Disease relevance of Ssty1

• Here we report the identification of a more extensive Yq deletion that abolishes Ssty expression and results in severe sperm defects and sterility [1].

High impact information on Ssty1

• Spin exhibits high homology to a multicopy gene, Y-linked spermiogenesis-specific transcript (Ssty), and together they form a new gene family expressed during gametogenesis [2].
• A new deletion of the mouse Y chromosome long arm associated with the loss of Ssty expression, abnormal sperm development and sterility [1].
• XY(RIII)qdel males have a smaller interstitial Yq deletion, removing approximately two thirds of Ssty/Sly gene copies, and display an increased incidence of mild sperm head anomalies with impairment of fertility and an intriguing distortion in the sex ratio of offspring in favor of females [3].
• A protein encoded by a member of the multicopy Ssty gene family located on the long arm of the mouse Y chromosome is expressed during sperm development [4].
• We have now identified an Ssty-encoded protein (Ssty1) that is expressed in spermatids [4].

Biological context of Ssty1

• More strongly transcribed recombinant loci were identified that included Asty exons 2-4 preceded by Ssty1 exons 1, 2 and part of exon 3 [5].
• Furthermore, no protein was produced by a strongly transcribed intronless Ssty transgene, raising doubts as to the protein-encoding potential of these intronless genes [4].
• This approach, aided by accumulating mouse MSYq sequence information, identified transcripts derived from two further spermatid-expressed multicopy MSYq gene families; like Ssty, each of these new MSYq gene families has multicopy relatives on the X chromosome [5].
• Thus, Spin/Ssty genes might be important in the transition from sperm cells and oocytes to the early embryo, as well as in mitosis [6].
• BACKGROUND: The homologous genes Spin (spindlin) and Ssty were first identified as genes involved in gametogenesis and seem to occur in multiple copies in vertebrate genomes [6].

Anatomical context of Ssty1

• The protein is absent from spermatids of mice that lack Yq, but is not reduced in mice with a two-thirds reduction of Ssty copies, implying that most do not produce this protein [4].
• The Spin/Ssty repeat: a new motif identified in proteins involved in vertebrate development from gamete to embryo [6].

References