THE APPLICATION OF CELL-FREE FETAL DNA (cff-DNA) AND SIBLINGS DNA METHODS IN THE PROCESS OF PATERNITY TEST THROUGH CODIS STR LOCI (CSF1PO, THO1, TPOX, AND vWA)

Background: The non-invasive cff-DNA and siblings DNA methods are the latest breakthroughs in the forensic identification process. The use of cff-DNA and siblings DNA as non-invasive techniques in the forensic identification process has, hitherto, not been widely proven. Methods and Materials: This was an analytic observational study. The sample of this study consisted of peripheral blood of women in the second trimester of pregnancy and their two biological children. The kinship analysis was carried out through siblings' DNA and cff-DNA from the mothers through CODIS STR loci (CSF1PO, THO1, TPOX, and vWA). Results: The means of allele sharing between full siblings in loci CSF1PO, THO1, TPOX, and vWA were 0 (13.75%), 1 (44.75%), and 2 (41.50%). The allele sharing found in the study is in line with the one in previous research conducted by Wenk (1998) and the theory proposed by O'Connor (2011), indicating that one allele sharing dominates, contrasting with the finding of previous research conducted by Sosiawan (2020) revealing that 2-allele sharing was more superior. The variation is caused by the ethnicity having a different genetic contribution among the population. The variation can be attributed to historical and demographical processes leading to genetic drift. Conclusion: The mean of SI in 1 allele sharing in CODIS STR loci (CSF1PO, THO1, TPOX, and vWA) has the highest value of 44.5%. The use of cff-DNA of pregnant women as one of the non-invasive techniques can serve as an alternative material in a paternity test.

Genomic Signature of Sexual Reproduction in the Bdelloid Rotifer Macrotrachella quadricornifera

Bdelloid rotifers, common freshwater invertebrates of ancient origin and worldwide distribution have long been thought to be entirely asexual, being the principal exception to the view that in eukaryotes the loss of sex leads to early extinction. That bdelloids are facultatively sexual is shown by a study of allele sharing within a group of closely related bdelloids of the species Macrotrachella quadricornifera, supporting the view that sexual reproduction is essential for long-term success in all eukaryotes.

Rank-invariant estimation of inbreeding coefficients

The two alleles an individual carries at a locus are identical by descent (ibd) if they have descended from a single ancestral allele in a reference population, and the probability of such identity is the inbreeding coefficient of the individual. Inbreeding coefficients can be predicted from pedigrees with founders constituting the reference population, but estimation from genetic data is not possible without data from the reference population. Most inbreeding estimators that make explicit use of sample allele frequencies as estimates of allele probabilities in the reference population are confounded by average kinships with other individuals. This means that the ranking of those estimates depends on the scope of the study sample and we show the variation in rankings for common estimators applied to different subdivisions of 1000 Genomes data. Allele-sharing estimators of within-population inbreeding relative to average kinship in a study sample, however, do have invariant rankings across all studies including those individuals. They are unbiased with a large number of SNPs. We discuss how allele sharing estimates are the relevant quantities for a range of empirical applications.

Comparing genomic-based estimates of relatedness for use in pedigree-based conservation management

Researchers have long debated which genomic estimator of relatedness best captures the degree of relationship between two individuals. In the genomics era, this debate continues, with relatedness estimates being sensitive to the method used to generate genomic markers (e.g., reduced-representation sequencing, whole genome resequencing), marker quality, and levels of diversity in sampled individuals. Here, we compare six commonly used relatedness estimators (kinship genetic distance (KGD), Wang Maximum Likelihood (TrioML), Queller and Goodnight (Rxy), KING-robust, RAB, allele-sharing coancestry) across five species bred in captivity - including three birds and two mammals with varying degrees of reliable pedigree data, using reduced-representation and whole genome resequencing data. Relatedness estimates varied widely across estimators, sequencing method, and species, yet the most consistent results with known pedigree data were found using KING-robust and to a lesser extent KGD. The allele-sharing estimator was sensitive to missing data and inbreeding, attributes that make this estimator ill-suited for use in captive breeding programs. Our combined results indicate there is not a single genomic based estimator that is ideal across different species and data types. To enable researchers to evaluate the most appropriate relatedness estimator for each new data set, we provide a structured workflow that is broadly applicable to conservation breeding programs, particularly where genomic estimates of relatedness can complement and complete poorly pedigreed populations. Given a growing interest in wild pedigrees, our results and workflow are also applicable to in situ wildlife management.

