Meiotic homologous chromosomes. Medical search. Frequent questions

Homologs have the same genes in the same loci where they provide points along each chromosome which enable a pair of chromosomes to align correctly with each other before separating during meiosis. (wikipedia.org)
This mixing of maternal and paternal traits is enhanced by crossing over during meiosis, wherein lengths of chromosomal arms and the DNA they contain within a homologous chromosome pair are exchanged with one another. (wikipedia.org)
Later on during the 1930s Harriet Creighton and Barbara McClintock were studying meiosis in corn cells and examining gene loci on corn chromosomes. (wikipedia.org)
Homologous chromosomes are important in the processes of meiosis and mitosis. (wikipedia.org)
n. the separation of pairs of homologous chromosomes during meiosis or of the chromatids of a chromosome during anaphase of mitosis or meiosis. (oxfordreference.com)
The separation of homologous chromosomes at the anaphase stage of mitosis and meiosis , and movement towards the poles of the nuclear spindle. (oxfordreference.com)
In Which Part Of Meiosis Does Random Alignment Of Homologous Chromosomes Occur? (styleslicker.com)
Meiosis is a sequence of events that organize and separate chromosomes into daughter cells. (styleslicker.com)
During the interphase of meiosis, every chromosome is duplicated. (styleslicker.com)
How many homologous chromosome alignments are potential for independent assortment throughout meiosis? (styleslicker.com)
In mitosis, the daughter cells have the identical variety of chromosomes as the mother or father cell, while in meiosis, the daughter cells have half the variety of chromosomes as the parent. (styleslicker.com)
Cohesion between sister chromatids is essential for proper chromosome disjunction and homologous recombination in the mitotic cycle and in meiosis ( Nasmyth, 2001 ). (rupress.org)
The unique chromosome dynamics of meiosis have fascinated scientists for well over a century, but in recent years there has been a proliferation of new data concerning the pairing, recombination, and segregation of chromosomes. (nhbs.com)
In 'Meiosis', expert researchers explore recent advances in three main areas, including: quantitative genetic methods for analysis of homologous recombination and chromosome pairing, development of direct physical assays for DNA intermediates and products of recombination, and cytological methods for characterizing chromosome behaviors and the patterns by which specific proteins associate with meiotic chromosomes. (nhbs.com)
Meiosis: Volume 1, Molecular and Genetic Methods' details methods for culturing and manipulating commonly used model organisms and protocols for detecting and quantifying meiotic recombination events through genetic and physical analysis of DNA-DNA or Protein-DNA interactions. (nhbs.com)
Comprehensive and cutting edge, 'Meiosis: Volume 1, Molecular and Genetic Methods' is an essential guidebook, providing up-to-date and critical new protocols for the study of meiotic chromosome dynamics. (nhbs.com)
In humans meiotic chromosome segregation errors increase with maternal age (reviewed in Hassold and Hunt 2001 Approximately 80% of these segregation errors occur during meiosis I and 20% result from meiosis II non-disjunction (Sherman et al. (cancer-ecosystem.com)
2005 Studies on chromosome 21 non-disjunction show that only 6-10% of all trisomy 21 cases are due to errors in spermatogenesis but meiosis I and meiosis II errors contribute equally to these male germline non-disjunction events (Sherman et al 2005 Additionally there is also evidence to suggest that sperm quality decreases with age (Malaspina et al. (cancer-ecosystem.com)
DNA damage checkpoint response to accidental DSBs during mitosis requires the Rad53 effector kinase, whereas the meiosis-specific Mek1 kinase, together with Red1 and Hop1, mediates the recombination checkpoint in response to programmed meiotic DSBs. (unimi.it)
