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C. M. Woolf - One of the best experts on this subject based on the ideXlab platform.
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influence of stochastic events on the phenotypic variation of common white leg markings in the Arabian Horse implications for various genetic disorders in humans
Journal of Heredity, 1995Co-Authors: C. M. WoolfAbstract:One method of assessing the influence of stochastic events on phenotypic variation is to study morphological differences in paired limbs of the same individual. These limbs have identical genotypes and similar intra-uterine environments and are analogous to monozygotic twins. Common white leg markings have a multifactorial mode of inheritance in the Arabian Horse. Asymmetry occurs frequently for these markings. Using computerized registration records obtained from the Arabian Horse Registry of America, Inc., the types of markings were quantified in the left foreleg and left hind leg of bay and chestnut Horses when a specific marking occurred in (1) a paired right leg, (2) both right legs, and (3) both right legs and the other left leg. The variation in the markings in the left legs of these Horses is evidence of the role of stochastic events during development. The relatively high frequency of a specific type of asymmetry, with one leg being completely pigmented, is of special biological interest and has implications for various human disorders that are characterized by reduced penetrance and variable expressivity.
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Common White Facial Markings in Bay and Chestnut Arabian Horses and Their Hybrids
The Journal of heredity, 1991Co-Authors: C. M. WoolfAbstract:Common white facial and leg markings have a multifactorial mode of inheritance in Equus caballus. Evidence for the complexity of the genetic component is the observation that chestnut (e/e) Horses have more extensive white markings than do bay (E/-) Horses. Computerized records obtained from the Arabian Horse Registry of America, Inc., were used to determine if heterozygous (E/e) bay Horses have more extensive white facial markings than do homozygous (E/E) bay Horses. Thirty-five sire families were analyzed. Each sire family consists of a sire, his foals, and the dams of those foals. The facial region was divided into five areas, and each Horse was given a score from 0 to 5 according to the number of areas with whiteness. Since dams and foals with E/E genotypes cannot be identified in these sire families, mean facial scores were compared in dams and foals that were E/e and E/-. It was assumed that if a difference exists between E/e and E/E Horses, the presence of E/E Horses in the E/- group would reduce the mean of the E/- group. The results show that Arabian Horses with the genotype E/e have more white markings than do Horses with the genotype E/-, leading to the conclusion that Horses with the genotypes e/e, E/e, and E/E vary as to the quantitative expression of white facial markings, with heterozygotes having an intermediate expression.
Anas M Khanshour - One of the best experts on this subject based on the ideXlab platform.
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Maternal phylogenetic relationships and genetic variation among Arabian Horse populations using whole mitochondrial DNA D-loop sequencing
BMC Genetics, 2013Co-Authors: Anas M Khanshour, Ernest Gus CothranAbstract:Background Maternal inheritance is an essential point in Arabian Horse population genetics and strains classification. The mitochondrial DNA (mtDNA) sequencing is a highly informative tool to investigate maternal lineages. We sequenced the whole mtDNA D-loop of 251 Arabian Horses to study the genetic diversity and phylogenetic relationships of Arabian populations and to examine the traditional strain classification system that depends on maternal family lines using native Arabian Horses from the Middle East. Results The variability in the upstream region of the D-loop revealed additional differences among the haplotypes that had identical sequences in the hypervariable region 1 (HVR1). While the American-Arabians showed relatively low diversity, the Syrian population was the most variable and contained a very rare and old haplogroup. The Middle Eastern Horses had major genetic contributions to the Western Horses and there was no clear pattern of differentiation among all tested populations. Our results also showed that several individuals from different strains shared a single haplotype, and individuals from a single strain were represented in clearly separated haplogroups. Conclusions The whole mtDNA D-loop sequence was more powerful for analysis of the maternal genetic diversity in the Arabian Horses than using just the HVR1. Native populations from the Middle East, such as Syrians, could be suggested as a hot spot of genetic diversity and may help in understanding the evolution history of the Arabian Horse breed. Most importantly, there was no evidence that the Arabian Horse breed has clear subdivisions depending on the traditional maternal based strain classification system.
