Comparative Proteome Analysis of Four Stages of Spermatogenesis in the Small-Spotted Catshark (Scyliorhinus canicula), Using High-Resolution NanoLC-ESI-MS/MS

Spermatogenesis is a highly specialized process of cellproliferationand differentiation leading to the production of spermatozoa fromspermatogonial stem cells. Due to its testicular anatomy, Scyliorhinus canicula is an interesting model toexplore stage-based changes in proteins during spermatogenesis. Theproteomes of four testicular zones corresponding to the germinativeniche and to spermatocysts (cysts) with spermatogonia (zone A), cystswith spermatocytes (zone B), cysts with young spermatids (zone C),and cysts with late spermatids (zone D) have been analyzed by nanoLC-ESI-MS/MS.Gene ontology and KEGG annotations were also performed. A total of3346 multiple protein groups were identified. Zone-specific proteinanalyses highlighted RNA-processing, chromosome-related processes,cilium organization, and cilium activity in zones A, D, C, and D,respectively. Analyses of proteins with zone-dependent abundance revealedprocesses related to cellular stress, ubiquitin-dependent degradationby the proteasome, post-transcriptional regulation, and regulationof cellular homeostasis. Our results also suggest that the roles ofsome proteins, such as ceruloplasmin, optineurin, the pregnancy zoneprotein, PA28 beta or the Culling-RING ligase 5 complex, as wellas some uncharacterized proteins, during spermatogenesis could befurther explored. Finally, the study of this shark species allowsone to integrate these data in an evolutionary context of the regulationof spermatogenesis. Mass spectrometry data are freely accessible viaiProX-integrated Proteome resources (https://www.iprox.cn/) for reuse purposes.

Automated summary

This study analyzed the proteomes of different stages of spermatogenesis in Scyliorhinus canicula and identified proteins related to RNA processing, chromosome-related processes, cilium organization, and cilium activity. Proteins involved in cellular stress, ubiquitin-dependent degradation, post-transcriptional regulation, and regulation of cellular homeostasis were also found. Additionally, the study highlighted the potential roles of some proteins in spermatogenesis that need further exploration and emphasized the evolutionary context of spermatogenesis regulation.