Growth/differentiation factor 3 is a member of GDF/BMP subfamily of the TGF-beta superfamily, which has been reported to be implicated in testis carcinoma and deposition of adipose tissue. Interestingly, present work indicated that GDF3/Gdf3 genes were expressed in cerebral cortex, hippocampus as well as in cerebellum, as revealed by RT-PCR, in situ hybridization and immunostaining. Results of RT-PCR in 10 human tissues and 12 rat tissues indicated that GDF3/Gdf3 genes were abundantly transcribed in both human and murine brain, including cerebral cortex, hippocampus and cerebellum. In situ hybridization and immunohistochemistry results revealed that in cerebral cortex, GDF3 was evenly distributed. In hippocampus, it was expressed in most of the neurons in CA2 and DG region, especially only in a restricted number of neurons in the regions of CA1 and CA3 and in Purkinje cells in cerebellum. Present data suggested that GDF3 might play important roles in the central nervous system (CNS), especially in cerebral cortex, hippocampus and cerebellum, and it shed new light on further research of GDF3 in the central nervous system.

Several protein kinases have been shown to be involved in spermatogenesis. Recently, a novel subfamily of serine/threonine kinases has been isolated whose expression is limited to testis. Here, we report the fifth family member, named TSSK5, which encodes a 328 amino acid protein. RT-PCR analysis showed that TSSK5 is exclusively expressed in human testis. We isolated cAMP responsive element binding protein (CREB), a TSSK5 interacting protein via yeast two-hybrid system. The in vitro kinase assay showed that TSSK5 phosphorylated CREB at Ser-133. Using a CRE reporter system, we found that TSSK5 could stimulate the CREB/CRE responsive pathway in Hek293 cells. These results suggest that this kinase may be involved in spermatogenesis through phosphorylating CREB and then stimulating the CREB/CRE responsive pathway.

ABC Fax + 41 61 306 12 34 E-mail karger@karger.ch www.karger.com © 2004 S. Karger AG, Basel 0301–0171/04/1061–0091$21.00/0 Accessible online at: www.karger.com/cgr Abstract. ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.

ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.

ABC Fax + 41 61 306 12 34 E-mail karger@karger.ch www.karger.com © 2004 S. Karger AG, Basel 0301–0171/04/1061–0091$21.00/0 Accessible online at: www.karger.com/cgr Abstract. ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.