Sex differences in Ngn3 expression in primary hypothalamic neurons is determined by sex chromosomes

• Autores: Cisternas, Carla Daniela; Tomé, Karina; Scerbo Jaureguiberry, Maria Julia; Cambiasso, María Julia
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: documento de conferencia
• Materia: Neurogenina; Diferencias sexuales; Crecimiento y diferenciación neuronal; Estradiol
• Institución: Universidad Nacional de Córdoba

Fil: Cisternas, Carla Daniela. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentina.
Fil: Tomé, Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Scerbo Jaureguiberry, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cambiasso, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina
Brain phenotype is determined by the hormonal profile generated by the gonads during the critical period of development (E18-PN10). Over the years it has been accumulated evidence showing the existence of sex differences before this critical period. Previous works have demonstrated that male hypothalamic neurons, which show a retarded neuritic differentiation compared to female neurons, showed also decreased RNA levels of the neuritogenic factor Ngn3. In order to study if cell autonomous actions of sex chromosomes are involved in the generation of sex differences in the brain we evaluated Ngn3 mRNA in neuronal cultures of transgenic mice which combine a deletion of the Sry gene from the Y chromosome with its reinsertion into an autosome. This model comprises XX and XY gonadal males (XXM and XYM) and XX and XY gonadal females (XXF and XYF). Neuronal hypothalamic cultures of E14 embryos were performed segregated by sex and genotype. After 72h in vitro RNA were extracted and DNA obtained by reverse transcription. The RNA transcript levels of Ngn3 were measured by qRT-PCR. Neurons carrying XY chromosomes (XYM and XYF) showed lower expression levels of Ngn3 than those carrying XX (XXM and XXF; p<0.001), irrespectively of the gonadal type. Our findings indicate that the expression of the autosomal Ngn3 gene must be downstream the expression of X or Y genes that results from the inherent sex difference in the number (two copies of X) and/or type (presence of Y) of sex chromosome.
http://www.saneurociencias.org.ar/libro-de-resumenes-san2013-satelite/
Fil: Cisternas, Carla Daniela. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentina.
Fil: Tomé, Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Scerbo Jaureguiberry, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cambiasso, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina
Bioquímica y Biología Molecular (ídem 3.1.10)