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Maternal phylogenetic relationships and genetic variation among Arabian Horse populations using whole mitochondrial DNA D-loop sequencing
BMC genetics, 2013Co-Authors: Anas M Khanshour, Ernest Gus CothranAbstract:Maternal inheritance is an essential point in Arabian Horse population genetics and strains classification. The mitochondrial DNA (mtDNA) sequencing is a highly informative tool to investigate maternal lineages. We sequenced the whole mtDNA D-loop of 251 Arabian Horses to study the genetic diversity and phylogenetic relationships of Arabian populations and to examine the traditional strain classification system that depends on maternal family lines using native Arabian Horses from the Middle East. The variability in the upstream region of the D-loop revealed additional differences among the haplotypes that had identical sequences in the hypervariable region 1 (HVR1). While the American-Arabians showed relatively low diversity, the Syrian population was the most variable and contained a very rare and old haplogroup. The Middle Eastern Horses had major genetic contributions to the Western Horses and there was no clear pattern of differentiation among all tested populations. Our results also showed that several individuals from different strains shared a single haplotype, and individuals from a single strain were represented in clearly separated haplogroups. The whole mtDNA D-loop sequence was more powerful for analysis of the maternal genetic diversity in the Arabian Horses than using just the HVR1. Native populations from the Middle East, such as Syrians, could be suggested as a hot spot of genetic diversity and may help in understanding the evolution history of the Arabian Horse breed. Most importantly, there was no evidence that the Arabian Horse breed has clear subdivisions depending on the traditional maternal based strain classification system.
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Microsatellite Analysis of Genetic Diversity and Population Structure of Arabian Horse Populations
The Journal of heredity, 2013Co-Authors: Anas M Khanshour, Eleanore Conant, Rytis Juras, E. G. CothranAbstract:The Arabian Horse ignites imagination throughout the world. Populations of this breed exist in many countries, and recent genetic work has examined the diversity and ancestry of a few of these populations in isolation. Here, we explore 7 different populations of Arabians represented by 682 Horses. Three of these are Middle Eastern populations from near the historical origin of the breed, including Syrian, Persian, and Saudi Arabian. The remaining Western populations are found in Europe (the Shagya Arabian and Polish Arabian) and in America (American Arabian). Analysis of genetic structure was carried out using 15 microsatellite loci. Genetic distances, analysis of molecular variance, factorial correspondence analysis, and a Bayesian method were applied. The results consistently show higher level of diversity within the Middle Eastern populations than the Western populations. The Western Arabian populations were the main source among population variation. Genetic differentiation was not strong among all Middle Eastern populations, but all American Arabians showed differentiation from Middle Eastern populations and were somewhat uniform among themselves. Here, we explore the diversities of many different populations of Arabian Horses and find that populations not from the Middle East have noticeably lower levels of diversity, which may adversely affect the health of these populations.
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Microsatellite analysis for parentage testing of the Arabian Horse breed from Syria
TURKISH JOURNAL OF MEDICAL SCIENCES, 2013Co-Authors: Anas M Khanshour, Eleanore Conant, Rytis Juras, E. G. CothranAbstract:Parentage testing is very important for genetically determining the accuracy of the pedigree of domestic animals. The Arabian Horse population in Syria might be expected to have a high level of homozygosity because the traditional method of breeding results in such a small population. For this reason, using a set of highly polymorphic markers such as microsatellites is required for parentage testing. The purpose of this study was to analyze the usefulness of 16 STR markers for routine parentage testing in 94 samples from registered and nonregistered Horses collected from Syria. The mean number of alleles was 5.69 per locus in the registered group and 7.69 in the nonregistered group. The nonregistered group had a mean polymorphic information content (PIC) of 0.715, which was significantly higher than the PIC in the registered group. The individual probability of exclusion per locus ranged from 32% for HTG7 to 80% for ASB17 in the registered group and 41% for HTG7 to 84% for ASB17 in the nonregistered group. The results of this study indicate no serious loss of heterozygosity and confirm that 13 STR markers can be used in parentage testing with high efficiency for the Arabian Horses from Syria.
Ernest Gus Cothran - One of the best experts on this subject based on the ideXlab platform.
