Almyah Maysoon Khudheyer, Albadran Adnan Issa
Department of Biology, College of Science, University of Basrah, Basrah, Iraq.
Mol Biol Res Commun. 2019 Dec;8(4):156-165. doi: 10.22099/mbrc.2019.34274.1423.
The prevalence of obesity and diabetes changes dramatically with lifestyle and unequal risk among individuals have made scientists interested to understand how the environment interferes with genetic factors to make it so-called genetic predisposition. This study aimed to explore wherethe most variable region is in leptin gene and analyse microsatellite repeats with direct sequencing in Iraqis and compare our alleles with other populations as a risk for obesity and T2D predisposition. DNA was extracted from blood of 60 type 2 diabetics and 70 non diabetics individuals, 5‛UTR, exon 2 and 3 were screened in 45 individuals (24 type 2 diabetes patients and 21 non- diabetics), TTTC repeats region were amplified in all 130 participants from which 22 control samples were purified and sequenced, superimposed sequences were analyzed manually. Sequencing results showed G>A polymorphism (rs2167270) in 5‛UTR region. No polymorphisms detected in exons 2 and 3. microsatellites alleles were classified depending on sizes into class1 < (220bp) and class2 (> 220bp). Analysis of 22 control samples sequences of microsatellite region resulted in 6 type1 allele (unique sequence) and 5 type 3 allele (13 different isoforms) depending on TTTC arrangement separated by Ts bases. We concluded that variations were in non- coding regions and no significant difference was observed in allele frequency between both groups, but there was a huge diversity in microsatellite repeat number and context among individuals. This may affects gene function thus prepare a predisposition for obesity and type 2 diabetes.
肥胖和糖尿病的患病率会随着生活方式的改变而显著变化，个体之间风险的不平等使得科学家们有兴趣了解环境如何干扰遗传因素，从而形成所谓的遗传易感性。本研究旨在探索瘦素基因中变化最大的区域，通过直接测序分析伊拉克人的微卫星重复序列，并将我们的等位基因与其他人群进行比较，以评估肥胖和2型糖尿病易感性的风险。从60名2型糖尿病患者和70名非糖尿病个体的血液中提取DNA，对45名个体（24名2型糖尿病患者和21名非糖尿病患者）的5'UTR、外显子2和3进行筛选，在所有130名参与者中扩增TTTC重复区域，从中纯化并测序22个对照样本，对叠加序列进行人工分析。测序结果显示5'UTR区域存在G>A多态性（rs2167270）。在外显子2和3中未检测到多态性。微卫星等位基因根据大小分为1类（<220bp）和2类（>220bp）。对22个微卫星区域对照样本序列的分析产生了6个1型等位基因（独特序列）和5个3型等位基因（13种不同的异构体），这取决于由T碱基分隔的TTTC排列。我们得出结论，变异存在于非编码区域，两组之间的等位基因频率没有显著差异，但个体之间微卫星重复数和背景存在巨大差异。这可能会影响基因功能，从而为肥胖和2型糖尿病奠定易感性基础。