However, the latter can trigger phosphorylation of a protein fusion between Rad53 and the Mec1-interacting protein Ddc2, suggesting that the inability of Rad53 to transduce the meiosis-specific DSB signals might be due to its failure to access the meiotic recombination sites. (unimi.it)
Ameiotic1 ( Am1 ) encodes a plant-specific nuclear protein (AM1) required for meiotic entry and progression through early prophase I. Pollen mother cells (PMCs) remain mitotic in most am1 mutants including am1-489 , while am1-praI permits meiotic entry but PMCs arrest at the leptotene/zygotene (L/Z) transition, defining the roles of AM1 protein in two distinct steps of meiosis. (biomedcentral.com)
Therefore, understanding the molecular changes that specify the archesporial cells, the progenitors of meiotic cells, is crucial in defining the network of cellular processes leading to a successful switch from mitosis to meiosis. (biomedcentral.com)
Normal egg cells form after meiosis and are haploid, with half as many chromosomes as their mother's body cells. (alchetron.com)
Many other cases of obligate parthenogenesis (or gynogenesis) are found among polyploids and hybrids where the chromosomes cannot pair for meiosis. (alchetron.com)
Quantitative approaches to understanding the dynamics of the self-assembled spindle and studying its relationship to chromosome dynamics in meiosis. (usal-csic.es)
As a cell divides by meiosis, chromosomes condense, which is subsequently followed by the aligning of the 23 pairs of homologous chromosomes to form tetrads. (howto.org)
In prophase I of meiosis , the homologous chromosomes form the tetrads. (howto.org)
A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes , each composed of two sister chromatids. (howto.org)
D. Genetic material may be exchanged between chromosomes during prophase I of meiosis. (replicadb4.com)
During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. (replicadb4.com)
In what phase of meiosis are tetrads separated as homologous chromosomes are pulled to opposite poles of the cell? (replicadb4.com)
The events that occur in meiosis but not mitosis include homologous chromosomes pairing up, crossing over, and lining up along the metaphase plate in tetrads. (replicadb4.com)
Meiosis consists of two divisions, both of which follow the same stages as mitosis (prophase, metaphase, anaphase, telophase) Meiosis is preceded by interphase, in which DNA is replicated to produce chromosomes consisting of two sister chromatids. (replicadb4.com)
DMC1 is a necessary meiotic specific protein for homologous chromosome pairing and recombinant repair during meiosis. (nefu.edu.cn)
The first division, meiosis I , separates the homologous chromosomes, so that each cell now has only one of each pair. (blogspot.com)
The second division, meiosis II, separates the chromatids of each chromosome. (blogspot.com)
A specialized division of chromosomes called meiosis occurs during the formation of the reproductive cells, or gametes, of sexually reproducing organisms. (foobrdigital.com)
In meiosis the two chromatids making up each chromosome remain together, so that whole chromosomes are separated from their homologous partners. (foobrdigital.com)
Errors in homologous chromosome segregation during meiosis are the leading cause of birth defects, spontaneous abortions, and contribute to infertility. (grantome.com)
The outcomes are expected to be significant because they will unravel the epigenetic mechanisms underlying proper DNA repair and homologous chromosome segregation during meiosis, which safeguards the next generation. (grantome.com)
This project uses the mouse meiosis model and combines genome-wide, genetic, and cellular approaches to unravel chromatin based mechanisms controlling the function of the DNA recombination machinery, and ultimately the association of meiotic chromosomes, which is of paramount importance in preventing the chromosome segregation errors that lead to birth defects. (grantome.com)
Cyril Darlington pioneered plant cytogenetics in 1920-30 and made important advances in our understanding of mechanisms of chiasma formation and the behavior of sex chromosomes in meiosis [ 7 ]. (biomedcentral.com)

