Expression of P450arom and Estrogen Receptor Alpha in the Oviduct of Chinese Brown Frog (Rana dybowskii) during Prehibernation

Abstract

One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed that there were significant differences in both oviductal weight and size with values markedly higher in prehibernation than in the breeding period. P450arom was observed in stromal tissue in both the breeding period and prehibernation. ERα was expressed in stromal tissue and epithelial cells in both periods, whereas ERβ could not be detected. The mean protein and mRNA levels of P450arom and ERα were significantly higher in prehibernation as compared to the breeding period. Besides, oviductal content of 17β-estradiol was also higher in prehibernation than in the breeding period. These results suggested that estrogen may play autocrine/paracrine roles mediated by ERα in regulating the oviductal hypertrophy during prehibernation.

Immunoreactivities of AR, ERα, ERβ and aromatase in the nuptial pad of Chinese brown frog (<em>Rana dybowskii</em>) during pre-hibernation and the breeding period

“…The specificity of aromatase and ER antibodies in this amphibian was previously confirmed. 17 The immunostained slides were examined using a photomicroscope (BX51, Olympus, Tokyo, Japan). The immunohistochemical staining was determined as positive (+), strong positive (++), very strong positive (+++), and negative (-).…”

“…16 The Chinese brown frog (R. dybowskii) is a special amphibian, whose oviduct expands prior to hibernation instead of expanding during the breeding period, and inhabits the northeastern of China (provinces Heilongjiang, Liaoning and Jilin). 17 R. dybowskii hibernates from October to February and then come with reproduction from March to June affected by the latitude and altitude. The nuptial pads of R. dybowskii are mainly composed of at least two thickened skins at the base of the first finger.…”

DE NOVOSEQUENCING AND ANALYSIS OF THERANA CHENSINENSISTRANSCRIPTOME TO DISCOVER PUTATIVE GENES ASSOCIATED WITH POLYUNSATURATED FATTY ACIDS

“…R. chensinensis is a cold-tolerant vertebrate amphibian that grows for ≤6 months in hibernation [12]. Maintaining the fluidity of the cell membrane in a low-temperature environment ensures that it can perform its normal physiological functions [8].…”

Expressions of TLR4, MyD88, IRAK4 and NF-κΒ in the oviduct of Chinese brown frog (Rana dybowskii)

“…As a result, its morphology and function change periodically to best support the reproductive processes. 1,2 The oviduct is not only a passive channel for gamete and embryo transport, but also a highly active secretory organ and its oviductal fluid formed by the oviduct epithelium and plasma plays an important role in the reproductive process. For example, it can provide the optimal microenvironment for the final gamete maturation, sperm capacitation, fertilization, and the early embryonic development.…”