Genomic history and forensic characteristics of Sherpa highlanders on the Tibetan Plateau inferred from high-resolution genome-wide InDels and SNPs

Sherpa people, one of the high-altitude hypoxic adaptive populations, mainly reside in Nepal and the southern Tibet Autonomous Region. The genetic origin and detailed evolutionary profiles of Sherpas remain to be further explored and comprehensively characterized. Here we analyzed the newly-generated InDel genotype data from 628 Dingjie Sherpa people by merging with 4222 worldwide InDel profiles and collected genome-wide SNP data (approximately 600K SNPs) from 3324 individuals in 382 modern and ancient populations to explore and reconstruct the fine-scale genetic structure of Sherpas and their relationships with nearby modern and ancient East Asians based on the shared alleles and haplotypes. The forensic parameters of 57 autosomal InDels (A-InDels) included in our used new-generation InDel amplification system showed that this updated InDel panel is informative and polymorphic in Sherpas, suggesting that it can be used as the supplementary tool for forensic personal identification and parentage testing in the highland East Asians. Descriptive findings from the PCA, ADMIXTURE and TreeMix-based phylogeny suggested that Sherpas showed excess allele sharing with neighboring Tibeto-Burman Tibetans. Furthermore, patterns of allele sharing in f-statistics demonstrated that Sherpa people had a different evolutionary history compared with their neighbors from Nepal (Newar and Gurung) but showed genetic similarity with 2700-year-old Chokhopani and modern Tibet Tibetans. QpAdm/qpGraph-based admixture sources and models further showed that Sherpa, core Tibetans and Chokhopani formed one clade which could be fitted as having the main ancestry from late Neolithic Qijia millet farmers and other deep ancestries from early Asians. Chromosome painting profiles and shared IBD fragments inferred from FineStructure and ChromoPainter not only confirmed the abovementioned genomic affinity patterns but also revealed the fine-scale microstructures among Sino-Tibetan speakers. Finally, natural-selection signals revealed via iHS, nSL, and iHH12 showed signatures associated with disease susceptibility in Sherpa people. Generally, we provided the comprehensive landscape of admixture and evolutionary history of Sherpa people based on the shared alleles and haplotypes from the low-density forensic markers and high-density genome-wide SNP data. The more detailed genetic landscape of Sherpa people should be further confirmed and characterized via ancient genomes or single-molecule real-time sequencing technology.

Sibling Indices as Comparisons in Personal Identification Process through Short Tandem Repeats [STR] Loci CSF1PO, THOI, TPOX, vWA of Maduranese Ethnic in Surabaya

Sibling indices can be used as a comparison through alleles Short Tandem Repeats [STR] loci. This is an observational study among Maduranese with 4 STR loci (CSF1PO, THOI, TPOX, vWA) obtained from their blood samples. The percentage of alleles shared: 82.5% [33 times] with 2 allele sharing, 12.5% [5 times] with 1 allele sharing, and 5 % [2 times] with 0 sharing alleles. Sibling indices (SI) calculation results: 65% of sibling indices pairs have SI greater than 100 and 15% of them were between 10-100 (strong and very strong). Sibling indices interpretation is supported; therefore, the claimed sibling indices relationships were indeed true among Maduranese ethnic group in Surabaya.

Whole genome phylogenies reflect the distributions of recombination rates for many bacterial species

Although recombination is accepted to be common in bacteria, for many species robust phylogenies with well-resolved branches can be reconstructed from whole genome alignments of strains, and these are generally interpreted to reflect clonal relationships. Using new methods based on the statistics of single-nucleotide polymorphism (SNP) splits, we show that this interpretation is incorrect. For many species, each locus has recombined many times along its line of descent, and instead of many loci supporting a common phylogeny, the phylogeny changes many thousands of times along the genome alignment. Analysis of the patterns of allele sharing among strains shows that bacterial populations cannot be approximated as either clonal or freely recombining, but are structured such that recombination rates between lineages vary over several orders of magnitude, with a unique pattern of rates for each lineage. Thus, rather than reflecting clonal ancestry, whole genome phylogenies reflect distributions of recombination rates.