the moving apart of chromosomes during anaphase of mitotic or meiotic. (oxfordreference.com)
It is presently unclear how L2-d cells are programmed to be pre-meiotic within anthers or how this identity is retained during the mitotic divisions prior to PMC maturation. (biomedcentral.com)
Meiotic prophase I is much longer that mitotic prophase. (replicadb4.com)
Copy and complete the table to show the different outcome of mitotic and meiotic division of a Drosophila cell. (blogspot.com)
The homologous chromosomes are then separated to opposite poles of the meiotic spindle by microtubules similar to those of the mitotic spindle. (foobrdigital.com)
Chromatin remodeling complexes are required to repair DSBs in meiotic and mitotic dividing cells, but how they control recruitment and activity of the HR repair machinery at DSBs is unclear. (grantome.com)

Since homologous chromosomes are not identical and do not originate from the same organism, they are different from sister chromatids. (wikipedia.org)
In meiotic prophase, the sister chromatids of each chromosome develop a common axial element (AE) that is integrated into the synaptonemal complex (SC). (rupress.org)
A pair of homologous, synapsed chromosomes, consisting of four chromatids, during the first meiotic division. (biologyideas.com)
Each pair of chromosomes-called a tetrad, or a bivalent-consists of four chromatids. (howto.org)
Tetrads are composed of two chromosomes or four chromatids. (howto.org)
b : a group of four synapsed chromatids that become visibly evident in the pachytene stage of meiotic prophase. (howto.org)
Duplicated chromosomes are called sister chromatids. (replicadb4.com)
This results from independent assortment of the chromosomes as the bivalents line up on the equator during metaphase I, and also from crossing over between the chromatids of homologous chromosomes during prophase I. (blogspot.com)
During DNA replication, each chromosome duplicates into two attached chromatids. (foobrdigital.com)
Cell division then occurs, followed by a second division that resembles mitosis more closely in that it separates the two chromatids of each remaining chromosome. (foobrdigital.com)
We now recognize that, following DNA replication, the metaphase chromosome consists of two chromatids held together by a centromere and by cohesin. (biomedcentral.com)

Explanation: During prophase I homologous chromosomes will line up with one another, forming tetrads . (howto.org)
During prophase I homologous chromosomes make contacts with each other called chiasmata and "crossing over" occurs….Memory Tricks. (replicadb4.com)

In diploid (2n) organisms, the genome is composed of one set of each homologous chromosome pair, as compared to tetraploid organisms which may have two sets of each homologous chromosome pair. (wikipedia.org)
One set of 23 chromosomes (n) is from the mother (22 autosomes, 1 sex chromosome (X only)) and one set of 23 chromosomes (n) is from the father (22 autosomes, 1 sex chromosome (X or Y)). Ultimately, this means that humans are diploid (2n) organisms. (wikipedia.org)
The authors deliberately induced a single DSB in one of the homologous chromosomes in a diploid yeast strain and achieved homologous recombination-based "loss of heterozygosity" events within 20 kb of the target site. (life-science-alliance.org)
Haploid individuals, however, are usually non-viable, and parthenogenetic offspring usually have the diploid chromosome number. (alchetron.com)
Depending on the mechanism involved in restoring the diploid number of chromosomes, parthenogenetic offspring may have anywhere between all and half of the mother's alleles . (alchetron.com)
Homologous chromosomes are DNA fragments within a diploid organism of the same size one from each parental source. (howto.org)
4 The diploid (2n) chromosome number of Drosophila is 8. (blogspot.com)
Given that the diploid (2n) chromosome number is 8, calculate the number of genetically different spermatozoa that can be produced. (blogspot.com)

The second meiotic division begins with half of the original number of chromosomes. (styleslicker.com)
This activation requires homologous chromosome segregation and delays the second meiotic division. (unimi.it)

These DNA breaks are repaired by homologous recombination, which facilitates proper chromosome segregation and enables the reciprocal exchange of DNA segments between homologous chromosomes2. (uzh.ch)

To ensure that every homologous chromosome pair forms at least one crossover-and, perhaps, to aid homologues finding each other in the first place-meiotic cells generate a vast excess of DNA double-strand breaks (DSBs), most of which are then repaired by "noncrossover" recombination pathways that restore intact DNA molecules without resulting in a crossover. (rupress.org)
In mammals, this process relies on the repair of DNA double-strand breaks (DSBs) by homologous recombination (HR) that generates crossover recombination events (COs) [ 1 ]. (nature.com)
Role of the Saccharomyces cerevisiae Rad53 checkpoint kinase in signaling double-strand breaks during the meiotic cell cycle / H. Cartagena-Lirola, I. Guerini, N. Manfrini, G. Lucchini, M.P. Longhese. (unimi.it)
In addition, sexual reproduction provides the benefit of meiotic recombination between non-sister chromosomes, a process associated with repair of DNA double-strand breaks and other DNA damages that may be induced by stressful conditions. (alchetron.com)

