Genetic polymorphisms of 12 X-chromosomal STR loci in Taiwanese individuals and likelihood ratio calculations applied to case studies of blood relationships.

Allele frequencies for the 12 short tandem repeat loci of the Investigator Argus X-12 kit were obtained from 514 unrelated Taiwanese individuals (327 males and 187 females). Hardy-Weinberg equilibrium tests with samples demonstrated no significant deviation from expected values for all 12 loci (p > 0.05). The linkage disequilibrium for the 12 loci in the female samples was identical to what was observed in other Han Chinese populations, with only the DXS10103 and DXS10101 loci showing significant linkage disequilibrium after corrected by Bonferroni's correction for multiple testing (p < 0.05/66). No significant differences were observed by population pairwise genetic distance analysis between Taiwanese and other Han Chinese populations. When compared with other Asian, European, and African populations, however, significant differences were observed at more than one locus. The combined mean exclusion chance was 0.99999 in duo cases and 0.99999999 in trio cases. This study used mathematical logic inferred likelihood ratio calculation formulas for full-sister, half-sister from the same father, and paternal grandmother-granddaughter relationships. The results for these three real familial cases suggest that these 12 short tandem repeat loci may appropriate for forensic relationship testing.

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.

Y-chromosomal STRs haplotypes in the Taiwanese Paiwan population.

The distribution of Y-chromosomal short tandem repeat (Y-STR) haplotypes was determined in a population of Taiwanese Paiwan aboriginals. Using 17 Y-STR markers, a total of 135 haplotypes were observed, 102 of which were unique. The overall haplotype diversity for the 17 Y-STR loci tested was 0.9922 and the discrimination capacity was 0.6490. In addition, three novel intermediate alleles at the DYS448 locus were also found.

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.

Genetic polymorphisms of 17 Y-chromosomal short tandem repeat loci in Atayal population of Taiwan.

AIM: To define the Y-chromosomal genetic structure in a sample of Atayal men from Taiwan. METHODS: Buccal swab samples were collected from 170 unrelated healthy male volunteers from Taiwanese aboriginal Atayal population. Genomic DNA was extracted and 17 Y chromosome-specific short tandem repeat loci (DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a/b, DYS393, DYS391, DYS439, DYS635, DYS392, Y GATA H4, DYS437, DYS438, and DYS448) were analyzed using the AmpFlSTR Yfiler Polymerase Chain Reaction Amplification Kit. RESULTS: A total of 99 different haplotypes were identified, 69 (69.7%) of which were unique. Total haplotype diversity was 0.9887. The most common haplotype was shared by 9 individuals in the study sample. Gene diversities ranged from 0.0574 for DYS438 to 0.6749 for DYS456. CONCLUSION: Our results will help provide the molecular genetic evidence for human settlement of the Pacific.

Simultaneous detection and differentiation of Newcastle disease and avian influenza viruses using oligonucleotide microarrays.

Newcastle disease (ND) and avian influenza (AI) are two of the most important zoonotic viral diseases of birds throughout the world. These two viruses often have a great impact upon the poultry industry. Both viruses are associated with transmission from wild to domestic birds, and often display similar signs that need to be differentiated. A rapid surveillance among wild and domestic birds is important for early disease detection and intervention, and is the basis for what measures should be taken. The surveillance, thus, should be able to differentiate the diseases and provide a detailed analysis of the virus strains. Here, we described a fast, simultaneous and inexpensive approach to the detection of Newcastle disease virus (NDV) and avian influenza virus (AIV) using oligonucleotide microarrays. The NDV pathotypes and the AIV haemagglutinin subtypes H5 and H7 were determined at the same time. Different probes on a microarray targeting the same gene were implemented in order to encompass the diversified virus strains or provide multiple confirmations of the genotype. This ensures good sensitivity and specificity among divergent viruses. Twenty-four virus isolates and twenty-four various combinations of the viruses were tested in this study. All viruses were successfully detected and typed. The hybridization results on microarrays were clearly identified with the naked eyes, with no further imaging equipment needed. The results demonstrate that the detection and typing of multiple viruses can be performed simultaneously and easily using oligonucleotide microarrays. The proposed method may provide potential for rapid surveillance and differential diagnosis of these two important zoonoses in both wild and domestic birds.

Sex identification of owls (family Strigidae) using oligonucleotide microarrays.

Molecular sexing of the diversified avian family Strigidae is difficult. Sex identification using the intron length difference between W and Z chromosomal CHD1 genes, as visualized by agarose gel electrophoreses, often produces ambiguous results. Here we describe a simple method for sexing a variety of Strigidae species using oligonucleotide microarrays, on which several sex-specific probes operated complementarily or in concert. The sex of 8 owl species was identified clearly on the microarrays through sequence recognition. This sequence-directed method can be easily applied to a wider range of Strigidae species.

CPI distribution and cutoff values for duo kinship testing.

