目的  对内蒙古白绒山羊精子膜蛋白Izumo的基因编码区cDNA序列进行扩增并对其结构作初步分析。方法  以已知的内蒙古白绒山羊Izumo部分基因序列为模板，采用cDNA末端快速扩增技术扩增3′端和5′端未知序列，钓取基因编码区，并分析编码区氨基酸序列。结果  经序列扩增和拼接，得到1035 bp的Izumo编码区cDNA序列，后者编码由344个氨基酸组成的蛋白。氨基酸序列中包含免疫球蛋白样结构域。Izumo编码区的疏水性平均值为-0.181。找到4个位于Izumo蛋白胞外区的潜在磷酸化位点。结论  进一步确定Izumo属于免疫球蛋白超家族的一员，初步得出Izumo是一种亲水性蛋白，根据潜在磷酸化位点的位置，推断磷酸化可能不是Izumo蛋白发挥作用的机制。

Objective  To amplify a cDNA sequence of coding region of Izumo protein in Inner Mongolian white cashmere goats and preliminarily analyze the protein structure. Methods  Part of the known Izumo gene sequence of Inner Mongolian white cashmere goats was used as a template. The unknown sequences at 3' and 5' ends were amplified with rapid amplification of cDNA ends to produce a cDNA sequence encoding Izumo protein. The amino acid sequences of the coding region were analyzed. Results  A 1035 bp cDNA sequence coding a 344 amino acid protein was obtained. The deduced amino acid sequence contained a immunoglobulin-like domain. The grand average of hydrophobicity was -0.181. Four potential phosphorylation sites were located in extracellular region. Conclusions  The protein was further identified as one of the members of immunoglobulin superfamily. A preliminary conclusion was drawn that Izumo was a hydrophilic protein. Phosphorylation may not be the mechanism of Izumo protein in fertilization according to the phosphorylation sites.