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Induction of spawning in catfish is well demonstrated in females while stimulation of spermiation in males seems difficult. This has led to least understanding of gene profile changes during testicular maturation. Expression of the factors after hormonal induction that control reproductive processes has become an intense research area in fish endocrinology. In view of this, de novo assemblies of testicular transcriptomes of the Asian catfish, Clarias batrachus and the African catfish, C. gariepinus, were performed to identify genes/factors involved in testicular maturation. For testicular induction, human chorionic gonadotropin (hCG) was administered in vivo to both the catfish species during active phase of reproduction. 1,68,071 and 1,26,232 assembled transcripts were obtained from C. batrachus and C. gariepinus testicular transcriptomes and were annotated using different databases. Further, in silico analysis suggested the presence of several transcripts that were involved in steroidogenesis and male reproduction. Comparison of transcriptomes of both species revealed the presence of certain unique genes related to reproduction differentially. Expression profiles after hCG induction in testis showed higher expression of certain steroidogenesis related genes such as star , cyp11b1 , cyp17a and cyp21a in both the species. Further, expression levels of crucial factors related to testis, such as dmrt1/2/3, were also found to be significantly higher after gonadotropin induction. However, amh , tgfα and dmrt4/5 expression levels were significantly low. Factors related to male reproduction i.e. , tekt1 , tekt2 , sox9 , spag1 , spata2 and spata7 were found to be differentially upregulated in hCG treated testicular tissues of both the species. Histology analysis indicated that the gonadotropin induction either short or long term is a better strategy to highlight expression profile changes during testicular maturation in teleost. • Testicular transcriptome sequencing of C. batrachus and C. gariepinus • Identification of testis-related genes and testicular histology analysis • Gonadotropin dependency of testis-related genes in both the species [ABSTRACT FROM AUTHOR]

The article focuses on a study involving the observation of the reproductive cycle of the Okinawa rail (Gallirallus okinawae) in the wild. It describes the Okinawa rail as an almost flightless bird that is endemic to the northern part of Okinawa Island in Japan which has seen a decline in its wild populations caused by habitat loss and predation. Under the study, the testes and ovaries of 50 wild Okinawa rails have been examined postmortem. Findings recommend the use of female Okinawa rails in and after the second breeding season and of adult males to ensure effective captive breeding pairs.