SSR individual identification system construction and population genetics analysis for Chamaecyparis formosensis.

Chamaecyparis formosensis is an endemic species of Taiwan, threatened from intensive use and illegal felling. An individual identification system for C. formosensis is required to provide scientific evidence for court use and deter illegal felling. In this study, 36 polymorphic simple sequence repeat markers were developed. By applying up to 28 non-linked of the developed markers, it is calculated that the cumulative random probability of identity (CPI) is as low as 1.652 × 10-12, and the identifiable population size is up to 60 million, which is greater than the known C. formosensis population size in Taiwan. Biogeographical analysis data show that C. formosensis from four geographic areas belong to the same genetic population, which can be further divided into three clusters: SY (Eastern Taiwan), HV and GW (Northwestern Taiwan), and MM (Southwestern Taiwan). The developed system was applied to assess the provenance of samples with 88.44% accuracy rate and therefore can serve as a prescreening tool to reduce the range required for comparison. The system developed in this study is a potential crime-fighting tool against illegal felling.

Development and technical application of SSR-based individual identification system for Chamaecyparis taiwanensis against illegal logging convictions.

Chamaecyparis taiwanensis is an endemic plant suffering illegal logging in Taiwan for its high economic value. Lack of direct evidence to correlate stump and timber remains a hurdle for law enforcement. In this report, 23 polymorphic Genomic Simple Sequence Repeat (gSSR) and 12 Expressed Sequence Tag (EST)-SSR markers were developed and their transferability was assessed. The individual identification system built from selected non-linkage 30 SSR markers has a combined probability of identity as 5.596 × 10-12 equivalents to identifying an individual in a population of up to 18 million C. taiwanensis with 99.99% confidence level. We also applied the system in an actual criminal case by selecting 19 of these markers to correlate illegally felled timbers and victim trees. Our data demonstrate that molecular signals from three timbers hit with three victim trees with confidence level more than 99.99%. This is the first example of successfully applying SSR in C. taiwanensis as a court evidence for law enforcement. The identification system adapted advanced molecular technology and exhibits its great potential for natural resource management on C. taiwanensis.

Isolation and characterization of SSR and EST-SSR loci in Chamaecyparis formosensis (Cupressaceae).

PREMISE OF THE STUDY: Simple sequence repeat (SSR) and expressed sequence tag (EST)-SSR markers were developed as tools for marker-assisted selection of Chamaecyparis formosensis and for the molecular differentiation of cypress species. METHODS AND RESULTS: Based on the SSR-enriched genomic libraries and transcriptome data of C. formosensis, 300 primer pairs were selected for initial confirmation, of which 19 polymorphic SSR and eight polymorphic EST-SSR loci were chosen after testing in 92 individuals. The number of alleles observed for these 27 loci ranged from one to 17. The levels of observed and expected heterozygosity ranged from 0.000 to 1.000 and from 0.000 to 0.903, respectively. Most markers also amplified in C. obtusa var. formosana. CONCLUSIONS: The developed SSR and EST-SSR sequences are the first reported markers specific to C. formosensis. These markers will be useful for individual identification of C. formosensis and to distinguish cypress species such as C. obtusa var. formosana.

The strategies to DVI challenges in Typhoon Morakot.

Small village populations in which there is a high amount of kinship can cause complications in cases of disaster victim identification. This problem was highlighted by the loss of life after Typhoon Morakot struck Taiwan where over 500 people from small isolated communities lost their lives. Most of the victims were buried by landslides in the remote mountainous areas of southern Taiwan. Only 146 pieces of human remains were recovered after searching for 4 months. Most of the human remains were received for examination as severely damaged fragments prevented possible identification by morphological features. DNA testing using the traditional duo parent/child or sibling screening by STR data opens the possibility of including not only the actual victim but also false positives. Variable likelihood ratios were obtained when comparing DNA types from human remains to those from potential relatives; however, with the DNA typing of numerous members of the same living family, multiple matches to potential families were avoided. Of the 146 samples obtained and collapsed to 130 victims, they were linked to 124 individuals resulting in their identification when compared to a pool of 588 potential relatives. Six of the human remains could not be linked to any living relative and remain unknown.

Population data on X chromosome short tandem repeat loci HPRTB and AR in Taiwan.

This report contains the results of population studies on the X chromosome STR HPRTB and AR carried out in Taiwan. The numbers of unrelated individuals were 428: female 143 and male 285 for HPRTB locus, and 416: female 142 and male 274 for AR locus.