A New Deletion of the Mouse Y Chromosome Long Arm Associated With the Loss of Ssty Expression, Abnormal Sperm Development and Sterility

Abstract

The mouse Y chromosome carries 10 distinct genes or gene families that have open reading frames suggestive of retained functionality; it has been assumed that many of these function in spermatogenesis. However, we have recently shown that only two Y genes, the testis determinant Sry and the translation initiation factor Eif2s3y, are essential for spermatogenesis to proceed to the round spermatid stage. Thus, any further substantive mouse Y-gene functions in spermatogenesis are likely to be during sperm differentiation. The complex Ssty gene family present on the mouse Y long arm (Yq) has been implicated in sperm development, with partial Yq deletions that reduce Ssty expression resulting in impaired fertilization efficiency. Here we report the identification of a more extensive Yq deletion that abolishes Ssty expression and results in severe sperm defects and sterility. This result establishes that genetic information (Ssty?) essential for normal sperm differentiation and function is present on mouse Yq.

Y chromosome microdeletions: are they implicated in teratozoospermia?

“…Studies in mice have shown an important relationship between certain Y chromosome deletions and sperm head abnormalities (Suh et al, 1989;Styrna et al, 1991Styrna et al, , 2003Toure et al, 2004). Toure et al (2004) showed that Yq deletion with abolished Ssty expression resulted in severe sperm morphological abnormalities.…”

“…Studies in mice have shown an important relationship between certain Y chromosome deletions and sperm head abnormalities (Suh et al, 1989;Styrna et al, 1991Styrna et al, , 2003Toure et al, 2004). Toure et al (2004) showed that Yq deletion with abolished Ssty expression resulted in severe sperm morphological abnormalities. Similarly, reduced Rbm expression in mice has been suggested to be responsible for, or to contribute to, the abnormal sperm development (Mahadevaiah et al, 1998).…”

“…A role for Y chromosome on sperm morphological abnormalities in mice was suggested long ago (Krzanowska, 1969) and has been extensively studied since then (reviewed by Burgoyne, 1998). Several candidate genes including Rbm and Ssty have been suggested to play a role in sperm morphology (Mahadevaiah et al, 1998;Toure et al, 2004). In humans, studies on the genetics of teratozoospermia have mostly concentrated on sperm chromosomal aneuploidies (Lewis-Jones et al, 2003;Vicari et al, 2003;Burrello et al, 2004).…”

Gonadal mosaicism mediated female-biased gender control in mice

“…Sly , Ssty1 , Ssty2 as multicopy genes with highly repetitive DNA sequences, are located at the long arm of mouse Y chromosome (MSYq) (Fig. 1 A) (Toure et al, 2004 ). To target the repetitive sequence on Y chromosome via CRISPR/Cas9, firstly we designed three sgRNAs targeting each gene, with each sgRNA recognizing more than 100 copies of DNA on MSY (Fig.…”

Effects of the Sex Chromosome Complement, XX, XO, or XY, on the Transcriptome and Development of Mouse Oocytes During Follicular Growth

“…In our study, all these genes except for Usp9y, Sry, and Rbmy were transcribed at high levels in the XY oocytes of 50-60 µm. By contrast, the newly acquired ampliconic gene families on the long arm, Sly, Ssty, and Srsy, which are reported to be expressed predominantly in the male germline (Toure et al, 2004;Reynard and Turner, 2009), were undetectable in XY oocytes. However, other newly identified but poorly characterized genes on the Y long arm were transcribed at moderate levels in XY oocytes.…”