Unveiling genetic diversity and forensic utility of SureID® human DNA identification kits: a comprehensive analysis of 44 autosomal STR loci in English and Irish populations.

Background: Human identification and kinship testing in forensic science rely on Short Tandem Repeat (STR) multiplex kits, typically containing loci recommended by standard sets. However, complementary kits with additional STR loci can be valuable in complex cases. Allele frequency databases specific to the population are essential for accurate forensic analysis.Aim: This study aimed to generate allele frequencies and population genetic data for 44 autosomal STR loci from SureID® PanGlobal and 27comp kits in English and Irish populations for forensic casework, human identification, and kinship testing.Subjects and methods: Buccal swab samples from 645 White Caucasians (365 English, 280 Irish) were collected. DNA was extracted and amplified using the mentioned kits. Quality control, statistical analysis, and genetic distance calculations were performed.Results: Both kits demonstrated robustness with no significant deviations from Hardy-Weinberg Equilibrium (HWE). Variant alleles and minor discordances between kits were observed. Syntenic STR pairs were identified but showed no significant linkage. A close genetic relationship was found between English and Irish populations, allowing for combined databases.Conclusions: The SureID® PanGlobal and 27comp kits showed high discriminatory power and reliability in the English and Irish populations. Care is needed when handling variant alleles, discordances, and syntenic loci. Combining data from both populations is feasible for a comprehensive database. Further studies are required to explore their effectiveness in diverse populations.

Validation of reduced volume VeriFiler™ Express PCR Amplification Kit for buccal swab samples extracted using Prep-n-Go™ Buffer.

The efficiency of reduced volume PCR amplification was studied using the VeriFiler™ Express PCR Amplification Kit. Full (25 µL) and reduced (5 µL) volumes were tested in parallel to identify any differences in template DNA sensitivity and other electropherogram parameters. Both volumes produced full DNA profiles down to 0.08 ng/µL DNA concentration at 26 PCR cycles; however, reduced volume produced higher peak heights due to increased signal intensities. Significant difference (p-value ≤ 0.05) in heterozygote peak height ratios was observed between both volumes, where the reduced volume threshold was lowered to 0.6 to accommodate all data points. However, no significant difference (p-value > 0.05) was identified in the stutter ratios between both volumes. The analytical threshold for reduced volume was also determined to be 150 RFU with the presence of template DNA in PCR amplification. When the optimized reduced volume parameters were tested on DNA extracted from buccal swab samples using Prep-n-Go™ Buffer, good quality DNA profiles were produced. Overall, the reduced volume not only showed better results compared to the full volume, but also enable more samples to be processed with a PCR amplification kit, thus reduced the cost.

Population genetics data for 22 autosomal STR loci in European, South Asian and African populations using SureID® 23comp Human DNA Identification Kit.

Allele frequency data for 22 short tandem repeat loci; D18S1364, D1S1656, D13S325, D5S2800, D9S1122, D4S2366, D3S1744, D12S391, D11S2368, D21S2055, D20S482, D8S1132, D7S3048, D2S441, D19S253, D10S1248, D17S1301, D22-GATA198B05, D16S539, D6S474, D14S1434 and D15S659 from the SureID® 23comp Human DNA Identification Kit have been determined for unrelated individuals in European, South Asian and African populations. Deviations from Hardy-Weinberg equilibrium were observed in loci D1S1656 and D19S253 in European; D18S1364, D6S474 and D14S1434 in South Asian; and D9S1122 and D8S1132 in African populations (p-value <0.05). However, after Bonferroni correction no significant deviations were observed (p-value <0.002). The most discriminating loci were D1S1656 and D12S391 for European (PD=0.977), D21S2055 for South Asian (PD=0.980), and D21S2055 and D7S3048 for African (PD=0.972) populations. The match probabilities were 1 in 6.7×1025 for European, 1 in 1.4×1026 for South Asian and 1 in 1.6×1026 for African populations. These findings established the high discriminatory capacity and robustness of the tested STR loci for forensic identification and kinship testing.

Recognition specificity and RAR1/SGT1 dependence in barley Mla disease resistance genes to the powdery mildew fungus.

A large number of resistance specificities to the powdery mildew fungus Blumeria graminis f. sp. hordei map to the barley Mla locus. This complex locus harbors multiple members of three distantly related gene families that encode proteins that contain an N-terminal coiled-coil (CC) structure, a central nucleotide binding (NB) site, a Leu-rich repeat (LRR) region, and a C-terminal non-LRR (CT) region. We identified Mla12, which encodes a CC-NB-LRR-CT protein that shares 89 and 92% identical residues with the known proteins MLA1 and MLA6. Slow Mla12-triggered resistance was altered dramatically to a rapid response by overexpression of Mla12. A series of reciprocal domains swaps between MLA1 and MLA6 identified in each protein recognition domain for cognate powdery mildew fungus avirulence genes (AvrMla1 and AvrMla6). These domains were within different but overlapping LRR regions and the CT part. Unexpectedly, MLA chimeras that confer AvrMla6 recognition exhibited markedly different dependence on Rar1, a gene required for the function of some but not all Mla resistance specificities. Furthermore, uncoupling of MLA6-specific function from RAR1 also uncoupled the response from SGT1, a protein known to associate physically with RAR1. Our findings suggest that differences in the degree of RAR1 dependence of different MLA immunity responses are determined by intrinsic properties of MLA variants and place RAR1/SGT1 activity downstream of and/or coincident with the action of resistance protein-containing recognition complexes.