The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.

Standardized nomenclature for inbred strains of mice: sixth listing. (1/1093)

Rules for designating inbred strains of mice are presented, along with a list of strains with their origins and characteristics, a table of biochemical polymorphisms, and standard subline designations.  (+info)

Mapping of the homothallic genes, HM alpha and HMa, in Saccharomyces yeasts. (2/1093)

Two of the three homothallic genes, HM alpha and HMa, showed direct linkage to the mating-type locus at approximately 73 and 98 strans (57 and 65 centimorgans [cM], respectively, whereas, the other, HO, showed no linkage to 25 standard markers distributed over 17 chromosomes including the mating-type locus. To determine whether the HM alpha and HMa loci located on the left or right side of the mating-type locus, equations for three factor analysis of three linked genes were derived. Tetrad data were collected and were compared with expected values by chi 2 statistics. Calculations indicated that the HM alpha gene is probably located on the right arm at 95 strans (65 cM) from the centromere and the HMa locus at approximately 90 strans (64 cM) on the left arm of chromosome III.  (+info)

SWM1, a developmentally regulated gene, is required for spore wall assembly in Saccharomyces cerevisiae. (3/1093)

Meiosis in Saccharomyces cerevisiae is followed by encapsulation of haploid nuclei within multilayered spore walls. Formation of this spore-specific wall requires the coordinated activity of enzymes involved in the biosynthesis of its components. Completion of late events in the sporulation program, leading to spore wall formation, requires the SWM1 gene. SWM1 is expressed at low levels during vegetative growth but its transcription is strongly induced under sporulating conditions, with kinetics similar to those of middle sporulation-specific genes. Homozygous swm1Delta diploids proceed normally through both meiotic divisions but fail to produce mature asci. Consistent with this finding, swm1Delta mutant asci display enhanced sensitivity to enzymatic digestion and heat shock. Deletion of SWM1 specifically affects the expression of mid-late and late sporulation-specific genes. All of the phenotypes observed are similar to those found for the deletion of SPS1 or SMK1, two putative components of a sporulation-specific MAP kinase cascade. However, epistasis analyses indicate that Swm1p does not form part of the Sps1p-Smk1p-MAP kinase pathway. We propose that Swm1p, a nuclear protein, would participate in a different signal transduction pathway that is also required for the coordination of the biochemical and morphological events occurring during the last phase of the sporulation program.  (+info)

Genealogies and weak purifying selection. (4/1093)

The assumption that selection alters the genealogical tree of a sample of alleles from a population relative to the neutral expectation underlies several "tests of neutrality." Two recent papers have studied the effect of purifying selection; their suggestive but incomplete results indicate that, in the single site case, the shape of a gene genealogy for a locus may differ only from the neutral expectation. We verify this finding for weak selection using the "ancestral selection graph." We consider a wider range of models, including both a four-allele single-site model and an infinite-sites model. Our results confirm the previous claim for the symmetric-mutation single site model. We emphasize, however, that a neutral-seeming genealogy is consistent with detectable effects of selection on the distribution of allele frequences within the sample. With selection operating, the information about a sample cannot be reduced to the genealogy. As a result, a distinction needs to be made between the selected sites themselves, for which the genealogy offers insufficient information, and linked neutral variation. This distinction seems to have been overlooked in previous papers, yet it has significant implications for the interpretation of data on DNA sequence variation. In particular, it predicts that under purifying selection, the frequency spectrum of neutral mutations will not reflect the skew toward rare polymorphisms at replacement sites even if there is no recombination between them. We caution, however, that the effect of weak selection on the genealogy is specific to the model; a (more realistic) model of multiple linked sites could lead to a more distorted genealogy than is observed for a single site.  (+info)

The relationship between DNA methylation and chromosome imprinting in the coccid Planococcus citri. (5/1093)

