奶牛产奶性状与乳房炎相关基因CpG含量及分布特征的比较分析

DNA甲基化是表观遗传学的重要组成部分,基因启动子区及第一外显子区的CpG甲基化通常抑制该基因的表达,而去甲基化则促进基因表达。已有的研究发现荷斯坦牛的乳房炎指标SCC(Somatic cell count)与产奶量呈较强负相关。文章分析并比较了这两类性状的相关基因的启动子区、第一外显子、下游2 000 bp序列中CpG含量及分布特征。结果表明,乳房炎相关基因的启动子、第一外显子中CpG含量显著低于产奶性状相关基因,而两类性状基因下游2 000 bp序列中CpG含量无显著性差异。另外,文中提出了两个量化基因序列中CpG特征的指标,一个是CpG平均距离,用来衡量序列中的CpG分布;另一个是条件概率p(G|C),用以量化序列中二核苷酸CpG随碱基C出现的可能性,并对两类基因的启动子和第一外显子区域的这两个指标做了统计检验。研究结果对产奶性状与乳房炎相关基因的DNA甲基化调控研究奠定了基础。

基于黄褐棉导入系的抗黄萎病QTL鉴定分析

棉花是我国重要的经济作物,对纺织工业发展和提高人民生活水平具有重要作用。陆地棉是最主要的栽培棉种,占棉花产量的90%以上,然而其对黄萎病抗性仍有待提高。黄褐棉对黄萎病抗性强,且作为与陆地棉遗传距离较远的异源四倍体野生棉,很可能具备一些优异的抗病等位基因供发掘利用。以陆地棉PD94042为轮回亲本,以黄褐棉为供体亲本,经过杂交以及高世代回交,并结合分子标记辅助选择,建立一套渐渗有黄褐棉的导入系,成功检测到10个黄萎病抗性相关数量性状基因座(quantitative trait locus,简称QTL),解释表型变异范围为14.0%~39.3%。这些结果为进一步开展QTL精细定位,服务于棉花抗黄萎病育种实践奠定了基础。

Expression characteristics of neutrophil and mononuclear-phagocyte related genes mRNA in the stable angina pectoris and acute myocardial infarction stages of coronary artery disease

Objective To investigate expression differences of neutrophil and mononuclear phagocyte related gene mRNAs among acute myocardial infarction （AMI）, stable angina （SA） and control groups, and then discuss their expression characteristics in the stable angina pectoris （SAP） and AMI stages of coronary artery disease （CAD）. Methods Whole Human Genome Oligo Microarrays were applied to assess the differential expression characteristics of neutrophil and mononuclear phagocyte related mRNAs in patients with AMI （n = 20）, SA （n = 20） and controls （n = 20）. Results （1） Almost all colony-stimulating factors （CSF） and their receptors related mRNAs was up-regulated in AMI and SA groups compared with the control group, and the expression of granulocyte-macrophage colony stimulating factor receptor （GM-CSFR） and granulocyte colony stimulating factor receptor （G-CSFR） mRNAs in the AMI group was significantly up-regulated compared with the other two groups （P 〈 0.01）. （2） The expression of mRNAs related to monocyte chemoattractant protein-1 （MCP-1）, CCR2 （MCP-1 receptor） and CXCR2 （IL-8 receptor） was significantly up-regulated （P 〈 0.01） in AMI group compared with SA and control groups IL-8 mRNA expression in the AMI group was clearly higher than the controls （P 〈 0.05）. （3） All mRNAs expression related to opsonic re- ceptors （IgG FoR and C3bR/C4bR） was significantly up-regulated in AMI group compared with SA and control group （P 〈 0.01）, and the SA group showed an upward trend compared with controls. （4） Most pattern recognition receptor （PRR）-related mRNAs expression was up-regulated in AMI group compared with SA and control groups. Most toll-like receptor （TLR） mRNAs expression was significantly up-regulated （P 〈 0.01） than the SA and control groups, macrophage scavenger receptor （MSR） mRNA was significantly up-regulated in AMI group compared with the control group （P 〈 0.01）, and the SA group showed an upward trend compared with the controls. Conclusions The expression of most neutrophil and mononuclear-macrophage function related genes mRNAs was significantly up-regulated by stages during the progression of CAD, suggesting that the adhesive, chemotactic and phagocytic functions of neutrophil and mononudear-macrophage were strengthened in the occurrence and development of coronary atherosclerosis and AMI. This also showed a stepped up- ward trend as the disease progressed.

籽鹅卵巢5个基因产蛋前期与产蛋期mRNA表达的研究

为了进一步分析从消减文库获得的未知基因表达与产蛋性能的相关性,利用SYBR GreenⅠ实时荧光定量PCR方法分析籽鹅卵巢组织中5个基因EST4、EST5、EST6、EST7和EST8产蛋前期与产蛋期的mRNA表达。结果显示,EST4、EST5、EST6、EST8的产蛋期表达量显著高于产前期(P<0.05),EST7的产蛋期表达量极显著高于产蛋前期(P<0.01)。研究结果提示,这5个基因参与鹅产蛋性状的分子调控。

柑橘遗传连锁图谱构建及重要性状QTL的研究进展

对柑橘遗传连锁图谱的构建以及抗病、抗虫、抗非生物胁迫、果实与种胚发育、品质等重要性状相关的QTL定位研究进展进行了综述,对其未来研究趋势和前景提出了展望。