STR分型技术在一宗寻亲案中嵌合体法医学分析中的应用

Forensic Analysis into a Chimera by Multiple STR Loci about a Searching-son Case

嵌合体是包含有两个或以上不同细胞系的生物个体。本文运用STR分型技术对一宗寻亲案中的男性嵌合体的类型、形成机制及其不同组织样本中的嵌合现象进行探究。结果表明,该嵌合体属于四配子异源嵌合体,为卵母细胞孤雌分裂产生的两个相同配子双受精后发生融合所形成。由于两个细胞系分布情况不同,嵌合体的不同样本检出了不同的STR分型,最后通过精液检出的男性分型成功比中了其失踪多年的儿子。

Chimerism or mosaicism implicates the presence of two or more genetically-distinct cell lines in the same one organism.A father,involved with a case about searching for his son,was found to be a chimera.Therefore,his multiple STR loci were detected to explore the resulted genotypes,and followed to ascertain the causal mechanism plus patterned chimerism with different tissues from the chimera.The results showed that the chimeric father is a tetragametic chimera who was presumably formed during the course of his maternal impregnation of him where the occurrence of parthenogenetic division of his mother’s duplicated oocyte happened to fertilization with two spermatozoa and supervened of inosculation of the two feritilized ova.The chimera displayed discrepant STR genotypes with the samples from his different tissues due to diverse distribution of the two inosculated cell lines.The sought son has finally been determined through the genotypes detected from the chimera’s semen,accodingly bringing the searching-son case into end.