Identification of sex chromosomes in Eremias velox (Lacertidae, Reptilia) using lampbrush chromosome analysis

By

Lisachov, Artem
Galkina, Svetlana
Saifitdinova, Alsu
Romanenko, Svetlana
Andreyushkova, Daria
Trifonov, Vladimir
Borodin, P. M. (Pavel Mikhaĭlovich)

Type

Article

Date of Publication

2019

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

13

Series / Issue

Issue: 2

Pages

121-132

Subjects

heterochromatin , lampbrush chromosomes , lizard , Meiosis , microdissection , sex chromosomes

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.v13i2.34116

 

Abstract

Reptiles are good objects for studying the evolution of sex determination, since they have different sex determination systems in different lineages. Lacertid lizards have been long-known for possessing ZZ/ZW type sex chromosomes. However, due to morphological uniformity of lacertid chromosomes, the Z chromosome has been only putatively cytologically identified. We used lampbrush chromosome (LBC) analysis and FISH with a W-specific probe in Eremiasvelox (Pallas, 1771) to unequivocally identify the ZW bivalent and investigate its meiotic behavior. The heterochromatic W chromosome is decondensed at the lampbrush stage, indicating active transcription, contrast with the highly condensed condition of the lampbrush W chromosomes in birds. We identified the Z chromosome by its chiasmatic association with the W chromosome as chromosome XIII of the 19 chromosomes in the LBC karyotype. Our findings agree with previous genetic and genomic studies, which suggested that the lacertid Z chromosome should be one of the smaller macrochromosomes.