LPXRFa and LPXRFa-R in the female swamp eel (Monopterus albus): Molecular cloning, tissue distribution and gonadal function

Bihui Chao; Bowen Lv; Mengtao Wang; Yichuan Hu; Pengshuo Jia; Xuanyu Fang; Xingliang Guo; Zhuqing Yang; Qiubai Zhou; Liufeng Xiong; Yazhou Zhang

Aquaculture Reports (Feb 2024)

LPXRFa and LPXRFa-R in the female swamp eel (Monopterus albus): Molecular cloning, tissue distribution and gonadal function

Bihui Chao,
Bowen Lv,
Mengtao Wang,
Yichuan Hu,
Pengshuo Jia,
Xuanyu Fang,
Xingliang Guo,
Zhuqing Yang,
Qiubai Zhou,
Liufeng Xiong,
Yazhou Zhang

Affiliations

Bihui Chao: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Bowen Lv: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Mengtao Wang: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Yichuan Hu: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Pengshuo Jia: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Xuanyu Fang: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Xingliang Guo: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
Zhuqing Yang: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; Key Laboratory of Featured Hydrobios Nutritional Physiology and Healthy Breeding, Nanchang 330045, China; Research Institute of Special Fisheries, Jiangxi Agricultural University, Nanchang 330045, China
Qiubai Zhou: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; Key Laboratory of Featured Hydrobios Nutritional Physiology and Healthy Breeding, Nanchang 330045, China; Research Institute of Special Fisheries, Jiangxi Agricultural University, Nanchang 330045, China
Liufeng Xiong: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; Key Laboratory of Featured Hydrobios Nutritional Physiology and Healthy Breeding, Nanchang 330045, China; Research Institute of Special Fisheries, Jiangxi Agricultural University, Nanchang 330045, China
Yazhou Zhang: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; Key Laboratory of Featured Hydrobios Nutritional Physiology and Healthy Breeding, Nanchang 330045, China; Research Institute of Special Fisheries, Jiangxi Agricultural University, Nanchang 330045, China; Corresponding author at: College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China.

Journal volume & issue: Vol. 34
p. 101872

Abstract

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Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide known for inhibiting gonadotropin release. In teleosts, it is also referred to as LPXRFa. While the effects of LPXRFa on gonadotropin synthesis and release, and its impact on pituitary function in teleosts have been widely studied, its specific mechanism in fish reproduction remains relatively unexplored. In this paper, LPXRFa and LPXRFa-R genes were isolated from the swamp eel brain to assess the roles of LPXRFa in the swamp eel. Their ORFs were 612 bp and 1284 bp, encoding proteins of 203 and 427 amino acids, respectively. The LPXRFa gene encodes a polypeptide possibly cleaved into three mature peptides (LPXRFa-1, −2, and −3). The LPXRFa-R receptor protein comprises seven conserved transmembrane domains. Tissue distribution analysis revealed that LPXRFa-R expression was the highest in the hypothalamus, while LPXRFa showed the highest expression in the rest of brain, with little to no expression in other tissues. The role of LPXRFa in the reproduction of the swamp eel was investigated by studying the effect of intraperitoneal injection with each of the three peptides. The intraperitoneal injection of LPXRFa-2 down-regulated serum FSH and LH levels, while that of LPXRFa-3 down-regulated serum FSH but up-regulated LH levels. Additionally, both LPXRFa-2 and LPXRFa-3 increased the expression levels of fshr, cbx3, dmrt1, gsdf, sox9al, amh, foxl2, and rab37 in the ovaries. Moreover, LPXRFa-2 also increased the ovarian expression of lhr, while LPXRFa-3 had no effect on it. Except upregulating cbx3 and foxl2 expression, LPXRFa-1 neither impacted the serum FSH and LH levels, nor did it alter the expression of other gonadal and reproductive-related genes. In summary, our findings provide the first evidence of a LPXRFa/LPXRFa-R system in the order Synbranchiformes and suggest its involvement in sex differentiation, gonadal development, and sexual reversal in the swamp eel.

Published in Aquaculture Reports

ISSN: 2352-5134 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Agriculture: Aquaculture. Fisheries. Angling
Website: http://www.journals.elsevier.com/aquaculture-reports/

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