FLT4 Regulates Melanogenesis In Alpaca Melanocytes

Vascular endothelial growth factor receptor(VEGFR-3,FLT4)is related to the growth of melanoma cells,which suggests that FLT4 may be related in melanogenesis.In order to investigate the effect of FLT4 gene on melanogenesis:Immunohistochemistry,qRT-PCR,western blotting methods were used.In vitro,the sixth generation alpaca melanocytes were treated with the different does of FLT4(0,1,10,50,100 ng/mL),To study changes in levels of tyrosinase related protein 1(TYRP1),microphthalmia-associated transcription.factor(MITF),tyrosinase(TYR),and tyrosine kinase receptors(c-KIT)mRNA and protein expression compared with the control group.Experimental content and the results are as follow:1 The expression of FLT4 was studied by immunohistochemistry,qRT-PCR and western blotting in alpaca skin hair follicles of different coat colors.The result of immunohistochemistry showed that FLT4 was expressed in the out root sheath and dermal papilla of skins with different coat color.qRT-PCR and western blotting results showed that the levels of mRNA and protein expression of FLT4 were significant higher in alpaca skin with brown hair color than that in alpaca skins with white hair(P<0.01).2 In vitro,the sixth generation alpaca melanocytes were treated with the different does of FLT4(0,1,10,50,100 ng/mL).The results showed that compared with the control group,the levels of TYR,c-KIT,TYRP1 and MITF mRNA and protein expression were increased significantly,and the expression levels were highest at the addition does of 10 ng/mL,the expression levels were highest(P<0.01).The melanin assay results showed that compared with control group,melanocytes production was significantly higher,and the production of melanin was highest at the addition does of 10 ng/mL(P<0.01).The above results suggested that FLT4 may have a functional role in the melanogenesis by regulating the expression of hair color related genes.