不同线性回归方程计算细菌质粒的分子量

Comparison of Different Linear Regression Formulas for Size Estimation of Plasmids in Bacteria

以大肠杆菌Ｖ５１７株的８个不同大小质粒为标准，报道了计算细菌质粒的分子量时所采用的较适线性回归方程。利用大肠杆菌Ｖ５１７的质粒检测所得数据，建立了两个不同的线性回归方程ｌｏｇＭＷ＝Ａ＋Ｂ（Ｄ），ｌｏｇＭＷ＝Ａ＋Ｂ（ＲＭ）。以建立的两个线性回归方程和传统的线性回归方程ｌｏｇＭＷ＝Ａ＋Ｂ（ｌｏｇＲＭ）来分别计算质粒的分子量，并加以比较，其中ｌｏｇＭＷ是质粒分子量的对数；Ｄ是质粒ＤＮＡ带的迁移距离；ＲＭ是质粒ＤＮＡ带的相对迁移率。根据线性回归的相关系数ｒ，以上述方程分别计算所得大肠杆菌Ｖ５１７株８个不同大小质粒的分子量以及在２７次实验中所得ＲＭ值的相似性，可以提出质粒分子量计算的较适方程为：ｌｏｇＭＷ＝Ａ＋Ｂ（ＲＭ），优于传统所用的方程：ｌｏｇＭＷ＝Ａ＋Ｂ（ｌｏｇＲＭ）．

With E.coli V517 harboured plasmids of different sizes as a reference strian,the suitable linear regression formulas used for molecular weight estimation of bacterial plasmids are reported.From data of plasmid detecion in E.coli V517 to estimate MW of plasmid three linear regression formulas were compared.They were logMW=A+B(D),logMW=A+B(RM),and logMW=A+B(logRM).In which MW represented molecular weight of plasmid, D represented migration distrance,and RM represented relative mobility of plasmid DNA bands. According to the correlation coefficient(r) of linear regression,the molecular weight of plasmids in E.coli V517 estimated by LR formulas described above,and the similar RM values obtained in 27 experiments,it can be proposed that the formula:logMW=A+B(RM) is the suitable formula for size estimation of bacterial plasmids.It is better than the traditional one:logMW=A+B(logRM).