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Abstract

Insulin-like growth factor 1 (IGF1) is involved in various physiological functions that are regulated by somatotropic (GH-IGF1) axis. To decipher the role of IGF1 in the HPG-L axis gene encoding igf1 cDNA of female catfish, Heteropneustes fossilis, has been sequenced followed by in silico analysis as well as seasonal expression of igf1 in brain, liver and ovary organs. The mRNA expression of igf1 gene in these three organs elucidates that it plays a pivotal role in the HPG-L axis. In ovary, igf1 gene expression exhibits a direct correlation with gonadosomatic index, whereas, an inverse relationship has been observed in brain and liver tissues. Hence upregulation of igf1 in brain and liver, during the post-spawning phase and downregulation in ovary shows the shift from gonadal growth to somatic growth in resting phase. In silico analysis depicts that IGF1 is stable and hydrophilic in nature with 159 amino acid (aa) and molecular weight of 17.65 kDa. Secondary structure shows the presence of maximum random coils and alpha-helix. It is secretory protein showing maximum interaction with IGF1R, estrogen receptor alpha and GH. Protein structures of IGF1, luteinizing hormone beta (LHβ), follicle stimulating hormone beta (FSHβ) and growth hormone (GH) have been constructed and interaction among them has been docked which suggests that gonadal and somatic axes are probably interlinked and may regulate the neuroendocrine system of fish.

Keywords

Insulin-like growth factor 1 (IGF1) in silico analysis Hypothalamo-pituitary-gonadal-liver (HPG-L) axis Seasonal reproduction Heteropneustes fossilis

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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The authors transfer the copyrights of their papers to the Iranian Society of Ichthyology. However, the information could be used in accordance with the Creative Commons licence (Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Author Biographies

Uma Bharati SAHU, Department of Zoology, University of Delhi, Delhi, India.

Uma Bharati Sahu is a Ph. D. research scholar at Department of Zoology, University of Delhi, Delhi, India-110007.

Kumari Vandana RANI, Department of Zoology, Kalindi College, University of Delhi, Delhi, India.

Dr. Kumari Vandana Rani is Assistant Professor in Department of Zoology, Kalindi College, University of Delhi, Delhi, India- 110008

How to Cite
SAHU, U. B., RANI, K. V., & SEHGAL, N. (2024). Insulin-like growth factor 1 (IGF1) in the hypothalamo-pituitary-gonadal-liver (HPG-L) axis: identification, sequencing, gene expression and in silico analysis in the Indian freshwater catfish, <i>Heteropneustes fossilis</i>. Iranian Journal of Ichthyology, 11(2), 124–146. https://doi.org/10.22034/iji.v11i2.1006
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