Generation of Cyp17iCre transgenic mice and their application to conditionally delete estrogen receptor alpha (Esr1) from the ovary and testis

Abstract

A transgenic mouse line that expresses iCre under regulation of the Cytochrome P(450) 17alpha-hydroxylase/17, 20-lyase (Cyp17) promoter was developed as a novel transgenic mouse model for the conditional deletion of genes specifically in the theca/interstitial cells of the ovary and Leydig cells of the testis. In this report, we describe the development of Cyp17iCre mice and the application of these mice for conditional deletion of the estrogen receptor alpha (Esr1) gene in the theca/interstitial and Leydig cells of the female and male gonad, respectively. These mice will prove a powerful tool to inactivate genes in the gonad in a cell-specific manner.

Figure 1

Schematic representation of the Cyp17iCre transgene construct. A) Plasmid map of the completed Cyp17iCre construct. B) Linearlized structure of Kpn 1 /Sal 1 fragment of the construct. This DNA fragment was used for oocyte injection.

Figure 2

β-galactosidase expression in gonadal tissues of Cyp17iCre/ROSA26 mice. Upper panels: Direct X-gal staining of the adult female and male gonads. Sectioned images of the ovary and testis are shown. The sections were counterstaining with nuclear fast red. Lower panels: Direct X-gal staining of embryonic day 16.5 female and male gonads. Sectioned images of the ovary and testis are shown. The sections were counterstaining with nuclear fast red.

Figure 3

β-galactosidase expression in non-gonadal tissues of Cyp17iCre/ROSA26 mice. Upper panels: Direct X-gal staining of the pituitary and placenta of a female mouse. Lower panels: Direct X-gal staining of the embryonic day 16.5 adrenal gland. Sectioned images of the male and female embryonic adrenal gland are shown. The sections were counterstaining with nuclear fast red.

Figure 4

Gonad-specific deletion of Esr1 gene by Cyp17iCre mice. Upper panels: Expression of Esr1 in the reproductive tissues of a female Esr1 ^flox/flox Cyp17iCre mouse. Note strong Esr1 expression both in oviduct and uterus but not in the ovary except for ovarian surface epithelial cells. Lower panels: Expression of Esr1 in the reproductive tissues of a male Esr1 ^flox/flox Cyp17iCre mouse. Note strong Esr1 expression in the efferent ductile and epididymis but not the testis.

Figure 5

Successful deletion of Esr1 by the application of Cyp17iCre mice. Upper panels: Expression of Cyp17 and Esr1 in the ovary of Esr1 ^flox/flox and Esr1^flox/flox Cyp17iCre mice. Note that Esr1 expression is absent in the theca/interstitial cells of the Esr1^flox/flox Cyp17iCre mouse ovary while Cyp17 expression persists. Lower panels: Expression of Cyp17 and Esr1 in the testis of Esr1 ^flox/flox and Esr1^flox/flox Cyp17iCre mice. Note that Esr1 expression is absent in the Leydig cells of the Esr1^flox/flox Cyp17iCre mouse testis while Cyp17 expression persists.