How do small chromosomes know they are small? Maximizing meiotic break formation on the shortest yeast chromosomes

Murakami, Hajime; Mu, Xiaojing; Keeney, Scott

doi:10.1007/s00294-021-01160-9

Cited by 10 publications

(12 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Specifically, studies in disparate taxa show that the total number and distribution of COs (and also initial meiotic DSBs) on a specific chromosome depends on several factors, such as chromosome size, and an individual’s sex and age ( Pardo-Manuel De Villena and Sapienza, 2001 ; Lynn et al, 2004 ; Garcia-Cruz et al, 2011 ; Ruiz-Herrera et al, 2017 ; Wang et al, 2019 ). Larger chromosomes tend to accumulate more COs (but see recent data in yeast, Murakami et al, 2021 ), and each chromosome arm generally presents at least one CO (the obligatory chiasmata) ( Sun et al, 2017 ). Thus, because both geckos and the bearded dragon have lower diploid numbers (2n = 32–36) than the painted turtle (2n = 50), differences in meiotic DSBs (COs were not reported in this study) are expected among groups.…”

Section: Discussionmentioning

confidence: 99%

Meiotic chromosome dynamics and double strand break formation in reptiles

Marín-Gual

González-Rodelas

Garcias

et al. 2022

Front. Cell Dev. Biol.

View full text Add to dashboard Cite

During meiotic prophase I, tightly regulated processes take place, from pairing and synapsis of homologous chromosomes to recombination, which are essential for the generation of genetically variable haploid gametes. These processes have canonical meiotic features conserved across different phylogenetic groups. However, the dynamics of meiotic prophase I in non-mammalian vertebrates are poorly known. Here, we compare four species from Sauropsida to understand the regulation of meiotic prophase I in reptiles: the Australian central bearded dragon (Pogona vitticeps), two geckos (Paroedura picta and Coleonyx variegatus) and the painted turtle (Chrysemys picta). We first performed a histological characterization of the spermatogenesis process in both the bearded dragon and the painted turtle. We then analyzed prophase I dynamics, including chromosome pairing, synapsis and the formation of double strand breaks (DSBs). We show that meiosis progression is highly conserved in reptiles with telomeres clustering forming the bouquet, which we propose promotes homologous pairing and synapsis, along with facilitating the early pairing of micro-chromosomes during prophase I (i.e., early zygotene). Moreover, we detected low levels of meiotic DSB formation in all taxa. Our results provide new insights into reptile meiosis.

show abstract

Section: Discussionmentioning

confidence: 99%

Meiotic chromosome dynamics and double strand break formation in reptiles

Marín-Gual

González-Rodelas

Garcias

et al. 2022

Front. Cell Dev. Biol.

View full text Add to dashboard Cite

show abstract

“…During canonical meiosis, maintenance of homolog pairing depends on COs. Therefore, the number and spatial distribution of COs are crucial for regular chromosome segregation during M I, necessitating careful regulation by processes including CO assurance, interference and homeostasis [ 45 – 47 ]. As a result, there is often around one CO per chromosome arm in many species.…”

Section: Discussionmentioning

confidence: 99%

Dispersive forces and resisting spot welds by alternative homolog conjunction govern chromosome shape in Drosophila spermatocytes during prophase I