The phenomenon of chromosome, or genomic, imprinting indicates the relevance of parental origin in determining functional differences between alleles, homologous chromosomes, or haploid sets. In mealybug males (Homoptera, Coccoidea), the haploid set of paternal origin undergoes heterochromatization at midcleavage and remains so in most of the tissues. This different behavior of the two haploid sets, which depends on their parental origin, represents one of the most striking examples of chromosome imprinting. In mammals, DNA methylation has been postulated as a possible molecular mechanism to differentially imprint DNA sequences during spermatogenesis or oogenesis. In the present article we addressed the role of DNA methylation in the imprinting of whole haploid sets as it occurs in Coccids. We investigated the DNA methylation patterns at both the molecular and chromosomal level in the mealybug Planococcus citri. We found that in both males and females the paternally derived haploid set is hypomethylated with respect to the maternally derived one. Therefore, in males, it is the paternally derived hypomethylated haploid set that is heterochromatized. Our data suggest that the two haploid sets are imprinted by parent-of-origin-specific DNA methylation with no correlation with the known gene-silencing properties of this base modification.  (+info)

The Yck2 yeast casein kinase 1 isoform shows cell cycle-specific localization to sites of polarized growth and is required for proper septin organization. (6/1093)

Casein kinase 1 protein kinases are ubiquitous and abundant Ser/Thr-specific protein kinases with activity on acidic substrates. In yeast, the products of the redundant YCK1 and YCK2 genes are together essential for cell viability. Mutants deficient for these proteins display defects in cellular morphogenesis, cytokinesis, and endocytosis. Yck1p and Yck2p are peripheral plasma membrane proteins, and we report here that the localization of Yck2p within the membrane is dynamic through the cell cycle. Using a functional green fluorescent protein (GFP) fusion, we have observed that Yck2p is concentrated at sites of polarized growth during bud morphogenesis. At cytokinesis, GFP-Yck2p becomes associated with a ring at the bud neck and then appears as a patch of fluorescence, apparently coincident with the dividing membranes. The bud neck association of Yck2p at cytokinesis does not require an intact septin ring, and septin assembly is altered in a Yck-deficient mutant. The sites of GFP-Yck2p concentration and the defects observed for Yck-deficient cells together suggest that Yck plays distinct roles in morphogenesis and cytokinesis that are effected by differential localization.  (+info)

Genetic factors affecting the impact of DNA polymerase delta proofreading activity on mutation avoidance in yeast. (7/1093)

Base selectivity, proofreading, and postreplication mismatch repair are important for replication fidelity. Because proofreading plays an important role in error correction, we have investigated factors that influence its impact in the yeast Saccharomyces cerevisiae. We have utilized a sensitive mutation detection system based on homonucleotide runs of 4 to 14 bases to examine the impact of DNA polymerase delta proofreading on mutation avoidance. The contribution of DNA polymerase delta proofreading on error avoidance was found to be similar to that of DNA polymerase epsilon proofreading in short homonucleotide runs (A4 and A5) but much greater than the contribution of DNA polymerase epsilon proofreading in longer runs. We have identified an intraprotein interaction affecting mutation prevention that results from mutations in the replication and the proofreading regions, resulting in an antimutator phenotype relative to a proofreading defect. Finally, a diploid strain with a defect in DNA polymerase delta proofreading exhibits a higher mutation rate than a haploid strain. We suggest that in the diploid population of proofreading defective cells there exists a transiently hypermutable fraction that would be inviable if cells were haploids.  (+info)

Maximal stimulation of meiotic recombination by a yeast transcription factor requires the transcription activation domain and a DNA-binding domain. (8/1093)

The DNA sequences located upstream of the yeast HIS4 represent a very strong meiotic recombination hotspot. Although the activity of this hotspot requires the transcription activator Rap1p, the level of HIS4 transcription is not directly related to the level of recombination. We find that the recombination-stimulating activity of Rap1p requires the transcription activation domain of the protein. We show that a hybrid protein with the Gal4p DNA-binding domain and the Rap1p activation domain can stimulate recombination in a strain in which Gal4p-binding sites are inserted upstream of HIS4. In addition, we find recombination hotspot activity associated with the Gal4p DNA-binding sites that is independent of known transcription factors. We suggest that yeast cells have two types of recombination hotspots, alpha (transcription factor dependent) and beta (transcription factor independent).  (+info)

Haploidy is a term used in genetics to describe the condition of having half the normal number of chromosomes in a cell or an organism. In humans, for example, a haploid cell contains 23 chromosomes, whereas a diploid cell has 46 chromosomes.

