Functional transformation of the chromatoid body in mouse spermatids requires testis-specific serine/threonine kinases.
The cytoplasmic chromatoid body (CB) organizes mRNA metabolism and small regulatory RNA pathways, in relation to haploid gene expression, in mammalian round spermatids. However, little is known about functions and fate of the CB at later steps of spermatogenesis, when elongating spermatids undergo chromatin compaction and transcriptional silencing. In mouse elongating spermatids, we detected accumulation of the testis-specific serine/threonine kinases TSSK1 and TSSK2, and the substrate TSKS, in a ring-shaped structure around the base of the flagellum and in a cytoplasmic satellite, both corresponding to structures described to originate from the CB. At later steps of spermatid differentiation, the ring is found at the caudal end of the newly formed mitochondrial sheath. Targeted deletion of the tandemly arranged genes Tssk1 and Tssk2 in mouse resulted in male infertility, with loss of the CB-derived ring structure, and with elongating spermatids possessing a collapsed mitochondrial sheath. These results reveal TSSK1- and TSSK2-dependent functions of a transformed CB in post-meiotic cytodifferentiation of spermatids.
Shang
Peng
P
Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
Baarends
Willy M
WM
Hoogerbrugge
Jos
J
Ooms
Marja P
MP
van Cappellen
Wiggert A
WA
de Jong
Antonius A W
AA
Dohle
Gert R
GR
van Eenennaam
Hans
H
Gossen
Jan A
JA
Grootegoed
J Anton
JA
D000818:Animals; D015153:Blotting, Western; D003594:Cytoplasmic Granules / Q000201:enzymology*; D003598:Cytoskeletal Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010750:Phosphoproteins; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D013087:Spermatids / Q000201:enzymology* / Q000378:metabolism* / Q000648:ultrastructure; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology; D013737:Testis / Q000201:enzymology* / Q000648:ultrastructure
D003598:Cytoskeletal Proteins; D010750:Phosphoproteins; C530613:TSKS protein, mouse; C475219:Tsk1 protein, mouse; D017346:Protein Serine-Threonine Kinases; C529882:Tssk2 protein, mouse