MIRANDA leandro Andres
congresos y reuniones científicas
Fish sex determination: The interaction among genes and environment.
Mar del Plata
Jornada; XXV Jornadas de la Sociedad Argentina de Biología; 2023
Institución organizadora:
Sociedad Argentina de Biología
Even though in mostvertebrates gonadal sex is determined genetically (a phenomenon known asGenotic Sex Determination, GSD), the gene that determines sex is not always thesame. However, in some ectothermic animals gonadal differentiation can bemodulated by the environment, being the influence of temperature the bestknown, although not the only one. This phenomenon is called Temperature SexDetermination (TSD). In this sense, Atheriniformeshave become interesting vertebrate models to study. In two native species ofArgentina, Odontesthes hatcheri (Patagonian pejerrey) and Odontesthesbonariensis (pejerrey), a Y-linked gene, amhy, has been identified,which is the determinant of testicular morphogenesis. It has also been seenthat the expression of this gene is differentially regulated by watertemperature, demonstrating that there is an interaction between both mechanismsof sexual determination (GSD-TSD). This fact makes possible to evaluate therelationship between genotypic sex (evidenced by PCR) and phenotypic sex(evidenced both by visual observation and histology) to study possiblemismatches among them influenced by the environment revealing sexualinversions.Our studies with pejerreyshow that, even though the presence of the amhy gene is important forthe differentiation of males, we found sexual inversions (both in theenvironment, as well as in experimental conditions in the laboratory or insemi-controlled conditions in the field) that can be explained by the influenceof the environment, not only by effects of natural environmental factors butalso by anthropic influence.In the present work we willnot only present a theoretical introduction of the phenomena of determinationand sexual differentiation in pejerrey but also the comparison betweenexperiments carried out in laboratory conditions and experiments carried out inthe field.