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1.
H.G. Fan D.S. Wang T. Kobayashi B. Senthilkumaran C.C. Sudhakumari M. Yoshikuni Y. Nagahama 《Fish physiology and biochemistry》2003,28(1-4):143-144
Gonadotropin (GTH)α, FSHβ and LHβ cDNAs were cloned from the Nile tilapia. Northern blot analysis detected a single band for each subunit. Preliminary studies indicate that FSHβ is expressed as early as 0 days after hatching (dah) in the fish pituitaries. 相似文献
2.
Nyuji M Selvaraj S Kitano H Ohga H Yoneda M Shimizu A Kaneko K Yamaguchi A Matsuyama M 《Fish physiology and biochemistry》2012,38(3):883-897
The endocrine regulation of reproduction in a multiple spawning fish with an asynchronous-type ovary remains largely unknown. The objectives of this study were to monitor changes in the mRNA expression of three gonadotropin (GtH) subunits (GPα, FSHβ, and LHβ) during the reproductive cycle of the female chub mackerel Scomber japonicus. Cloning and subsequent sequence analysis revealed that the cDNAs of chub mackerel GPα, FSHβ, and LHβ were 658, 535, and 599 nucleotides in length and encoded 117, 115, and 147 amino acids, respectively. We applied a quantitative real-time PCR assay to quantify the mRNA expression levels of these GtH subunits. During the seasonal reproductive cycle, FSHβ mRNA levels remained high during the vitellogenic stages, while GPα and LHβ mRNA levels peaked at the end of vitellogenesis. The expression of all three GtH subunits decreased during the post-spawning period. These results suggest that follicle-stimulating hormone (FSH) is involved in vitellogenesis, while luteinizing hormone (LH) functions during final oocyte maturation (FOM). Both GPα and FSHβ mRNA levels remained high during the FOM stages of the spawning cycle and increased further just after spawning. Thus, FSH synthesis may be strongly activated just after spawning to accelerate vitellogenesis in preparation for the next spawning. Alternatively, LHβ mRNA levels declined during hydration and then increased after ovulation. This study demonstrates that chub mackerel are a good model for investigating GtH functions in multiple spawning fish. 相似文献
3.
Jan Bogerd 《Fish physiology and biochemistry》2005,31(2-3):247-254
In mammals, the specificity of FSH–FSH receptor (FSHR), LH–LH receptor (LHR) and TSH–TSH receptor couples is such that no
cross-activation occurs under normal physiological conditions. The interactions between fish gonadotropins and their receptors,
however, appear to be less discriminatory. For example, the catfish FSHR is highly responsive to both catfish LH and catfish
FSH, while the catfish LHR is specific for its cognate LH. Comparative structure–function studies aimed at elucidating the
molecular basis of ligand promiscuity (in fish) and ligand selectivity (in mammals) are described in this paper. 相似文献
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Weiren Huang Yong Zhang Xiaoping Jia Xilan Ma Shuisheng Li Yun Liu Pei Zhu Danqi Lu Huihong Zhao Wenna Luo Shibai Yi Xiaochun Liu Haoran Lin 《Fish physiology and biochemistry》2010,36(2):237-249
Environmental estrogens, such as bisphenol A (BisA) and nonylphenol (NP), have been shown to affect the estrogen receptor (ER) expression and induce male reproductive abnormalities. To elucidate molecular mechanisms of action of xenoestrogenic chemicals on the expression of estrogen receptors in the testes of Nile tilapia (Oreochromis niloticus), three full-length cDNAs respectively encoding ntERα, ntERβ1 and ntERβ2 were cloned from testes. The amino acid sequences of ntERα, ntERβ1 and ntERβ2 showed a high degree of similarity to the relevant fish species. Tissue-specific expression study showed that three receptors were highly expressed in pituitary, liver, testis, kidney and intestine tissues. The ntERα, ntERβ1 and ntERβ2 mRNA expressions were significantly higher at the sexual early recrudescing stage than at other recrudesced stages. After being exposed to xenoestrogens from weeks 2 to 4, the ntERα mRNA levels were increased significantly in testes after NP treatment at all sampling times or after 4 weeks of exposure to BPA. The ntERβ1 mRNA levels remained unchanged, while a significant decrease of the ntERβ2 mRNA level was observed in testes after exposure to NP and BPA. The present study demonstrates that the regulation of all three ntER subtypes in testes may act via different molecular mechanisms of exposure to NP and BPA. 相似文献
7.
