Understanding the Role of Protein Modifications in Development of Early Zebrafish Embryos

Abstract

Eukaryotic cells rely heavily on histones, a family of highly conserved proteins, to keep DNA in order and under tight control. These proteins have crucial roles in the organisation of chromosomes, which are made up of a complex of DNA and proteins called chromatin. Histones preserve genomic integrity by compacting and packing DNA, controlling gene expression, and regulating chromatin structure. Histones undergo what are known as post translational modifications (PTMs) after they have been synthesised. The regulation of chromatin structure and gene expression relies heavily on these alterations. Histone post translational modifications (PTMs) can regulate DNA accessibility to transcriptional machinery and attract specialised protein complexes. During embryonic development, different tissues and organs require careful regulation of gene expression. Histone modifications play an essential role in controlling gene expression, choosing cell fates, and establishing distinct cellular identities. Several histone modifications are well known and have been thoroughly studied, however a new histone modification - the serotonylation of histone H3 has been uncovered. Being fairly recent, there is much to be studied about this modification. Although serotonin is popularly known for its role as the "Happy Hormone", its functions extend far beyond, including protein modifications. Serotonin has been observed for years to be present at the pre-neural stages in several organisms, including in early zebrafish embryos, right from the one cell stage. In this body of work, we take the first steps to examine whether we can use a novel serotonin sensor as a tool to detect serotonin in early zebrafish embryos. Using western blotting and immunofluorescence, we also aim to lay the groundwork in studying this particular histone modification in early zebrafish embryos