INVESTIGADORES
MIRANDA Leandro Andres
congresos y reuniones científicas
Título:
Temperature influences the aromatase and estrogen receptor mRNA expression during the critic period of sex determination/differentiation in pejerrey fish (Odontesthes bonariensis) brain.
Autor/es:
PABLO H. STROBL-MAZZULLA; LEONARDO G. GUILGUR; JUAN I. FERNANDINO; LEANDRO A. MIRANDA; GUSTAVO M. SOMOZA
Lugar:
Faro
Reunión:
Congreso; V Congreso Associación Ibérica de Endocrinologia Comparada; 2005
Institución organizadora:
Asociación Ibérica V de Endocrinologia Comparada
Resumen:
Water temperature has an important influence not only on gonadal sex differentiation, but also on the development of the central neuroendocrine system in pejerrey fish (Odontesthes bonariensis). It is known that estrogens play an important role in the differentiation of the ovary in non-mammalian species. It is also known that estrogens are crucial in teleost brain differentiation and maturation. In this context, semi-quantitative RT-PCR method was used in order to investigate the effects of temperature on the ontogenetic expression of brain aromatase enzyme (CYP19A2) and estrogen-receptors (ERs) in the developing brain of pejerrey fish. Temperature-induced sex differentiation in pejerrey larvae (19¨¬C all females and 28¨¬C all males) was applied during 5 weeks and then kept at 24¨¬C until the histological sex ratios could be determined. Every week 6 fish were sampled, and their head dissected heads were sampled and individually processed for semi-quantitative analysis. CYP19A2 transcripts could be first detected on day 14 post-hatching (dph) at both temperatures. However, on days 14, 21 and 28 dph CYP19A2 expression was higher at male-forming temperature, reaching a peak at 21 dph. ER¥á and ¥â were firstly detected on day 7 at both temperatures. On days 7 and 14 the ER¥â expression was higher a female-forming temperature, but at day 21 the expression reach a peak at male-forming temperature and was almost undetectable at female-forming temperature. After the day 21 CYP19A2 and ER¥â transcripts show the same expression pattern at both temperatures, suggesting a correlation in their expression. On the other hand, ER¥á was clearly not related to temperature and a peak was detected at day 28 at both temperatures. Taking together these data suggest that both CYP19A2 and ER¥â are temperature-dependent during the critical period of sex determination. Their timing and expression could then be related with the brain sex-differentiation and the concomitant gonadal differentiation.