Molecular cloning, characterization, and expression profiles of the Sox3 gene in Chinese loach Paramisgurnus dabryanus

Abstract

A number of studies have established that in vertebrates, Sox3 is involved in a wide range of developmental processes, including sex differentiation and neurogenesis. However, the exact functions of the Sox3 gene have not been documented so far in teleosts. Here, we cloned the full length cDNA of Sox3 from the teleost fish, Paramisgurnus dabryanus, which we designated PdSox3. Sequence analysis revealed that PdSox3 encodes a hydrophilic protein, and shares high homology with Sox3 in other species, ranging from mammals to fishes. Quantitative real-time reverse transcription PCR, and in situ hybridization showed that PdSox3 is consistently expressed during embryogenesis, mainly localized in the developing central nervous system. Tissue distribution analyses revealed that PdSox3 is abundant in the adult brain, especially in particle cell layer. Furthermore, PdSox3 expression was higher in gonads, in primary spermatocyte cells, primary oocytes, and previtellogenic oocyte cells. All of these results suggest that PdSox3 plays an important role in early embryonic development, in particular the formation and development of the nervous system, and gonad development, similarly to other vertebrates. This is the first report describing Sox3 gene expression from this species, and the results are necessary to provide fundamental information on both the functional and evolutionary role of Sox3 across different species.

A review on sox genes in fish

“…Sox3 is broadly expressed in the central nervous system of M. anguillicaudatus, with peak expression during the neurula stage of embryogenesis, suggesting that sox3 is involved in neurogenesis of M. anguillicaudatus (Xia et al 2017a). Sox3 is consistently expressed in the developing central nervous system of P. dabryanus, suggesting that sox3 plays an important role in particular the formation and development of the nervous system (Xia et al 2018a). Expression of sox3 is specific in central nervous system, suggesting that sox3 may play a key role in central nervous system development of E. coioides (Yao et al 2003).…”

“…Sox3 is consistently expressed in the developing central nervous system of P. dabryanus , suggesting that sox3 plays an important role in particular the formation and development of the nervous system (Xia et al . 2018a). Expression of sox3 is specific in central nervous system, suggesting that sox3 may play a key role in central nervous system development of E. coioides (Yao et al .…”

“…2017a; Xia et al . 2018a). Sox4 is ubiquitously expressed during embryogenesis of M. anguillicaudatus and P. dabryanus , suggesting that sox4 may be involved in embryogenesis (Xia et al .…”

“…2017a; Xia et al . 2018a). Overall, sox B1 ( sox2 and sox3 ) may play an essential regulatory role in gonadal development of fish.…”

“…Sox3 transcripts are significantly increased during ovarian development of Japanese eels (Anguilla japonica) and have also been found in the differentiated testes, suggesting that sox3 may play a major role in ovarian and testicular development (Jeng et al 2018). Sox3 is abundant in the gonads of M. anguillicaudatus and P. dabryanus, including primary oocytes, primary spermatocytes cells and pre-vitellogenic oocyte cells, suggesting that sox3 is involved in the development of gonads (Xia et al 2017a;Xia et al 2018a). Overall, soxB1 (sox2 and sox3) may play an essential regulatory role in gonadal development of fish.…”