Development of a Linkage Map and Mapping of Phenotypic Polymorphisms in a Free-Living Population of Soay Sheep (Ovis aries)

Identifying the genes that underlie phenotypic variation in natural populations is a central objective of evolutionary genetics. Here, we report the identification of the gene and causal mutation underlying coat colour variation in a free-living population of Soay sheep ( Ovis aries ). We targeted tyrosinase-related protein 1 ( TYRP1 ), a positional candidate gene based on previous work that mapped the Coat colour locus to an approximately 15 cM window on chromosome 2. We identified a non-synonymous substitution in exon IV that was perfectly associated with coat colour. This polymorphism is predicted to cause the loss of a cysteine residue that is highly evolutionarily conserved and likely to be of functional significance. We eliminated the possibility that this association is due to the presence of strong linkage disequilibrium with an unknown regulatory mutation by demonstrating that there is no difference in relative TYRP1 expression between colour morphs. Analysis of this putative causal mutation in a complex pedigree of more than 500 sheep revealed almost perfect co-segregation with coat colour ( Χ 2 -test, p <0.0001, LOD=110.20), and very tight linkage between Coat colour and TYRP1 (LOD=29.50).

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Sex Differences in Feeding Behaviour at Feeding Station Scale in Soay Sheep (Ovis Aries)

Behaviour ◽

10.1163/1568539042360143 ◽

2004 ◽

Vol 141 (8) ◽

pp. 999-1020 ◽

Cited By ~ 7

Author(s):

◽

Keyword(s):

Feeding Behaviour ◽

Ovis Aries ◽

Intake Rate ◽

Same Sex ◽

Soay Sheep ◽

Food Items ◽

Feeding Station ◽

Foraging Decisions ◽

Mouth Size ◽

Mechanistic Response

AbstractHerbivorous ungulates live in a spatially heterogeneous environment making foraging decisions at a range of hierarchical scales, from bite size to landscape. We investigated the factors that control intake rate in Soay sheep (Ovis aries) when discrete items of food were sparsely distributed at the feeding station scale. Within the feeding station we varied the difficulty of accessing food, distance between items of food, difficulty of finding the food and complexity of the feeding station and recorded how intake rate responded in relation to body size, mouth size and the sex of the animal. Our findings demonstrated how increasing difficulty of accessing food, and increasing complexity of the feeding station negatively affected intake rate. The expected mechanistic response that smaller animals or animals with smaller mouth size were better at handling discrete small items of food, was overridden by individual and sexual differences in behaviour. We also considered that intake rate within a feeding station could be maximised by optimising the spatial pattern of offtake, and the results clearly indicated that both sexes tended to show clustered patterns of offtake. Animals of the same sex responded in a similar way to the difficulty in handling food items; males persevered more than females and consequently were less handicaped by having larger mouths. We discussed these results in relation to behavioural and body mass differences between the sexes and animals.

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The genetic architecture of helminth-specific immune responses in a wild population of Soay sheep (Ovis aries)

PLoS Genetics ◽

10.1371/journal.pgen.1008461 ◽

2019 ◽

Vol 15 (11) ◽

pp. e1008461 ◽

Cited By ~ 7

Author(s):

Alexandra M. Sparks ◽

Kathryn Watt ◽

Rona Sinclair ◽

Jill G. Pilkington ◽

Josephine M. Pemberton ◽

...

Keyword(s):

Immune Responses ◽

Genetic Architecture ◽

Wild Population ◽

Ovis Aries ◽

Soay Sheep

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Epidemiology of nematode infections of Soay sheep (Ovis aries L.) on St Kilda

Parasitology ◽

10.1017/s0031182000074667 ◽

1992 ◽

Vol 105 (3) ◽

pp. 481-492 ◽

Cited By ~ 69

Author(s):

F. M. D. Gulland ◽

M. Fox

Keyword(s):

