Project description:The Kashmiri population is an ethno-linguistic group that resides in the Kashmir Valley in northern India. A longstanding hypothesis is that this population derives ancestry from Jewish and/or Greek sources. There is historical and archaeological evidence of ancient Greek presence in India and Kashmir. Further, some historical accounts suggest ancient Hebrew ancestry as well. To date, it has not been determined whether signatures of Greek or Jewish admixture can be detected in the Kashmiri population. Using genome-wide genotyping and admixture detection methods, we determined there are no significant or substantial signs of Greek or Jewish admixture in modern-day Kashmiris. The ancestry of Kashmiri Tibetans was also determined, which showed signs of admixture with populations from northern India and west Eurasia. These results contribute to our understanding of the existing population structure in northern India and its surrounding geographical areas.
Project description:Modern genetic data combined with appropriate statistical methods have the potential to contribute substantially to our understanding of human history. We have developed an approach that exploits the genomic structure of admixed populations to date and characterize historical mixture events at fine scales. We used this to produce an atlas of worldwide human admixture history, constructed using genetic data alone and encompassing over 100 events occurring over the past 4,000 years. We identify events whose dates and participants suggest they describe genetic impacts of the Mongol Empire, Arab slave trade, Bantu expansion, first millennium CE migrations in eastern Europe, and European colonialism, as well as unrecorded events, revealing admixture to be an almost universal force shaping human populations. 158 indviduals of Eurasian descent included as part of a global analysis of admixture
Project description:The glaucomas are a group of diseases characterized by optic nerve damage that together represent a leading cause of blindness in the human population and in domestic animals. Here we report a mutation in LTBP2 that causes primary congenital glaucoma (PCG) in domestic cats. We identified a spontaneous form of PCG in cats and established a breeding colony segregating for PCG consistent with fully penetrant, autosomal recessive inheritance of the trait. Elevated intraocular pressure, globe enlargement and elongated ciliary processes were consistently observed in all affected cats by 8 weeks of age. Varying degrees of optic nerve damage resulted by 6 months of age. Although subtle lens zonular instability was a common feature in this cohort, pronounced ectopia lentis was identified in less than 10% of cats examined. Thus, glaucoma in this pedigree is attributed to histologically confirmed arrest in the early post-natal development of the aqueous humor outflow pathways in the anterior segment of the eyes of affected animals. Using a candidate gene approach, significant linage was established on cat chromosome B3 (LOD 18.38, q = 0.00) using tightly linked short tandem repeat (STR) loci to the candidate gene, LTBP2. A 4 base-pair insertion was identified in exon 8 of LTBP2 in affected individuals that generates a frame shift that completely alters the downstream open reading frame and eliminates functional domains. Thus, we describe the first spontaneous and highly penetrant non-rodent model of PCG, identifying a valuable animal model for primary glaucoma that closely resembles the human disease providing valuable insights into mechanisms underlying the disease and a valuable animal model for testing therapies.
Project description:Modern genetic data combined with appropriate statistical methods have the potential to contribute substantially to our understanding of human history. We have developed an approach that exploits the genomic structure of admixed populations to date and characterize historical mixture events at fine scales. We used this to produce an atlas of worldwide human admixture history, constructed using genetic data alone and encompassing over 100 events occurring over the past 4,000 years. We identify events whose dates and participants suggest they describe genetic impacts of the Mongol Empire, Arab slave trade, Bantu expansion, first millennium CE migrations in eastern Europe, and European colonialism, as well as unrecorded events, revealing admixture to be an almost universal force shaping human populations.
Project description:MicroRNAs negatively regulate gene expression and may serve as biomarkers for human cardiomyopathy. In the domestic cat, hypertrophic cardiomyopathy (HCM) represents the most common primary cardiomyopathy. In humans, the etiology of HCM is linked to mutations in genes of contractile muscle proteins, while in cats a clear proof for causal mutations is missing. The etiology of feline HCM is uncertain. Diagnosis is made by heart ultrasound examination and measuring the serum level of N-terminal pro B-type natriuretic peptide. The purpose of this study was to investigate whether microRNA profiles in the serum of cats with HCM are different from the profiles of healthy cats and whether specific miRNAs can be detected to serve as potential biomarkers for feline HCM or may help in understanding the etiology of this disease Blood was drawn from two groups of cats: 12 healthy cats and 11 cats suffering from hypertrophic cardiomyopathy. After clotting, samples were centrifuged and total mRNA was extracted from serum. These 23 serum samples were analyzed and the groups were compared
Project description:BACKGROUND: MicroRNAs negatively regulate gene expression and play a pivotal role in the pathogenesis of human type 2 diabetes mellitus (T2DM). As the domestic cat presents a spontaneous animal model for human T2DM, the purpose of this study was to investigate whether microRNAs are detectable in feline serum and whether microRNA expression profiles differ between healthy and diabetic cats. METHODS: Total RNA was extracted from 400 M-BM-5l serum of healthy lean (HL) and newly diagnosed diabetic (D) cats. MicroRNA microarrays representing 1079 distinct mouse miRNA targets were used to measure miRNA expression in samples from eight HL and eight D cats. RESULTS: By microarray, 227 distinct microRNAs were identified. Nineteen miRNAs were differentially expressed in diabetic cats, but only two reached statistical significance after correction for multiple comparisons. In qRT-PCR, miR-122* was found to be upregulated in diabetic cats more than 40-fold compared to HL cats, while miR-193b was upregulated about 10-fold. MiR-483* showed a 6- fold increase in diabetic cats compared to HL cats. CONCLUSIONS: Small volumes of serum samples yield sufficient material to detect altered microRNA expression profiles in diabetic cats. The domestic cat may be considered a useful animal model for studying miRNAs involved in human T2DM. Blood was drawn from two groups of cats: 8 healthy cats and 8 cats suffering from diabetes. After clotting, samples were centrifuged and total mRNA was extracted from serum. These 16 serum samples were analyzed and the groups were compared. Due to technical problems during hybridization (leaking chamber), sample 1_4_B (Serum_diabetic_8) was not included into analysis.
