Cloning, expression of, and evidence of positive selection for, the prolactin receptor gene in Chinese giant salamander (Andrias davidianus)

Abstract

Prolactin receptor (PRLR) is a protein associated with reproduction in mammals and with osmoregulation in fish. In this study, the complete length of Chinese giant salamander Andrias davidianus prolactin receptor (AD-prlr) was cloned. Andrias davidianus prlr expression was high in the kidney, pituitary, and ovary and low in other examined tissues. The AD-prlr levels were higher in ovary than in testis, and increased in ovaries with age from 1 to 6 years. To determine effect of exogenous androgen and aromatase inhibitor on AD-prlr expression, methyltestosterone (MT) and letrozole (LE) were injected, resulting in decreased AD-prlr in both brain and ovary, with MT repressing prlr transcription more rapidly than did LE. The molecular evolution of prlr was assessed, and found to have undergone a complex evolution process. The obranch-site test detected four positively selected sites in ancestral lineages prior to the separation of mammals and birds. Fourteen sites underwent positive selection in ancestral lineages of birds and six were positively selected in amphibians. The site model showed that 16, 7, and 30 sites underwent positive selection in extant mammals, amphibians, and birds, respectively. The positively selected sites in amphibians were located outside the transmembrane domain, with four in the extracellular and three in the intracellular domain, indicating that the transmembrane region might be conserved and essential for protein function. Our findings provide a basis for further studies of AD-prlr function and molecular evolution in Chinese giant salamander. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 707-719, 2015. © 2015 Wiley Periodicals, Inc.

Integrated chromatin accessibility and DNA methylation analysis to reveal the critical epigenetic modification and regulatory mechanism in gonadal differentiation of the sequentially hermaphroditic fish, Monopterus albus

“…The expression of various tissues, developing gonads, and gonadal cells in M. albus were analysed by quantitative real-time PCR (qRT-PCR) according to a previous description [ 37 ]. ef1a was used as the internal control gene, cDNA was used as a template, tissues from three individuals were used, and each reaction was repeated three times.…”

Sexually Dimorphic Expression of Foxl2 and Ftz‐F1 in Chinese Giant Salamander Andrias Davidianus

“…whether exogenous androgen and AI limit the expression of adFoxl2 and adFtz‐f1 , the expression profile was analyzed after methyltestosterone (MT) and letrozole (LE) injection. The injection was prepared and conducted as previously described (Hu et al., ). After injection, A. davidianus were held in the rearing container.…”

Effects of temperature and sex steroids on sex ratio, growth, and growth-related gene expression in the Chinese giant salamander Andrias davidianus

“…The RNA was extracted using the TRIZOL method from brain and pituitary at 201 dph and 270 dph from the high temperature treated group and control, respectively, and then the total RNA was treated with RNase-free DNasel (Tiangen) at 37°C for 1 h. Finally, cDNA synthesis was carried out as described in Hu et al (2017). Quantitative real-time PCR (qRT-PCR) was conducted on a QuantStudio 5 real-time PCR system (Applied Biosystems) as described in Hu et al (2015). mRNA expression for each gene was analysed at least in 3 samples and independently in triplicate.…”