Melanin-Concentrating Hormone (MCH) is a cyclic peptide initially isolated from salmon and later found to be conserved in mammals. It plays a role in regulating melanin changes and rhythmic behaviors such as sleep and feeding, though its relationship with these processes is not fully understood. Our preliminary research revealed significant differences in melanin degradation in zebrafish under varying light conditions, suggesting a link to MCH. This study aims to explore MCH’s role in lighting-induced changes in rhythmic behavior patterns and melanin of zebrafish.

Sialylation plays important roles in animals, affecting numerous molecular and cell interactions. In Drosophila, sialylation regulates neural transmission and mediates communication between neurons and glia. Drosophila CMP-sialic acid synthetase (CSAS), a key enzyme of the sialylation pathway, is localized to the Golgi and modified by N-glycosylation, suggesting that this modification can affect CSAS function. Here we tested this hypothesis using in vitro and in vivo approaches. We found that CSAS proteins from divergent Drosophila species have two conserved N-glycosylation sites, including the rarely glycosylated non-canonical N-X-C sequon.