Pigment pattern during embryonic stages in heteroploid Bufo regularis

In the present book, larval stages of the Egyptian toad Bufo regularis (Bufonidae) were used. Three groups of newly fertilized eggs were analyzed. One group was irradiated with ultraviolet (i.e, haploid), the second was heat- shocked (i.e, triploid) and the third one was used as control (i.e, diploid). Transverse sections of diploid, haploid and triploid embryos at different embryonic stages were used to study the distribution of melano-macrophage centres (MMCs). The pigment cells and MMCs were detected using the light microscopical study in the liver, kidney and spleen of the three tested group of B. regularis tadpoles. Moreover, the electron microscopical study of the MMCs in liver, kidney and spleen at different embryonic stages of B. regularis were also characterized. On the other hand, by using a highly sensitive reverse transcription- polymerase chain reaction (RT-PCR) assay detected tyrosinase mRNA in liver and spleen of three tested group of B. regularis tadpoles; therefore the liver and spleen pigment cells (KCs) are able to synthesize melanin. mRNA tyrosinase not expressed in kidney;so the pigment cells of kidney are melanin- phagocytosing macrophage.