Haploid cells are typically produced through a process called meiosis, which is a type of cell division that occurs in the reproductive organs of sexually reproducing organisms. During meiosis, a diploid cell undergoes two rounds of division to produce four haploid cells, each containing only one set of chromosomes.

In humans, haploid cells are found in the sperm and egg cells, which fuse together during fertilization to create a diploid zygote with 46 chromosomes. Haploidy is important for maintaining the correct number of chromosomes in future generations and preventing genetic abnormalities that can result from having too many or too few chromosomes.

Diploidy is a term used in genetics to describe the state of having two sets of chromosomes in each cell. In diploid organisms, one set of chromosomes is inherited from each parent, resulting in a total of 2 sets of chromosomes.

In humans, for example, most cells are diploid and contain 46 chromosomes arranged in 23 pairs. This includes 22 pairs of autosomal chromosomes and one pair of sex chromosomes (XX in females or XY in males). Diploidy is a characteristic feature of many complex organisms, including animals, plants, and fungi.

Diploid cells can undergo a process called meiosis, which results in the formation of haploid cells that contain only one set of chromosomes. These haploid cells can then combine with other haploid cells during fertilization to form a new diploid organism.

Abnormalities in diploidy can lead to genetic disorders, such as Down syndrome, which occurs when an individual has three copies of chromosome 21 instead of the typical two. This extra copy of the chromosome can result in developmental delays and intellectual disabilities.