To achieve a better understanding of the role of gonadotropins (GTHs) in the stickleback we have cloned the full-length cDNAs of the β-subunits of follicle stimulating hormone (FSH) and luteinizing hormone (LH), and analysed the expression during the seasonal cycle. In females, LH-β levels were low during winter and early spring, increased to a peak in late May and declined to low levels again in July. FSH-β expression peaked earlier, in January and declined spring. In males, LH-β expression peaked in May. During June–September, when spermatogenesis occurs, LH-β levels were very low. FSH-β expression peaked earlier, in January, and reached the lowest levels in July. Thus, when spermatogenesis starts, the expression of both GTH-β mRNAs display their lowest levels. 相似文献
8.
Wei Ge 《Fish physiology and biochemistry》2005,31(2-3):209-214
Pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), play fundamental roles in vertebrate
ovarian development and function. However, there has been an increasing body of evidence that the actions of FSH and LH are
mediated or modulated by a variety of locally produced peptide or protein factors, which form an intimate regulatory network
within and between the ovarian follicles. In the past few years, a variety of growth factors have been identified and characterized
in the zebrafish ovary including activin and epidermal growth factor (EGF), which are important components of the intraovarian
communication network. To understand how this local network interacts with the gonadotropins from the pituitary, we have recently
cloned and characterized all the subunits of zebrafish FSH and LH from the pituitary as well as their receptors (FSHR and
LHR) from the ovary. Using the Chinese hamster ovary (CHO) cells as the bioreactor, we have produced recombinant zebrafish
FSH and LH with biological activities. With the recombinant hormones available, the functions of zebrafish FSH and LH in the
ovary and their interactions with the local factors will be an important issue to address in the future. This review briefly
summarizes some recent work from our laboratory and others on both gonadotropins and their potential intraovarian signaling
factors in the zebrafish. 相似文献
9.
T. Morita G. Yoshizaki M. Kobayashi T. Takeuchi 《Fish physiology and biochemistry》2003,28(1-4):473-474
The feasibility of using rainbow trout Oncorhynchus mykiss embryos as an expression system for proteins was investigated. For model proteins, we selected two goldfish gonadotropins (GTHs), follicle-stimulating hormone (FSH) and luteinizing hormone (LH). To produce single-chain goldfish FSH (scgfFSH) and LH (scgfLH), cDNAs encoding glycoprotein hormone (GP) α and FSHβ were fused in tandem, and cDNAs encoding GPα and LHβ were fused in tandem. The fused cDNAs were ligated with β-actin promoter, and microinjected into fertilized rainbow trout eggs. After 4-days incubation, the embryos were subjected to western blotting and in vitro bioassays. The recombinant proteins produced by the embryos were immunoreactive to antisera against goldfish GPα, N-glycosylated, and biologically active. We conclude that scgfFSH and scgfLH were successfully produced in transgenic rainbow trout. 相似文献
10.
Ni Lar Shein M. Takushima M. Nagae H. Chuda K. Soyano 《Fish physiology and biochemistry》2003,28(1-4):107-108
The cDNA for glycoprotein hormone (GPH) α-subunit, β-subunits of the FSH (GtH I) and LH (GtH II) were isolated, cloned, and sequenced from sevenband grouper pituitary using RACE PCR. These results show that sevenband grouper has two different types of gonadotropins FSH (GtH I) and LH (GtH II), as other teleosts. 相似文献
11.
Wei Ge Nga-Ling Ko Flora Yee-Man Pang Me-Fong Chung Sze-Wah Lin Chi-Wai Yuen Man-Tat Lau Lin Liu Young Chang Sohn Makito Kobayashi Katsumi Aida 《Fish physiology and biochemistry》2003,28(1-4):65-71
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) play critical roles in controlling vertebrate gonadal development and function. Activin, a dimeric growth factor initially identified in the gonads, is important in the differential regulation of the two gonadotropins in mammals. Using goldfish as a model, we have demonstrated that activin stimulates FSHβ but suppresses LHβ expression. The present study demonstrated that the 5′-flanking region of goldfish FSHβ gene is functional in the mouse gonadotrope cell line, LβT2 cells. Similar to its effect on the cultured pituitary cells, activin stimulated FSHβ promoter activity in the LβT2 cells and the effect could be blocked by its binding protein follistatin. Follistatin also significantly suppressed the basal FSHβ promoter activity, suggesting secretion of endogenous activin by the LβT2 cells. Further characterization of the cis-regulatory elements responsible for activin stimulation is now under way in our laboratory. 相似文献
12.
