Where the ends meet: an overview of sex determination in atheriniform fishes.

CARLOS A. STRÜSSMANN; YOJI YAMAMOTO; RICARDO S. HATTORI; JUAN I. FERNANDINO; GUSTAVO M. SOMOZA

SEXUAL DEVELOPMENT

KARGER

Lugar: Basel; Año: 2021 vol. 15 p. 80 - 92

1661-5425

Atheriniform fishes have recently emerged as attractive models for evolutionary, ecological, and molecular/physiological studies on sex determination. Many species in this group have marked temperature-dependent sex determination (TSD) and yet many species also have a sex determinantgene that provides a strong drive for male differentiation. Thus, in these species the two forms sex determination that were once considered to be mutually exclusive, environmental (ESD) andgenotypic (GSD) sex determination, can coexist at environmentally relevant conditions. Here wereview the current knowledge on sex determination in atheriniform fishes, with emphasis on themolecular and physiological mechanisms of ESD and GSD, the coexistence and cross-talk betweenthese two mechanisms, the possibility of extragonadal transduction of environmental informationand/or extragonadal onset of sex determination, and the results of field studies applying novel toolssuch as otolith increment analysis and molecular markers of genetic sex developed for selected New World and Old World atheriniform species. We also discuss the existence of molecular and histological mechanisms to prevent the discrepant differentiation in parts of the gonads because of ambiguous or conflicting environmental and genetic signals, and particularly the possibility that the female is the default state in these species.