DNA-based tests commonly use 13 STR (short tandem repeat) loci in human identification and paternity testing--the Combined DNA Index System or CODIS. Its average degree of accuracy of paternity identification is greater than 0.9999 under the circumstance of a mother, a child and a putative father. However, the possibility of false inclusions increases under circumstances such as [1] only two members of a family group are available--a duo case during determination of paternity or [2] identification of human remains while only one living relative is present. In Taiwan, the National Unidentified Human Remains Database uses the CODIS 13 STR for the identification of family members. Two or more reference samples in the DNA database have been found to share one allele at all loci tested. Then the Combined Paternity Index (CPI) is used to determine and provide an estimate of kinship in such cases. Combining 499,500 sets of DNA data for the 13 STR CODIS loci, totally 431 (0.086%) cases are false inclusions where all 13 loci shared at least one allele. Simulated partial DNA profiles (not all 13 loci yielded results) were created to mimic the mutation and degradation process. All 431 real duo cases were analyzed to evaluate sensitivity and specificity. This report provided four kinship-matching situations with CPI cutoff values when the number of allele-sharing loci exceeded 11. CPI values greater or lesser than the suggested cutoff point will provide a greater degree of confidence in determining whether two samples are derived from first-degree relatives.

Sexing a wider range of avian species based on two CHD1 introns with a unified reaction condition.

Identifying the sex of a bird is important to ensure successful breeding strategies and effective conservation programs. Sex may be identified from the intron size of the CHD1 gene located on the avian sex chromosomes Z and W. However, because of the great nucleotide diversity across different avian species, no given intron is in widespread use without ambiguous results. Complicated modifications of the reaction condition are required to suit different species. Two CHD1 introns were used with a unified reaction condition in this study to simplify the procedure. Consequently, genders of 73 avian species covering 19 families were successfully identified based on this two-intron approach. This means the ability to sex a wider range of avian species using a simplified procedure, greatly assisting in population management at zoos. Zoo Biol 26:425-431, 2007. (c) 2007 Wiley-Liss, Inc.

The Genetic Relatedness in Groups of Joint-Nesting Taiwan Yuhinas: Low Genetic Relatedness with Preferences for Male Kin.

The relative importance of direct and indirect fitness and, thus, the role of kinship in the evolution of social behavior is much debated. Studying the genetic relatedness of interacting individuals is crucial to improving our understanding of these issues. Here, we used a seven-year data set to study the genetic structure of the Taiwan yuhina (Yuhina brunneciceps), a joint-nesting passerine. Ten microsatellite loci were used to investigate the pair-wised relatedness among yuhina breeding group members. We found that the average genetic relatedness between same-sex group members was very low (0.069 for male dyads and 0.016 for female dyads). There was also a low ratio of closely-related kin (r>0.25) in the cooperative breeding groups of yuhinas (21.59% and 9.68% for male and female dyads, respectively). However, the relatedness of male dyads within breeding groups was significantly higher than female dyads. Our results suggest that yuhina cooperation is maintained primarily by direct fitness benefits to individuals; however, kin selection might play a role in partner choice for male yuhinas. Our study also highlights an important, but often neglected, question: Why do animals form non-kin groups, if kin are available? We use biological market theory to propose an explanation for group formation of unrelated Taiwan yuhinas.

Population data on the X chromosome short tandem repeat loci DXS10011, DXS101, DXS6789, DXS7132, DXS8377, and DXS9895 in Taiwan.

X chromosome linked short tandem repeat (STR) are powerful auxiliary systems to genomic STR, they are helpful for differentiating if two women have the same father directly, avoiding some of the ambiguity generated from sibship estimation. This report contains the results of population studies on the X chromosome STR DXS10011, DXS101, DXS6789, DXS7132, DXS8377 and DXS9895 carried out in Taiwan. The common alleles of each locus were sequenced and used in a control ladder to type unknown samples. The numbers of unrelated individuals were 273 (female 92 and male 181) for DXS10011 locus, 448 (female 135 and male 313) for DXS101 locus, 447 (female 135 and male 312) for DXS6789 locus, 414 (female 119 and male 295) for DXS7132 locus, 450 (female 135 and male 315) for DXS8377 locus and 413 (female 120 and male 293) for DXS9895 locus. These STR polymorphisms will be a useful marker for parentage testing especially when disputed blood relative is female.

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.

Asian online Y-STR Haplotype Reference Database.

For several years Y-chromosomal microsatellites (short tandem repeats, STRs) have been well established in forensic practice. In this context, the genetic characteristics of the Y chromosome (i.e. its paternal inheritance and lack of recombination) render STRs particularly powerful. However, genetic differences between male populations appear to be larger for Y-STRs than for autosomal STRs, a fact that is most likely due to the higher sensitivity of Y-chromosomal lineages to genetic drift (Forensic Sci Int 118 (2001) 153). The assessment of probabilities for matches between haplotyped male persons or traces/persons requires the typing of a large number of haplotypes in the appropriate reference populations. The haplotype data of a large number of European as well as South and North American populations have been collected and are continuously published online (Y-STR Haplotype Reference Database--YHRD; http://www.ystr.org). The most recent multicentric effort has led to the establishment of an Asian YHRD (http://www.ystr.org/asia) which has been available since January 2002. All databases are maintained and curated at the Institute of Legal Medicine, Humboldt-University, Berlin and will soon be fused to a global repository including populations from all continents.

