scholarly journals Pigment Intensity in Dogs is Associated with a Copy Number Variant Upstream of KITLG

Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
Kalie Weich ◽  
Verena Affolter ◽  
Daniel York ◽  
Robert Rebhun ◽  
Robert Grahn ◽  
...  
Keyword(s):  
Copy Number ◽  
Genome Wide Association Study ◽  
Coat Color ◽  
Sequence Data ◽  
Copy Number Variant ◽  
Color Variation ◽  
Domestic Dog ◽  
Whole Genome Sequence ◽  
Hair Color ◽  
A Genome

Dogs exhibit a wide variety of coat color types, and many genes have been identified that control pigment production, appearance, and distribution. Some breeds, such as the Nova Scotia Duck Tolling Retriever (NSDTR), exhibit variation in pheomelanin pigment intensity that is not explained by known genetic variants. A genome-wide association study comparing light red to dark red in the NSDTR identified a significantly associated region on canine chromosome 15 (CFA 15:23 Mb–38 Mb). Coverage analysis of whole genome sequence data from eight dogs identified a 6 kb copy number variant (CNV) 152 kb upstream of KITLG. Genotyping with digital droplet PCR (ddPCR) confirmed a significant association between an increased copy number with the dark-red coat color in NSDTR (p = 6.1 × 10−7). The copy number of the CNV was also significantly associated with coat color variation in both eumelanin and pheomelanin-based Poodles (p = 1.5 × 10−8, 4.0 × 10−9) and across other breeds. Moreover, the copy number correlated with pigment intensity along the hair shaft in both pheomelanin and eumelanin coats. KITLG plays an important role in melanogenesis, and variants upstream of KITLG have been associated with coat color variation in mice as well as hair color in humans consistent with its role in the domestic dog.

scholarly journals Variants at the ASIP locus contribute to coat color darkening in Nellore cattle

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Beatriz B. Trigo ◽  
Adam T. H. Utsunomiya ◽  
Alvaro A. A. D. Fortunato ◽  
Marco Milanesi ◽  
Rafaela B. P. Torrecilha ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Coat Color ◽  
The Body ◽  
Color Variation ◽  
Whole Genome Sequence ◽  
Potential Contribution ◽  
Sequencing Data ◽  
Functional Variants ◽  
A Genome ◽  
Nellore Cattle

Abstract Background Nellore cattle (Bos indicus) are well-known for their adaptation to warm and humid environments. Hair length and coat color may impact heat tolerance. The Nellore breed has been strongly selected for white coat, but bulls generally exhibit darker hair ranging from light grey to black on the head, neck, hump, and knees. Given the potential contribution of coat color variation to the adaptation of cattle populations to tropical and sub-tropical environments, our aim was to map positional and functional candidate genetic variants associated with darkness of hair coat (DHC) in Nellore bulls. Results We performed a genome-wide association study (GWAS) for DHC using data from 432 Nellore bulls that were genotyped for more than 777 k single nucleotide polymorphism (SNP) markers. A single major association signal was detected in the vicinity of the agouti signaling protein gene (ASIP). The analysis of whole-genome sequence (WGS) data from 21 bulls revealed functional variants that are associated with DHC, including a structural rearrangement involving ASIP (ASIP-SV1). We further characterized this structural variant using Oxford Nanopore sequencing data from 13 Australian Brahman heifers, which share ancestry with Nellore cattle; we found that this variant originates from a 1155-bp deletion followed by an insertion of a transposable element of more than 150 bp that may impact the recruitment of ASIP non-coding exons. Conclusions Our results indicate that the variant ASIP sequence causes darker coat pigmentation on specific parts of the body, most likely through a decreased expression of ASIP and consequently an increased production of eumelanin.

scholarly journals A structural variant in the 5’-flanking region of the TWIST2 gene affects melanocyte development in belted cattle

2016 ◽  
Author(s):  
Nivedita Awasthi Mishra ◽  
Cord Drögemüller ◽  
Vidhya Jagannathan ◽  
Rémy Bruggmann ◽  
Julia Beck ◽  
...  
Keyword(s):  
Neural Crest ◽  
Copy Number ◽  
Genetic Variant ◽  
Coat Color ◽  
Sequence Data ◽  
Ectopic Expression ◽  
Copy Number Variant ◽  
Whole Genome Sequence ◽  
Transgenic Zebrafish ◽  
Aberrant Expression