Homologous chromosomes are made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. (wikipedia.org)
The alleles on the homologous chromosomes may be different, resulting in different phenotypes of the same genes. (wikipedia.org)
Using test cross experiments, he revealed that, for a single parent, the alleles of genes near to one another along the length of the chromosome move together. (wikipedia.org)
Using this logic he concluded that the two genes he was studying were located on homologous chromosomes. (wikipedia.org)
Homologous chromosomes are chromosomes which contain the same genes in the same order along their chromosomal arms. (wikipedia.org)
In humans, the 22 pairs of homologous autosomal chromosomes contain the same genes but code for different traits in their allelic forms, as one was inherited from the mother and one from the father. (wikipedia.org)
This is essential in determining the genes carried by a gamete, as each will solely obtain one of many two homologous chromosomes. (styleslicker.com)
Our analysis of anther transcriptome modulations by two distinct am1 alleles, am1-489 and am1-praI , redefines the role of AM1 as a modulator of expression of a subset of meiotic genes, important for meiotic progression and provided stage-specific insights into the genetic networks associated with meiotic entry and early prophase I progression. (biomedcentral.com)
Moreover, RNA-seq results indicated that 46 differentially expressed genes (DEGs) involved in meiotic cell cycle, synaptonemal complex assembly and spermatogenesis were upregulated in the hemicastration group, while 197 DEGs were downregulated, which were related to arachidonic acid metabolism. (animbiosci.org)
The chromosomes composed of these matching genes are called homologs. (foobrdigital.com)
In 1944 it was realized that genetic transformation in bacteria was due to DNA and not protein and that DNA was the molecule responsible for heredity in genes and chromosomes [ 8 ]. (biomedcentral.com)

Mitosis is the equational division in which the chromosome number of the parent is conserved in the daughter cell. (mycollegebag.in)
Mitosis ends with 2 identical cells , each with 2N chromosomes and 2X DNA content. (howto.org)
The result of mitosis is two identical daughter cells , genetically identical to the original cell, all having 2N chromosomes. (howto.org)
DNA condenses into chromosomes only during prophase of mitosis. (replicadb4.com)

disjunction The separation of the two members of each pair of homologous chromosomes that occurs during meiotic anaphase. (oxfordreference.com)
Disjunction mutants arise when chromosomes are partitioned unequally between daughter cells as a result of. (oxfordreference.com)
The first Aim will investigate the roles for the PBAF- specific subunit Baf200, and the BAF-specific subunit Baf250A, in meiotic DSB repair, crossover formation, and the association and disjunction of homologous chromosomes. (grantome.com)

Meiotic spermatocytes lacking CNTD1 generated DSBs and paired up their homologous chromosomes as usual. (rupress.org)
Here we provide evidence that exogenous DSBs lead to Rad53 phosphorylation during the meiotic cell cycle, whereas programmed meiotic DSBs do not. (unimi.it)
Altogether, these data indicate that Rad53 prevents sister chromatid segregation in the presence of unrepaired programmed meiotic DSBs, thus providing a salvage mechanism ensuring genetic integrity in the gametes even in the absence of the recombination checkpoint. (unimi.it)
Proper chromosome segregation requires pairwise associations of maternal and paternal homologous chromosomes via crossovers, generated by homologous recombination (HR)-mediated repair of double-strand DNA breaks (DSBs). (grantome.com)
The PBAF and BAF chromatin remodelers are connected to histone modifications occurring at meiotic DSBs, and function in recruiting HR repair factors to DSBs. (grantome.com)
Our central hypothesis is that PBAF and BAF link histone marks surrounding DSBs with the recruitment and activation of the meiotic HR machinery. (grantome.com)

It the first meiotic division, the homologous chromosomes pair and form bivalents, and undergo crossing over. (mycollegebag.in)
The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. (replicadb4.com)
It was 2n = 30 in chromosome number, and ten bivalents plus ten univalents were formed in meiotic prophase and metaphaseⅠ. (jipb.net)

I've learnt that the crossing-over in metaphase I only exchanges small portions of DNA at the tips of the chromosomes. (stackexchange.com)
In metaphase I, SMC1β, SMC3, SCP2, and SCP3 disappeared from the chromosome arms and accumulated around the centromeres, where they stayed until anaphase II. (rupress.org)
Metaphase: This phase is marked by the alignment of chromosomes at the equatorial plate. (mycollegebag.in)
In metaphase I, the tetrads line themselves up at the metaphase plate and homologous pairs orient themselves randomly . (howto.org)

