Executive Summary : | In India, fish production has reached 14.16 million metric tons in 2019–2020 and provides livelihood opportunities to more than 28 million people (Economic Survey, 2020–2021). Not surprisingly, in 2020 prime minister Narendra Modi launched the PM Matsaya Sampada Yojana to reduce the critical gaps in productivity, quality, management and technology. It aims to increase the consumption of fish from 5 kg per person to 12 kg and to increase the productivity from 13.75 million metric tons in 2018-19 to 22 million metric tons by 2025. The scheme also aims to increase the productivity per hectare from 3 tons at present to 5 million tons (dof.gov.in). Reproduction, Growth and Immunity of fish are the three pillars of successful aquaculture. Recently, a peptide hormone, asprosin has been discovered (Romere et al., 2016), which is implicated in various metabolic functions such as glucose release from the liver (Li et al., 2019), insulin secretion and inflammation in pancreas (Lee et al., 2019) and orexigenic effect in the brain (Mishra et al., 2022). Other than the metabolic regulation, asprosin is seen to be involved in modulation of various reproductive functions in mammals (Keskin et al., 2022, Maylem et al., 2021-22, Maurya et al., 2022). For instance, asprosin is reported to regulate steroidogenesis, spermatogenesis, sperm motility and male fertilization capacity in mammals (Maurya et al., 2022, Wei et al., 2019). The hormone asprosin is encoded by the C-terminal region of the FBN1 gene. It encodes a pro-fibrillin protein, which is enzymatically cleaved by furin into mature fibrillin 1 and asprosin protein (Romere et al., 2016). Asprosin in mammals are shown to act through diverse receptors such as G-protein coupled receptor, olfr734, TLR4 and Ptprd depending on different tissues. Surprisingly, till date no reports on asprosin are available in any non-mammalian vertebrate. In our laboratory, we have observed the robust expression of fbn1 and furin in the gonads of teleost Channa punctata, suggesting the biosynthesis of asprosin in the gonads. Further, we have cloned the C-terminal region of fbn1 responsible for encoding asprosin into a vector having histidine tag and expressed it in the bacterial cells. In view of our observations and the important role played by asprosin in mammalian reproduction, the project has been conceived to purify and characterize recombinant teleost asprosin, to explore its receptor and signaling and to understand the effect of asprosin on reproductive functions in teleost Channa punctata. The fish, Channa punctata is an economically important species found in South East Asian countries. The fish is highly valued for its gastronomic, nutritional and medicinal properties. Identification and characterization of teleost asprosin, purification of fish recombinant asprosin, and understanding the effect of asprosin on reproduction would be an important milestone in aquaculture practices. |