematodes, ecologically and taxonomically distinct from other nematodes for which genomic data is available. (
  • The maize chromosomes are found in varying numbers in the first cells of the embryo but are then selectively eliminated to leave only the wheat genomic complement. (
  • Our work into the use of mapping populations based on chromosome substitution lines focuses less on molecular or microscopic techniques, but is aimed at defining challenging research questions and answering these using chromosome substitution lines by growing, crossing and phenotyping plants. (
  • She has experience with classical cytogenetic techniques (chromosome aberrations, micronuclei) and molecular methods (comet analysis and gel electrophoresis in a constant electric field/CFGE). (
  • Detailed analyses at the molecular level will reveal the evolution of chromosome structure and the distribution and physical location of additional breakpoints and rearrangements within homoeologous group 4 chromosomes of hexaploid wheat. (
  • Together with the lack of proteins homologous to effectors from other plant parasitic nematodes, this confirms the distinctive molecular basis of plant parasitism in the Bursaphelenchus lineage. (
  • High resolution molecular karyotyping indicated that the six homologous chromosomes of the sexual female parent paired at random, whereas preferential pairing of subgenomes was observed in the apomictic male parent. (
  • POLYPLOIDY is widely acknowledged as a major mechanism of adaptation and speciation in plants. (
  • Polyploidy is the result of multiplication of the complete chromosome complement and is frequent among higher plants. (
  • It is estimated that most flowering plants are polyploid, including most agricultural crops ( 3 - 7 ). (
  • Our group is interested in the interplay between genetic and epigenetic changes, in epigenetic diversity in polyploid plants, in different ecotypes and after exposure to abiotic stress. (
  • Chromosomes 1U g and 1M g increased the proportion of polymeric glutenin proteins, while the addition of chromosomes 1U b and 6U b led to its decrease. (
  • We conclude that also a non-wilt-inducing Fo pathogen relies on effector proteins for successful infection and that the Forc pathogenicity chromosome contains all the information necessary for causing root rot of cucurbits. (
  • s qd, hrb27C and otu mutants also share a nurse cell chromosome organization defect, indicating that these proteins function together in other processes during oogenesis. (
  • We report the identification of several proteins that interact with each other and regulate both grk RNA localization and nurse cell chromosome dynamics during oogenesis. (
  • Today we know that a chromosome contains a single molecule of DNA along with several kinds of proteins. (
  • Plant and animal pathogens use related systems to target proteins to host cells ( 35 ), but such proteins have not been identified in rhizobia. (
  • Each chromosome consists enormously long linear DNA molecule associated with proteins that fold and pack the fine thread of DNA into a more compact structure. (
  • 1995) Chromosome condensation induced by fostriecin does not require p34 cdc2 kinase activity and histoneH1 phosphorylation, but is associated with enhanced histone H2A and H3 phosphorylation. (
  • This is in part because of difficulties in distinguishing among the 38 small chromosomes of B. napus , and because of a lack of cytological markers. (
  • Several of the features of the PEP cluster -- a cluster of pathogenicity genes, the presence of transposable elements, and differences in codon usage and GC content from other portions of the genome -- are shared by pathogenicity islands in pathogenic bacteria of plants and animals. (
  • The findings identify easily measured characteristics that vary with imbalances of specific chromosomes, said Brian Dilkes, a Purdue assistant professor of horticulture . (
  • Goatgrass, a progenitor of our common wheat, can carry up to 8 of these supernumerary chromosomes. (
  • Adult plant resistance (APR) to leaf rust and stripe rust derived from the wheat ( Triticum aestivum L.) line PI250413 was previously identified in RL6077 (=Thatcher*6/PI250413). (
  • Dyck PL, Samborski DJ (1979) Adult-plant leaf rust resistance in PI 250413, an introduction of common wheat. (
  • The AX content in wheat was increased by the addition of chromosomes 5U g , 7U g , and 1U b while water-soluble AX was increased by the addition of chromosomes 5U, 5M, and 7M, and to a lesser extent by chromosomes 3, 4, 6U g , and 2M b . (
  • Chromosomes 5U g and 7M b also affected the structure of wheat AX, as shown by the pattern of oligosaccharides released by digestion with endoxylanase. (
  • Addition of Aegilops U- and M-genome chromosomes 5 and 7 improves seed protein and fiber content and composition in wheat. (
  • Nine wheat-barley addition lines were utilized to determine which barley chromosomes and chromosome arms carry resistance genes. (
  • The incidence of bunt infection in wheat-barley hybrid plants was examined. (
  • Several loci have been identified that affect chromosome pairing in hexaploid wheat (reviewed by S ears 1976 ). (
  • Distal chromosome pairing initiation in wheat explains the failure of homologous synapsis after colchicine-induced inhibition of bouquet formation ( C orredor and N aranjo 2007 ). (
  • Several of the 21 chromosomes of hexaploid wheat contain translocations of considerable size ( G ale 1990 ). (
  • It is reasonable to expect that undetected chromosome structural variations exist in hexaploid wheat. (
  • E ndo (1988) ( 1990 ) ascertained that certain Aegilops chromosomes, particularly from Aegilops cylindrica host, when present as monosomic additions to wheat, caused random, mostly terminal, deletions in wheat chromosomes. (
  • The characterization of paleo-duplicationsrepresented by 11,737 orthologs and 4,382 paralogs identified in fivespecies belonging to three of the agronomically most importantsubfamilies of grasses, that is, Ehrhartoideae (rice) Panicoideae (sor-ghum, maize), and Pooideae (wheat, barley), permitted us to proposea model for an ancestral genome with a minimal size of 33.6 Mbstructured in five proto-chromosomes containing at least 9,138 pre-dicted proto-genes. (
  • He has pioneered the use of flow cytometry in plant science for the analysis of nuclear genome size and regularly holds international training courses on the subject. (
  • He is a taxonomist specializing in plant biosystematics, including genome size determination and has co-authored a book on taxonomy analysis. (
  • The correlations of genome size with chromosome number and size, with the phylogeny of the group and with growth forms and habitats were also examined. (
  • This is substantially larger than estimates for other dioecious plants with homomorphic sex chromosomes, especially given the small genome size of M. annua . (
  • This research has been going on for a while, but the newest publishing shows that the mini-chromosome can be passed on to the next generation as a normal chromosome. (
  • We have no idea what that something is, but it suggests there are multigenerational consequences to changes in chromosome dosage. (
  • The distal regions of chromosome arms showed higher numbers of loci than the proximal regions, with the exception of 4DL. (