Avian oncogenic virus differential diagnosis in chickens using oligonucleotide microarray.

Avian oncogenic viruses include the avian leukosis virus (ALV), reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). Multiple oncogenic viral infections are frequently seen, with even Marek's disease vaccines reported to be contaminated with ALV and REV. The gross lesions caused by avian oncogenic viruses often overlap, making differentiation diagnosis based on histopathology difficult. The objective of this study is to develop a rapid approach to simultaneously differentiate, subgroup and pathotype the avian oncogenic viruses. The oligonucleotide microarray was employed in this study. Particular DNA sequences were recognized using specific hybridization between the DNA target and probe on the microarray, followed with colorimetric development through enzyme reaction. With 10 designed probes, ALV-A, ALV-E, ALV-J, REV, MDV pathogenic and vaccine strains were clearly discriminated on the microarray with the naked eyes. The detection limit was 27 copy numbers, which was 10-100 times lower than multiplex PCR. Of 102 field samples screened using the oligonucleotide microarray, 32 samples were positive for ALV-E, 17 samples were positive for ALV-J, 6 samples were positive for REV, 4 samples were positive for MDV, 7 samples were positive for both ALV-A and ALV-E, 5 samples were positive for ALV-A, ALV-E and ALV-J, one sample was positive for both ALV-J and MDV, and 3 samples were positive for both REV and MDV. The oligonucleotide microarray, an easy-to-use, high-specificity, high-sensitivity and extendable assay, presents a potent technique for rapid differential diagnosis of avian oncogenic viruses and the detection of multiple avian oncogenic viral infections under field conditions.

Allele frequency of CODIS 13 in Indonesian population.

Since the first application of DNA technology in 1985 in forensic cases, and the acceptance of this technology in 1988 at court, the DNA typing is widely used in personal identification, parentage cases and tracing the source of biological samples found in the crime scene. The FBI on 1990 had recommended the forensic labs to used 13 loci of Short Tandem Repeats (STR), known as CODIS 13, as the loci of choice for forensic use. The research on the population DNA database on these loci is extremely important for calculating the Paternity Index as well as Matching Probability for forensic application of DNA technology. As many as 402 unrelated persons, consisted of 322 from western part of Indonesia and 80 from eastern part of Indonesia, were chosen as the respondents of this research, after signing the informed consent. The peripheral blood sample was taken using sterile lancets and dropped onto FTA classic cards. The DNA was extracted by FTA purification solution (3x) and TE(-1) (2x), and amplified by PCR mix, either Cofiler or Profiler Plus (Perkin Elmers), followed by sequencing using ABI Prism type 3100 Avant Genetic Analyzer. The analysis showed that the alleles frequencies of Indonesian is specific, different with the other Asian populations with some specific alleles and microvariant were found.

Increasing the confidence in half-sibship determination based upon 15 STR loci.

A half-sibship relationship is when two siblings share only one parent. It may be necessary to determine if two individuals are half-siblings in cases of immigration, inheritance, genetic counseling or the identification of human remains. In such instances a combined half-sibship index (CHSI) can be calculated. Support for this kinship is also based upon the number of shared-alleles at DNA loci. We report on the combination of the calculation of CHSI with the all-shared-alleles (ASA) to enhance the specificity of any half-sibship test. The 15 STR loci (including CODIS 13) that comprise the Identifiler loci were applied to three populations using 355,620 simulated pairs of half-siblings and 178,815 unrelated pairs. Based upon the data obtained, the sensitivity and specificity can be evaluated to determine the existence of half-sibship. This report highlights the uncertainty problems inherent in this form of indirect kinship testing and recommends a combination evaluation of CHSI and ASA.

Systematic evaluation of sensitivity and specificity of sibship determination by using 15 STR loci.

Paternity disputes and other forms of kinship testing are routinely resolved using short tandem repeat (STR) DNA loci. Sibship determination is encountered in instances where the DNA profiles of two individuals are compared to determine if they are siblings. If either parent is available for testing then the situation is simplified but if neither parent of the two individuals is available for DNA testing, a combined sibling indices (CSI) for the determination of sibship between two people can be determined. Support for kinship is also based upon the sharing of alleles, particularly when both alleles are shared at the same locus, termed two-allele-sharing-loci (TASL). We report on the combination of CSI and TASL to enhance the determination of sibship. The 15 STR loci that comprise the Identifiler loci were applied to three populations using pairs of full siblings or unrelated pairs. Based upon the data obtained, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) can be applied to determining whether two DNA profiles come from full or non-sibling pairs. This report highlights the problems inherent in this form of kinship testing and recommends a combination use of CSI and TASL for sibship determination.