Different sox17 transcripts during sex differentiation in sea bass, Dicentrarchus labrax

• Published in: Molecular and cellular endocrinology Vol. 299; no. 2; pp. 240 - 251
• Main Authors: Navarro-Martín, Laia, Galay-Burgos, Malyka, Sweeney, Glen, Piferrer, Francesc
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 27.02.2009
• Subjects: Alternative splicing; Amino Acid Sequence; Animals; Aromatase - genetics; Aromatase - metabolism; Base Sequence; Bass - genetics; Brain; Conserved Sequence; Development; Differentiation; Female; Fish; Gene Expression Profiling; Gene Expression Regulation; Genes; Gonadal differentiation; Gonads - enzymology; Male; Marine; Molecular Sequence Data; Phylogeny; Promoter Regions, Genetic - genetics; Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sea bass; Sequence Alignment; Sex; Sex Differentiation - genetics; sox17; SOXF Transcription Factors - genetics; SOXF Transcription Factors - metabolism; Splicing; Temperature; Vertebrates - genetics; Gonadal differentiation; Development; Alternative splicing; sox17; Sea bass
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/j.mce.2008.11.013

Sox genes participate in several developmental processes, including sex determination and differentiation. In this study, the genomic structure of sox17 was characterized in the sea bass (sb). Two transcripts, one producing a normal protein (sb Sox17) and another producing a truncated protein (sb t-Sox17) were detected. A third, novel transcript, originated by intron retention (sb i-sox17) was also observed. Sb sox17 was widely distributed, whereas sb i-sox17 was predominantly found in skin and brain. In gonads, sb sox17 expression first increased at 150 days of age, coinciding with the onset of sex differentiation. At 250 days and onwards, sb sox17 expression was significantly higher in females, and mRNA levels correlated with those of gonadal aromatase. Thus, this study provides the first evidence for the presence of alternative splicing by intron retention in a Sox17 gene, and for sex-related differences in expression, implicating sox17 in ovarian development and function in fish.