Over the past few decades, the zebrafish has become a popular model to study how genes regulate the development of an embryo.

The main key Indian researchers in embryonic development in zebrafish were from the National Centre for Biological Sciences (NCBS), Bangalore and their interest focused on how neurons are connected together and perform essential tasks such as coding for movement. This team used zebrafish as a model system as the embryonic and larval stages of these fish are transparent, which allows for direct visual observation of developing organs.

They discovered that Mn treated zebrafish larvae exhibited specific postural and locomotor defects.

Vatsala Thirumalai’s group found that Cx35 served as a neuronal connexin in the radial glia lining of the rhombencephalic ventricle at 5dpf in zebrafish embryos. This pattern of Cx35 immunoreactivity continued to be stable until 15dpf. Furthermore, their study provided a better understanding of several dye-coupled neurons within the reticulospinal network suggesting that there was the functional connection of gap junction in the developing zebrafishbrain.27

Dr. Sreelaja Nair’s group, Vertebrate Embryogenesis Lab at Tata Institute of Fundamental Research (TIFR),Mumbai, exploited the mechanism that drove the development of a single cell zygote into a multicellular embryo using zebrafish as a model organism.This group sought to clarify the mechanism of mid blastula transition ( MBT) in vertebrates, which helps to link disease states condition to altered tran-scriptional profiles.

Dr. Sanjeev Galande’s group from the Center of Excellence in Epigenetics at Indian Institute of Science Education and Research (IISER), Pune focused on studying how the dynamic changes in higher-order chromatin assembly control gene expression in a spatial and temporal manner. This team was also interested to understand the role of chromatin organizer and global regulator SATB1 in Wnt signaling during the early development of model systems.

They identified a novel family of active HATs which are specific for histone H4 acetylation, located in perinuclear and essential for zebrafish development.30Spirita Sharmili’s group at Scott Christian College (SCC), Nagercoil checked the detergenttoxicity in different developmental stages in zebrafish embryo. They explained the seven broad periods of embryogenesis, including the zygote, cleavage, segmentation, blastula, gastrula, pharyngula, and hatching periods in the zebrafish.

A group led by Prof. Katti Pancharatna at the Karnatak University (KUD), Dharwad is actively involved in understanding the embryonic development of zebrafish. They found the spinal curvature, cardiac anomalies, pectoral fin malformation, and behavioral alterations by ibuprofen, a nonselective COX inhibitor, in the fish. They confirmed that both acetaminophen (paracetamol) and ibuprofen can delay the hatch and growth rate in zebrafish embryos.

A group from Jai Research Foundation, Gujarat, also proved the hepatotoxicity of acetaminophen in the zebrafish. The other laboratory led by Prof.Malathi Ragunathan from the University of Madras (UNOM), Chennai also found the formation of abnormal blood vessels, tail bending, and developmental delay in theophylline-treated zebrafish embryos. Zebrafish is an excellent model for cellular meiotic and mitotic studies in the laboratory.

Dr. Sudipta Maitra’s laboratory at Visva-Bharati University (VBU),Santiniketan revealed the interaction between MAPK3/1c andAMP-dependent protein kinase at meiotic G2–M1 transition state in the zebrafish oocyte. His team justified the synergism between a maturational steroid, 17a,20b-dihydroxy-4-pregnen-3-one (DHP), and Igf1to overcome E2 inhibition of meiosis resumption in oocytes. The group also studied the important effect of PI3K/Akt signaling pathway on meiotic maturation in the zebrafish oocytes.

In the other laboratory from the same institute, Dr. Ansuman’s team concluded that sodium fluoride can cause genotoxic effects in zebrafish. Dr. Prakash Vincent’s group at Manonmaniam Sundaranar University (MSU), Rajak kamangalam tried to understand thePax6 transcription factor expression and quantified its amount during early embryonic and larval development or embryo-genesis using zebrafish as a model organism. They also found that the herb extract-treated embryo showed many genetic defects at the stage of organogenesis in the zebrafish.

Deepak Kumar Sinha’s group at Indian Association for the Cultivation of Sciences found that in zebrafish embryos the Lipid Droplet geometry and its regulation brought new insights to the mechanism associated with specific functions of Lipid Droplet (LD’s) such as their storage capacity for fats or proteins, lipolysis, and so on.

Dr. Rayrikar from Agharkar Re-search Institute, Pune focused on the distribution of endothelialcells (ECs) in the adult zebrafish heart. Interestingly, they found that active coronary vessel growth is present in zebrafish and*39% of cells in the zebrafish heart are ECs and cardiomycetes. Dr.Sivaram Mylavarpu’s laboratory at Regional Centre for Biotechnology, Faridabad revealed that the mitotic functions of Light Intermediate Chain (LIC) homologs are essential for early embryonic divisions and development in zebrafish.

Zebrafish embryonic studies have been another area that throws light on the untapped potential using zebrafish model as a research tool.