Moriwaki J, Kajita E, Kirikoshi H, Koike J, Sagara N, Yasuhiko Y, Saitoh T, Hirai M, Katoh M, Shiokawa K
Laboratory of Molecular Embryology, Department of Integrated Biosciences, Graduate School of Frontier Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
Biochem Biophys Res Commun. 2000 Nov 19;278(2):377-84. doi: 10.1006/bbrc.2000.3808.
Frizzled genes, encoding WNT receptors, play key roles in cell fate determination. Here, we isolated two Xenopus frizzled genes (Xfz10A and Xfz10B), probably reflecting pseudotetraploidy in Xenopus. Xfz10A (586 amino acids) and Xfz10B (580 amino acids) both encoded by a single exon, consisted of the N-terminal cysteine-rich domain, seven transmembrane domains, and the C-terminal Ser/Thr-X-Val motif. Xfz10A and Xfz10B were 97.0% identical at the amino acid level, and Xfz10B was 100% identical to previously reported Xfz9, yet Xfz10A was 85.3% and 62.4% identical to FZD10 and FZD9, respectively. Xfz10 mRNA appeared as 3.4 kb in adult tissues and embryos. RT-PCR analyses revealed the expression of more Xfz10A mRNA in stomach, kidney, eye, skeletal muscle, and skin, and more Xfz10B mRNA in heart and ovary, but in embryos, two mRNAs were equally expressed from the blastula stage with their peak expression at the late gastrula stage. The main site of Xfz10 mRNA expression was neural fold at the neurula stage and the dorsal region of midbrain, hindbrain, and spinal cord at the tadpole stage. These results suggest that Xfz10 has important roles in neural tissue formation.
编码WNT受体的卷曲基因在细胞命运决定中起关键作用。在此，我们分离出两个非洲爪蟾卷曲基因（Xfz10A和Xfz10B），这可能反映了非洲爪蟾的假四倍体现象。Xfz10A（586个氨基酸）和Xfz10B（580个氨基酸）均由单个外显子编码，由N端富含半胱氨酸结构域、七个跨膜结构域和C端丝氨酸/苏氨酸-X-缬氨酸基序组成。Xfz10A和Xfz10B在氨基酸水平上有97.0%的同一性，Xfz10B与先前报道的Xfz9有100%的同一性，而Xfz10A与FZD10和FZD9的同一性分别为85.3%和62.4%。Xfz10 mRNA在成年组织和胚胎中表现为3.4 kb。逆转录聚合酶链反应分析显示，Xfz10A mRNA在胃、肾、眼、骨骼肌和皮肤中表达较多，Xfz10B mRNA在心脏和卵巢中表达较多，但在胚胎中，两种mRNA从囊胚期开始等量表达，在原肠胚晚期达到表达峰值。Xfz10 mRNA的主要表达部位在神经胚期是神经褶，在蝌蚪期是中脑、后脑和脊髓的背侧区域。这些结果表明Xfz10在神经组织形成中起重要作用。
