Meiotic chromosome pairing between homoeologous chromosomes was reported in many nascent allopolyploids. Homoeologous pairing is gradually eliminated and replaced by exclusive homologous pairing in well-established allopolyploids, an evolutionary process referred to as the diploidization of allopolyploids. A fundamental question of the diploidization of allopolyploids is whether and to what extent the DNA sequence variation among homoeologous chromosomes contribute to the establishment of exclusive homologous chromosome pairing. We developed aneuploid tetraploid maize lines that contain three copies of chromosome 10 derived from inbred lines B73 and H99. We were able to identify the parental origin of each copy of chromosome 10 in the materials using oligonucleotide-based haplotype-specific chromosome painting. We demonstrate that the two identical copies of chromosome 10 from H99 pair preferentially over chromosome 10 from B73 in different stages of prophase I and metaphase I during meiosis. Thus, homologous chromosome pairing is favored to partners with the most similar DNA sequences and can be discriminated based on cryptic sequence variation. We propose that innate preference of homologous chromosome pairing exists in nascent allopolyploids and serves as the first layer that would eventually block all homoeologous chromosome pairing in allopolyploids.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/nph.17098 | DOI Listing |
J Cell Biol
March 2025
Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
The synaptonemal complex (SC) is a zipper-like protein structure that aligns homologous chromosome pairs and regulates recombination during meiosis. Despite its conserved appearance and function, how synapsis occurs between chromosome axes remains elusive. Here, we demonstrate that Polo-like kinases (PLKs) phosphorylate a single conserved residue in the disordered C-terminal tails of two paralogous SC subunits, SYP-5 and SYP-6, to establish an electrostatic interface between the SC central region and chromosome axes in C.
View Article and Find Full Text PDFPlant Biotechnol J
December 2024
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
The interaction dynamics of homologous chromosomes during meiosis, such as recognition, pairing, synapsis, recombination, and segregation are vital for species fertility and genetic diversity within populations. Meiotic crossover (CO), a prominent feature of meiosis, ensures the faithful segregation of homologous chromosomes and enriches genetic diversity within a population. Nevertheless, visually distinguishing homologous chromosomes and COs remains an intractable challenge in cytological studies, particularly in non-model or plants with small genomes, limiting insights into meiotic dynamics.
View Article and Find Full Text PDFGenome Res
December 2024
School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom;
A single guide RNA (sgRNA) directs Cas9 nuclease for gene-specific scission of double-stranded DNA. High Cas9 activity is essential for efficient gene editing to generate gene deletions and gene replacements by homologous recombination. However, cleavage efficiency is below 50% for more than half of randomly selected sgRNA sequences in human cell culture screens or model organisms.
View Article and Find Full Text PDFHeredity (Edinb)
November 2024
Plant Breeding Department, INRES, University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
Nat Commun
November 2024
MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!