Transcriptional and proteomic profiling of flatfish (Solea senegalensis) spermatogenesis

17 pages, 7 figures, 2 tables.

The Senegalese sole (Solea senegalensis) is a marine flatfish of high economic value and a target species for aquaculture. The efforts to reproduce this species in captivity have been hampered by the fact that farmed males (F1) often show lower sperm production and fertilization capacity than wild-type males (F0). Our knowledge on spermatogenesis is however limited to a few studies. In a previous work, we identified by 2-D DIGE several potential protein markers in testis for the poor reproductive performance of F1 males. Therefore, the objectives of the present study were, first, to investigate changes in genes and proteins expressed in the testis throughout spermatogenesis in F0 males by using a combination of transcriptomic and proteomic approaches and, second, to further compare the testis proteome between late spermatogenic stages of F0 and F1 fish to identify potential indicators of hampered reproductive performance in F1 fish. We identified approximately 400 genes and 49 proteins that are differentially expressed during the progression of spermatogenesis and that participate in processes such as transcriptional activation, the ubiquitin–proteasome system, sperm maturation and motility or cytoskeletal remodeling. Interestingly, a number of these proteins differed in abundance between F0 and F1 fish, pointing toward alterations in cytoskeleton, sperm motility, the ubiquitin–proteasome system and the redox state during spermiogenesis as possible causes for the decreased fertility of F1 fish.

This research was supported by the PLEUROGENE project funded by a Genome Spain-Genome Canada joint program. I. F. and R. M. J. were supported by predoctoral fellowships from the Scientific Park of Barcelona (University of Barcelona) and the Spanish Ministry of Education and Science (FPI program), respectively. The authors thank Esther Asensio and Pedro Cañavate (IFAPA, Cádiz) for their help with collection of samples from wild fish. They also thank Montserrat Carrascal (CSIC/UAB Proteomics Laboratory) for her support on MS identification, Maite del Hierro (Oryzon Genomics, Barcelona, Spain) for her help with 2-DE and Arjan Palstra for help with PCA. The CSIC/UAB Proteomics Laboratory is a member of ProteoRed.

Peer reviewed