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Maternal phylogenetic relationships and genetic variation among Arabian Horse populations using whole mitochondrial DNA D-loop sequencing
BMC Genetics, 2013Co-Authors: Anas M Khanshour, Ernest Gus CothranAbstract:Background Maternal inheritance is an essential point in Arabian Horse population genetics and strains classification. The mitochondrial DNA (mtDNA) sequencing is a highly informative tool to investigate maternal lineages. We sequenced the whole mtDNA D-loop of 251 Arabian Horses to study the genetic diversity and phylogenetic relationships of Arabian populations and to examine the traditional strain classification system that depends on maternal family lines using native Arabian Horses from the Middle East. Results The variability in the upstream region of the D-loop revealed additional differences among the haplotypes that had identical sequences in the hypervariable region 1 (HVR1). While the American-Arabians showed relatively low diversity, the Syrian population was the most variable and contained a very rare and old haplogroup. The Middle Eastern Horses had major genetic contributions to the Western Horses and there was no clear pattern of differentiation among all tested populations. Our results also showed that several individuals from different strains shared a single haplotype, and individuals from a single strain were represented in clearly separated haplogroups. Conclusions The whole mtDNA D-loop sequence was more powerful for analysis of the maternal genetic diversity in the Arabian Horses than using just the HVR1. Native populations from the Middle East, such as Syrians, could be suggested as a hot spot of genetic diversity and may help in understanding the evolution history of the Arabian Horse breed. Most importantly, there was no evidence that the Arabian Horse breed has clear subdivisions depending on the traditional maternal based strain classification system.
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Maternal phylogenetic relationships and genetic variation among Arabian Horse populations using whole mitochondrial DNA D-loop sequencing
BMC genetics, 2013Co-Authors: Anas M Khanshour, Ernest Gus CothranAbstract:Maternal inheritance is an essential point in Arabian Horse population genetics and strains classification. The mitochondrial DNA (mtDNA) sequencing is a highly informative tool to investigate maternal lineages. We sequenced the whole mtDNA D-loop of 251 Arabian Horses to study the genetic diversity and phylogenetic relationships of Arabian populations and to examine the traditional strain classification system that depends on maternal family lines using native Arabian Horses from the Middle East. The variability in the upstream region of the D-loop revealed additional differences among the haplotypes that had identical sequences in the hypervariable region 1 (HVR1). While the American-Arabians showed relatively low diversity, the Syrian population was the most variable and contained a very rare and old haplogroup. The Middle Eastern Horses had major genetic contributions to the Western Horses and there was no clear pattern of differentiation among all tested populations. Our results also showed that several individuals from different strains shared a single haplotype, and individuals from a single strain were represented in clearly separated haplogroups. The whole mtDNA D-loop sequence was more powerful for analysis of the maternal genetic diversity in the Arabian Horses than using just the HVR1. Native populations from the Middle East, such as Syrians, could be suggested as a hot spot of genetic diversity and may help in understanding the evolution history of the Arabian Horse breed. Most importantly, there was no evidence that the Arabian Horse breed has clear subdivisions depending on the traditional maternal based strain classification system.
Samantha A. Brooks - One of the best experts on this subject based on the ideXlab platform.
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use of principle component analysis to quantitatively score the equine metabolic syndrome phenotype in an Arabian Horse population
PLOS ONE, 2018Co-Authors: Samantha L Lewis, M F Mallicote, Heather M Holl, Maureen T Long, Samantha A. BrooksAbstract:Equine metabolic syndrome (EMS), like human metabolic syndrome, comprises a collection of clinical signs related to obesity, insulin dysregulation and susceptibility to secondary inflammatory disease. Although the secondary conditions resulting from EMS can be life-threatening, diagnosis is not straightforward and often complicated by the presence of other concurrent conditions like pituitary pars intermedia dysfunction (PPID). In order to better characterize EMS, we sought to describe the variation within, and correlations between, typical physical and endocrine parameters for EMS. Utilizing an unsupervised statistical approach, we evaluated a population of Arabian Horses using a physical examination including body measurements, as well as blood plasma insulin, leptin, ACTH, glucose, and lipid values. We investigated the relationships among these variables using principle component analysis (PCA), hierarchical clustering, and linear regression. Owner-assigned assessments of body condition were one full score (on a nine-point scale) lower than scores assigned by researchers, indicating differing perception of healthy equine body weight. Rotated PCA defined two factor scores explaining a total of 46.3% of variation within the dataset. Hierarchical clustering using these two factors revealed three groups corresponding well to traditional diagnostic categories of “Healthy”, “PPID-suspect”, and “EMS-suspect” based on the characteristics of each group. Proxies estimating up to 93.4% of the composite “EMS-suspect” and “PPID-suspect” scores were created using a reduced set of commonly used diagnostic variables, to facilitate application of these quantitative scores to Horses of the Arabian breed in the field. Use of breed-specific, comprehensive physical and endocrinological variables combined in a single quantitative score may improve detection of Horses at-risk for developing EMS, particularly in those lacking severe clinical signs. Quantification of EMS without the use of predetermined reference ranges provides an advantageous approach for future studies utilizing genomic or metabolomics approaches to improve understanding of the etiology behind this troubling condition.
