title: Identification and characterization of a progestin and adipoQ receptor (PAQR) structurally related to Paqr7 in the ovary of Cynoglossus semilaevis and its potential role in regulating oocyte maturation.
abstract: Membrane progestin receptors (mPRs) play an important role in the regulation of oocyte meiotic maturation in fish. However, details of the molecular endocrine mechanism regulating oocyte maturation in multiple spawning fish with asynchronous ovarian development remain unclear. The cDNA encoding a novel progestin and adipoQ receptor with structural similarity to mPRα (Paqr7), herein called Paqr7b, was cloned and sequenced from the ovary of half-smooth tongue sole Cynoglossus semilaevis. Phylogenetic analysis showed that Paqr7b represents an evolutionary intermediate between mPRα and mPRβ and shares high homology with other similar Paqr proteins in other teleost species. However, the tongue sole Paqr7b protein showed much greater homology to teleost mPRαs (average 52%) than mPRβs (average 40%), suggesting it may have arisen from gene duplication of mPRα. paqr7b and paqr7 mRNA exhibited similar patterns of tissue expression. The mRNA and protein of Paqr7b were ubiquitously detected in all tissues analyzed, including the ovary. Moreover, in situ hybridization results revealed that paqr7b was expressed in stage V oocytes, as well as in scattered cells in the pituitary. The expression of paqr7b mRNA in brain and ovary significantly increased from ovarian development stage II to stage V (P<0.05), and was maximal at stage V, and then sharply decreased at stage VI. The transcript level of paqr7b mRNA in the pituitary also peaked at stage V (P<0.05). Treatment of tongue sole ovarian follicles with gonadotropin consistently increased the expression level of Paqr7b protein and mRNA in both a dose- and stage-dependent manner. Microinjection of tongue sole oocytes with a morpholino antisense oligonucleotide to Paqr7b blocked the progestin induction of oocyte maturation. Our findings demonstrate an important role of Paqr7b in the regulation of oocyte maturation in tongue sole and suggest the receptor may also influence other aspects of reproduction, such as pituitary function.
authors.affiliation: Key Laboratory for the Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Bao
authors.initials: B
authors.lastname: Shi
authors.affiliation: Key Laboratory for the Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China. Electronic address: Liuxz@ysfri.ac.cn.
authors.forename: Xuezhou
authors.initials: X
authors.lastname: Liu
authors.affiliation: Marine Science Institute, University of Texas At Austin, Port Aransas, TX 78373, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Thomas
authors.affiliation: Marine Science Institute, University of Texas At Austin, Port Aransas, TX 78373, USA.
authors.forename: Yefei
authors.initials: Y
authors.lastname: Pang
authors.affiliation: Key Laboratory for the Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Yongjiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Key Laboratory for the Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Xiaoni
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory for the Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D005412:Flatfishes / Q000378:metabolism*; D020869:Gene Expression Profiling; D006062:Gonadotropins / Q000378:metabolism; D008845:Microinjections; D060172:Morpholinos / Q000494:pharmacology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009928:Organ Specificity / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D010802:Phylogeny; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D040681:Structural Homology, Protein; D026801:Synteny / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D006062:Gonadotropins; D060172:Morpholinos; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D011980:Receptors, Progesterone
keywords: Cynoglossus semilaevis; Expression; Oocyte maturation; Progestin and adipoQ receptor-related to mPRα (Paqr7b); Reproduction