RESUMEN
Objective To investigate the genetic polymorphism of DXS8378 STR locus of chromosome X in Chinese Lisu,Pumi and De'ang populations in Yunnan and construct relative standard allelic ladders.Methods After being amplified by PCR,different STR allelic fragments were isolated from the PAG electrophoresis.The STR allelic fragments were extracted by kit and reamplified by PCR to obtain purified allelic fragments.Next,the purified allelic fragments were subcloned individually into the PUC plasmid vectors,and the size and structure of the inserts were confirmed by the analysis of their DNA sequences.Then we transfected it into competent E.coli DH5?TM cells,and finally,the recombinant plasmids DNA with the inserts were used as template for reamplification to generate the standard ladders.Results The standard allelic ladder for DXS8378 locus was obtained,with which the genetic polymorphisms of DXS8378 locus in three Chinese populations in Yunnan were studied.Conclusion The standard ladder made by this method is excellent,and DXS8378 is powerful for forensic practice in Chinese population.