scholarly journals Synapsis and meiotic recombination analyses: MLH1 focus in the XY pair as an indicator

2005 ◽  
Vol 20 (8) ◽  
pp. 2133-2139 ◽  
Author(s):  
Montserrat Codina-Pascual ◽  
Maria Oliver-Bonet ◽  
Joaquima Navarro ◽  
Mercè Campillo ◽  
Ferran García ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Mlh1 Focus

scholarly journals Higher Intercellular Variation in Genome-Wide Recombination Rate in Female Mice

2021 ◽  
pp. 1-7
Author(s):  
April L. Peterson ◽  
Bret A. Payseur
Keyword(s):  
Natural Selection ◽  
Sex Difference ◽  
Meiotic Recombination ◽  
Recombination Rate ◽  
Inbred Strains ◽  
House Mice ◽  
Mlh1 Focus ◽  
Female Mice ◽  
Genome Wide ◽  
Recombination Pathway

Meiotic recombination affects fertility, shuffles genomes, and modulates the effectiveness of natural selection. Despite conservation of the recombination pathway, the rate of recombination varies among individuals and along chromosomes. Recombination rate also differs among cells from the same organism, but this form of variation has received less attention. To identify patterns that characterize intercellular variation in the genome-wide recombination rate, we counted foci of the MLH1 recombination-associated protein in oocytes and spermatocytes from a panel of wild-derived inbred strains of house mice. Females show higher intercellular variation in MLH1 focus count than males from the same inbred strains. This pattern is consistent across strains from multiple subspecies, including 2 strains in which the average MLH1 focus count is higher in males. The sex difference in genome-wide recombination rate we report suggests that selection targeting recombination rate will be more efficient in males than in females.

Male Meiotic Recombination in the Steppe Agama, Trapelus sanguinolentus (Agamidae, Iguania, Reptilia)

2019 ◽  
Vol 157 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
Artem P. Lisachov ◽  
Katerina V. Tishakova ◽  
Yakov A. Tsepilov ◽  
Pavel M. Borodin
Keyword(s):  
Meiotic Recombination ◽  
Mammalian Species ◽  
Recombination Rates ◽  
Mlh1 Focus ◽  
Closely Related Species ◽  
Lateral Element ◽  
Recombination Nodules ◽  
Repair Protein ◽  
Mlh1 Foci ◽  
Mismatch Repair Protein

Meiotic recombination rates and patterns of crossover distributions along the chromosomes vary considerably even between closely related species. The adaptive significance of these differences is still unclear due to the paucity of empirical data. Most data on recombination come from mammalian species, while other vertebrate clades are poorly explored. Using immunolocalization of the protein of the lateral element of the synaptonemal complex (SYCP3) and the mismatch-repair protein MLH1, which marks mature recombination nodules, we analyzed recombination rates and crossover distribution in meiotic prophase chromosomes of the steppe agama (Trapelus sanguinolentus, Agamidae, Acrodonta, Iguania) and compared them with data obtained for the genus Anolis (Dactyloidae, Pleurodonta, Iguania). We found that, despite a smaller genome size, the total SC length and the MLH1 focus number per cell are much higher in the agama than in the anoles. The distributions of the MLH1 foci in the agama are multimodal in larger chromosomes and bimodal in smaller chromosomes without a significant centromere effect, resembling the patterns known for birds. A possible relationship between karyotype remodeling and the evolution of recombination in Iguania is discussed.

Meiotic Recombination in the Giraffe (G. reticulata)

2017 ◽  
Vol 152 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Miluse Vozdova ◽  
Jan Fröhlich ◽  
Svatava Kubickova ◽  
Hana Sebestova ◽  
Jiri Rubes
Keyword(s):  
Meiotic Recombination ◽  
Mammalian Species ◽  
Distinct Species ◽  
Pseudoautosomal Region ◽  
Mlh1 Focus ◽  
Strand Breaks ◽  
Complex Protein ◽  
Nucleolus Organiser ◽  
Mlh1 Foci ◽  
Pachytene Spermatocytes

Recently, the reticulated giraffe (G. reticulata) was identified as a distinct species, which emphasized the need for intensive research in this interesting animal. To shed light on the meiotic process as a source of biodiversity, we analysed the frequency and distribution of meiotic recombination in 2 reticulated giraffe males. We used immunofluorescence detection of synaptonemal complex protein (SYCP3), meiotic double strand breaks (DSB, marked as RAD51 foci) in leptonema, and crossovers (COs, as MLH1 foci) in pachynema. The mean number of autosomal MLH1 foci per cell (27), which resulted from a single, distally located MLH1 focus observed on most chromosome arms, is one of the lowest among mammalian species analysed so far. The CO/DSB conversion ratio was 0.32. The pseudoautosomal region was localised in the Xq and Yp termini by FISH and showed an MLH1 focus in 83% of the pachytene cells. Chromatin structures corresponding to the nucleolus organiser regions were observed in the pachytene spermatocytes. The results are discussed in the context of known data on meiosis in Cetartiodactyla, depicting that the variation in CO frequency among species of this taxonomic group is mostly associated with their diploid chromosome number.

Sign in / Sign up

Export Citation Format

Share Document