奥利亚罗非鱼雌激素β受体两种亚型cDNA的克隆、组织分布及雌激素对其表达的影响 总被引：1，自引：1，他引：0
采用RT-PCR和RACE技术,克隆了奥利亚罗非鱼β雌激素受体基因(estrogen receptorβ,ERβ)两种亚型的cDNA全序列(ERβ1和ERβ2)。荧光定量PCR分析雌雄奥利亚罗非鱼两种亚型的组织分布,并观察注射外源雌激素对雄性奥利亚罗非鱼下丘脑-垂体-性腺轴雌激素受体ERα和β(β1/β2)基因表达的影响。序列分析表明,ERβ1cDNA全长为4262bp,其中包含239bp5′非编码区,2349bp3′非编码区和1674bp的开放阅读框,共编码557个氨基酸。ERβ2 cDNA全长为2506bp,包含5′非编码区393bp,3′非编码区109bp,阅读框为2004bp,共编码667个氨基酸。氨基酸序列同源性分析显示奥利亚罗非鱼ERβ1与尼罗罗非鱼的相似性高达99.1%,而与鲈形目其它鱼类的相似性为82.6%～94.2%。ERβ2氨基酸序列与尼罗罗非鱼的相似性为98.7%,与大口黑鲈、虹鳟、底鳉及斑马鱼的相似性分别为81.8%、76.3%、64.7%和55.0%。在系统进化树上奥利亚罗非鱼的ERβ1和ERβ2分别与尼罗罗非鱼的相应受体聚类。奥利亚罗非鱼ERβ1/β2基因在所检测的10种组织中均有... 相似文献
13.
We have isolated and characterized the cDNAs encoding the gonadal FSHR and LHR in a protandrous hermaphrodite, the gilthead seabream. The differential expression, distribution and regulation of FSHR and LHR in the ambisexual gonad during the process of sex reversal are addressed. 相似文献
14.
S. Yamaguchi K. Gen K. Okuzawa N. Kumakura H. Kagawa M. Matsuyama 《Fish physiology and biochemistry》2003,28(1-4):111-112
To examine the roles of gonadal steroids in the regulation of expression of gonadotropin subunit genes, male red seabream were gonadectomized and a sub-group was treated with 11-ketotestosterone (11-KT). Castration of males during the early stage of spermatogenesis elicited a significant increase in FSHβ mRNA levels, which was prevented by 11-KT replacement. By contrast, LHβ mRNA levels were not changed by castration or 11-KT replacement. In addition, administration of 11-KT to sham-operated males suppressed the steady-state FSHβ and LHβ mRNA levels. These results indicate that 11-KT may function as a negative feedback regulator of FSHβ gene expression, and may act through the testis to down-regulate LHβ mRNA levels in male red seabream during this period. 相似文献
15.
Koichiro Gen Sonoko Yamaguchi Koichi Okuzawa Naoki Kumakura Hideki Tanaka Hirohiko Kagawa 《Fish physiology and biochemistry》2003,28(1-4):77-80
The duality of gonadotropins (GTHs), follicle-stimulating hormone (FSH) and luteinizing hormone (LH), has been confirmed in most teleost species, but very little is known about their biological functions. To elucidate the physiological roles of FSH and LH in fish reproduction, the expression profiles of GTH subunit genes during gonadal development were analyzed in both male and female red seabream. Furthermore, in vitro studies were carried out to examine the effects of GTHs on steroid hormone production and cytochrome P450 aromatase (P450arom) expression in red seabream gonads. In both sexes, LHβ mRNA was maintained at high levels from the early gametogenesis until spawning season, and declined with gonadal regression. Interestingly, FSHβ mRNA levels in males increased in parallel with testicular development, whereas those in female were remained low throughout oocyte development. From in vitro studies using purified red seabream FSH and LH, both GTHs had a similar potency in stimulating 11-ketotestosterone production by testicular slices, while the biological activity of FSH was much lower than that of LH in stimulating production of estradiol-17β by vitellogenic follicles. Moreover, expression of P450arom mRNA was induced by LH, but not FSH, in ovarian follicles in vitro. FSH was also ineffective in inducing maturational competence and final oocyte maturation. These results suggest that, unlike salmonids, FSH may play an important role during gametogenesis in male, but not female, red seabream, whereas LH may be involved in regulation of both early and late gametogenesis in both sexes. 相似文献
16.
