• The physical role of the centromere is to act as the site of assembly of the kinetochores - a highly complex multiprotein structure that is responsible for the actual events of chromosome segregation - i.e. binding microtubules and signaling to the cell cycle machinery when all chromosomes have adopted correct attachments to the spindle, so that it is safe for cell division to proceed to completion and for cells to enter anaphase. (wikipedia.org)
  • It is now believed that this complex is mostly released from chromosome arms during prophase, so that by the time the chromosomes line up at the mid-plane of the mitotic spindle (also known as the metaphase plate), the last place where they are linked with one another is in the chromatin in and around the centromere. (wikipedia.org)
  • The position of the centromere relative to any particular linear chromosome is used to classify chromosomes as metacentric, submetacentric, acrocentric, telocentric, or holocentric. (wikipedia.org)
  • When the centromeres are metacentric, the chromosomes appear to be "x-shaped. (wikipedia.org)
  • Telocentric chromosomes have a centromere at one end of the chromosome and therefore exhibit only one arm at the cytological (microscopic) level. (wikipedia.org)
  • We demonstrate that (i) F1 hybrids are highly heterozygous with nearly all chromosomes participating in the formation of trivalents at the first meiotic division, and (ii) that from F1 to F4 the number of trivalents decreases and the number of bivalents increases. (frontiersin.org)
  • The internal chromosomes of the chain (8 and 12) show the greatest differentiation, which may reflect pairing and recombination properties of internal and external elements in a meiotic chain. (conicet.gov.ar)
  • Centromeres provide chromosomal points of attachment to the cellular segregation machinery, linking chromosomes to the proteins that pull them to the cell poles during both somatic and germline cell divisions. (jax.org)
  • The PAR is a region of conserved sequence identity between the X and Y chromosomes over which the meiotic program of pairing, synapsis, and recombination unfolds to ensure correct sex chromosome segregation. (jax.org)
  • Microtubules are important for the formation of meiotic spindles to support right segregations of chromosomes. (styleslicker.com)
  • The second meiotic division begins with half of the original number of chromosomes. (styleslicker.com)
  • 4) Centromeres are essential for the proper segregation of chromosomes at mitosis and meiosis. (bdword.com)
  • During the process of meiosis, a molecular complex called the centromere guides the collection and assortment of chromosomes into their respective daughter cells. (gcrle.org)
  • We propose that in the absence of SGS1 chromosomes may sometimes remain entangled at the end of pre-meiotic replication. (le.ac.uk)
  • Simchen.An initial chromosomal part with major roles inside the yeast chromosome I11 meiotic disjunction, recombination and double strand holiday breaks. (realprowa.com)
  • However, particularly in cereal crops including barley meiotic recombination events are limited and skewed towards chromosome ends whereby a large portion of the genetic information keeps untapped in breeding programs. (ipk-gatersleben.de)
  • Embarking on molecular genetics, biochemistry and cytogenetic approaches, the overarching aim of the group is to alter the outcome of meiotic recombination with a focus on barley. (ipk-gatersleben.de)
  • Development and application of Crystal Digital PCR-based single pollen nucleus genotyping to measure meiotic recombination rates in barley (Hordeum vulgare) in high-throughput. (ipk-gatersleben.de)
  • High throughput measuring of meiotic recombination rates in barley pollen nuclei using Crystal Digital PCR TM. (ipk-gatersleben.de)
  • Methodology/Principal Findings: In this work, we observed an increase in meiotic recombination between diverged sequences (homeologous recombination) and an increase in unequal sister chromatid events when SGS1 is deleted. (le.ac.uk)
  • families from 2x4x crosses revealed that at least 20 of the 26 female parents form 2n female gametophytes that are predominantly or exclusively of the second meiotic division restitution (SDR) type. (tamu.edu)
  • SDR 2n gametophytes genetically equate to gametophytes that would result from restitution of the second meiotic division. (tamu.edu)
  • 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)
  • 5) Regions of the germline with cells in mitosis or different stages of meiotic prophase are indicated. (bdword.com)
  • Despite their fundamental significance for chromosome transmission and genome stability, little is known about the levels and patterns of genetic diversity across centromeres and the PAR, or the biological impacts of this variation. (jax.org)
  • Recently, the group identified the centromere as a natural fragile site in the genome, particularly when the replication fork is disrupted. (usc.edu)
  • High temperature increases centromere-mediated genome elimination frequency and enhances haploid induction in Arabidopsis. (ipk-gatersleben.de)
  • Loss of centromere identity in meiotic cells leads to spontaneous abortion or developmental defects.By studying evolutionary conserved structural features in the centromeric and evolutionary related telomeric DNA, we are trying to identify epigenetic universal hallmarks, which identify the centromere position in a newly replicated genome. (ceitec.eu)
  • Two of these driving loci are linked by a chromosomal translocation and thus constitute a novel type of paired meiotic drive complex. (elifesciences.org)
