The zebrafish (Danio rerio) has become a prevailing vertebrate model for developmental biology studies due to its ease of care, rapid embryogenesis stages development and translucent embryos. In this studies, ATM Kinase and MRN complex role as DNA damage response proteins during embryogenesis was examined by using specific MRN complex (Mirin) and ATM Kinase inhibitors (Ku60019 and Ku55933). To create DNA lesions in zebrafish, embryos at mid-blastula transition (MBT) stage were exposed to inhibitors (Mirin, Ku60019 or Ku55933) and later exposed to UVC irradiation wavelength of between 100 to 280 nm. Hatching but with visible physical deformation was observed for embryos treated with Mirin, Ku60019 or Ku55933 and UVC exposure at concentration of 3µM, 1.5 nM and 3nM or lower, respectively up to 72 hours-post fertilisation (hpf). On the other hand, no deformities were observed for all control as well as mock treated embryos. This study confirmed that DNA damage response proteins are crucial during embryo development to prevent undesired abnormal biological development. Thus, it is proven that protein inhibitors are a cheaper alternative in valuating specific protein roles during embryogenesis compared to both genomic and transcription modification tools.