... already plays an important role in hybrid cultivar production of vegetables, and the potential for ornamental ... Combined with doubled haploidy it becomes more effective. In marker assisted backcross conversion, a recipient parent is ... The number of species amenable to doubled haploidy has reached a staggering 250 in just a few decades. Response efficiency has ... The over-usage of doubled haploidy may reduce genetic variation in breeding germplasm. Hence one has to take several factors ...
Haploidy from Hordeum interspecific crosses. I. Polyhaploids of H. parodii and H. procerum. Theor. Appl. Genet. 49:209 217. ...
Due to their haploidy, HAP1 cells are very useful in biomedical research and genetic experiments. When working in diploid cells ... Near-haploidy in acute leukemia". Cancer. 40 (3): 1143-1148. doi:10.1002/1097-0142(197709)40:3. 3.0.co;2-4. ISSN 1097-0142. ...
doi:10.1002/j.1537-2197.1975.tb14077.x. Jackson, R. C.; Jordan, R. G. (1975). "Haploidy in Haplopappus gracilis (N = 2)". ...
Haploidy or diploidy: which is better? Nature 351:314-315 Kondrashov AS & Kondrashov FA. 1999. Interactions among quantitative ...
6: Distant Hybridisation and Doubled-Haploidy Breeding". In Pratap, Aditya; Kumar, Jitendra (eds.). Alien Gene Transfer in Crop ...
Hagerup, O. (1944) On fertilization, polyploidy and haploidy in Orchis maculatus L. sens. lat. Dansk Botanisk Arkiv 11 (5): 1- ... Hagerup, O. (1945) Facultative parthenogenesis and haploidy in Epipactis latifolia. Biologiske Meddelelser, Kongelige Danske ...
Thus the NLH - and more generally, the idea that haploidy is selected by harsher conditions - is cast into doubt by these ... The term ploidy is a back-formation from haploidy and diploidy. "Ploid" is a combination of Ancient Greek -πλόος (-plóos, "- ... Some studies suggest that selection is more likely to favor diploidy in host species and haploidy in parasite species. However ... In unicellular organisms the ploidy nutrient limitation hypothesis suggests that nutrient limitation should encourage haploidy ...
ISBN 978-0-299-20270-5. Peabody DC, Peabody RB (1985). "Widespread haploidy in monokaryotic cells of mature basidiocarps of ...
Aneuploidy, ranging from haploidy to tetraploidy, and CpG island hypermethylation have also been shown to be frequent and ...
Gene haploidy may result in a single, functional allele making sufficient protein to produce a phenotype identical to that of ...
Bennett made him shift his interests to insect evolution and examined male haploidy in insects. He identified the elimination ...
... a method of heating multiple buildings from a central location Doubled haploidy, a genetic status Deuterium:protium (D:H), a ...
... hypotheses point to the function of imprinting as a way of establishing the proper amount of expression or functional haploidy ...
ISBN 978-1-4615-1365-0. RNA polymerase Haploidy Cytokinins Gibberellins List of alumni of St. Stephen's College, Delhi List of ...
... haploidy MeSH G13.700.740 - polyploidy MeSH G13.810.200 - sequence homology, amino acid MeSH G13.810.550 - sequence homology, ...
Haploidy and androgenesis in Drosophila Surrogate mother for endangered Cupressus Clonal reproduction by males and females in ...
This inbreeding has been proposed to have reduced the haploidy-induced relatedness symmetries, and also allowed for an ...
Doubled haploidy already plays an important role in hybrid cultivar production of vegetables, and the potential for ornamental ... Combined with doubled haploidy it becomes more effective. In marker assisted backcross conversion, a recipient parent is ... The number of species amenable to doubled haploidy has reached a staggering 250 in just a few decades. Response efficiency has ... The over-usage of doubled haploidy may reduce genetic variation in breeding germplasm. Hence one has to take several factors ...
Haploidy PubMed MeSh Term *Overview. Overview. subject area of * Comparative Haploid Genetic Screens Reveal Divergent Pathways ...
Haploidy* * Humans * Membrane Proteins / genetics * Membrane Proteins / metabolism * Membrane Transport Proteins / genetics ...
Stettler, R. F., K. S. Bawa, and G. K. Livingston. 1969. Haploidy: an approach to the development of high-yielding varieties. ...
Haploidy; Mice; Microsatellite Instability*; Mutation Rate; Saccharomyces cerevisiae Proteins/genetics; Saccharomyces ...
Categories: Haploidy Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, CopyrightRestricted 14 images ...
The Constrained Maximal Expression Level Owing to Haploidy Shapes Gene Content on the Mammalian X Chromosome. PLOS Biology, ...
Protection of skin against UV light requires a coordinated interaction between melanocytes and keratinocytes. Melanosomes are lysosome-related organelles that originate in melanocytes and are transferred into keratinocytes where they form a supranuclear cap. The mechanism responsible for melanosome …
Chromatin is reprogrammed after fertilization to produce a totipotent zygote with the potential to generate a new organism. The maternal genome inherited from the oocyte and the paternal genome provided by sperm coexist as separate haploid nuclei in the zygote. How these two epigenetically distinct …
Section 1 (eight chapters) covers historical and fundamental aspects of haploidy in crop improvement. Section 2 deals with ...
7. Adult acute lymphoblastic leukemia with near haploidy, hyperdiploidy and Ph positive lines: a rare entity with poor ... 5. Hyperdiploidy arising from near-haploidy in childhood acute lymphoblastic leukemia.. Onodera N; McCabe NR; Nachman JB; ...
