• Here, we report that the vegetative cell nuclei (VN) of the male gametophyte (pollen) invariably undergo extensive decondensation of centromeric heterochromatin and lose centromere identity. (omicsdi.org)
  • 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)
  • Centromeres are the specialized regions of the chromosomes that direct faithful chromosome segregation during cell division. (bvsalud.org)
  • When they tried to cross wild-type Arabidopsis with plants with modified CENH3, they got plants with half the normal number of chromosomes. (thescitech.com)
  • Recently, other labs have created plants with one set of chromosomes by manipulating CENH3, but it's not clear how the results are related. (thescitech.com)
  • The researchers revealed a high frequency of centromere repositioning on 14 out of 20 chromosomes. (detlef-stein.de)
  • Centromeres are involved with the dynamic interactions between chromosomes and other parts of the nuclear environment, such as the nuclear matrix and inner nuclear membrane, and they also engage with the spindle when the order within the nucleus changes during its division. (aber.ac.uk)
  • CenH3 core particles obtained by hydroxylapatite enrichment of chromatin followed by immunoprecipitation were visualized by an anti-CenH3 atomic force microscopy tip (A). The recognition signal is detected as dark spots in the recognition image (B). In the overlay shown in (C), the recognition signal is marked with green dots for visual clarity using custom software. (biomedcentral.com)
  • In Arabidopsis, the major heterchromatin regions are present at around centromeres (pericentromeric regions) and at a region on the short arm of chromosome 4 (heterochromatin knob). (omicsdi.org)
  • High temperature increases centromere-mediated genome elimination frequency and enhances haploid induction in Arabidopsis. (ipk-gatersleben.de)
  • 2021) A CENH3 mutation promotes meiotic exit and restores fertility in SMG7-deficient Arabidopsis. (oeaw.ac.at)
  • The H3 histone chaperone NASP(SIM3) escorts CenH3 in Arabidopsis. (imp.ac.at)
  • The signal for formation of a regional centromere appears to be epigenetic. (wikipedia.org)
  • The centromeres are the most dynamic and least well understood part of the nucleus, subject to rapid evolutionary change and with an epigenetic mark based on a special form of histone CENH3. (aber.ac.uk)
  • Nonetheless, the centromere epigenetic mark has been inherited for millions of years by a process that is a complete mystery. (aber.ac.uk)
  • The mechanistic basis of CENH3 effects on haploid induction was mysterious," Comai said. (thescitech.com)
  • The researchers from Dr. Han Fangpu's research team from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences performed a comprehensive pan-centromere analysis using CENH3-ChIP-seq data obtained from 27 soybean accessions. (detlef-stein.de)
  • Researchers from China studying soybean genome evolution have focused on the phenomenon of centromere repositioning, which involves the formation of new centromeres at different chromosomal locations without altering the underlying DNA sequences. (detlef-stein.de)
  • 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)
  • Despite their functional conservation, centromeres display features of rapidly evolving DNA and wide evolutionary diversity in size and organization. (bvsalud.org)
  • Furthermore, we applied the single-molecule technique of AFM and DNA:RNA immunoprecipitation with deep sequencing to validate R-loop enrichment in oat centromeres. (bvsalud.org)
  • They had modified a protein called CENH3, found in the centromere, a structure in the center of a chromosome. (thescitech.com)
  • Mohan Marimuthu, researcher at the UC Davis Genome Center and Department of Plant Biology, with Comai, Maruthachalam (now at the Indian Institute of Science Education and Research, Kerala) and colleagues found that when CENH3 protein is altered, it is removed from the DNA in the egg before fertilization, weakening the centromere. (thescitech.com)
  • Taken together, our study elucidates the fundamental character of non-B-form DNA in the oat genome and reveals its potential role in centromeres. (bvsalud.org)
  • Yang Liu et al, Pan-centromere reveals widespread centromere repositioning of soybean genomes, Proceedings of the National Academy of Sciences (2023). (detlef-stein.de)
  • Any piece of DNA with the point centromere DNA sequence on it will typically form a centromere if present in the appropriate species. (wikipedia.org)
  • Previous work found that the noncanonical B-form DNA structures are abundant in the centromeres of several eukaryotic species with a possible implication for centromere specification. (bvsalud.org)
  • Point centromeres" bind to specific proteins that recognize particular DNA sequences with high efficiency. (wikipedia.org)
  • 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)
  • this accurately positioned oat centromeres with different ploidy levels and identified a series of centromere-specific sequences including minisatellites and retrotransposons. (bvsalud.org)
  • To define genetic characteristics of oat centromeres, we surveyed the repeat sequences and found that dyad symmetries were abundant in oat centromeres and were predicted to form non-B-DNA structures in vivo. (bvsalud.org)
  • Einkorn centromeres are highly dynamic, showing evidence of ancient and recent centromere shifts caused by structural rearrangements. (edu.sa)
  • These structures including bent DNA, slipped DNA, Z-DNA, G-quadruplexes, and R-loops were prone to form within CENH3-binding regions. (bvsalud.org)
  • Here, we applied the oat system to investigate the role of non-B-form DNA in centromeres. (bvsalud.org)
  • Interestingly, many of these newly formed centromeres were found in close proximity to the native centromeres. (detlef-stein.de)
  • There are, broadly speaking, two types of centromeres. (wikipedia.org)
  • In summary, this groundbreaking research has unveiled the extensive phenomenon of centromere repositioning within the soybean genome. (detlef-stein.de)
  • The finding that any selective depletion of CENH3 engenders centromere weakness explains the original results by Chan and Maruthachalam as well as new results from other labs in wheat and maize, Comai said. (thescitech.com)
  • The results showed that a significant proportion of centromeres in the S9 generation underwent changes in both size and position compared to their parental counterparts. (detlef-stein.de)
  • No recognition signal is seen after incubation with a peptide corresponding to the CenH3 epitope (D). The bar is 100 nm and the Z range and volt scale are shown at the bottom of the images. (biomedcentral.com)