Rössler P, Mezler M, Breer H
University Stuttgart-Hohenheim, Institute of Physiology, Stuttgart, Germany.
J Comp Neurol. 1998 Jun 8;395(3):273-80.
Mature olfactory receptor neurons of mammals are characterized by the expression of the highly conserved olfactory marker protein (OMP) encoded by single copy genes. In Xenopus laevis, two homologous genes encoding olfactory marker proteins have been identified that share a sequence identity with mammalian OMPs of about 50%. Sequence comparison revealed significant variability in the N-terminus and C-terminus regions; in contrast, two internal domains were highly conserved between amphibian and mammalian OMPs, suggesting some functional relevance. The two OMP subtypes were regionally expressed in the olfactory nasal epithelium of Xenopus. XOMP1 transcripts were more abundant in the lateral diverticulum and XOMP2 in the medial diverticulum. The lateral location of XOMP1 and medial location of XOMP2 correspond to the suggested locations of olfactory receptor neurons responsive to water-borne and air-borne odorants, respectively.
哺乳动物成熟的嗅觉受体神经元的特征在于由单拷贝基因编码的高度保守的嗅觉标记蛋白（OMP）的表达。在非洲爪蟾中，已鉴定出两个编码嗅觉标记蛋白的同源基因，它们与哺乳动物OMP的序列同一性约为50%。序列比较显示，N端和C端区域存在显著变异性；相比之下，两栖动物和哺乳动物OMP之间的两个内部结构域高度保守，这表明存在一些功能相关性。这两种OMP亚型在非洲爪蟾的嗅鼻上皮中呈区域表达。XOMP1转录本在外侧憩室中更为丰富，而XOMP2在内侧憩室中更为丰富。XOMP1的外侧位置和XOMP2的内侧位置分别对应于对水生和空气传播气味剂作出反应的嗅觉受体神经元的假定位置。
