INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ABOLITION OF THE SEX DIFFERENCE IN Ngn3 BY ESTRADIOL IS DEPENDING ON SEX CHROMOSOME COMPLEMENT
Autor/es:
TOMÉ, K; CISTERNAS, C.D.; SCERBO, M.J.; CAMBIASSO, M.J.
Lugar:
Huerta Grande Cordoba
Reunión:
Congreso; XXIV Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2014
Institución organizadora:
SAN
Resumen:
ABOLITION OF THE SEX
DIFFERENCE IN Ngn3 BY ESTRADIOL IS DEPENDING ON SEX CHROMOSOME COMPLEMENT
Tomé K, Cisternas CD, Scerbo MJ, Cambiasso MJ
Instituto Ferreyra, INIMEC-CONICET-Universidad de Córdoba.
Córdoba-Argentina
E-mail: ktome@immf.uncor.edu
Although the role of gonadal steroids in sexual
dimorphism is undeniable, a growing body of evidences indicates that some
sexually dimorphic traits cannot be solely explained as a result of gonadal
steroid action. Recent works from our laboratory have shown that the sex difference
in the neuritogenic transcription factor neurogenin3 (Ngn3) in hypothalamic
neurons is depending on sex chromosome complement; moreover 17β-estradiol (E2)
abolishes this sex difference. In order to study if cell-autonomous actions of sex chromosomes are involved in the effect of
E2 on Ngn3, 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 E15 embryos were performed segregated by sex and
genotype. After 72h in vitro the
cultures were incubated for 2 h with E2 (10-10M) or vehicle. The mRNA
transcript levels of Ngn3 were measured by qRT-PCR. The E2-treatment resulted
in a significant increase in the expression of Ngn3 only in cultures of neurons
carrying XY chromosomes (p<0.001), irrespectively of the gonadal type (XYM
and XYF). E2 did not significantly affect Ngn3 mRNA levels in XX cultures.
These findings indicate that sex chromosome complement mediates both cell-autonomous and hormonal actions on Ngn3 in
the hypothalamus.