PT - JOURNAL ARTICLE AU - Shang, Peng AU - Baarends, Willy M. AU - Hoogerbrugge, Jos AU - Ooms, Marja P. AU - van Cappellen, Wiggert A. AU - de Jong, Antonius A. W. AU - Dohle, Gert R. AU - van Eenennaam, Hans AU - Gossen, Jan A. AU - Grootegoed, J. Anton TI - Functional transformation of the chromatoid body in mouse spermatids requires testis-specific serine/threonine kinases AID - 10.1242/jcs.059949 DP - 2010 Feb 01 TA - Journal of Cell Science PG - 331--339 VI - 123 IP - 3 4099 - http://jcs.biologists.org/content/123/3/331.short 4100 - http://jcs.biologists.org/content/123/3/331.full SO - J. Cell Sci.2010 Feb 01; 123 AB - 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.