Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt)

Abstract

The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; Stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function.

Androgen receptor, aromatase, oestrogen receptor α/β and G protein‐coupled receptor 30 expression in the testes and epididymides of adult sheep

“…It was expression in Leydig, Sertoli and germ cells, with successive increases in expression in the caput, corpus and cauda epididymides. P450arom expression has been previously demonstrated in the testes and epididymides of male rhesus monkeys and wild ground squirrels (Li et al, ; Pereyra‐martinez et al, ), consistent with our results. This indicates that the epididymis and testis can autonomously synthesize oestrogen and that the level of oestrogen synthesis increases gradually with the production and maturation of spermatozoa, suggesting that oestrogen plays important roles in spermatogenesis and sperm maturation and storage in the epididymides.…”

“…These results suggest that the regulation of epididymal function by oestrogen depends on which receptor it binds. In sheep testes, ERα is present in Leydig and Sertoli cells, and ERβ in Leydig cells, Sertoli cells and spermatogonia, consistent with their expression patterns in wild squirrels (Li et al, ). This suggests that oestrogen may regulate steroid production through ERα and ERβ to promote gamete formation.…”

“…Nuclear ERs have been observed in the epididymides and testes of many species, but the expression and distribution patterns of ERα and ERβ differ (Hess & Roser, ; Hess & Carnes, ; Li et al, ). ER expression in these organs depends on the cell type, developmental stage and receptor type (Hess & Roser, ; Hess & Carnes, ).…”

Sequential testicular atrophy involves changes in cellular proliferation and apoptosis associated with variations in aromatase P450 expression levels in Irs‐2‐deficient mice

“…; Li et al. ), suggesting that oestrogens have a physiological role in the regulation and control of postmeiotic spermatogenesis and sperm survival (Carreau, ).…”

Histochemistry today: Detection and location of single molecules

“…Several papers were aimed at illustrating the tissue organization and protein expression of still poorly described organs from various Vertebrate and Invertebrate species: [42][43][44][45][46][47][48][49][50][51][52][53][54] here, the morphological description of the microanatomical and histological features was paralleled by the detection of specific molecules responsible for the tissue functional characteristics, also as a consequence of seasonal dynamic changes. [55][56][57] The immunolabeling of marker proteins was extensively applied in studies aimed at distinguishing stem/progenitor cells or at elucidating the process of cell differentiation and morphogenesis during pre-and post-natal development in mammals, including humans, [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76] with special attention to the nervous system, 65,66 sensory organs, [67][68][69] skin, 70 lung, 70,71 and the skeletal apparatus. [72][73][74][75] Also in plants, the histochemical d...…”