title: Cloning and differential expression pattern of vasa in the developing and recrudescing gonads of catfish, Clarias gariepinus.
abstract: Vasa gene codes for a DEAD box family protein, which plays a crucial role in primordial germ cell proliferation. In this study, we report cloning of vasa from gonads of air-breathing catfish, Clarias gariepinus, a seasonally reproducing teleost fish. We studied the expression pattern of vasa during gametogenesis using real-time PCR. We also examined the hormonal regulation on vasa in gonads of catfish. RT-PCR analysis revealed that vasa was detectable only in the gonads. Further, real-time PCR results showed that expression of vasa was seen throughout the development from embryonic stage to adult. However, the expression was more in ovary than in testis during gonadal development. In adult testis, the vasa transcripts were significantly high during spermatogenesis and it declined during spermiation. On the other hand, during ovarian recrudescence, vasa transcripts were high in immature oocytes (stages I and II oocytes) when compared to mature oocytes (stages III and IV oocytes). Human chorionic gonadotropin treatment in recrudescing ovary (in vivo) as well as in testicular slices (in vitro) resulted in up regulation of vasa mRNA in a time-dependent manner. These results together suggest that vasa gene has got an important role to play in spermatogenesis and oogenesis during recrudescence in addition to development.
authors.affiliation: Department of Animal Sciences, School of Life Sciences-Centre for Advanced Studies, University of Hyderabad, P. O. Central University, Hyderabad-500 046, Andhra Pradesh, India.
authors.forename: Kavarthapu
authors.initials: K
authors.lastname: Raghuveer
authors.forename: Balasubramanian
authors.initials: B
authors.lastname: Senthilkumaran
mesh_terms: D000818:Animals; D002397:Catfishes / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D053487:DEAD-box RNA Helicases / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006062:Gonadotropins / Q000378:metabolism; D006801:Humans; D010053:Ovary / Q000254:growth & development* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D006062:Gonadotropins; D012333:RNA, Messenger; D053487:DEAD-box RNA Helicases