title: The rat Tspy is preferentially expressed in elongated spermatids and interacts with the core histones.
abstract: The testis specific protein Y encoded (TSPY) gene is a tandemly repeated gene on the mammalian Y chromosome. It encodes several slightly variant proteins that harbor a conserved domain of approximately 170 amino acids, termed TSPY/SET/NAP1 domain, capable of binding to cyclin B. The human TSPY is preferentially expressed in spermatogonia and to lesser extent in the spermatids. Although rat harbors a single functional Tspy gene on its Y chromosome, the human and rat genes differ in their expression patterns, suggesting that they might serve different or variant functions in the testis. Transcripts of rTspy were first detected in the testis of 28-day-old rats, at which time the first wave of meiotic division was occurring. The rTspy protein was initially detected in stage-9 elongating spermatids and peaked at stage-13 spermatids in adult testis, but not in spermatogonia, unlike the expression pattern of the human TSPY gene. Using a GST pull-down assay, we demonstrated that rTspy could bind to the core histones H2A, H2B, H3, and H4. Rat Tspy co-localized with the histones in the cytoplasm of selected elongated spermatids. Our results suggest that the rTspy may play critical roles as a histone chaperone during maturation of the elongating spermatids in the rat testis.
authors.affiliation: Division of Cell and Developmental Genetics, Department of Medicine, Veterans Affairs Medical Center, University of California, San Francisco, CA 94121, USA.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kido
authors.forename: Yun-Fai Chris
authors.initials: YF
authors.lastname: Lau
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D048430:Cell Shape; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D009928:Organ Specificity; D011485:Protein Binding; D051381:Rats; D013087:Spermatids / Q000166:cytology* / Q000378:metabolism*; D013737:Testis / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D006657:Histones; C497749:TSPY1 protein, human; C497748:Tspy1 protein, rat