Population Density ◽

Infection Intensity ◽

Host Population ◽

Ovis Aries ◽

Sheep Population ◽

Soay Sheep ◽

Infective Larvae ◽

Population Crash ◽

Faecal Egg Counts ◽

Bad Weather

SUMMARYThe epidemiology of nematode infections of Soay sheep on the island of St Kilda over a period of 2 years (August 1988–August 1990) spanning a host population crash is described. Infective larvae (L3) levels on pasture were high (2422±365 L3/kg D.M. grass in midsummer 1988) when host population density was high, decreasing after the sheep population declined by 70% in early 1989 (601 ±14 L3/kg D.M. in midsummer 1989). The availability of infective larvae to sheep increased during the winter of 1988–1989, probably as a result of concentration of existing larvae on grass as vegetation was destroyed by bad weather and overgrazing. Increased availability of pre-parasitic stages was accompanied by a marked increased in faecal egg counts from sheep of all ages and both sexes. Prevalence and intensity of infection (faecal egg counts) were higher in males than females throughout the 2-year study (χ2 = 208.3, P < 0.005 and F1.2000 = 304, P < 0.001 respectively), except during the lambing periods, and decreased with age in both sexes. Changes in prevalence and intensity of strongyle infections were associated with changes in host population density. Prevalence and intensity of Dictyocaulus filaria larvae in faeces increased during the host population crash. Infection intensity decreased with age (F1.203 = 44.02, P < 0.001) and was higher in males than females (F1.203 = 13.45, P < 0.001).

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Haplotyping MHC class IIa by high throughput screening in an isolated sheep population

10.1101/2020.07.20.212225 ◽

2020 ◽

Author(s):

K.L. Dicks ◽

J.M. Pemberton ◽

K.T. Ballingall ◽

S.E. Johnston

Keyword(s):

High Throughput Screening ◽

Population Data ◽

Ovis Aries ◽

Island Population ◽

Sheep Population ◽

Soay Sheep ◽

Histocompatibility Complex ◽

Content Variation ◽

Sanger Sequence ◽

Polymorphic Gene

AbstractInvestigating the current evolutionary processes acting on a highly polymorphic gene region, such as the major histocompatibility complex (MHC), requires extensive population data for both genotypes and phenotypes. The MHC consists of several tightly linked loci with both allelic and gene content variation, making it challenging to genotype. Eight class IIa haplotypes have previously been identified in the Soay sheep (Ovis aries) of St. Kilda using Sanger sequencing and cloning, but no single locus is representative of all haplotypes. Here, we exploit the closed nature of the island population of Soay sheep and its limited haplotypic variation to identify a panel of SNPs that enable imputation of MHC haplotypes. We compared MHC class IIa haplotypes determined by Sanger sequence-based genotyping of 135 individuals to their SNP profiles generated using the Ovine Infinium HD BeadChip. A panel of 11 SNPs could reliably determine MHC diplotypes, and two additional SNPs within the DQA1 gene enabled detection of a recombinant SNP haplotype. The panel of 13 SNPs was genotyped in 5951 sheep, of which 5349 passed quality control. Using the Soay sheep pedigree, we were able to trace the origin and inheritance of a recombinant SNP haplotype.

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Genetic Diversity of Cryptosporidium spp. within a Remote Population of Soay Sheep on St. Kilda Islands, Scotland

Applied and Environmental Microbiology ◽

10.1128/aem.02823-12 ◽

2013 ◽

Vol 79 (7) ◽

pp. 2240-2246 ◽

Cited By ~ 27

Author(s):

L. Connelly ◽

B. H. Craig ◽

B. Jones ◽

C. L. Alexander

Keyword(s):

