寿光鸡ADSL基因5′调控区的克隆、序列分析以及单核苷酸多态性的研究

Molecular Cloning,Sequences Analysis and Single Nucleotide Polymorphism Analysis of the Flanking Region for ADSL gene of Shouguang Chicken( Gallus gallus )

腺苷酸琥珀酸裂解酶(ADSL)是双功能酶,催化嘌呤核苷酸的起始合成与嘌呤核苷酸的循环。通过对寿光鸡ADSL5′调控区1035bp的序列进行克隆和测序分析,发现其具有典型的管家基因特征:没有真核基因明显的TATA盒和CAAT盒出现,并且位于起始密码子(ATG)前234个碱基具有非常高的GC含量达72.65%。在邻近起始密码子“ATG”处,5′调控区含有两个核呼吸因子-2(NRF-2),在相同位置上人类ADSL基因也具有与此类似的两个核呼吸因子-2结合位点,被认为在嘌呤核苷酸合成途径起到重要作用。值得一提的是位于寿光鸡5′侧翼调控区-27号碱基发生C→T突变,存在于所有研究的寿光鸡个体中,频率为1。该突变使得本来不是NRF-2(核呼吸因子2)结合位点的CTCC突变为NRF-2结合位点CTTC。而人类却恰恰与此相反第一个NRF-2结合位点发生了突变(CTTC→CTCC),并导致出现ADSL缺陷症状。

Adenylosuccinate lyase (ADSL) is a bifunctional enzyme catalyzing de novo purine synthesis and purine nucleotide recycling.The 1035bp promoter region of adsl gene of Shouguang chicken( Gallus gallus ),one of the most important strains cultivated in China,was cloned and characterized in this study.The promoter of chicken ADSL gene shows typical features of house keeping genes:No canonical TATA and CAAT boxes were observed;this region contains 72.65% GC in 234bp near the start codon;there are two NRF-2 binding sites like the human near initiation codon involved in the regulation of purine biosynthesis possibly.What deserves to be mentioned is one SNP(C/T at -27of 5′UTR) was found among individuals in all Shouguang chicken studied frequency is 1.The SNP make CTCC which is non-potential binding site for NRF-2 (nuclear respiratory factor 2) mutate to CTTC for binding site NRF-2 suddenly.Contrary to this exactly,there is a SNP(CTTC→CTCC) in the first binding site for NRF-2 in humanbeing,and lead to the fact that ADSL defect symptom appears.