Gatphayak K, Knorr C, Beck J, Brenig B
Institute of Veterinary Medicine, Göttingen, Germany.
Cytogenet Genome Res. 2004;106(1):98-106. doi: 10.1159/000078571.
Hyaluronidase genes (HYAL) encode hyaluronidase enzymes required for hyaluronan degradation. Both in humans and in mouse, clustered hyaluronidase genes have been identified. Here, the porcine hyaluronidase cluster consisting of genes HYAL1, HYAL2 and HYAL3 was characterized. The porcine cDNA sequences and proteins share homologies to human orthologs of 85 and 81% for HYAL1, 87 and 89% for HYAL2 and 86 and 83% for HYAL3, respectively. The porcine hyaluronidase proteins approximately share a 40% homology with each other. Furthermore, genes FUS1 and FUS2 were found within this cluster, which was assigned to SSC13q21. A total of seven SNPs were detected in the genes (four in HYAL1, two in HYAL2 and one in HYAL3). Three of the four SNPs in HYAL1 led to amino acid exchanges (C622G --> Asp24 to Glu; C633T --> Pro28 to Leu, and G1298T --> Ala250 to Ser). The amino acid replacements induce putative changes in the extended strand at Asp24, in the extended strand and the random coil at Pro28, and finally in the random coil and the alpha helix at Ala250. Frequency estimations for four SNPs located in genes HYAL1 and HYAL3 using animals (n = 295) of nine European and six Chinese pig breeds indicated several significant deviations. For example, there were no significant differences in allele frequencies between pigs representing breeds Hampshire and Jiangquhai at SNP C633T (HYAL1), but between Hampshire respectively Jiangquhai animals and Rongchang pigs. Analysis of the same breeds at SNP C588T (HYAL3) indicates significant differences between Hampshire and Jiangquhai respectively Rongchang, but not between Jiangquhai and Rongchang. The breed Göttingen Minipig displayed significant differences concerning two SNPs with respect to the other European pig breeds tested. For all three hyaluronidase genes, N-glycosylation sites are typical. For HYAL2 the lysosomal character was proven. The catalytic site responsible for HAase activity is conserved in the three enzymes. Expression of hyaluronidases was determined by RT-PCR and quantitative PCR. Broad gene expression was observed in different tissues for the three genes, respectively.
透明质酸酶基因（HYAL）编码降解透明质酸所需的透明质酸酶。在人类和小鼠中，都已鉴定出成簇的透明质酸酶基因。在此，对由HYAL1、HYAL2和HYAL3基因组成的猪透明质酸酶基因簇进行了表征。猪的cDNA序列和蛋白质与人类直系同源物的同源性分别为：HYAL1的cDNA序列同源性为85%、蛋白质同源性为81%；HYAL2的cDNA序列同源性为87%、蛋白质同源性为89%；HYAL3的cDNA序列同源性为86%、蛋白质同源性为83%。猪的透明质酸酶蛋白质彼此之间大约有40%的同源性。此外，在该基因簇中发现了FUS1和FUS2基因，该基因簇定位于猪13号染色体q21区域。在这些基因中总共检测到7个单核苷酸多态性（SNP）（HYAL1中有4个，HYAL2中有2个，HYAL3中有1个）。HYAL1中的4个SNP中有3个导致了氨基酸交换（C622G→Asp24变为Glu；C633T→Pro28变为Leu，以及G1298T→Ala250变为Ser）。这些氨基酸替换分别在Asp24处的延伸链、Pro28处的延伸链和无规卷曲以及Ala250处的无规卷曲和α螺旋中引起了推测的变化。使用9个欧洲猪品种和6个中国猪品种的动物（n = 295）对位于HYAL1和HYAL3基因中的4个SNP进行频率估计，结果显示出一些显著差异。例如，在SNP C633T（HYAL1）处，代表汉普夏猪和姜曲海猪品种的猪之间的等位基因频率没有显著差异，但汉普夏猪和姜曲海猪与荣昌猪之间存在差异。在SNP C588T（HYAL3）处对相同品种的分析表明，汉普夏猪与姜曲海猪以及荣昌猪之间存在显著差异，但姜曲海猪和荣昌猪之间没有差异。哥廷根小型猪品种在两个SNP方面与其他测试的欧洲猪品种存在显著差异。对于所有三种透明质酸酶基因，N - 糖基化位点都是典型的。已证实HYAL2具有溶酶体特征。三种酶中负责透明质酸酶活性的催化位点是保守的。通过逆转录 - 聚合酶链反应（RT - PCR）和定量PCR测定透明质酸酶的表达。分别在不同组织中观察到这三个基因有广泛的基因表达。
