Genetics. Published Articles Ahead of Print: May 5, 2008, Copyright © 2008
doi:10.1534/genetics.108.088088


A more recent version of this article appeared on May 1, 2008.

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Chromosome 11 Region from Strain 129 Provides Protection from Sex Reversal in XYPOS Mice

Ganka Nikolova 1, Janet S Sinsheimer 1, Eva M Eicher 2 and Eric Vilain 1*

1 David Geffen School of Medicine at UCLA
2 The Jackson Laboratories

* To whom correspondence should be addressed. E-mail: evilain{at}ucla.edu.

Submitted on February 12, 2008
Revised on February 27, 2008
Accepted on 27 February 2008


Abstract

C57BL/6J (B6) mice containing the Mus domesticus poschiavinus Y chromosome, YPOS, develop ovarian tissue, whereas testicular tissue develops in DBA/2J or 129S1/SvImJ (129) mice containing the YPOS chromosome. To identify genes involved in sex determination, we used a congenic strain approach to determine which chromosomal regions from 129Sl/SvImJ provide protection against sex reversal in XYPOS C57BL/6J.129-YPOS mice. Genome scans using microsatellite and SNP markers identified a chromosome 11 region of 129 origin in C57BL/6J.129-YPOS mice. To determine if this region influenced testis development in XYPOS mice, two strains of C57BL/6J-YPOS mice were produced and used in genetic experiments. XYPOS adults homozygous for the 129 region had a lower incidence of sex reversal than XYPOS adults homozygous for the B6 region. In addition, many homozygous 129 XYPOS fetuses developed normal appearing testes, an occurrence never observed in XYPOS C57BL/6J-YPOS mice. Finally, the amount of testicular tissue observed in ovotestes of heterozygous 129/B6 XYPOS fetuses was greater than the amount observed in ovotestes of homozygous B6 XYPOS fetuses. We conclude that a chromosome 11 locus derived from 129Sl/SvImJ essentially protects against sex reversal in XYPOS mice. A number of genes located in this chromosome 11 region are discussed as potential candidates.

Key Words: Gonad development, Ovotestis, Sex determination, Sry