Molecular characterization and expression patterns of glucocorticoid receptors in the viviparous black rockfish Sebastes schlegelii

• Published in: General and comparative endocrinology Vol. 316; p. 113947
• Main Authors: Wang, Xiaojie, Meng, Wei, Qi, Xin, Li, Yun, Li, Jifang, Lyu, Likang, Li, Jianshuang, Yao, Yijia, Yan, Shaojing, Zuo, Chenpeng, Xie, Songyang, Wen, Haishen
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-01-2022
• Subjects: Animals; Black rockfish; Fish Proteins - metabolism; Fishes - genetics; Fishes - metabolism; Gene expression profile; Glucocorticoid receptor; Gonads - metabolism; In vitro treatment; Localization; Male; Parturition; Perciformes - genetics; Perciformes - metabolism; Phylogeny; Receptors, Glucocorticoid - metabolism; Steroid 11β-hydroxylase; Viviparity; Parturition; Viviparity; In vitro treatment; Glucocorticoid receptor; Black rockfish; Localization; Steroid 11β-hydroxylase; Gene expression profile
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/j.ygcen.2021.113947

•Black rockfish GRs has four modularized domains of nuclear receptor family.•Transcripts of grs are widely expressed in various tissues, including ovary.•In ovary, grs transcripts are localized in ovarian wall, follicle and oocytes.•Expression level of gr1 rises up significantly after parturition.•Glucocorticoids inhibits the expression of anti-inflammatory cytokines in ovary.
Glucocorticoid receptors (GRs) are ligand-activated transcription factors associated with anti-inflammation, stress, metabolism and gonadal development. In this study, two gr genes (gr1 and gr2) were cloned and analyzed from a viviparous teleost, black rockfish (Sebastes schlegelii). The phylogenetic analysis of GRs showed that GR1 and GR2 clustered into teleost GR1 and GR2 separately and differed from the GRs of tetrapods or basal ray-finned fishes. Black rockfish GRs possess four modular domains of the nuclear receptor superfamily: an N-terminal domain (NTD), a DNA-binding domain (DBD), a hinge region (HR) and a ligand-binding domain (LBD). Nine conserved amino acid inserts were found in the GR1 DBD, and the ligand cavity-related amino acids of GR1 and GR2 LBD were slightly different. Tissue distribution analysis revealed that grs was widely expressed in various tissues, while cyp11b was mainly expressed in the testis and head kidney. The cyp11b transcripts were localized in the interrenal glands of the head kidney, the main source of cortisol; grs transcripts were detected in oocytes, the follicle layer and the ovarian wall. Histologically, significant blood vessel dilation was observed in the fetal membrane during or after parturition of black rockfish. The highest levels of serum cortisol and ovarian cyp11b mRNA were detected in parturition. In addition, the relative expression level of gr1 was upregulated significantly after delivery, while the levels of gr2 showed no significant change. In addition, in vitro GC treatment inhibited the expression of il1b but significantly upregulated the transcription of il1r1. These data provide evidence that GRs are likely to work as anti-inflammatory factors by inhibiting the functions of pro-inflammatory factors in the parturition of black rockfish.