The fitness of aquatic ecosystems is critical to life on Earth. The impact of ultra violet radiation (UVR) is one potential stress factor that can have a negative impact on the health of certain species within these ecosystems. Although there is a paucity of data and information regarding the effect of UVR on total ecosystem structure and function, several recent studies have addressed the effects on various species within each tropic level. Climate change, acid deposition, and changes in other anthropogenic stressors such as pollutants alter UV exposure levels in inland and coastal marine waters. These factors potentially have important consequences for a variety of aquatic organisms. This work reports the UVB exposure of the zebra fish embryo, which is a small, inexpensive, wholeanimal model which may replace higher animal models in some areas of bio medical and aquaculture research. We described a series of stages for development of the embryo of the zebra fish, Danio (BrachyDanio) rerio under varying wavelength of UVR exposure and defined broad periods of embryogenesis — the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods. The gene level studies helps in better understanding of mechanism of UV induced skin carcinogenesis and to study the role of identity genes which are major helpful in relation to plasticity and tumorigenicity of cancer. Zebra fishes are hardy and well adapted to a laboratory environment. Nevertheless, reducing stress should aid in preventing disease outbreaks and maintaining growth and fecundity of this popular laboratory fish species. Overall, embryonic zebra fish studies will be a baseline data for their suitability for photo activation and photo repair studies in future. Our present study discuss the changes in Zebra fish embryos in different stages like 2, 4, blastula and Morula stages with wild and UV irradiation pattern by Histpathological, Scanning electron microscope followed by the expression of embryonic stem cell identity genes OCT4, SOX2, NANOG, and FOXD3 in relation to skin carcinogenesis induced by UV studied using qRT-PCR assays. This study implies that the loss of pluripotency and self-renewal, seen in the subsequent differentiation steps, via expression of these factors, seen in later stages, are more when compared to the earlier stages. The promotion of mutagenesis has been confirmed by the upregulation of expression of all genes.Immunohistochemistry of the respective genes with zebrafish embryos expressed a positive approach as per the above molecular reports.