Vernizzi

Lehner

2022

PLoS Genet

View full text Add to dashboard Cite

The bivalent chromosomes that are generated during prophase of meiosis I comprise a pair of homologous chromosomes. Homolog pairing during prophase I must include mechanisms that avoid or eliminate entanglements between non-homologous chromosomes. In Drosophila spermatocytes, non-homologous associations are disrupted by chromosome territory formation, while linkages between homologous chromosomes are maintained by special conjunction proteins. These proteins function as alternative for crossovers that link homologs during canonical meiosis but are absent during the achiasmate Drosophila male meiosis. How and where within bivalents the alternative homolog conjunction proteins function is still poorly understood. To clarify the rules that govern territory formation and alternative homolog conjunction, we have analyzed spermatocytes with chromosomal aberrations. We examined territory formation after acute chromosome cleavage by Cas9, targeted to the dodeca satellite adjacent to the centromere of chromosome 3 specifically in spermatocytes. Moreover, we studied territory organization, as well as the eventual orientation of chromosomes during meiosis I, in spermatocytes with stable structural aberrations, including heterozygous reciprocal autosomal translocations. Our observations indicate that alternative homolog conjunction is applied in a spatially confined manner. Comparable to crossovers, only a single conjunction spot per chromosome arm appears to be applied usually. These conjunction spots resist separation by the dispersing forces that drive apart homologous pericentromeric heterochromatin and embedded centromeres within territories, as well as the distinct chromosomal entities into peripheral, maximally separated territories within the spermatocyte nucleus.

show abstract

“…5B). During meiosis, small chromosomes such as Chr1 experience higher frequencies of meiotic crossovers per kilobase than larger chromosomes 26,27 , and crossover analysis in a hybrid diploid strain with two linear homologs of Chr1 demonstrated that 86% of spores inherited a recombinant Chr1 chromatid 28 . Therefore, in the likely scenario that Chr1 chromatids become involved in multiple meiotic crossovers, the formation of additional acentric and dicentric products would result in increased aneuploidization of Chr1 and further reductions in spore viability.…”

Section: Chr1b Is the Source Of Poor Spore Viability In Yjm311mentioning

confidence: 99%

Genomic characterization of a pathogenic isolate of Saccharomyces cerevisiae reveals an extensive and dynamic landscape of structural variation

Heasley

Argueso

2021

Preprint

View full text Add to dashboard Cite

The budding yeast Saccharomyces cerevisiae has been extensively characterized for many decades and is a critical resource for the study of numerous facets of eukaryotic biology. Recently, the analysis of whole genome sequencing data from over 1000 natural isolates of S. cerevisiae has provided critical insights into the evolutionary landscape of this species by revealing a population structure comprised of numerous genomically diverse lineages. These survey-level analyses have been largely devoid of structural genomic information, mainly because short read sequencing is not suitable for detailed characterization of genomic architecture. Consequently, we still lack a complete perspective of the genomic variation the exists within the species. Single molecule long read sequencing technologies, such as Oxford Nanopore and PacBio, provide sequencing-based approaches with which to rigorously define the structure of a genome, and have empowered yeast geneticists to explore this poorly described realm of eukaryotic genomics. Here, we present the comprehensive genomic structural analysis of a pathogenic isolate of S. cerevisiae, YJM311. We used long read sequence analysis to construct a haplotype-phased, telomere-to-telomere length assembly of the YJM311 diploid genome and characterized the structural variations (SVs) therein. We discovered that the genome of YJM311 contains significant intragenomic structural variation, some of which imparts notable consequences to the genomic stability and developmental biology of the strain. Collectively, we outline a new methodology for creating accurate haplotype-phased genome assemblies and highlight how such genomic analyses can define the structural architectures of S. cerevisiae isolates. It is our hope that through continued structural characterization of S. cerevisiae genomes, such as we have reported here for YJM311, we will comprehensively advance our understanding of eukaryotic genome structure-function relationships, structural diversity, and evolution.

show abstract

How do small chromosomes know they are small? Maximizing meiotic break formation on the shortest yeast chromosomes

Cited by 10 publications

References 52 publications

Meiotic chromosome dynamics and double strand break formation in reptiles

Meiotic chromosome dynamics and double strand break formation in reptiles

Dispersive forces and resisting spot welds by alternative homolog conjunction govern chromosome shape in Drosophila spermatocytes during prophase I

Genomic characterization of a pathogenic isolate of Saccharomyces cerevisiae reveals an extensive and dynamic landscape of structural variation

Contact Info

Product

Resources

About