山羊碱性氨基酸转运载体基因SLC3A1 cDNA序列克隆及表达

Cloning and Expression of Caprine Cationic Amino Acid Transporter Gene SLC3A1 cDNA Sequence

试验旨在克隆山羊碱性氨基酸转运载体基因SLC3A1cDNA序列,探究其表达的组织特异性及其在小肠中的表达发育模式。参考GenBank已发表的绵羊、牛SLC3A1基因mRNA序列设计引物,克隆山羊SLC3A1基因的cDNA序列,采用实时荧光定量PCR的方法分析其在1日龄山羊11种组织及其在1日龄、6月龄、8月龄、10月龄、12月龄山羊十二指肠、空肠、回肠中的mRNA表达情况。结果表明,成功克隆得到了山羊SLC3A1基因cDNA序列,其与绵羊、牛、野猪、人、小鼠、大鼠的同源性分别为99%、97%、88%、86%、80%和79%。SLC3A1基因转录表达有明显的组织特异性,其在1日龄山羊肾脏、回肠、空肠、结肠中表达量依次降低（P〈0.05）,其他组织中表达量很低。同一月龄山羊,SLC3A1基因在不同肠段的表达量数值上回肠〉空肠〉十二指肠。SLC3A1基因在不同月龄山羊十二指肠表达量以1日龄山羊为最高（P〈0.05）,6~12月龄山羊相同肠段之间表达量无显著差异（P〉0.05）;空肠表达量随山羊年龄的增加均呈现逐步降低的趋势;回肠表达量在各个月龄山羊之间差异不显著（P〉0.05）。结果说明,山羊碱性氨基酸转运载体基因SLC3A1的主要表达部位在肾脏和肠道,推测b0,＋碱性氨基酸转运系统转运氨基酸的主要部位为肾脏和肠道。SLC3A1基因在山羊小肠受肠段和发育阶段的影响,具有不同的表达发育模式。

The objective of this study was to clone caprine cationic amino acid transporter gene SLC3A1 and investigate its mRNA expression in different tissues and its development regularity in small intestine.The cDNA sequence of caprine SLC3A1 gene was cloned with the primer which was designed according to mRNA sequence of Ovis aries and Bos taurus in GenBank.Then its expression was quantified by Real-time PCR in 11 tissues from goats at the age of day 1and duodenum,jejunum and ileum from goats at the age of day 1,month 6,month 8,month 10 and month12.The results indicated that cDNA sequence of SLC3A1 gene was obtained,and its homologywith SLC3A1 gene in Ovis aries,Bos taurus,Sus scrofa,Homo sapiens,Mus musculus and Rattus norvegicus were 99%,97%,88%,86%,80%,79%,respectively.SLC3A1 gene was expressed in all of these collected tissues,whereas the expression level varied from tissues.Specifically,its expression in kidney,jejunum,ileum and colon were significant higher than that in other tissues at the age of day 1and decreased systematically（P〈0.05）.The expression of SLC3A1 in small intestine at the same age of goat was ileum〉jejunum〉duodenum.SLC3A1 gene expression in duodenum at the age of day 1was significant higher than that at the other ages（P〈0.05）,it decreased with age in jejunum,and there was no significant difference among ileum with age（P〉0.05）.In conclusion,SLC3A1 gene and b0,＋cationic amino acid transporter system were mainly expressed in kidney and intestine.The expression of SLC3A1 gene was differentially regulated and distributed by developmental stages and segments of small intestine in goat.