Therefore, when two chromosomes containing the relatively same structure exist (e.g., maternal chromosome 15 and paternal chromosome 15), they are able to pair together via the process of synapsis to form homologous chromosomes. (wikipedia.org)
Homologous chromosome synapsis and recombination are key events that occur during meiotic prophase and result in the formation of chromatin structures called chiasmata. (uni-goettingen.de)

The Origin Recognition Complex (ORC) binds to sites in chromosomes to specify the location of origins of DNA replication. (imperial.ac.uk)
Once cells possess inserted the meiotic plan they go Stattic through pre-meiotic DNA replication which is certainly accompanied by two rounds of chromosome segregation. (cancer-ecosystem.com)
S (Synthesis) phase marks the phase of DNA replication and chromosome duplication. (mycollegebag.in)

Before meiotic divisions, chromosomes form crossovers, which represent the reciprocal exchanges between the DNA molecules of the homologous partner chromosomes. (rupress.org)
The absence of CNTD1 caused immature, precrossover sites containing MutSγ and RNF212 to persist throughout meiotic prophase I. But this wasn't simply due to the failure of crossover maturation: MutSγ foci were gradually eliminated in MutLγ-deficient spermatocytes unable to form mature crossovers. (rupress.org)
A pathway that depends on the MLH1-MLH3 (MutLγ) nuclease has been implicated in the biased processing of meiotic recombination intermediates into crossovers by an unknown mechanism3,4,5,6,7. (uzh.ch)
Rad51b c.92delT/c.92delT mice exhibited meiotic DNA repair defects due to RAD51 and HSF2BP/BMRE1 accumulation in the chromosome axes leading to a reduction in the number of crossovers. (nature.com)
The highly skewed distribution of recombination events towards the chromosome ends in zebra finches and other estrildid species may function to minimize crossovers in the inverted regions. (biomedcentral.com)
In heterokaryotypic individuals (those that are heterozygous for an inversion) recombination within the inverted region is largely suppressed, either because homologous pairing is partially inhibited or because crossovers give rise to unbalanced gametes (carrying deletions or duplications) which will lead to the death of the zygote [ 1 ]. (biomedcentral.com)

the separation of chromosomes at anaphase during nuclear. (oxfordreference.com)
In striking contrast, REC8 persisted along the chromosome arms until anaphase I and near the centromeres until anaphase II. (rupress.org)
In anaphase I, centromeres break down and homologous chromosomes separate. (howto.org)

The centrosomes, that are the buildings that manage the microtubules of the meiotic spindle, additionally replicate. (styleslicker.com)
Another line of interest in the lab is the development of new quantitative approaches to understand chromosomal dynamics within other fundamental stages of gametogenesis, such as the structural steps of bouquet formation itself, spindle self-assembly along meiotic divisions as well as the detection of aneuploidy. (usal-csic.es)

A couple of homologous chromosomes, or homologs, are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization. (wikipedia.org)

Instead, it probably processes meiotic recombination intermediates by nicking double-stranded DNA adjacent to the junction points9. (uzh.ch)
As DNA nicking by MutLγ depends on its co-factors, the asymmetric distribution of MutSγ and RFC-PCNA on meiotic recombination intermediates may drive biased DNA cleavage. (uzh.ch)

Prophase: The chromosome condensation occurs during prophase. (mycollegebag.in)
Tetrad formation occurs during the zygotene stage of meiotic prophase. (howto.org)
In prophase I, tetrads of homologous chromosomes form and crossing over occurs. (replicadb4.com)

The additional 23rd pair is the sex chromosomes, X and Y. Note that the pair of sex chromosomes may or may not be homologous, depending on the sex of the individual. (wikipedia.org)
Conversely, males contain XY, which means that they have a non-homologous pair of sex chromosomes as their 23rd pair of chromosomes. (wikipedia.org)
The 23rd pair, the intercourse chromosomes, differ between men and women. (styleslicker.com)

A male gamete (sperm) is haploid and has 23 chromosomes. (stackexchange.com)

It is formed during the ZYGOTENE STAGE of the first meiotic division. (online-medical-dictionary.org)

Experiments in Aim 1 and 2 will also inform the molecular aspects of how changes in chromatin structure influence meiotic recombination for the first time. (grantome.com)

