Sexually dimorphic expression of receptor-alpha in the cerebral cortex of neonatal Caiman latirostris (Crocodylia: Alligatoridae)

详细信息    查看全文

• 作者：Jorgelina Varayoud ; Lucas Monje ; Guillermo Samuel Moreno-Piovano ; Germ¨¢n Hugo Galoppo ; Enrique Hugo Luque ; M¨®nica Mu?oz-de-Toro ; Jorge Guillermo Ramos
• 关键词：ERs ; estrogen receptors ; TSD ; temperature-dependent sex determination ; MC ; medial cortex ; DC ; dorsal cortex ; LC ; lateral cortex ; HSD ; hormone-dependent sex determination ; DCX ; doublecortin ; GFAP ; glial fibrillary acidic protein ; Neun ; neuron-specific nucl
• 刊名：General and Comparative Endocrinology
• 出版年：2012
• 出版时间：1 November, 2012
• 年：2012
• 卷：179
• 期：2
• 页码：205-213
• 全文大小：1703 K

文摘

In mammals, estrogens have been described as endocrine and paracrine modulators of neuronal differentiation and synapse formation. However, the functional role of circulating estrogens and the distribution of estrogen receptors (ERs) in the cerebral cortex of reptiles have not been clearly established. Caiman latirostris (C. latirostris) is a South American species that presents temperature-dependent sex determination (TSD). By using immunohistochemistry, we have studied the distribution of ER¦Á in the cerebral cortex of neonatal caimans. We studied brain samples from ten-day-old TSD-females and TSD-males and from female caimans that were administered estradiol during embryonic development (hormone-dependent sex determination, HSD-females). ER¦Á was detected in the medial (MC), dorsal (DC) and lateral (LC) cortices. ER¦Á expression in the MC showed sex-associated differences, being significantly greater in TSD-females compared to TSD-males. Interestingly, the highest ER¦Á expression in the MC was exhibited by HSD-females. In addition, the circulating levels of estradiol were significantly higher in females (both TSD and HSD) than in TSD-males. Double immunostaining showed that ER¦Á is expressed by neural precursor cells (as detected by ER¦Á/doublecortin or ER¦Á/glial fibrillary acidic protein) and mature neurons (ER¦Á/neuron-specific nuclear protein). Our results demonstrate that the expression of ER¦Á in the neonatal caiman cortex is sexually dimorphic and is present in the early stages of neuronal differentiation.