Cryptosporidium Parvum ◽

Nested Pcr ◽

Fragment Length Polymorphism ◽

Ovis Aries ◽

Isolated Population ◽

Content Type ◽

Soay Sheep ◽

Population Crash ◽

Nested Pcr Assays ◽

High Diversity

ABSTRACTThis is the first report to characterize the genotypes and subtypes ofCryptosporidiumspecies infecting a geographically isolated population of feral Soay sheep (Ovis aries) on Hirta, St. Kilda, Scotland, during two distinct periods: (i) prior to a population crash and (ii) as host numbers increased.CryptosporidiumDNA was extracted by freeze-thawing of immunomagnetically separated (IMS) bead-oocyst complexes, and species were identified following nested-PCR-restriction fragment length polymorphism (RFLP)/PCR sequencing at twoCryptosporidium18S rRNA loci. Two hundred fifty-five samples were analyzed, and the prevalentCryptosporidiumspecies in single infections were identified asC. hominis(11.4% of all samples tested),C. parvum(9%),C. xiaoi(12.5%), andC. ubiquitum(6.7%).Cryptosporidium parvumwas also present with otherCryptosporidiumspecies in 27.1% of all samples tested.Cryptosporidium parvum- andC. hominis-positive isolates were genotyped using two nested-PCR assays that amplify theCryptosporidiumglycoprotein 60 gene (GP60).GP60gene analysis showed the presence of twoCryptosporidiumgenotypes, namely,C. parvumIIaA19G1R1 andC. hominisIbA10G2. This study reveals a higher diversity ofCryptosporidiumspecies/genotypes than was previously expected. We suggest reasons for the high diversity ofCryptosporidiumparasites within this isolated population and discuss the implications for our understanding of cryptosporidiosis.

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Osteoarthritis of the temporo-mandibular joint in free-living Soay sheep on St Kilda

The Veterinary Journal ◽

10.1016/j.tvjl.2014.10.014 ◽

2015 ◽

Vol 203 (1) ◽

pp. 120-125 ◽

Cited By ~ 8

Author(s):

Colin Arthur ◽

Kathryn Watt ◽

Daniel H. Nussey ◽

Josephine M. Pemberton ◽

Jill G. Pilkington ◽

...

Keyword(s):

Free Living ◽

Soay Sheep ◽

Mandibular Joint

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Parasite-Mediated Selection against Inbred Soay Sheep in a Free-Living, Island Population

Evolution ◽

10.2307/2640828 ◽

1999 ◽

Vol 53 (4) ◽

pp. 1259 ◽

Cited By ~ 245

Author(s):

David W. Coltman ◽

Jill G. Pilkington ◽

Judith A. Smith ◽

Josephine M. Pemberton

Keyword(s):

Island Population ◽

Free Living ◽

Soay Sheep

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Adrenal responsiveness in domestic sheep (Ovis aries) to acute and chronic stressors as predicted by remote monitoring of cardiac frequency

Canadian Journal of Zoology ◽

10.1139/z87-307 ◽

1987 ◽

Vol 65 (8) ◽

pp. 2021-2027 ◽

Cited By ~ 26

Author(s):

Henry J. Harlow ◽

E. Tom Thorne ◽

Elizabeth S. Williams ◽

E. Lee Belden ◽

William A. Gern

Keyword(s):

Heart Rate ◽

Chronic Stress ◽

Acute Stress ◽

Ovis Aries ◽

Domestic Sheep ◽

Free Living ◽

Chronic Stressors ◽

Cortisol Responses ◽

Adrenal Response ◽

Induced Changes

The concept of stress and the general adaptive syndrome as advanced by Hans Selye has received considerable attention during the past decade primarily in its interpretation of physiological changes associated with chronic stress. Our work with domestic sheep (Ovis aries) habituated to stalls and fitted with halters carrying indwelling electrocardiogram leads and jugular vein cannulas allowed us to remotely test heart rate and blood cortisol responses of these animals to graded stressors. A radioimmunoassay was validated on domestic sheep plasma. We were unable to identify significant alterations of the adrenal response test by sheep exposed to synthetic adrenocorticotropic hormone after 34 days of chronic stress, suggesting neither adrenal exhaustion nor hypersensitivity. As an indicator of acute stress, we obtained a correlation coefficient of 0.91 between heart rate and blood cortisol, which suggests that heart rate has a strong potential of being a reliable predictor of cortisol values. With a regression equation, the heart rate of observed free-living sheep monitored by telemetry could be used to predict plasma cortisol levels and that, in turn, to predict potential stress-induced changes in animal production, including immunity.

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