Tspy is nonfunctional in the Mongolian gerbil but functional in the Syrian hamster.
The TSPY gene is conserved in placental mammals and encodes the testis-specific protein, Y encoded. Within the testis, TSPY expression is restricted to germ cells, and it is assumed that TSPY plays a role in the proliferation of germ cells. Since it was first discovered in humans, TSPY orthologous gene families have been subsequently characterized in many mammalian lineages. In contrast to the situation in cattle and primates, in which TSPY is organized in a moderately repetitive cluster, including functional members and pseudogenes, a peculiar situation is observed in rodents, in which Tspy has been become low or single copy and degenerated to a pseudogene in some species of the subgenus Mus. We have extended this approach and investigated Tspy gene evolution in the Syrian hamster (Mesocricetus auratus) and the Mongolian gerbil (Meriones unguiculatus). Whereas the Syrian hamster Tspy is functionally conserved, organized in multiple copies, and expressed only in testis, the closely related Mongolian gerbil possesses a single-copy pseudogene that is unable to generate a functional transcript. Thus, the Tspy locus has degenerated at least twice at different points of rodent evolution, strongly supporting the hypothesis that the decay of Y-chromosomal genes is an intrinsic evolutionary process. TSPY is the first example of a Y-chromosomal tandem repetitive gene whose decay could be studied in two independent mammalian lineages.
Karwacki
Violetta
V
Institute of Human Genetics, Medical School Hannover, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany.
Kovac
Judit
J
Mauceri
Grazia
G
Backhaus
Arne
A
Föhse
Lisa
L
Schmidtke
Jörg
J
Schubert
Stephanie
S
D000818:Animals; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics*; D006224:Cricetinae; D019143:Evolution, Molecular; D005260:Female; D015870:Gene Expression; D050173:Genes, Y-Linked; D005849:Gerbillinae / Q000235:genetics*; D007438:Introns; D008297:Male; D008647:Mesocricetus / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D046888:Tissue Array Analysis
D018797:Cell Cycle Proteins; C497749:TSPY1 protein, human; C497748:Tspy1 protein, rat