Project description:BACKGROUND: MicroRNAs negatively regulate gene expression and play a pivotal role in the pathogenesis of human type 2 diabetes mellitus (T2DM). As the domestic cat presents a spontaneous animal model for human T2DM, the purpose of this study was to investigate whether microRNAs are detectable in feline serum and whether microRNA expression profiles differ between healthy and diabetic cats. METHODS: Total RNA was extracted from 400 µl serum of healthy lean (HL) and newly diagnosed diabetic (D) cats. MicroRNA microarrays representing 1079 distinct mouse miRNA targets were used to measure miRNA expression in samples from eight HL and eight D cats. RESULTS: By microarray, 227 distinct microRNAs were identified. Nineteen miRNAs were differentially expressed in diabetic cats, but only two reached statistical significance after correction for multiple comparisons. In qRT-PCR, miR-122* was found to be upregulated in diabetic cats more than 40-fold compared to HL cats, while miR-193b was upregulated about 10-fold. MiR-483* showed a 6- fold increase in diabetic cats compared to HL cats. CONCLUSIONS: Small volumes of serum samples yield sufficient material to detect altered microRNA expression profiles in diabetic cats. The domestic cat may be considered a useful animal model for studying miRNAs involved in human T2DM.
Project description:MicroRNAs negatively regulate gene expression and may serve as biomarkers for human cardiomyopathy. In the domestic cat, hypertrophic cardiomyopathy (HCM) represents the most common primary cardiomyopathy. In humans, the etiology of HCM is linked to mutations in genes of contractile muscle proteins, while in cats a clear proof for causal mutations is missing. The etiology of feline HCM is uncertain. Diagnosis is made by heart ultrasound examination and measuring the serum level of N-terminal pro B-type natriuretic peptide. The purpose of this study was to investigate whether microRNA profiles in the serum of cats with HCM are different from the profiles of healthy cats and whether specific miRNAs can be detected to serve as potential biomarkers for feline HCM or may help in understanding the etiology of this disease
Project description:The genetic structure of some native Bolivians has been substantially influenced by admixture from Europeans, which we estimate to have occurred approximately 360 – 384 years ago. Consistent with historical accounts of male admixture, Y-chromosome haplogroups typical of Europeans were found in 39% of our Bolivian samples. No evidence of African admixture was found in native Bolivians. The Mesoamerican Totonacs have little evidence of European or African admixture. Our analysis indicates that some admixed Bolivians have Native American mtDNA and Y-chromosomes but harbor up to 30% European autosomal ancestry, demonstrating the need for autosomal markers to assess ancestry in admixed populations. From a dense genome-wide panel of 815,377 markers, we developed a set of 324 AIMs, specific for Native American ancestry. As few a 40-50 of these markers successfully predict New World ancestry in the ascertainment panel of Bolivians and Totonacs. The markers easily distinguish New World from Old World ancestry, even for populations more closely related to the Americas such as central and eastern Asians, and were effective for New World vs. Old World comparisons in five other geographically and culturally distinct populations of the Americas. SNPs demonstrating very high divergence between the two Native American populations and major Old World populations are found on haplotypes that are shared and occur at similar frequencies in other indigenous low-admixture American populations examined here (i.e. Pima, Maya, Colombian, Karitiana, and Surui). After excluding the possibility of recent relatedness, our results indicate that native Bolivians and Totonacs share ancestry with other American populations through a substantial contribution from a common founding population, population bottlenecks, and possible natural selection on functional variation.
Project description:Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient human ancestors and have demonstrated that contemporary humans harbour genetic material from ancient close relatives, the Neanderthals and Denisovans, and that ancient human individuals are often genetically distinct from nearby extant populations whilst also showing affinities with populations from further afield. Across West Eurasia, there is growing genetic evidence of large-scale, dynamic population movements over the period between 10,000 to 2,000 years ago, such that the ancestry across present-day populations is likely to be a mixture of several ancient groups. Whilst these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled, or have been either too regional or global in their outlook. Here, using recently described haplotype-based techniques, we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1500 years are likely to have maintained differentiation amongst groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. 20 individuals from Croatia included as part of an analysis of admixture in West Eurasia