AbstractBelted cattle have a circular belt of unpigmented hair and skin around their midsection. The belt is inherited as a monogenic autosomal dominant trait. We mapped the causative variant to a 54 kb segment on bovine chromosome 3. Whole genome sequence data of 2 belted and 130 control cattle yielded only one private genetic variant in the critical interval in the two belted animals. The belt-associated variant was a copy number variant (CNV) involving the quadruplication of a 6 kb non-coding sequence located approximately 16 kb upstream of the TWIST2 gene. Increased copy numbers at this CNV were strongly associated with the belt phenotype in a cohort of 239 cases and 1303 controls (p = 1.3 x 10-278). We hypothesized that the CNV causes aberrant expression of TWIST2 during neural crest development, which might negatively affect melanoblasts. Functional studies showed that ectopic expression of bovine TWIST2 in neural crest in transgenic zebrafish led to a decrease in melanocyte numbers. Our results thus implicate an unsuspected involvement of TWIST2 in regulating pigmentation and reveal a non-coding CNV underlying a captivating Mendelian character.Author SummaryBelted cattle, a spontaneous coat color mutant, have been recognized at least 600 years ago. The striking pigmentation pattern probably has arisen in medieval cattle of the Alpine region. The belt still segregates in Brown Swiss cattle and it has become a breed-defining character in the Lakenvelder or Dutch Belted cattle. The belted allele has also been introgressed into Galloways to form the Belted Galloways. We report here the causative genetic variant, a non-coding copy number variant (CNV) upstream of the TWIST2 gene. We hypothesize that the CNV leads to ectopic expression of TWIST2 in the neural crest, which negatively affects melanocyte development. Overexpression of bovine TWIST2 in transgenic zebrafish embryos led to a decrease in melanocyte numbers, which provides functional support for our hypothesis.

scholarly journals Mapping the genetic basis of diabetes mellitus in the Australian Burmese cat (Felis catus)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Georgina Samaha ◽  
Claire M. Wade ◽  
Julia Beatty ◽  
Leslie A. Lyons ◽  
Linda M. Fleeman ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Genome Wide Association Study ◽  
Genetic Model ◽  
Sequence Data ◽  
Pancreatic Beta Cell ◽  
Whole Genome Sequence ◽  
Cell Dysfunction ◽  
Genome Wide ◽  
A Genome ◽  
Pathologic Features

Abstract Diabetes mellitus, a common endocrinopathy affecting domestic cats, shares many clinical and pathologic features with type 2 diabetes in humans. In Australia and Europe, diabetes mellitus is almost four times more common among Burmese cats than in other breeds. As a genetically isolated population, the diabetic Australian Burmese cat provides a spontaneous genetic model for studying diabetes mellitus in humans. Studying complex diseases in pedigreed breeds facilitates tighter control of confounding factors including population stratification, allelic frequencies and environmental heterogeneity. We used the feline SNV array and whole genome sequence data to undertake a genome wide-association study and runs of homozygosity analysis, of a case–control cohort of Australian and European Burmese cats. Our results identified diabetes-associated haplotypes across chromosomes A3, B1 and E1 and selective sweeps across the Burmese breed on chromosomes B1, B3, D1 and D4. The locus on chromosome B1, common to both analyses, revealed coding and splice region variants in candidate genes, ANK1, EPHX2 and LOX2, implicated in diabetes mellitus and lipid dysregulation. Mapping this condition in Burmese cats has revealed a polygenic spectrum, implicating loci linked to pancreatic beta cell dysfunction, lipid dysregulation and insulin resistance in the pathogenesis of diabetes mellitus in the Burmese cat.

scholarly journals Characterizing rare and low-frequency height-associated variants in the Japanese population

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Masato Akiyama ◽  
Kazuyoshi Ishigaki ◽  
Saori Sakaue ◽  
Yukihide Momozawa ◽  
Momoko Horikoshi ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Rare Variants ◽  
Sequence Data ◽  
Low Frequency ◽  
European Population ◽  
Genotype Imputation ◽  
Whole Genome Sequence ◽  
General Tendency ◽  
Phenotypic Variance ◽  
A Genome

