Parentage testing anomalies in Hong Kong SAR of China

Objective To determine if there are any differences in the number of exclusions from paternity of men using an anonymous parentage testing service compared with that of men using an in-person parentage testing service provided by the same company in Hong Kong SAR of China. Methods Comparable numbers of consecutive anonymous and in-person parentage tests conducted by the same company were analyzed. Results Men using an anonymous parentage testing service were excluded from paternity at a significantly greater rate (P<0.001), compared with men using an in-person parentage test service. Conclusions The results obtained from anonymous parentage testing indicate that the number of families containing children of doubtful parentage is much greater than expected previously. As illegitimate children are known to suffer greater degrees of abuse and neglect, this finding poses serious social questions regarding the welfare of families, which the relevant authorities should acknowledge and address.

Characterization of 12 polymorphic microsatellite markers in the Chinese tree shrew(Tupaia belangeri chinensis)

The Chinese tree shrew(Tupaia belangeri chinensis)is a small experimental animal with a close affinity to primates.This species has long been proposed to be an alternative experimental animal to primates in biomedical research.Despite decades of study,there is no pure breed for this animal,and the overall genetic diversity of wild tree shrews remains largely unknown.In order to obtain a set of genetic markers for evaluating the genetic diversity of tree shrew wild populations and tracing the lineages in inbreeding populations,we developed 12 polymorphic microsatellite markers from the genomic DNA of the tree shrew.An analysis of a wild population of 117 individuals collected from the suburb of Kunming,China,showed that these loci exhibited a highly expected heterozygosity(0.616).These 12 microsatellites were sufficient for individual identification and parentage analysis.The microsatellite markers developed in this study will be of use in evaluating genetic diversity and lineage tracing for the tree shrew.

An inter-laboratory study of DNA-based identity,parentage and species testing in animal forensic genetics

The probative value of animal forensic genetic evidence relies on laboratory accuracy and reliability.Inter-laboratory comparisons allow laboratories to evaluate their performance on specific tests and analyses and to continue to monitor their output.The International Society for Animal Genetics(ISAG)administered animal forensic comparison tests(AFCTs)in 2016 and 2018 to assess the limitations and capabilities of laboratories offering forensic identification,parentage and species determination services.The AFCTs revealed that analyses of low DNA template concentrations(≤300 pg/μL)constitute a significant challenge that has prevented many laboratories from reporting correct identification and parentage results.Moreover,a lack of familiarity with species testing protocols,interpretation guidelines and representative databases prevented over a quarter of the participating laboratories from submitting correct species determination results.Several laboratories showed improvement in their genotyping accuracy over time.However,the use of forensically validated standards,such as a standard forensic short tandem repeat(STR)kit,preferably with an allelic ladder,and stricter guidelines for STR typing,may have prevented some common issues from occurring,such as genotyping inaccuracies,missing data,elevated stutter products and loading errors.The AFCTs underscore the importance of conducting routine forensic comparison tests to allow laboratories to compare results from each other.Laboratories should keep improving their scientific and technical capabilities and continuously evaluate their personnel’s proficiency in critical techniques such as low copy number(LCN)analysis and species testing.Although this is the first time that the ISAG has conducted comparison tests for forensic testing,findings from these AFCTs may serve as the foundation for continuous improvements of the overall quality of animal forensic genetic testing.