Characterization of Chicken α2A-Adrenoceptor: Molecular Cloning, Functional Analysis, and Its Involvement in Ovarian Follicular Development

Abstract

Adrenoceptors are suggested to mediate the functions of norepinephrine (NE) and epinephrine (EPI) in the central nervous system (CNS) and peripheral tissues in vertebrates. Compared to mammals, the functionality and expression of adrenoceptors have not been well characterized in birds. Here, we reported the structure, expression, and functionality of chicken functional α2A-adrenoceptor, named ADRA2A. The cloned chicken ADRA2A cDNA is 1335 bp in length, encoding the receptor with 444 amino acids (a.a.), which shows high amino acid sequence identity (63.4%) with its corresponding ortholog in humans. Using cell-based luciferase reporter assays and Western blot, we demonstrated that the ADRA2A could be activated by both NE and EPI through multiple signaling pathways, including MAPK/ERK signaling cascade. In addition, the mRNA expression of ADRA2A is found to be expressed abundantly in adult chicken tissues including thyroid, lung, ovary and adipose from the reported RNA-Seq data sets. Moreover, the mRNA expression of ADRA2A is also found to be highly expressed in the granulosa cells of 6–8 mm and F5 chicken ovarian follicles, which thus supports that ADRA2A signaling may play a role in ovarian follicular growth and differentiation. Taken together, our data provide the first proof that the α2A-adrenoceptor is functional in birds involving avian ovarian follicular development.

Cholecystokinin (CCK) and its receptors (CCK1R and CCK2R) in chickens: functional analysis and tissue expression

“…After 24 h of transfection, cells were treated with cCCK-8S (10 nM) or cCCK-4 (10 nM) for 10 min, respectively. After removal of the medium, cells were lysed and used for western blot detection of phosphorylated ERK1/2 (pERK1/2) and CREB (pCREB), as described in our previous studies ( Wu et al, 2019 ; Jiang et al, 2022 ). Additionally, the levels of β-actin protein were also examined and used as internal controls in each experiment.…”

Effects of Genetic Mutation Sites in ADR Genes on Modern Chickens Produced and Domesticated by Artificial Selection

“…Some traits are associated with sites that were affected by artificial selection. This shows that ADR gene mutations are likely related to behavior (emotion) because they are found inside membrane proteins at most mutation sites [1,[26][27][28][29][30]. This suggests a relationship between breed-specific behavior and these mutations.…”

Characterization of relaxin 3 and its receptors in chicken: Evidence for relaxin 3 acting as a novel pituitary hormone

“…According to our previously established methods ( Liu et al, 2019 ; Jiang et al, 2022 ), two cell-based luciferase reporter systems (pGL3-CRE-luciferase and pGL3-NFAT-RE-luciferase) were used to verify whether cRLN3 cm is biologically active and capable of activating cRXFP1 and cRXFP3. In brief, HEK293 cells transiently expressing each receptor (cRXFP1 and cRXFP3) were treated with 30 μl serum-free medium containing cRLN3 cm or pcDNA cm (0.001–10 μl) for 6 h, and the receptor-activated cAMP/PKA pathways and calcium mobilization were then monitored by pGL3-CRE-luciferase and pGL3-NFAT-RE-luciferase reporter systems, respectively.…”