Transformation of cholera toxin B subunit-human proinsulin chimeric gene to edible mushroom (Pleurotus ostreatus) and evaluation of its presence and expression

Diabetes is a disease in which the body does not produce or properly utilize insulin. Although insulin is predominantly made in bacteria or yeast for commercial production, there is a burgeoning need for alternative systems in the production of insulin. In this regard, edible oyster mushroom was studied as host for the production of insulin. Therefore, a binary vector pCAMBIACTB-INS was constructed containing the cholera toxin B subunit fused with human proinsulin gene under the control of glyceraldehyde-3-phosphate dehydrogenase as homologous promoter. Then it introduced into gill tissue of edible oyster mushroom, Pleurotus ostreatus isolate Iran1649c, via Agrobacterium Tumefaciens strain GV3101 (OD600nm) and co-cultivated with P. ostreatus at 25 °C on selective medium containing hygromycin and cefotaxime. After confirming Putative transformants by PCR using gene specific primers, stable integration of the CTB-proinsulin fusion gene into P. ostreatus genome was confirmed by Southern blotting analysis. Also, the expression of transgene was confirmed by RT-PCR, ELISA and immunoblotting methods and in transgenic mycelia the recombinant CTB-proinsulin showed an expression level by 0.04% of total soluble protein. In conclusion successful expression of foreign genes in transgenic mushrooms is promising for development of biopharmaceutical in edible mushrooms.
medium containing hygromycin and cefotaxime. After confirming Putative transformants using PCR with specific primers, stable integration of the CTB-proinsulin fusion gene into P. ostreatus genome was confirmed by Southern blotting analysis. Also, the expression of transgene was confirmed by RT-PCR, ELISA and immunoblotting methods and in transgenic mycelia the recombinant CTB-proinsulin showed an expression level by 0.04% of total soluble protein. In conclusion successful expression of foreign genes in transgenic mushrooms is promising for development of biopharmaceutical in edible mushrooms.