Its genome contains one genome copy from the S. uvarum parental genome and two heterozygous copies of the S. cerevisiae parental genome, with the exception of a monosomic S. cerevisiae chromosome III, where the sex-determining MAT locus is located. (frontiersin.org)
We speculate that as both ZZ and ZZW individuals develop male gonads, the ratio between the number of Z chromosomes and autosomes, and not the presence of the W chromosome in the genome, drives sex determination in the advanced snakes. (karger.com)
This whole package of DNA (genome) and protein (epigenome) in a chromosome is what controls the development and maintenance of eukaryotic organisms (protists, fungi, animals, and plants). (carnivorousplants.org)
The more similar the chromosomes (the genome and epigenome as well as chromosome number) the more likely hybrids will form and reproduce but also the more likely the net result will only be the introgression of genetic material from one species to the other. (carnivorousplants.org)

In Angiosperms meiotic cells originate from a handful of pluripotent somatic cells, derived from the L2 layer (L2-d) of a floral meristem. (biomedcentral.com)
L2-d cells that do not differentiate as archesporial cells form 3 somatic layers, each of a single cell type, that encircle the pre-meiotic population (Figure 1c ). (biomedcentral.com)
A highly condensed and transcriptionally inactive X chromosome found in the nuclei of somatic cells of female mammals. (biologyideas.com)
The review provides a brief account of the structure of somatic and meiotic chromosomes, stressing the high conservation of structure in plants and animals, with emphasis on aspects that require further research. (biomedcentral.com)
These studies reaffirmed that chromosome structure and behavior in somatic and germ cell divisions were common to all plants and animals. (biomedcentral.com)

To gain more insights into the roles of AM1 in the transcriptional pre-meiotic and meiotic programs, we report here an in depth analysis of gene expression alterations in carefully staged anthers at 1 mm (meiotic entry) and 1.5 mm (L/Z) caused by each of these am1 alleles. (biomedcentral.com)

then, at the first meiotic division, they are partitioned into completely different nuclei. (styleslicker.com)

If the chromosomes decondensed in telophase I, they condense again. (styleslicker.com)
Chromosomes become visible,or in other words they condense. (replicadb4.com)
The chromosomes start to condense (making them easier to pull apart later on). (replicadb4.com)

For instance, females contain XX, thus have a homologous pair of sex chromosomes. (wikipedia.org)
This means that females have 23 pairs of homologous chromosomes in total (i.e., 22 pairs of non-sex chromosomes (autosomes), 1 pair of sex chromosomes). (wikipedia.org)
You have to have at least one on every chromosome pair, and, if there are two, they can't be too close together. (rupress.org)
How many of the four meiotic daughter chromosomes of a homologous pair can be recombinant via crossover? (stackexchange.com)

Here, CDK2 is involved in the regulation of meiotic transcription, the pairing of homologous chromosomes, and the maturation of meiotic crossover sites. (lu.se)

2007 However how replicative age affects the meiotic divisions has not been studied in detail in any organism. (cancer-ecosystem.com)

Synaptonemal complex central element protein 1 is a major component of the transverse central element of synaptonemal complexes (SCS), formed between homologous chromosomes during meiotic prophase. (embl.de)

Humans have a total of 46 chromosomes, but there are only 22 pairs of homologous autosomal chromosomes. (wikipedia.org)

Total number unique chromosome combinations in fertilized egg? (stackexchange.com)

The mechanisms of transmission of both discontinuous and continuous characteristics across the generations were unknown before Mendel's laws were explained at the turn of the 20th Century by the behavior of chromosomes in germ cells [ 2 , 3 ]. (biomedcentral.com)

Since the genetic code was deciphered much has been learnt about the chromosome structure shared by all organisms from yeast to human. (biomedcentral.com)

A 1.7-kb hotspot for homologous recombination was previously identified wherein the relative risk of an exchange event is 50 times higher than in the surrounding 98.7% identical sequence shared by the CMT1A-REPs. To refine the region of exchange further, we designed a PCR strategy to amplify the recombinant CMT1A-REP from HNPP patients as well as the proximal and distal CMT1A-REPs from control individuals. (nih.gov)

Chromosomes are linear arrangements of condensed deoxyribonucleic acid (DNA) and histone proteins, which form a complex called chromatin. (wikipedia.org)
ii) Do specific histone marks control the recruitment of PBAF/BAF and the HR machinery to HR hotspot sites on meiotic chromosomes? (grantome.com)

