Abstract:
:The first studies that identified leptin and its receptor (LepR) in mammals were based on mutant animals that displayed dramatic changes in body-weight and regulation of energy homeostasis. Subsequent studies have shown that a deficiency of leptin or LepR in homoeothermic mammals results in hyperphagia, obesity, infertility and a number of other abnormalities. The physiological roles of leptin-mediated signaling in ectothermic teleosts are still being explored. Here, we produced medaka with homozygous LepR gene mutation using the targeting induced local lesions in a genome method. This knockout mutant had a point mutation of cysteine for stop codon at the 357th amino acid just before the leptin-binding domain. The evidence for loss of function of leptin-mediated signaling in the mutant is based on a lack of response to feeding in the expression of key appetite-related neuropeptides in the diencephalon. The mutant lepr−/− medaka expressed constant up-regulated levels of mRNA for the orexigenic neuropeptide Ya and agouti-related protein and a suppressed level of anorexigenic proopiomelanocortin 1 in the diencephalon independent of feeding, which suggests that the mutant did not possess functional LepR. Phenotypes of the LepR-mutant medaka were analyzed in order to understand the effects on food intake, growth, and fat accumulation in the tissues. The food intake of the mutant medaka was higher in post-juveniles and adult stages than that of wild-type (WT) fish. The hyperphagia led to a high growth rate at the post-juvenile stage, but did not to significant alterations in final adult body size. There was no additional deposition of fat in the liver and muscle in the post-juvenile and adult mutants, or in the blood plasma in the adult mutant. However, adult LepR mutants possessed large deposits of visceral fat, unlike in the WT fish, in which there were none. Our analysis confirms that LepR in medaka exert a powerful influence on the control on food intake. Further analyses using the mutant will contribute to a better understanding of the role of leptin in fish. This is the first study to produce fish with leptin receptor deficiency.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Chisada S,Kurokawa T,Murashita K,Rønnestad I,Taniguchi Y,Toyoda A,Sakaki Y,Takeda S,Yoshiura Ysubject
Has Abstractpub_date
2014-01-01 00:00:00pages
9-20eissn
0016-6480issn
1095-6840journal_volume
195pub_type
杂志文章abstract::The binding of 125I-labeled ovine prolactin (oPRL) to membrane preparations of tissue from freshwater-adapted tilapia (Sarotherodon mossambicus) was examined. Liver, ovary, and testis showed a relatively high specific binding (5-10%). A lower specific binding occurred consistently in intestine and gill tissue, and inc...
journal_title:General and comparative endocrinology
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doi:10.1016/0016-6480(84)90056-x
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1993.1152
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.07.018
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90062-5
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2007.02.006
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
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journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1006/gcen.2002.7778
更新日期:2002-03-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0033
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
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更新日期:1990-03-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.05.020
更新日期:2017-09-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.12.006
更新日期:2018-04-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.12.016
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.12.006
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abstract::Insulin is an extensively studied peptide hormone in mammals. However, insulin is not restricted to vertebrates, but has also been identified in invertebrates, among whom several insect species. These insulin-like peptides (ILPs) show structural and-at least some-functional homology with mammalian insulin and act thro...
journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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doi:10.1016/j.ygcen.2011.04.027
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abstract::Oligonucleotide probes were synthesized for the mRNAs of a pair of tilapia prolactins (tPRL177 and tPRL188) and growth hormone (tGH) based on cDNAs for the hormones of Oreochromis niloticus and amino acid sequences for the hormones of O. mossambicus. The three 45mer probes were labeled with 35S for hybridization studi...
journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90157-2
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abstract::Relaxin 3 (RLN3) is a newly-discovered member of the insulin superfamily. We isolated three RLN3-like cDNAs from the brain of the Japanese eel (Anguilla japonica). The deduced amino acid sequences of the RLN3-like cDNAs contained the two-chain structure common to relaxin including a RXXXRXXI/V motif in the B-chain. Ph...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.04.013
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abstract::Uptake of L-thyroxine (T4) by isolated trout hepatocytes was characterized after 1-min incubation of cells in a Hanks' balanced salts medium containing glucose and [125I]T4. Centrifugation through silicone oil and glycine buffer (pH 10.5) was used to separate cells from the medium and minimize extracellular binding of...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
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