PowerPlex^TM16体系OL等位基因序列分析及命名探讨

目的观察中国汉族人群PowerPlexTM16体系STR基因座分型标准物外等位基因(OL等位基因)的序列组成,探讨其类型及命名。方法应用PowerPlexTM16体系和ABI377或3100遗传分析仪,对10071名中国汉族无关个体的血样DNA进行15个STR基因座的分型,筛选出OL等位基因样本;对该样本进行单基因座扩增、聚丙稀酰胺凝胶电泳、银染显色,获取等位基因条带并再次扩增和测序。结果在11个基因座检见OL等位基因,共32个,频率0.05‰￣4.02‰,各基因座OL等位基因数目1￣9个不等。按其组成分为四类:(1)重复单位完整重复,但重复次数在ladder范围外;(2)不完整重复;(3)侧翼序列个别碱基的插入或缺失;(4)较大片断的缺失。结论OL等位基因类型不一,既有重复次数的变化,也有侧翼序列或核心序列的变化,现有命名原则尚不能反映其组成类型。     

Rapid and high-throughput forensic short tandem repeat typing using a 96-lane microfabricated capillary array electrophoresis microdevice

A 96-channel microfabricated capillary array electrophoresis (muCAE) device was evaluated for forensic short tandem repeat (STR) typing using PowerPlex 16 and AmpFlSTR Profiler Plus multiplex PCR systems. The high-throughput muCAE system produced high-speed <30-min parallel sample separations with single-base resolution. Forty-eight previously analyzed single-source samples were accurately typed, as confirmed on an ABI Prism 310 and/or the Hitachi FMBIO II. Minor alleles in 3:1 mixture samples containing female and male DNA were reliably typed as well. The instrument produced full profiles from sample DNA down to 0.17 ng, a threshold similar to that found for the ABI 310. Seventeen nonprobative samples from various evidentiary biological stains were also correctly typed. The successful application of the muCAE device to actual forensic STR typing samples is a significant step toward the development of a completely integrated STR analysis microdevice.     

Assessing the potential of bacterial DNA profiling for forensic soil comparisons

A pilot study was undertaken to evaluate DNA profiling of the bacterial community in soil as an alternative to geological methods for forensic soil comparisons. Soil samples from three different ecosystems were compared, and the variation within and between ecologically different sites was determined by using terminal restriction fragment (TRF) analysis of 16S ribosomal DNA. Comparison of TRF profiles revealed that samples from within a specific ecosystem (e.g., a field) showed a significantly higher similarity to each other than to those from another ecosystem (e.g., a forest). In addition, some profile features were unique to specific ecosystems. These features may allow the determination of characteristic profiles that will facilitate identification of ecologically different sites, so that a given sample collected from a suspect could be identified as originating from, for example, a field, rather than a forest. The implications of these preliminary findings for forensic investigations are discussed.