M. P. García Hernndez A. García Ayala B. Agulleiro A. García W. van Dijk R. W. Schulz 《Aquaculture (Amsterdam, Netherlands)》2002,210(1-4):203-218
Purified Mediterranean (M.) yellowtail luteinizing hormone-like gonadotropin (MyLH) and its β-subunit (MyLHβ) served to develop a radioimmunoassay (RIA) for MyLH. The rabbit antisera against MyLH and MyLHβ used for this purpose were tested on pituitary sections by immunocytochemistry. Anti-MyLHβ specifically detected a single type of cells, which were located at the periphery of the proximal pars distalis (PPD) and surrounding the pars intermedia (PI). Anti-MyLH, however, also recognized two other cell types, thyrotropin β-immunoreactive (ir) cells and putative follicle-stimulating hormone-like (MyFSH)-producing cells. Labeling of the two latter cell types was prevented by preabsorption of anti-MyLH with M. yellowtail pituitary glycoprotein -subunit. The standard curve for the RIA was generated using purified MyLH, 125I-labeled MyLHβ and anti-MyLHβ at a dilution of 1:70,000, which resulted in the binding of 30% of the tracer added. The standard curve ranged from 0.25 to 50 ng/ml. The midrange of the assay (ED50) was obtained with 5.48–7.87 ng LH/ml. The variation between assays was less than 15%. An average cross-reactivity of FSH in the LH RIA of 8.4% was found. Serial dilutions of M. yellowtail pituitary extracts displaced radiolabelled MyLHβ parallel to the MyLH standard. Application of the LH RIA to blood samples and pituitary cell culture medium provided physiological validation of the assay. Significant increases in LH levels were recorded after salmon GnRH treatments in vivo and in vitro. Serum LH levels from wild fish sampled at the spawning season were significantly higher than those from captive fish sampled in the same period. 相似文献
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F. Sakai I. Swapna C. C. Sudhakumari M. V. N. L. Ganesh H. Kagawa T. Kobayashi H. Fan Y. Nagahama B. Senthilkumaran 《Fish physiology and biochemistry》2005,31(2-3):177-181
Gonadal development and steroidogenesis in teleosts is regulated by two gonadotropic hormones; luteinizing hormone (LH) and
follicle-stimulating hormone (FSH). Earlier studies in tilapia have shown that FSH-β and LH-β appear by 14 days after hatching
(dah), results from the current study corroborate with these previous reports in tilapia. Here we demonstrate the appearance
of LH in pituitary between 14 and 20 dah. In addition to this the present study primarily focuses on any possible differences
in appearance of LH-β and FSH-β immunoreactivity between XX and XY population of Nile tilapia. LH immunoreactivity was found
to be lower in pituitary of XX fish when compared to XY fish. The development of FSH-β immunoreactivity in pituitary of the
Nile tilapia is also presented. Overall, it remains to be established what significance these findings on the appearance of
gonadotropins hold for sex differentiation in tilapia.
F. Sakai and I. Swapna contributed equally. 相似文献
19.
cDNA clones encoding gonadotropin (GTH) α, follicle-stimulating hormone (FSH) β and luteinzing hormone (LH) β were isolated from the pituitaries of maturing Manchurian trout (Brachymystax lenok tsinlingensis) and sequenced. The deduced amino acid sequences of GTH subunits showed high identities to masu salmon, Oncorhynchus masou: GTHα1 (95%), FSHβ (92%) and LHβ (97%), respectively. We are also attempting to produce recombinant FSH and LH using a eukaryotic expression system. In a pilot experiment, LH was secreted to the culture medium at 48 and 60 hrs after transfection. The results will be helpful to develop controlled reproduction of exterminating Manchurian trout. 相似文献