Differential expression of estrogen receptors (ERα/ERβ) in testis of mature and immature pigs

Abstract

High affinity estrogen receptors (ERs) mediate estrogen action in male reproductive tissues. The objective of the present study was the immunolocalization of estrogen receptor ␣ and estrogen receptor ␤ in immature and mature testes of pig, a species in which the role of estrogens on gonadal function is scarcely known. Testes from 3 and 18 month-old pigs were investigated. Immunohistochemistry was performed on paraffin embeddedtissues using both mouse anti-human monoclonal IgG ER␣ and IgG ER␤ 1 isoform. Western blot analysis demonstrated antibody specificity. ER␣ staining was not observed in immature testes, but it was detected in spermatogonia, spermatocytes and in the most Leydig cells of mature testes. ER␤ immunoreactivity was observed in spermatogonia and Leydig cells of immature gonads, while it was clearly detected in spermatogonia and in spermatocytes of adult pig testes. The differential ER␣/ER␤ expression in germ and somatic cells of the gonads suggest a role of estrogens in function and in development of pig testis.

Evidence for estrogen receptor α and β expression in skeletal muscle of pigs

“…In SM satellite cell myoblasts the staining was even restricted to the cytoplasm. Our results are consistent with the Wndings of Carpino et al (2004) and Rago et al (2004), who detected immunoreactivity of MCA-1974ST exclusively as nuclear staining in pig epididymis and testes, respectively. With regard to the polyclonal PA1-310B, Slomczynska and Wozniak (2001) reported immunoreactivity for the porcine ovary as nuclear and/or cytoplasm staining, which was dependent on the cell type and, in oocytes, on the developmental stage.…”

“…No immunoreactivity by Western blotting has been obtained with the MCA-1974ST antibody, which is in contrast to results reported by Rago et al (2004) for pig testis. The immunoblot with the polyclonal antibody PA1-310B revealed a positive detection of ER protein in all samples tested.…”

“…In order to detect the ER , the monoclonal mouse anti-human ER MCA-1974ST Rago et al 2004) and the polyclonal rabbit anti-rat ER PA1-310B (Slomczynska and Wozniak 2001) antibodies have been chosen by reference, as these have been used successfully to detect ER protein in porcine tissues. No immunoreactivity by Western blotting has been obtained with the MCA-1974ST antibody, which is in contrast to results reported by Rago et al (2004) for pig testis.…”

Cytochrome P450arom, androgen and estrogen receptors in pig sperm

“…In fact, proteins involved in estrogen biosynthesis and action, as aromatase (P450arom) and/or estrogen receptors (ERs), have been detected in developing sperm of numerous species such as rat [4-6], bank vole [7], rooster [8], boar [9,10], equine [11], brown bear [12], dog and cat [13], human [14,15]. …”

In vivo function of the 5′ flanking region of mouse estrogen receptor β gene

“…In addition, a recent investigation suggested that 17␤-estradiol and 5␣-androstane-3␤ (3␤-diol), a possible physiological ER␤ ligand converted from 5␣-dihydrotestosterone in the tissue, may modulate sertoli cell function through ER␤ [27]. Although expression of ER␤ in sertoli cells of the testis is evident in rats as well as mice, it remains controversial whether it is expressed in human testis [28]. ER␣ expression is regulated by multiple untranslated first exons and promoters.…”