本研究基于当代中国人群3D牙齿模型数据,参照拉美人群进化和多样性研究联合会(consortium for the analysis of the diversity and evolution of Latin America,CANDELA)所使用的牙齿特征点标记方法,使用牙齿特征点间的欧几里得线性距离...本研究基于当代中国人群3D牙齿模型数据,参照拉美人群进化和多样性研究联合会(consortium for the analysis of the diversity and evolution of Latin America,CANDELA)所使用的牙齿特征点标记方法,使用牙齿特征点间的欧几里得线性距离(Euclidean linear distances,ELD)表示的牙齿表型作为牙齿可观测特征的度量,探究个体因素(年龄、性别)和群体因素(民族)对当代中国人群牙齿可观测特征多样性的影响。通过对牙齿标记特征点的典型变量分析(canonical variate analysis,CVA)、交叉验证(cross validation,CV)、主成分分析(principal component analysis,PCA)以及对牙齿表型的Pearson相关性分析和差异分析,本研究发现进化上相近的群体牙齿可观测特征往往更接近。具体来说,汉族的上颌牙齿可观测特征和壮族、苗族较为接近而不同于蒙古族的,而藏族的上、下颌牙齿可观测特征不同于维吾尔族的;南北中汉族牙齿表型的差异具有明确的方向性,下颌牙齿差异比上颌更明显;从性别角度看,男女牙齿表型差异主要体现在尖牙上,男性尖牙平均宽度和高度显著大于女性的;对不同年龄群体的差异分析表明,遗传外因素对牙齿可观测特征的影响主要体现在尖牙、上颌第一磨牙、下颌第一前磨牙上。展开更多
The two-spotted spider mite, Tetranychus urticae Koch has two forms： green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing...The two-spotted spider mite, Tetranychus urticae Koch has two forms： green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic conse- quences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 （Tudnmt3） throughout their entire life cycle. Methylation-sensitive amplification polymorphism （MSAP） analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis （PCoA） indicates a significant epigenetic differentiation be- tween female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms.展开更多
文摘本研究基于当代中国人群3D牙齿模型数据,参照拉美人群进化和多样性研究联合会(consortium for the analysis of the diversity and evolution of Latin America,CANDELA)所使用的牙齿特征点标记方法,使用牙齿特征点间的欧几里得线性距离(Euclidean linear distances,ELD)表示的牙齿表型作为牙齿可观测特征的度量,探究个体因素(年龄、性别)和群体因素(民族)对当代中国人群牙齿可观测特征多样性的影响。通过对牙齿标记特征点的典型变量分析(canonical variate analysis,CVA)、交叉验证(cross validation,CV)、主成分分析(principal component analysis,PCA)以及对牙齿表型的Pearson相关性分析和差异分析,本研究发现进化上相近的群体牙齿可观测特征往往更接近。具体来说,汉族的上颌牙齿可观测特征和壮族、苗族较为接近而不同于蒙古族的,而藏族的上、下颌牙齿可观测特征不同于维吾尔族的;南北中汉族牙齿表型的差异具有明确的方向性,下颌牙齿差异比上颌更明显;从性别角度看,男女牙齿表型差异主要体现在尖牙上,男性尖牙平均宽度和高度显著大于女性的;对不同年龄群体的差异分析表明,遗传外因素对牙齿可观测特征的影响主要体现在尖牙、上颌第一磨牙、下颌第一前磨牙上。
文摘The two-spotted spider mite, Tetranychus urticae Koch has two forms： green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic conse- quences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 （Tudnmt3） throughout their entire life cycle. Methylation-sensitive amplification polymorphism （MSAP） analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis （PCoA） indicates a significant epigenetic differentiation be- tween female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms.