  • In humans, centromere positions define the chromosomal karyotype, in which each chromosome has two arms, p (the shorter of the two) and q (the longer). (wikipedia.org)
  • Here, we studied male meiotic chromosome behavior in four hybrid generations (F1-F4) between two chromosomal races of the Wood White butterfly Leptidea sinapis differentiated by at least 24 chromosomal fusions/fissions. (frontiersin.org)
  • This replication produces two equivalent copies, referred to as sister chromatids, which are held together at the centromere by cohesin proteins. (styleslicker.com)
  • Meiotic cohesin REC8 appeared shortly before premeiotic S phase in the nucleus and formed AE-like structures (REC8-AEs) from premeiotic S phase on. (rupress.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)
  • TurboID-based proteomic profiling of meiotic chromosome axes in Arabidopsis thaliana. (ipk-gatersleben.de)
  • Point centromeres" bind to specific proteins that recognize particular DNA sequences with high efficiency. (wikipedia.org)
  • During mitosis, spindle fibers attach to the centromere via the kinetochore. (wikipedia.org)
  • Kinetochore pairing may be a general feature that increases capture efficiency in meiotic cells. (nature.com)
  • MTs interact with a chromosome via the kinetochore (KC), a large protein complex located at the centromere. (nature.com)
  • Encodes a centromere-identifying protein histone H3 variant. (gifu-u.ac.jp)
  • 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)
  • In addition, it provides further support for models in which genetic conflicts, such as those caused by meiotic drive alleles, can drive speciation. (elifesciences.org)
  • Mutations that disrupt centromere integrity or reduce homology between X- and Y-linked PARs can lead to chromosome segregation errors and constitute important genetic mechanisms for cancer, cellular senescence, and infertility. (jax.org)
  • The centrosomes, that are the buildings that manage the microtubules of the meiotic spindle, additionally replicate. (styleslicker.com)
  • Mediates attachment of the chromosome to the meiotic or mitotic spindle . (amboss.com)
  • then, at the first meiotic division, they are partitioned into completely different nuclei. (styleslicker.com)
  • In striking contrast, REC8 persisted along the chromosome arms until anaphase I and near the centromeres until anaphase II. (rupress.org)
  • Metacentric means that the centromere is positioned midway between the chromosome ends, resulting in the arms being approximately equal in length. (wikipedia.org)
  • Full-grown oocytes are transcriptionally silent and must stably maintain the messenger RNAs (mRNAs) needed for oocyte meiotic maturation and early embryonic development. (bvsalud.org)
  • The meiotic topoisomerase VI B subunit (MTOPVIB) is essential for meiotic DNA double-strand break formation in barley (Hordeum vulgare L.). Plant Reprod. (ipk-gatersleben.de)
  • An acrocentric chromosome's centromere is situated so that one of the chromosome arms is much shorter than the other. (wikipedia.org)
  • At least three distinct meiotic drive alleles, one on each S. kambucha chromosome, independently contribute to hybrid infertility by causing nonrandom spore death. (elifesciences.org)
  • Larry Sandler and Ed Novitski first defined meiotic drive as a profound evolutionary force in natural populations. (genetics-gsa.org)
  • The centromere links a pair of sister chromatids together during cell division. (wikipedia.org)
  • Regarding mitotic chromosome structure, centromeres represent a constricted region of the chromosome (often referred to as the primary constriction) where two identical sister chromatids are most closely in contact. (wikipedia.org)
  • The centromere is a specialized region of the eukaryotic chromosome that links sister chromatids. (ceitec.eu)
  • These groups differ by Robertsonian fusions and/or whole-arm reciprocal translocations such that F1 hybrids have a chain-of- five meiotic configuration. (conicet.gov.ar)
  • The meiotic cell or meiotic is comparatively large and possesses a large nucleus. (biologystudypoint.com)
  • Regional centromeres" is the term coined to describe most centromeres, which typically form on regions of preferred DNA sequence, but which can form on other DNA sequences as well. (wikipedia.org)
  • A process of chromosome organization that is involved in a meiotic cell cycle. (mcw.edu)
  • Previous estimates obtained by half-tetrad analysis with 2n pollen placed the yellow-tuber flesh marker, Y, at 13 map units from its centromere. (tamu.edu)
  • Loss of centromere identity in mitotic cells results in aneuploidy (loss or gain of chromosome), which may lead to cancer. (ceitec.eu)
  • We divided mice into three groups: human recombinant centromere protein-A (human CENP-A, HA) and complete Freund's adjuvant (CFA) were used to immunize mice for the study group (HA + CFA), and mice injected with CFA (CFA group) or saline (Saline group), respectively, served as controls. (biomedcentral.com)
  • Genetically, FDR and FDR-NCO 2n gametophytes equate to those resulting from meiotic first division restitution, with, or with no crossing-over, respectively. (tamu.edu)
  • The highly repetitive sequence content of these regions poses a major barrier to their molecular analysis, and the PAR and centromeres remain unassembled or incompletely assembled on many of highest quality reference genomes, including mouse. (jax.org)
  • More recently, we found that embryos cultured with anti-CENP-A (centromere protein-A) antibody had significant growth impairment and/or high mortality [ 12 ]. (biomedcentral.com)
  • My group is leveraging state-of-the-art sequencing technologies and bioinformatic methods to catalog variation across the PAR and centromeres. (jax.org)