There are two main properties of homologous chromosomes: 1) the length of chromosomal arms and 2) the placement of the centromere. (wikipedia.org)
Both of these properties (i.e., the length of chromosomal arms, and the placement of the chromosomal centromere) are the main factors for creating structural homology between chromosomes. (wikipedia.org)
If you already know about chromosomal evolution or do not care, jump directly to information on Drosera chromosome numbers. (carnivorousplants.org)
Nuclear motions are transmitted to chromosomes by telomere bouquet formation, a transient chromosomal configuration in which telomeres are clustered in specific regions of the nuclear envelope, often near the centrosome. (usal-csic.es)

The resulting recombinase-coated ssDNA filaments can invade the homologous chromosome dsDNA, searching for a complementary sequence (chromosome pairing), which will foster genetic material exchange. (nature.com)
In spite of our lack of attention to chromosomes and chromosome numbers in formally defining species, it is the chromosomes and the genetic material they contain that define true species and control the evolution of new species. (carnivorousplants.org)
At this point, the homologous chromosomes exchange genetic material by the process of crossing over (see linkage group). (howto.org)

The majority of CDK2's known meiotic functions occur during prophase of the first meiotic division. (lu.se)

One version of childhood acute myeloid leukemia is the result of a cryptictranslocation with the breakpoints occurring within nuclear receptor-binding Su-var, enhancer ofzeste, and trithorax domain protein 1 on chromosome 5 and nucleoporin, 98-kd on chromosome11. (cancer-ecosystem.com)
The search for homologous chromosomes is facilitated by nuclear movements generated by cytoskeletal forces. (usal-csic.es)

Integrative analysis revealed that proteasome 26S subunit ATPase 3 interacting protein gene, which encodes a protein crucial for homologous recombination in spermatocytes, exhibited promoter hypomethylation and higher expression level in hemicastrated mice. (animbiosci.org)

It is called reduction division since it reduces the chromosome number by half while making the gametes. (mycollegebag.in)
Errors in the process of distributing chromosomes to the gametes are the major cause of spontaneous abortions and birth defects, and are an important contributor to infertility. (grantome.com)

During prophase of the first meiotic division, cells deliberately break their DNA1. (uzh.ch)
These results are consistent with the hypothesis that minimum efficient processing segments, which have been characterized in Escherichia coli, yeast, and cultured mammalian cells, may be required for efficient homologous meiotic recombination in humans. (nih.gov)
In budding yeast four different signals are necessary for cells to enter the meiotic program. (cancer-ecosystem.com)
Finally cells should be respiration capable (Honigberg and Purnapatre 2003 The mating-type dietary and respiration indicators converge at Ime1 a transcription aspect governing entry in to the meiotic plan. (cancer-ecosystem.com)
Chromosomes got their name by early cell biologists when they observed certain dark-staining objects in dividing cells. (carnivorousplants.org)
In human dividing cells 46 chromosomes can be observed. (carnivorousplants.org)
Meiotic division therefore produces four cells, each with one complete set of chromosomes. (blogspot.com)
Behavior of Meiotic Chromosomes in Pinus wallichiana Jacks, Pinus strobus L. and Their Hybrid and nrDNA Localization in Pollen Mother Cells of the Hybrid by Using FISH [J]. J Integr Plant Biol. (jipb.net)

GISH results indicated that its 20 chromosomes were highly homologous to chromosomes of allotetraploid species C. lacryma-jobi L. (2n = 20). (jipb.net)

Microtubules are important for the formation of meiotic spindles to support right segregations of chromosomes. (styleslicker.com)

In late meiotic prophase, HEI10 specifically concentrates at designated crossover sites, but this localization is lost in the absence of CNTD1. (rupress.org)