Signatures of Introgression across the Allele Frequency Spectrum

The detection of introgression from genomic data is transforming our view of species and the origins of adaptive variation. Among the most widely used approaches to detect introgression is the so-called ABBA–BABA test or D-statistic, which identifies excess allele sharing between nonsister taxa. Part of the appeal of D is its simplicity, but this also limits its informativeness, particularly about the timing and direction of introgression. Here we present a simple extension, D frequency spectrum or DFS, in which D is partitioned according to the frequencies of derived alleles. We use simulations over a large parameter space to show how DFS carries information about various factors. In particular, recent introgression reliably leads to a peak in DFS among low-frequency derived alleles, whereas violation of model assumptions can lead to a lack of signal at low frequencies. We also reanalyze published empirical data from six different animal and plant taxa, and interpret the results in the light of our simulations, showing how DFS provides novel insights. We currently see DFS as a descriptive tool that will augment both simple and sophisticated tests for introgression, but in the future it may be usefully incorporated into probabilistic inference frameworks.

Reconstructing the history of founder events using genome-wide patterns of allele sharing across individuals

Founder events play a critical role in shaping genetic diversity, impacting the fitness of a species and disease risk in humans. Yet our understanding of the prevalence and distribution of founder events in humans and other species remains incomplete, as most existing methods for characterizing founder events require large sample sizes or phased genomes. To learn about the frequency and evolutionary history of founder events, we introduce ASCEND (Allele Sharing Correlation for the Estimation of Non-equilibrium Demography), a flexible two-locus method to infer the age and strength of founder events. This method uses the correlation in allele sharing across the genome between pairs of individuals to recover signatures of past bottlenecks. By performing coalescent simulations, we show that ASCEND can reliably estimate the parameters of founder events under a range of demographic scenarios, with genotype or sequence data. We apply ASCEND to ~5,000 worldwide human samples (~3,500 present-day and ~1,500 ancient individuals), and ~1,000 domesticated dog samples. In both species, we find pervasive evidence of founder events in the recent past. In humans, over half of the populations surveyed in our study had evidence for a founder events in the past 10,000 years, associated with geographic isolation, modes of sustenance, and historical invasions and epidemics. We document that island populations have historically maintained lower population sizes than continental groups, ancient hunter-gatherers had stronger founder events than Neolithic Farmers or Steppe Pastoralists, and periods of epidemics such as smallpox were accompanied by major population crashes. Many present-day groups--including Central & South Americans, Oceanians and South Asians--have experienced founder events stronger than estimated in Ashkenazi Jews who have high rates of recessive diseases due to their history of founder events. In dogs, we uncovered extreme founder events in most groups, more than ten times stronger than the median strength of founder events in humans. These founder events occurred during the last 25 generations and are likely related to the establishment of dog breeds during Victorian times. Our results highlight a widespread history of founder events in humans and dogs, and provide insights about the demographic and cultural processes underlying these events.

Sexual Reproduction in Bdelloid Rotifers

ABSTRACTNearly all eukaryotes reproduce sexually, either constitutively or facultatively, and nearly all that are thought to be asexual arose recently from sexuals, suggesting that loss of sex leads to early extinction. In apparent exception, there are several groups of ancient origin that have been thought to be entirely asexual. Of these, the most extensively studied are the rotifers of Class Bdelloidea. Yet the evidence for their asexuality is entirely negative -- the failure to establish the existence of males or hermaphrodites. Nevertheless, there is a growing body of evidence that bdelloids do reproduce sexually, albeit rarely, retaining meiosis-associated genes and, in a limited study of allele sharing in the bdelloid Macrotrachela quadricornifera, displaying a pattern of genetic exchange indicating recent sexual reproduction. Here we present a much larger study of allele sharing in the same system, clearly showing the occurrence of sexual reproduction, thereby removing the principal challenge to the generalization that sexual reproduction is essential for long-term evolutionary success in eukaryotes. We also discuss the relation between bdelloid life history and population structure and a possible benefit of outcrossing in restoring beneficial genome-wide epistatic interactions disrupted by loss of heterozygosity.STATEMENT OF SIGNIFICANCEMany hypotheses have been advanced to explain why, despite its substantial costs, sexual reproduction is nearly universal in eukaryotes and why the loss of sex generally leads to early extinction--a major problem in current evolution theory. Posing a challenge to all such hypotheses are a few groups of ancient origin that have been thought to be entirely asexual. Of these, the most extensively studied are the rotifers of Class Bdelloidea. Here we show that a bdelloid species is facultatively sexual, removing what had been a long-standing challenge to hypotheses for the benefit of sex. We also suggest that genome-wide beneficial epistasis may contribute to the advantage of sex over asex in diploids and to the predominance of diploidy over haploidy in eukaryotes.