Uehara Shigeyuki, Izumi Yoshiko, Kubo Yuko, Wang Chi Chiu, Mineta Katsuhiko, Ikeo Kazuho, Gojobori Takashi, Tachibana Masayoshi, Kikuchi Toshihiko, Kobayashi Toshimitsu, Shibahara Shigeki, Taya Choji, Yonekawa Hiromichi, Shiroishi Toshihiko, Yamamoto Hiroaki
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Pigment Cell Melanoma Res. 2009 Feb;22(1):111-9. doi: 10.1111/j.1755-148X.2008.00513.x. Epub 2008 Oct 28.
Mammalian pigment cells produce melanin as the main pigment. Melanocytes, one of the two types of mammalian pigment cells, differentiate from the neural crest and migrate to a variety of organs during development. Melanocytes exist not only in the skin but also in other sites such as the cochlea where they are essential for hearing. Mitf(mi-bw) is one of the known recessive alleles of the mouse microphthalmia-associated transcription factor (Mitf) locus, which is essential for the development of pigment cells. Homozygous Mitf(mi-bw)/Mitf(mi-bw) mice have a completely white coat with black eyes and are deaf due to the lack of melanocytes. By comparing gene expression profiles in cochleae of wild-type and Mitf(mi-bw)/Mitf(mi-bw) mice, we now demonstrate the specific expression of glutathione S-transferase alpha 4 (Gsta4) in the stria vascularis. Gsta4 encodes one of the cytosolic glutathione S-transferases (GSTs) which participate in detoxification processes of many tissues. This gene is specifically expressed in intermediate cells of the stria vascularis, suggesting a novel function for cochlear melanocytes. Moreover, among mammalian pigment cells, expression of Gsta4 was restricted to cochlear melanocytes, suggesting that melanocytes in various tissues differentiate from one another depending on their location.
哺乳动物的色素细胞以黑色素作为主要色素。黑素细胞是哺乳动物的两种色素细胞之一，它由神经嵴分化而来，并在发育过程中迁移至多种器官。黑素细胞不仅存在于皮肤中，还存在于其他部位，如耳蜗，在耳蜗中它们对听力至关重要。Mitf(mi-bw)是小鼠小眼相关转录因子（Mitf）基因座的已知隐性等位基因之一，该基因座对色素细胞的发育至关重要。纯合的Mitf(mi-bw)/Mitf(mi-bw)小鼠有完全白色的皮毛和黑色的眼睛，并且由于缺乏黑素细胞而失聪。通过比较野生型和Mitf(mi-bw)/Mitf(mi-bw)小鼠耳蜗中的基因表达谱，我们现在证明了谷胱甘肽S-转移酶α4（Gsta4）在血管纹中的特异性表达。Gsta4编码一种胞质谷胱甘肽S-转移酶（GSTs），其参与许多组织的解毒过程。该基因在血管纹的中间细胞中特异性表达，提示耳蜗黑素细胞具有新功能。此外，在哺乳动物色素细胞中，Gsta4的表达仅限于耳蜗黑素细胞，这表明不同组织中的黑素细胞根据其位置而彼此分化。