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Molecular Detection of Severe Combined Immunodeficiency Disorder in Arabian Horses in Egypt.
Journal of equine veterinary science, 2018Co-Authors: Nahla A. Abouel Ela, Khalid A. El-nesr, Hanaa A. Ahmed, Samantha A. BrooksAbstract:Severe combined immunodeficiency (SCID) is a fatal genetic disorder and one of the common genetic diseases of the Arabian Horse. The genetic mutation responsible for this disease is a five base pair deletion (TCTCA) in the DNA-protein kinase catalytic subunit gene. Severe combined immunodeficiency is a recessive autosomal genetic disorder with 25% chance inheritance of the disease among the progeny of carrier parents. It causes complete absence of certain immune cells, like B and T lymphocytes, leaving foals with immunodeficiency and exposing them to early death within 4 to 6 months. This study aimed to establish a reliable DNA test for detection of asymptomatic SCID carriers in the Egyptian Arabian Horse population and to re-examine cases of unexplained foal death to exclude presence of SCID disease. Samples collected from live Horses were chosen at random from the registered population, as well as postmortem samples from reported cases died at different ages in Arabian farms. Among these samples, we did not identify SCID carriers. Improved SCID diagnostic assays will help in selection within breeding programs to avoid carrier-to-carrier mating and the birth of clinically affected foals. This will have a positive effect on the financial value of Arabian Horse production by decreasing economic losses due to affected foal deaths, extended veterinary care, and intensive but futile treatments. Application of the DNA test overall Egyptian population is recommended.
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Application of Genomic Estimation Methods of Inbreeding and Population Structure in an Arabian Horse Herd.
The Journal of heredity, 2017Co-Authors: Mohammed Al Abri, Uta König Von Borstel, Veronique Strecker, Samantha A. BrooksAbstract:Horse breeders rely heavily on pedigrees for identification of ancestry in breeding stock. Inaccurate pedigrees may erroneously assign individuals to false lineages or breed memberships resulting in wrong estimates of inbreeding and coancestry. Moreover, discrepancies in pedigree records can lead breeders seeking to limit inbreeding into making misguided breeding decisions. Genome-wide SNPs provide a quantitative tool to aid in the resolution of lineage assignments and the calculation of genomic measures of relatedness. The aim of this project was to pilot a comparison between pedigree and genomic relatedness and inbreeding measures in a herd of 36 pedigreed Egyptian Arabian Horses genotyped using the Equine SNP70 platform (Geneseek, Inc.). Moreover, we sought to estimate the minimum number of markers sufficient for genomic inbreeding calculations. Pedigree inbreeding values were moderately correlated with genomic inbreeding values (r = 0.406), whereas genomic relationships and pedigree relationships have a high correlation (r = 0.77). Although first degree relationships were successfully reconstructed, more distant relationships were difficult to resolve. Multi-dimensional scaling and clustering analysis agreed with within-herd pedigree information. In comparing the herd to a reference sample of United States, Polish, and Egyptian Arabian Horses, the herd's historically recorded Egyptian lineage was successfully recovered. We conclude that genomic estimates of inbreeding and relationships are superior to their pedigree counterparts. They can be thus utilized in conservation of valuable lines of livestock, and in breeds at risk for loss of genomic diversity. We also postulate a minimum of 2000 markers in linkage equilibrium to be used for inbreeding estimation.
