Molecular identification of genes involved in testicular steroid synthesis and characterization of the responses to hormones stimulation in testis of Japanese sea bass (Lateolabrax japonicas).
Testicular steroids are critical hormones for the regulation of spermatogenesis in male teleosts and their productions have been reported to be regulated by gonadotropins and gonadotropin-releasing hormone. In the Japanese sea bass (Lateolabrax japonicas), the reproductive endocrine, particularly regarding the production and regulation of testicular steroids, are not well understood. For this reason, we first cloned and characterized the response of several key genes regulating the production of testicular steroids and, second, we analyzed the changes of mRNA profiles of these genes during testicular development cycle and in the administration of hCG and GnRHa with corresponding testosterone level in serum, GSI and histological analyses. We succeeded in cloning the full-length cDNAs for the fushi tarazu factor-1 (FTZ-F1) homologues (FTZ-F1a and FTZ-F1b), steroidogenic acute regulatory protein (StAR) and anti-Müllerian hormone (AMH) in Japanese sea bass. Multiple sequence alignment and phylogenetic analysis of these proteins clearly showed that these genes in Japanese sea bass were homologous to those of other piscine species. During the testicular development cycle and hCG/GnRHa administration, quantification of jsbStAR transcripts revealed a trend similar to their serum testosterone levels, while a reciprocal relationship was founded between the serum concentrations of testosterone and jsbAMH and the links between gonadal expression of jsbStAR, jsbAMH and jsbFTZ-F1 were also observed. Our results have identified for the first time several key genes involved in the regulation of steroid production and spermatogenesis in the Japanese sea bass testis and these genes are all detected under gonadotropic hormone and gonadotropin-releasing hormone control.
Fisheries College, Ocean University of China, Qingdao 266003, China.
Mei L
ML
Chi
Fisheries College, Ocean University of China, Qingdao 266003, China. Electronic address: wenhaishen@ouc.edu.cn.
Hai S
HS
Wen
Fisheries College, Ocean University of China, Qingdao 266003, China.
Meng
M
Ni
Fisheries College, Ocean University of China, Qingdao 266003, China.
Feng
F
He
Fisheries College, Ocean University of China, Qingdao 266003, China.
Ji F
JF
Li
Fisheries College, Ocean University of China, Qingdao 266003, China.
Kun
K
Qian
Fisheries College, Ocean University of China, Qingdao 266003, China.
Pei
P
Zhang
Fisheries College, Ocean University of China, Qingdao 266003, China.
Sen H
SH
Chai
Fisheries College, Ocean University of China, Qingdao 266003, China.
Yu X
YX
Ding
Fisheries College, Ocean University of China, Qingdao 266003, China.
Xiang H
XH
Yin
D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000378:metabolism*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D017931:DNA Primers; D018076:DNA, Complementary; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D011863:Radioimmunoassay; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013256:Steroids / Q000096:biosynthesis*; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000097:blood; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D006063:Chorionic Gonadotropin; D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D013256:Steroids; D014157:Transcription Factors; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone
Japanese sea bass; Spermatogenesis; Steroidogenesis; hCG and GnRHa treatments