Adaptations for centromere function in meiosis

Abstract

The aim of mitosis is to segregate duplicated chromosomes equally into daughter cells during cell division. Meiosis serves a similar purpose, but additionally separates homologous chromosomes to produce haploid gametes for sexual reproduction. Both mitosis and meiosis rely on centromeres for the segregation of chromosomes. Centromeres are the specialized regions of the chromosomes that are attached to microtubules during their segregation. In this review, we describe the adaptations and layers of regulation that are required for centromere function during meiosis, and their role in meiosis-specific processes such as homolog-pairing and recombination. Since female meiotic divisions are asymmetric, meiotic centromeres are hypothesized to evolve quickly in order to favor their own transmission to the offspring, resulting in the rapid evolution of many centromeric proteins. We discuss this observation using the example of the histone variant CENP-A, which marks the centromere and is essential for centromere function. Changes in both the size and the sequence of the CENP-A N-terminal tail have led to additional functions of the protein, which are likely related to its roles during meiosis. We highlight the importance of CENP-A in the inheritance of centromere identity, which is dependent on the stabilization, recycling, or re-establishment of CENP-A-containing chromatin during meiosis.

Rewiring Meiosis for Crop Improvement

“…The structure and organization of the centromeres vary considerably between species with centromeres occupying a short sequence, a region or even the entire chromosome ( Steiner and Henikoff, 2015 ; Talbert and Henikoff, 2020 ). Point centromeres are typical in budding yeast ( Prosee et al, 2020 ) while C. elegans and some plants display holocentric chromosomes where the whole chromosome acts as a centromere ( Melters et al, 2012 ). Holocentric chromosomes impose a specific problem to meiosis and how meiosis is remodeled in holocentric plants is being extensively investigated ( Marques and Pedrosa-Harand, 2016 ).…”

Gametic specialization of centromeric histone paralogs in Drosophila virilis

“…Because of these disparate functions, CenH3 proteins may have different protein-coding requirements in different cellular contexts, especially in the germline ( Das et al, 2017 ; Prosee et al, 2020 ). Dissecting these multiple functional constraints in many model organisms (such as D. melanogaster and M. musculus ) is challenging because CenH3 is an essential single-copy gene in these species.…”

Trans-generational inheritance of centromere identity requires the CENP-A N-terminal tail in theC. elegansmaternal germ line

“…How centromeres are inherited from one generation to the next in multicellular organisms is less well understood [22]. However, the inheritance of CENP-A protein into the zygote is crucial for centromere functioning in the next generation prior to the onset of embryonic transcription.…”