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genomewide association study reveals a risk locus for equine metabolic syndrome in the Arabian Horse
Journal of Animal Science, 2017Co-Authors: S Lewis, Heather M Holl, C Streeter, Christian J Posbergh, B J Schanbacher, N J Place, M F Mallicote, Maureen T Long, Samantha A. BrooksAbstract:Equine obesity can cause life-threatening secondary chronic conditions, similar to those in humans and other animal species. Equine metabolic syndrome (EMS), primarily characterized by hyperinsulinemia, is often present in obese Horses and ponies. Due to clinical similarities to conditions such as pituitary pars intermedia dysfunction (formerly equine Cushing's disease), conclusive diagnosis of EMS often proves challenging. Aside from changes in diet and exercise, few targeted treatments are available for EMS, emphasizing the need for early identification of at-risk individuals to enable implementation of preventative measures. A genomewide association study (GWAS) using Arabian Horses with a history of severe laminitis secondary to EMS revealed significant genetic markers near a single candidate gene () that may play a role in cholesterol homeostasis. The best marker, BIEC2-263524 (chr14:69276814 T > C), was correlated with elevated insulin values and increased frequency of laminitis ( = 0.0024 and = 9.663 × 10, respectively). In a second population of Arabian Horses, the BIEC2-263524 marker maintained its associations with higher modified insulin-to-glucose ratio (MIRG) values ( = 0.0056) and BCS ( = 0.0063). Screening of the predicted coding regions by sequencing identified a polymorphic guanine homopolymer and 5 haplotypes in the 3' untranslated region (UTR). An 11 guanine (11-G) allele at was correlated with elevated insulin values in the GWAS population ( = 0.0008) and, in the second population, elevated MIRG and increased BCS > 6.5 ( = 0.0055 and = 0.0162, respectively). The BIEC2-263524-C and the 3' UTR -11(G) polymorphisms were correlated at a 98% frequency, indicating strong linkage disequilibrium across this 150-kb haplotype. Assays for these markers could diagnose Horses with a genetic predisposition to develop obesity. Additionally, discovery of FAM174A function may improve our understanding of the etiology of this troubling illness in the Horse and warrants investigation of this locus for a role in metabolic- and obesity-related disorders of other species.
Teimouri A Yansari - One of the best experts on this subject based on the ideXlab platform.
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isolation and identification of cellulolytic bacteria from gastrointestinal tract of Arabian Horse and investigation of their effect on the nutritional value of wheat straw
Journal of Applied Microbiology, 2019Co-Authors: Harsini M Shakarami, T Mohammadabadi, H Motamedi, M Sari, Teimouri A YansariAbstract:AIMS: This study was conducted to isolate and identify the cellulolytic bacteria from gastrointestinal tract of Arabian Horse and investigate their effect on the nutritional value of wheat straw (WS). METHODS AND RESULTS: Fresh faeces were collected from four Arabian Horses. The cellulose‐hydrolytic bacteria were isolated by using a medium amended with carboxymethyl cellulose (CMC). The activity of CMC was determined by measuring the release of reducing sugars from CMC. Among the isolates, four isolates (L11, L12, L2 and Z2) showed maximum hydrolysis capacity. 16S rRNA sequence analysis showed that these isolates possessed 99, 99, 99 and 98% similarity with Paenibacillus polymyxa, Paenibacillus polymyxa, Enterobacter cloacae and Escherichia coli respectively. Wheat straw was incubated with the isolated bacteria in liquid medium. Disappeared dry matter (DM) and crude protein (CP), neutral detergent fibre (NDF), indigestible NDF (iNDF) and acid detergent fibre (ADF) contents of WS were affected by microbial treatments (P < 0·05). The highest disappearance of DM and CP contents and the lowest NDF, iNDF and ADF contents of WS were observed by treating with P. polymyxa L11. The values of NDF, iNDF and ADF were the highest and CP was the lowest in control. Gas production parameters and digestibility of processed samples were determined. Bacterial treatments enhanced (P < 0·05) DM, OM, CP, NDF and ADF digestibility of WS. The highest and lowest (P < 0·05) DM, OM, CP, NDF and ADF digestibilities were observed for WS treated with isolates L12 and control respectively. Potential of gas production (b), truly degraded organic matter (TDOM) and microbial biomass of bacteria treatments were significantly higher (P < 0·05) compared to control. CONCLUSIONS: Generally, the results of this study showed that the isolated bacteria from Horse faeces are capable of changing the chemical composition, increasing digestibility as well as enhancing nutrition value of WS. SIGNIFICANCE AND IMPACT OF THE STUDY: Wheat straw is a major agro‐residue fed to ruminants. However, high fibre contents reduce digestibility and limit animal productivity. It seems that enhancement of ruminal degradation of these by‐products is necessary. The results of this study revealed that cellulolytic bacteria isolated from gastrointestinal tract of Horse can be used for biological treatment of WS.