Identification, cloning and expression profile of sycp3 during gonadal cycle and after siRNA silencing in catfish

Abstract

Molecular mechanisms underlying germ cell development, proliferation and maturation in teleosts revealed the importance of transcription factors through functional genomic approaches which is often comparable to mammals. In the present study, a proteomic approach was employed to find novel molecules with reference to germ cell development in teleosts. Based on this, current work utilized two-dimensional (2D) gel electrophoresis combined with matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF/TOF) mass spectrometry in an attempt to identify and compare the proteins which are expressed differentially in the male gonads of catfish during juvenile and adult stages. The 2D gel analysis identified the Sycp3 protein which was found to be up regulated in juvenile testis when compared to adult stages, and then the full length cDNA was cloned using the peptide sequence data from catfish testis. The spatio-temporal expression pattern of sycp3 was explored during the critical time period of gonadal development as well as at different phases of recrudescence in catfish using real-time PCR, followed by localization analysis by in situ hybridization and immunohistochemistry. In addition, in vivo transient knockdown using PEI mediated sycp3-esiRNA in adult catfish during recrudescence showed a decrease in sycp3 expression, which also affected the expression level of various testis-related genes. Present findings suggest that Sycp3 might have a potential role in the development and maintenance of testicular function in catfish.