Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica
{"title":"Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica","authors":"Jun-Hwan Byun, Ji-Yeon Hyeon, Sachithra Amarin Hettiarachchi, Shingo Udagawa, Angka Mahardini, Jong-Myoung Kim, Sung-Pyo Hur, Akihiro Takemura","doi":"10.1002/jez.2788","DOIUrl":null,"url":null,"abstract":"<p>Japanese eel (<i>Anguilla japonica</i>) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish. This study investigated the effects of melatonin and DA on the reproductive system of mature male Japanese eels to better understand reproductive regulation in fish. To clarify the effects of these hormones on sexual maturation in eels, a critical stage in the reproductive process, sexual maturation was induced by injecting human chorionic gonadotropin, which stimulates the production of sex hormones. To check the effect of melatonin and DA on sexual maturation, DA, melatonin, and DA + domperidone were intraperitoneally injected into fish from each group (six per treatment) at a dose of 1 mg/kg body weight. The fish were then examined using quantitative RT-PCR by comparing the messenger RNA level of reproduction-related genes (gonadotropin releasing hormone 1; <i>gnrh1</i>, gonadotropin releasing hormone 2; <i>gnrh2</i>, follicle stimulating hormone; <i>fshβ</i>, luteinizing hormone; <i>lhβ</i> and DA receptor 2b; <i>d2b</i>), involved in the gonadotropic axis in eels, to those that received a control injection. The results indicate significant differences in the expression levels of <i>gnrh1</i>, <i>gnrh2</i> and <i>d2b</i> in the brain and <i>d2b</i>, <i>fshβ</i>, <i>lhβ</i> in the pituitary at different stages of sexual maturation. Melatonin appears to enhance the production of sex gonadotropins, whereas DA inhibits them. These findings suggest an interaction between melatonin and DA in regulating reproduction in Japanese eels.</p>","PeriodicalId":15711,"journal":{"name":"Journal of experimental zoology. Part A, Ecological and integrative physiology","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of experimental zoology. Part A, Ecological and integrative physiology","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jez.2788","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ZOOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Japanese eel (Anguilla japonica) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish. This study investigated the effects of melatonin and DA on the reproductive system of mature male Japanese eels to better understand reproductive regulation in fish. To clarify the effects of these hormones on sexual maturation in eels, a critical stage in the reproductive process, sexual maturation was induced by injecting human chorionic gonadotropin, which stimulates the production of sex hormones. To check the effect of melatonin and DA on sexual maturation, DA, melatonin, and DA + domperidone were intraperitoneally injected into fish from each group (six per treatment) at a dose of 1 mg/kg body weight. The fish were then examined using quantitative RT-PCR by comparing the messenger RNA level of reproduction-related genes (gonadotropin releasing hormone 1; gnrh1, gonadotropin releasing hormone 2; gnrh2, follicle stimulating hormone; fshβ, luteinizing hormone; lhβ and DA receptor 2b; d2b), involved in the gonadotropic axis in eels, to those that received a control injection. The results indicate significant differences in the expression levels of gnrh1, gnrh2 and d2b in the brain and d2b, fshβ, lhβ in the pituitary at different stages of sexual maturation. Melatonin appears to enhance the production of sex gonadotropins, whereas DA inhibits them. These findings suggest an interaction between melatonin and DA in regulating reproduction in Japanese eels.
期刊介绍:
The Journal of Experimental Zoology – A publishes articles at the interface between Development, Physiology, Ecology and Evolution. Contributions that help to reveal how molecular, functional and ecological variation relate to one another are particularly welcome. The Journal publishes original research in the form of rapid communications or regular research articles, as well as perspectives and reviews on topics pertaining to the scope of the Journal. Acceptable articles are limited to studies on animals.