Chromosome number could be but is not considered a defining attribute of a taxonomic species. (carnivorousplants.org)
Chromosome number is not an effective feature in the definition of biological species either although differences in chromosome number can produce different biological species. (carnivorousplants.org)
Drosera can have anywhere from 8 to 80 chromosomes depending on the species. (carnivorousplants.org)
There are two factors related to chromosomes and species that work separately and together to make life interesting. (carnivorousplants.org)
Parthenogenetic offspring in species that use either the XY or the X0 sex-determination system have two X chromosomes and are female. (alchetron.com)
In species that use the ZW sex-determination system , they have either two Z chromosomes (male) or two W chromosomes (mostly non-viable but rarely a female), or they could have one Z and one W chromosome (female). (alchetron.com)
Phylogenomic studies using chromosome painting confirms the high conservation of DNA between even distantly related species [ 13 ]. (biomedcentral.com)

Then, at a critical point during interphase (called the S phase), the cell duplicates its chromosomes and ensures its systems are ready for cell division. (howto.org)

Subsequently, meiotic cohesin SMC1β, cohesin SMC3, and AE proteins SCP2 and SCP3 formed dots along REC8-AEs, which extended and fused until they lined REC8-AEs along their length. (rupress.org)
Each chromosome consists of one very long molecule of DNA twisted around proteins. (carnivorousplants.org)

5. Brown M S,Grubb J,Zhang A N,et al.Small Rad51 and Dmc1 complexes often Co-occupy both ends of a meiotic DNA double strand break[J].PLoS Genetics,2015,11(12):e1005653. (nefu.edu.cn)

Chromosomes and hybrids. (carnivorousplants.org)
The fate of plant hybrids in nature depends very much on the compatibility of the chromosomes of the parents, which parent is the seed parent, and the exact circumstances of the event. (carnivorousplants.org)
The more different the chromosomes of the hybrids are the more likely hybridization will result in a speciation event. (carnivorousplants.org)

So, humans have two sets of 23 chromosomes in each cell that contains a nucleus. (wikipedia.org)

Centromere placement on the chromosome can be characterized by four main arrangements, either metacentric, submetacentric, acrocentric, or telocentric. (wikipedia.org)
In particular, a distinction between those inversions which cover both chromosome arms and thus include the centromere (pericentric inversions) and those which are restricted to a single chromosome arm (paracentric inversions) has often been made [ 9 ]. (biomedcentral.com)

claiming that two homologous chromosomes paired between complementary sequences lead to the formation of a cross-stranded structure that physically links the two component helices. (iucr.org)

Augstenová B, Mazzoleni S, Kratochvíl L, Rovatsos M: Evolutionary dynamics of the W chromosome in caenophidian snakes. (karger.com)
In our lab we try to understand the molecular basis of chromosome dynamics during gametogenesis by developing new computational tools for segmentation and unsupervised time series analysis, spectral evaluation, motif discovery and causal network discovery in chromosome movements in the fission yeast Schizosaccharomyces pombe, one of the model systems in which chromosome dynamics during the telomere bouquet stage has been explored in the greatest detail. (usal-csic.es)
Modeling the dynamics of chromosome movements and their possible microvariations during meiotic prophase as a consequence of mutations or physico-chemical stresses. (usal-csic.es)

Anatomy68

Organisms13

Diseases22

Chemicals and Drugs38

Analytical, Diagnostic and Therapeutic Techniques and Equipment23

Psychiatry and Psychology1

Phenomena and Processes167

Disciplines and Occupations1

Technology, Industry, Agriculture2

Information Science4

Meiosis42

Mitotic6

Chromatids11

Prophase I homologous chromosomes2

Diploid8

Second meiotic division2

Repaired by homologous recombination1

Double-strand breaks4

Genes11

Mitosis4

Disjunction3

DSBs6

Bivalents3

Metaphase4

Synapsis2

Replication3

Crossovers6

Anaphase3

Spindle2

Maternal1

Recombination intermediates2

Occurs3

23rd pair3

Haploid1

ZYGOTENE STAGE1

Chromatin Structure1

Genome4

Somatic5

Alleles1

Nuclei1

Condense3

Pair4

Maturation1

Divisions1

Synaptonemal complexes1

Pairs1

Unique chromosome1

Mechanisms1

Organisms1

Recombinant1

Histone2

Chromosomal4

Genetic material3

Occur1

Nuclear2

Spermatocytes1

Gametes2

Cells8

Allotetraploid1

Microtubules1

Crossover sites1

Species7

Division1

Proteins2

Complexes1

Hybrids3

Humans1

Centromere2

Complementary1

Dynamics3