The present study aimed to investigate changes in the protein contents using SDS-PAGE, also using the random amplified polymorphic DNA (RAPD-PCR) assay to identify changes in DNA concentration in the embryos of Egyptian toad Bufo regularis. Our experiment started when tadpoles began to feed. The adapted embryos were divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Cluster method was used to indicate the distinct distance between the band patterns of different stages. An increase occurred in the concentration of protein fractions in these tadpoles upon metamorphosis and that when metamorphosis was completed. DNA concentration exhibited an evident low values at the premetamorphic stage 44 (105.85 ± 0.519 ng/µl) compared with the other more advanced developmental stages 55 and 56 (204.056 ± 0.651 ng/µl and 234.55 ± 2.325 ng/µl respectively). In conclusion, acquire information about the changes in the molecular content of Bufo regularis during metamorphosis has been estimated.

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The present study was carried out to investigate the histological and histochemical changes in the retina on different developmental stages of Egyptian toad Bufo regularis. Our experiment started when tadpoles begin to feed. The adapted embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Both histological and histochemical results showed that the general architecture of the retina organ is correlated with the state of development. Therefore, it displayed different characteristic features depending on the investigated developmental stage starting from the larval stage (feeding began, stage 44) and ending with the postmetamorphic stage 66. Also, the present work aimed to study the chronic effects of UVA on the retina structure of B. regularis during development and metamorphosis for the first time.