Abstract Human height is a representative phenotype to elucidate genetic architecture. However, the majority of large studies have been performed in European population. To investigate the rare and low-frequency variants associated with height, we construct a reference panel (N = 3,541) for genotype imputation by integrating the whole-genome sequence data from 1,037 Japanese with that of the 1000 Genomes Project, and perform a genome-wide association study in 191,787 Japanese. We report 573 height-associated variants, including 22 rare and 42 low-frequency variants. These 64 variants explain 1.7% of the phenotypic variance. Furthermore, a gene-based analysis identifies two genes with multiple height-increasing rare and low-frequency nonsynonymous variants (SLC27A3 and CYP26B1; PSKAT-O < 2.5 × 10−6). Our analysis shows a general tendency of the effect sizes of rare variants towards increasing height, which is contrary to findings among Europeans, suggesting that height-associated rare variants are under different selection pressure in Japanese and European populations.

scholarly journals Identification of loci associated with pathological outcomes in Holstein cattle infected with Mycobacterium avium subsp. paratuberculosis using whole-genome sequence data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Canive ◽  
Gerard Badia-Bringué ◽  
Patricia Vázquez ◽  
Oscar González-Recio ◽  
Almudena Fernández ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Mycobacterium Avium ◽  
Genome Wide Association Study ◽  
Cholesterol Metabolism ◽  
Sequence Data ◽  
Plasma Cholesterol ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Histological Lesion ◽  
A Genome

AbstractBovine paratuberculosis (PTB), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic granulomatous enteritis that affects cattle worldwide. According to their severity and extension, PTB-associated histological lesions have been classified into the following groups; focal, multifocal, and diffuse. It is unknown whether these lesions represent sequential stages or divergent outcomes. In the current study, the associations between host genetic and pathology were explored by genotyping 813 Spanish Holstein cows with no visible lesions (N = 373) and with focal (N = 371), multifocal (N = 33), and diffuse (N = 33) lesions in gut tissues and regional lymph nodes. DNA from peripheral blood samples of these animals was genotyped with the bovine EuroG MD Bead Chip, and the corresponding genotypes were imputed to whole-genome sequencing (WGS) data using the 1000 Bull genomes reference population. A genome-wide association study (GWAS) was performed using the WGS data and the presence or absence of each type of histological lesion in a case–control approach. A total of 192 and 92 single nucleotide polymorphisms (SNPs) defining 13 and 9 distinct quantitative trait loci (QTLs) were highly-associated (P ≤ 5 × 10−7) with the multifocal (heritability = 0.075) and the diffuse (heritability = 0.189) lesions, respectively. No overlap was seen in the SNPs controlling these distinct pathological outcomes. The identified QTLs overlapped with some QTLs previously associated with PTB susceptibility, bovine tuberculosis susceptibility, clinical mastitis, somatic cell score, bovine respiratory disease susceptibility, tick resistance, IgG level, and length of productive life. Pathway analysis with candidate genes overlapping the identified QTLs revealed a significant enrichment of the keratinization pathway and cholesterol metabolism in the animals with multifocal and diffuse lesions, respectively. To test whether the enrichment of SNP variants in candidate genes involved in the cholesterol metabolism was associated with the diffuse lesions; the levels of total cholesterol were measured in plasma samples of cattle with focal, multifocal, or diffuse lesions or with no visible lesions. Our results showed reduced levels of plasma cholesterol in cattle with diffuse lesions. Taken together, our findings suggested that the variation in MAP-associated pathological outcomes might be, in part, genetically determined and indicative of distinct host responses.

scholarly journals Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle

2019 ◽  
Vol 51 (1) ◽  
Author(s):  
Swati Jivanji ◽  
Gemma Worth ◽  
Thomas J. Lopdell ◽  
Anna Yeates ◽  
Christine Couldrey ◽  
...  
Keyword(s):  
Association Analysis ◽  
Molecular Mechanisms ◽  
Coat Color ◽  
Sequence Data ◽  
Genome Wide Association ◽  
Whole Genome Sequence ◽  
Genome Wide Association Analysis ◽  
Genome Wide ◽  
Holstein Friesian ◽  
A Genome

Abstract Background White spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein–Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein–Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date. Results Using imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region. Conclusions Our findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics.

scholarly journals Genome-wide identification of lineage and locus specific variation associated with pneumococcal carriage duration

2017 ◽  
Author(s):  
John A. Lees ◽  
Nicholas J. Croucher ◽  
Goldblatt David ◽  
Nosten Francois ◽  
Parkhill Julian ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Low Income ◽  
Genome Wide Association Study ◽  
Sequence Data ◽  
Genomic Variation ◽  
Whole Genome Sequence ◽  
Vaccine Response ◽  
Pneumococcal Carriage ◽  
Genome Wide ◽  
A Genome

