TY - JOUR

T1 - Immunocytological analysis of meiotic recombination in two anole lizards (Squamata, Dactyloidae)

AU - Lisachov, Artem P.

AU - Trifonov, Vladimir A.

AU - Giovannotti, Massimo

AU - Ferguson-Smith, Malcolm A.

AU - Borodin, Pavel M.

N1 - Publisher Copyright: © Artem P. Lisachov et al.

PY - 2017/3/6

Y1 - 2017/3/6

N2 - Although the evolutionary importance of meiotic recombination is not disputed, the significance of interspecies differences in the recombination rates and recombination landscapes remains under-appreciated. Recombination rates and distribution of chiasmata have been examined cytologically in many mammalian species, whereas data on other vertebrates are scarce. Immunolocalization of the protein of the synaptonemal complex (SYCP3), centromere proteins and the mismatch-repair protein MLH1 was used, which is associated with the most common type of recombination nodules, to analyze the pattern of meiotic recombination in the male of two species of iguanian lizards, Anolis carolinensis Voigt, 1832 and Deiroptyx coelestinus (Cope, 1862). These species are separated by a relatively long evolutionary history although they retain the ancestral iguanian karyotype. In both species similar and extremely uneven distributions of MLH1 foci along the macrochromosome bivalents were detected: approximately 90% of crossovers were located at the distal 20% of the chromosome arm length. Almost total suppression of recombination in the intermediate and proximal regions of the chromosome arms contradicts the hypothesis that "homogenous recombination" is responsible for the low variation in GC content across the anole genome. It also leads to strong linkage disequilibrium between the genes located in these regions, which may benefit conservation of co-adaptive gene arrays responsible for the ecological adaptations of the anoles.

AB - Although the evolutionary importance of meiotic recombination is not disputed, the significance of interspecies differences in the recombination rates and recombination landscapes remains under-appreciated. Recombination rates and distribution of chiasmata have been examined cytologically in many mammalian species, whereas data on other vertebrates are scarce. Immunolocalization of the protein of the synaptonemal complex (SYCP3), centromere proteins and the mismatch-repair protein MLH1 was used, which is associated with the most common type of recombination nodules, to analyze the pattern of meiotic recombination in the male of two species of iguanian lizards, Anolis carolinensis Voigt, 1832 and Deiroptyx coelestinus (Cope, 1862). These species are separated by a relatively long evolutionary history although they retain the ancestral iguanian karyotype. In both species similar and extremely uneven distributions of MLH1 foci along the macrochromosome bivalents were detected: approximately 90% of crossovers were located at the distal 20% of the chromosome arm length. Almost total suppression of recombination in the intermediate and proximal regions of the chromosome arms contradicts the hypothesis that "homogenous recombination" is responsible for the low variation in GC content across the anole genome. It also leads to strong linkage disequilibrium between the genes located in these regions, which may benefit conservation of co-adaptive gene arrays responsible for the ecological adaptations of the anoles.

KW - Anolis

KW - Chromosomes

KW - Crossing over

KW - Deiroptyx

KW - Lizard

KW - Reptilia

KW - Synaptonemal complex

UR - http://www.scopus.com/inward/record.url?scp=85021676121&partnerID=8YFLogxK

U2 - 10.3897/CompCytogen.v11i1.10916

DO - 10.3897/CompCytogen.v11i1.10916

M3 - Article

C2 - 28919954

AN - SCOPUS:85021676121

VL - 11

SP - 129

EP - 141

JO - Comparative Cytogenetics

JF - Comparative Cytogenetics

SN - 1993-0771

IS - 1

ER -