Abstract
Brain and skin are both initially part of the ectoderm during prenatal development, but they are separated during neurogenesis. There is growing evidence that brain and skin are functionally related and skin pigmentation and several behavioral traits, such as anxiety, are coinherited. Here we describe a novel protein, Myg1 (Melanocyte proliferating gene 1, also known as Gamm1). Myg1 is known as putative phosphoesterase that is under-expressed in mouse malignant melanoma compared to autonomously growing mouse melanocytes. In our lab we have found that Myg1 is most significantly overexpressed gene in the amygdaloid area of rats in response to anxiety reaction induced by cat odor. Using real time Q-PCR we detected Myg1 transcript in all 10 areas of the brain we examined. WebQTL analysis revealed that the expression level of Myg1 (located in chr 12) is strongly regulated by a certain locus in chr 19 that includes several QTL markers: Dark skin 1, Dopamine transporter density and Open field activity and conditioned avoidance. Thus Myg1 could be involved both in regulating skin pigmentation and behavioral responses. We also explored Myg1 expression in the skin samples of vitiligo patients. Vitiligo is a skin disease in which pigment cells (melanocytes) are destroyed or stop producing melanin, resulting in white patches on the skin. We found that Myg1 expression is significantly (p<0.01) increased in both damaged and normal skin of vitiligo patients (n=28) compared to the skin samples of the control group (n=21). We propose that Myg1 is involved in neuroendocrine stress response system that has both central (HPA-axis) and peripheral (skin response to stress) versions. Using YFP-tag we have seen that Myg1 is predominantly expressed in the cell nucleus, but is in a low rate also present in cytoplasm. The precise role of Myg1 in the neural system and in the pigmentation pathway remains to be elucidated.