AbstractStreptococcus pneumoniae is a leading cause of invasive disease in infants, especially in low-income settings. Asymptomatic carriage in the nasopharynx is a prerequisite for disease, and the duration of carriage is an important consideration in modelling transmission dynamics and vaccine response. Existing studies of carriage duration variability are based at the serotype level only, and do not probe variation within lineages or fully quantify interactions with other environmental factors.Here we developed a model to calculate the duration of carriage episodes from longitudinal swab data. By combining these results with whole genome sequence data we estimate that pneumococcal genomic variation accounted for 63% of the phenotype variation, whereas host traits accounted for less than 5%. We further partitioned this heritability into both lineage and locus effects, and quantified the amount attributable to the largest sources of variation in carriage duration: serotype (17%), drug-resistance (9%) and other significant locus effects (7%). For the locus effects, a genome-wide association study identified 16 loci which may have an effect on carriage duration independent of serotype. Hits at a genome-wide level of significance were to prophage sequences, suggesting infection by such viruses substantially affects carriage duration.These results show that both serotype and non-serotype specific effects alter carriage duration in infants and young children and are more important than other environmental factors such as host genetics. This has implications for models of pneumococcal competition and antibiotic resistance, and leads the way for the analysis of heritability of complex bacterial traits.Significance statementOther than serotype, the genetic determinants of pneumococcal carriage duration are unknown. In this study we used longitudinal sampling to measure the duration of carriage in infants, and searched for any associated variation in the pan-genome. While we found that the pathogen genome explains most of the variability in duration, serotype did not fully account for this. Recent theoretical work has proposed the existence of alleles which alter carriage duration to explain the puzzle of continued coexistence of antibiotic-resistant and sensitive strains. Here we have shown that these alleles do exist in a natural population, and also identified candidates for the loci which fulfil this role. Together these findings have implications for future modelling of pneumococcal epidemiology and resistance.

scholarly journals A Genome-Wide Association Study to Identify Potential Germline Copy Number Variants for Sporadic Breast Cancer Susceptibility

2016 ◽  
Vol 149 (3) ◽  
pp. 156-164 ◽  
Author(s):  
Yadav Sapkota ◽  
Ashok Narasimhan ◽  
Mahalakshmi Kumaran ◽  
Badan S. Sehrawat ◽  
Sambasivarao Damaraju
Keyword(s):  
Breast Cancer ◽  
Association Study ◽  
Copy Number ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Frequency Effect ◽  
Potential Candidate ◽  
Disease Etiology ◽  
Genome Wide ◽  
A Genome

Breast cancer (BC) predisposition in populations arises from both genetic and nongenetic risk factors. Structural variations such as copy number variations (CNVs) are heritable determinants for disease susceptibility. The primary objectives of this study are (1) to identify CNVs associated with sporadic BC using a genome-wide association study (GWAS) design; (2) to utilize 2 distinct CNV calling algorithms to identify concordant CNVs as a strategy to reduce false positive associations in the hypothesis-generating GWAS discovery phase, and (3) to identify potential candidate CNVs for follow-up replication studies. We used Affymetrix SNP Array 6.0 data profiled on Caucasian subjects (422 cases/348 controls) to call CNVs using algorithms implemented in Nexus Copy Number and Partek Genomics Suite software. Nexus algorithm identified CNVs associated with BC (731 autosomal CNVs with >5% frequency in the total sample and Q < 0.05). Thirteen CNVs were identified when Partek algorithm-called CNVs were overlapped with Nexus-identified CNVs; these CNVs showed concordances for frequency, effect size, and direction. Coding genes present within BC-associated CNVs were known to play a role in disease etiology and prognosis. Long noncoding RNAs identified within CNVs showed tissue-specific expression, indicating potential functional relevance of the findings. The identified candidate CNVs warrant independent replication.

A genome-wide association study of copy number variations with umbilical hernia in swine

2016 ◽  
Vol 47 (3) ◽  
pp. 298-305 ◽  
Author(s):  
Yi Long ◽  
Ying Su ◽  
Huashui Ai ◽  
Zhiyan Zhang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Association Study ◽  
Copy Number ◽  
Umbilical Hernia ◽  
Genome Wide Association Study ◽  
Copy Number Variations ◽  
Genome Wide Association ◽  
Genome Wide ◽  
A Genome
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