Neuroendocrine regulation of reproduction in fish – Mini review

This review highlights the recent developments regarding neuroendocrine mechanisms controlling teleost reproduction. In teleosts, the pituitary gland receives major neuronal innervations from Gnrh neurons as well as minor innervations from small population of neurons that will secrete neurotransmitters and/or neuropeptides. The diversity of Kiss/Kissr system in various teleost species and their actions in the context of HPG axis and reproduction has been extensively covered. In teleost model systems, zebrafish and medaka, mutant lines for key components of the HPG axis have been generated through targeted mutagenesis but surprisingly most of the mutants developed normally without major defects in reproduction; these mutant phenotypes are described. In the last decade, complex role of diverse neuropeptides in teleost reproduction is being revealed. A brief overview about the reproductive functions of neuropeptides is presented. Finally, the effects of environmental factors namely photoperiodism and temperature on the functions of HPG axis is summarised.