Differential expression of estrogen receptor alpha in the embryonic adrenal-kidney-gonadal complex of the oviparous lizard, Calotes versicolor (Daud.)

Inamdar, LS and Khodnapur, BS and Nindi, RS and Dasari, S and Seshagiri, PB (2015) Differential expression of estrogen receptor alpha in the embryonic adrenal-kidney-gonadal complex of the oviparous lizard, Calotes versicolor (Daud.). In: GENERAL AND COMPARATIVE ENDOCRINOLOGY, 220 (SI). pp. 55-60.

PDF Gen_and_Com_End_220_55_2015.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

Estrogen signalling is critical for ovarian differentiation in reptiles with temperature-dependent sex determination (TSD). To elucidate the involvement of estrogen in this process, adrenal-kidney-gonadal (AKG) expression of estrogen receptor (ER alpha) was studied at female-producing temperature (FPT) in the developing embryos of the lizard, Calotes versicolor which exhibits a distinct pattern of TSD. The eggs of this lizard were incubated at 31.5 +/- 0.5 degrees C (100% FPT). The torso of embryos containing adrenal-kidney-gonadal complex (AKG) was collected during different stages of development and subjected to Western blotting and immunohistochemistry analysis. The ER alpha, antibody recognized two protein bands with apparent molecular weight similar to 55 and similar to 45 kDa in the total protein extracts of embryonic AKG complex of C. versicolor. The observed results suggest the occurrence of isoforms of ER alpha. The differential expression of two different protein isoforms may reveal their distinct role in cell proliferation during gonadal differentiation. This is the first report to reveal two isoforms of the ER alpha in a reptile during development. Immunohistochemical studies reveal a weak, but specific, cytoplasmic ER alpha immunostaining exclusively in the AKG during late thermo-sensitive period suggesting the responsiveness of AKG to estrogens before gonadal differentiation at FPT. Further, cytoplasmic as well as nuclear expression of ER alpha in the medulla and in oogonia of the cortex (faint activity) at gonadal differentiation stage suggests that the onset of gonadal estrogen activity coincides with sexual differentiation of gonad. Intensity and pattern of the immunoreactions of ER alpha in the medullary region at FPT suggest endogenous production of estrogen which may act in a paracrine fashion to induce neighboring cells into ovarian differentiation pathway. (C) 2014 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	GENERAL AND COMPARATIVE ENDOCRINOLOGY
Publisher:	ACADEMIC PRESS INC ELSEVIER SCIENCE
Additional Information:	Copy right for this article belongs to the ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
Keywords:	Estrogen receptor (ER alpha); Adrenal-kidney-gonadal (AKG) complex; Lizard embryo; Ovarian differentiation; Western blotting; Immunohistochemistry
Department/Centre:	Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Date Deposited:	15 Oct 2015 06:34
Last Modified:	15 Oct 2015 06:34
URI:	http://eprints.iisc.ac.in/id/eprint/52556

Actions (login required)

View Item