Gene haploidy may result in a single, functional allele making sufficient protein to produce a phenotype identical to that of ...
Haploidy of cells was validated by re-hybridization of the same nuclei with centromeric probes for the chromosomes 10, 12 and 3 ... 2E). Further array Comparative Genomic Hybridization (aCGH) analysis with single cells from clumps confirmed the haploidy of ...
Adare, A., Christiansen, P., Gustafsson, H-Å., Haslum, E., Nystrand, J., Oskarsson, A., Otterlund, I., Rosendahl, S., Silvermyr, D., Stenlund, E., Tydesjö, H., Zou, L. & PHENIX Collaboration, 2016, p. 964-970. 7 p.. Research output: Contribution to conference › Paper, not in proceeding › peer-review ...
Importance of Haploidy. Genetically, all mammals are diploids as a result of the fusion of two haploid gametes. The haploid ...
The importance of haploidy for the propagation of resistance traits in A. fumigatus is also noteworthy and is considered ...
... and proteomic analysis of the difference in flavonoid content in three haploid ginkgos to investigate the effect of haploidy. ...
Leukemic cell karyotype with 23 chromosomes (haploidy), with , 46 chromosomes (hypodiploidy), or with 66 to 68 chromosomes ( ...
Five chromosomal abnormalities [KMT2A (MLL) translocations, t(9;22)/BCR-ABL1, t(17;19)/TCF3-HLF, near haploidy and low ... 26 Near haploidy and low hypodiploidy are defined by massive chromosomal loss resulting in a modal number of less than 30 ... haploidy or low hypodiploidy are high-risk biomarkers. t(9;22)/BCR-ABL1 patients require targeted treatment (imatinib/dasatinib ...
Haploid Cells use Haploidy Haploidentical Transplantation use Transplantation, Haploidentical Haploidentical Transplantations ...
Haploidy (cell structure). Code System Preferred Concept Name. Haploidy (cell structure). Concept Status. Published. ...
Brooke, M. H., Fenichel, G. M., Griggs, R. C., Mendell, J. R., Moxley, R. T., Miller, J. P., Kaiser, K. K., Florence, J. M., Pandya, S., Signore, L., King, W., Robison, J., Head, R. A., Province, M. A., Seyfried, W. & Mandel, S., Aug 1987, In: Archives of neurology. 44, 8, p. 812-817 6 p.. Research output: Contribution to journal › Article › peer-review ...
Michael J. Shen, Yi Wu, Kun Yang, Yunxiang Li, Hui Xu, Haoran Zhang, Bing Zhi Li, Xia Li, Wen Hai Xiao, Xiao Zhou, Leslie A. Mitchell, Joel S. Bader, Yingjin Yuan, Jef D. Boeke ...
Different therapeutic interventions for male infertility have to be developed depending on the severity of germ cell deficits in individual patients. In cases where undifferentiated germ cells are present in the testis, strategies based on sperm development from spermatogonial stem cells (SSCs) in vitro or in vivo need to be established. However, if no germ cells are present in the testis, somatic cells of such patients will be the only option from which to develop their own sperm. Development of these potential therapies requires detailed understanding of the entire process of sperm production from stem cells through to functional sperm. This information is still incomplete and fragmented ...
Haploidy Preferred Term Term UI T018914. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1968). ... Haploidy Preferred Concept UI. M0009795. Scope Note. The chromosomal constitution of cells, in which each type of CHROMOSOME is ... Haploidy. Tree Number(s). G05.700.456. Unique ID. D006238. RDF Unique Identifier. http://id.nlm.nih.gov/mesh/D006238 Scope Note ...
Haploidy Preferred Term Term UI T018914. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1968). ... Haploidy Preferred Concept UI. M0009795. Scope Note. The chromosomal constitution of cells, in which each type of CHROMOSOME is ... Haploidy. Tree Number(s). G05.700.456. Unique ID. D006238. RDF Unique Identifier. http://id.nlm.nih.gov/mesh/D006238 Scope Note ...
Andreyeva, E. N., Bernardo, T. J., Kolesnikova, T. D., Lu, X., Yarinich, L. A., Bartholdy, B. A., Guo, X., Posukh, O. V., Healton, S., Willcockson, M. A., Pindyurin, A. V., Zhimulev, I. F., Skoultchi, A. I. & Fyodorov, D. V., 2017, In: Genes and Development. 31, 6, p. 603-616 14 p.. Research output: Contribution to journal › Article › peer-review ...
... haploidy,noun,E0400244,no hyper,hyperhaploid,adj,E0511171,haploid,noun,E0428680,no hyper,hyperhaploid,noun,E0511172,haploid,adj ...
Microspore-derived embryos from Quercus suber anthers mimic zygotic embryos and maintain haploidy in long term anther culture. ...
  • t(12;21)/ ETV6-RUNX1 and high hyper-diploidy are good-risk prognostic biomarkers whereas KMT2A ( MLL ) translocations, t(17;19)/ TCF3-HLF , haploidy or low hypodiploidy are high-risk biomarkers. (haematologica.org)
  • Numerical aspects of chromosomes: A brief note on aneuploidy (monosomy and trisomy) and euploidy (haploidy, diploidy and polyploidy). (entranceindia.com)
  • Cells with a single set of chromosomes are also called monoploids and this condition is called monoploidy or haploidy. (aakash.ac.in)
  • This is possible with doubled haploidy organisms because of their true breeding nature and because they can conveniently be produced in large numbers. (wikipedia.org)
  • Studies were conducted comparing DH method and other conventional breeding methods and it was concluded that adoption of doubled haploidy does not lead to any bias of genotypes in populations, and random DHs were even found to be compatible to selected line produced by conventional pedigree method. (wikipedia.org)