Transcriptional evolution underlying vertebrate sexual development. Issue 4 (28th November 2012)

• Record Type: Journal Article
• Authors: Valenzuela, Nicole; Neuwald, Jennifer L.; Literman, Robert
• Is Part Of: Developmental dynamics. Volume 242:Issue 4(2013:Apr.)
• Page Start: 307
• Page End: 319
• Publication Date: 2012-11-28
• Subjects: Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.23897
• Languages: English
• ISSNs: 1058-8388

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Explaining the diversity of vertebrate sex‐determining mechanisms ranging from genotypic (GSD) to temperature‐dependent (TSD) remains a developmental and evolutionary conundrum. Using a phylogenetic framework, we explore the transcriptional evolution during gonadogenesis of several genes involved in sexual development, combining novel data from <italic>Chrysemys picta</italic> turtles (TSD) and published data from other TSD and GSD vertebrates. Our novel <italic>C. picta</italic> dataset underscores <italic>Sf1</italic> and <italic>Wt1</italic> as potential activators of the thermosensitive period and uncovered the first evidence of <italic>Dax1</italic> involvement in male development in a TSD vertebrate. Contrasting transcriptional profiles revealed male‐biased <italic>Wt1</italic> expression in fish while monomorphic expression is found in tetrapods but absent in turtles. <italic>Sf1</italic> expression appears highly labile with transitions among testicular, ovarian, and non‐sex‐specific gonadal formation patterns among and within lineages. <italic>Dax1</italic>'s dual role in ovarian and testicular formation is found in fish and mammals but is dosage‐sensitive exclusively in eutherian mammals due to its X‐linkage in this group. Contrastingly, <italic>Sox9</italic> male‐biased and <italic>Aromatase</italic> female‐biased expression appear ancestral and virtually conserved throughout vertebrates despite significant heterochronic changes in expression as other elements likely replaced their function in early gonadogenesis. Finally, research avenues are highlighted to further study the evolution of the regulatory network of sexual development. © 2012 Wiley Periodicals, Inc. Developmental Dynamics 242:307–319, 2013. © 2012 Wiley Periodicals, Inc.</p> </abstract>