Complex Structure of Lasiopodomys mandarinus vinogradovi Sex Chromosomes, Sex Determination, and Intraspecific Autosomal Polymorphism


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Authors
Romanenko, Svetlana A.  ORCID logo  https://orcid.org/0000-0002-0951-5209
Smorkatcheva, Antonina V. 
Kovalskaya, Yulia M. 
Prokopov, Dmitry Yu.  ORCID logo  https://orcid.org/0000-0001-8420-5203
Lemskaya, Natalya A. 
Abstract

The mandarin vole, Lasiopodomys mandarinus, is one of the most intriguing species among mammals with non-XX/XY sex chromosome system. It combines polymorphism in diploid chromosome numbers, variation in the morphology of autosomes, heteromorphism of X chromosomes, and several sex chromosome systems the origin of which remains unexplained. Here we elucidate the sex determination system in Lasiopodomys mandarinus vinogradovi using extensive karyotyping, crossbreeding experiments, molecular cytogenetic methods, and single chromosome DNA sequencing. Among 205 karyotyped voles, one male and three female combinations of sex chromosomes were revealed. The chromosome segregation pattern and karyomorph-related reproductive performances suggested an aberrant sex determination with almost half of the females carrying neo-X/neo-Y combination. The comparative chromosome painting strongly supported this proposition and revealed the mandarin vole sex chromosome systems originated due to at least two de novo autosomal translocations onto the ancestral X chromosome. The polymorphism in autosome 2 was not related to sex chromosome variability and was proved to result from pericentric inversions. Sequencing of microdissection derived of sex chromosomes allowed the determination of the coordinates for syntenic regions but did not reveal any Y-specific sequences. Several possible sex determination mechanisms as well as interpopulation karyological differences are discussed.

Description
Keywords
aberrant sex determination, chromosome painting, comparative cytogenetics, genome architecture, mandarin vole, microdissection, high-throughput sequencing, rearrangements, rodents, sex chromosomes
Journal Title
Genes
Conference Name
Journal ISSN
2073-4425
Volume Title
11
Publisher
MDPI
Sponsorship
Russian Science Foundation (19-14-00034)
Russian Foundation for Basic Research (19-04-00538)