scholarly journals Exposure to viral and bacterial pathogens among Soay sheep (Ovis aries) of the St Kilda archipelago

2016 ◽  
Vol 144 (9) ◽  
pp. 1879-1888 ◽  
Author(s):  
A. L. GRAHAM ◽  
D. H. NUSSEY ◽  
J. O. LLOYD-SMITH ◽  
D. LONGBOTTOM ◽  
M. MALEY ◽  
...  
Keyword(s):  
Bacterial Pathogens ◽  
Ovis Aries ◽  
Soay Sheep ◽  
Fitness Effects ◽  
Host Interaction ◽  
Faecal Samples ◽  
Border Disease ◽  
Transmission Ecology ◽  
Outer Hebrides ◽  
Local Transmission

SUMMARYWe assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure toLeptospiraspp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor toChlamydia abortus. Some sheep tested positive for antibodies againstMycobacterium aviumsubsp.paratuberculosis(MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.

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

Behaviour ◽  
2004 ◽  
Vol 141 (8) ◽  
pp. 999-1020 ◽  
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.

Identification of MHC-I Accessible Proteins from Salmonella Typhimurium

2001 ◽  
Vol 7 (S2) ◽  
pp. 616-617
Author(s):  
D. Ellefson ◽  
D. Parker ◽  
F. Heffron
Keyword(s):  
Salmonella Typhimurium ◽  
Host Cell ◽  
Antigen Processing ◽  
Bacterial Pathogens ◽  
Immune Surveillance ◽  
Class I ◽  
Whole Genome Analysis ◽  
Class I Mhc ◽  
Mhc I ◽  
Host Interaction

Intracellular bacterial pathogens such as Salmonella typhimurium secrete proteins into the host cell after infection. These proteins alter the normal structural and metabolic machinery of the host cell and benefit the bacterium by facilitating replication and avoidance of host immune surveillance. Since the host cytoplasmic localization of these proteins infers access to the class-I MHC antigen processing and presentation machinery of the host cell, we collectively refer to these proteins as Class- I Accessible Proteins (CAPs).The design of vaccines for new and emerging bacterial pathogens is often constrained by the selection of appropriate and specific antigens. While vaccine design is being greatly aided by whole genome analysis of bacterial pathogens, it has been of limited use in the assignment of function and host subcellular localization of a large percentage of bacterial proteins. in addition, analysis of the bacteria/host interaction is further complicated by the complex lifestyle of the pathogen.

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

PLoS Genetics ◽  
2019 ◽  
Vol 15 (11) ◽  
pp. e1008461 ◽  
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

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

Parasitology ◽  
1992 ◽  
Vol 105 (3) ◽  
pp. 481-492 ◽  
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).

scholarly journals Correlation of the Gastrointestinal Parasitism with the Phytominerals in the Grazing Sheep (Ovis aries)

2021 ◽  
Vol 26 (01) ◽  
pp. 60-68
Author(s):  
Hafiz Muhammad Rizwan
Keyword(s):  
Trace Elements ◽  
Soil Samples ◽  
Ovis Aries ◽  
Parasitic Infections ◽  
Faecal Samples ◽  
Eimeria Spp ◽  
Parasitic Burden ◽  
Pre Treatment ◽  
High Concentrations ◽  
Fasciola Spp

Trace elements play an important role to boost the immunity and fight against parasitic infections. Concentration of trace elements like Copper (Cu), Cobalt (Co), Manganese (Mn) and Zinc (Zn) were determined in soil, forages and sera of sheep. An associative analysis was also made between the burden of Gastrointestinal (GI) parasites and concentrations of trace elements of sheep sera. For this, 384 faecal and blood samples of sheep, an appropriate number of forages and soil samples were collected. The faecal samples were subjected to determine the species and burden of GI parasites. The sera, plant and soil samples were subjected to pre-treatment (digestion) required for the determination of trace elements. The overall prevalence of GI parasites was 32.81% and the most prevalent species were Haemonchus (H.) contortus followed in order by Eimeria spp., Strongyloides spp., Trichostrongylus spp. and Fasciola spp. Variables like age, sex, breed and tehsils of Silakot district showed an insignificant association with GI parasitic burden. Trace elements concentration of forages showed a significant (P < 0.05) variation while trace elements concentration of soil showed an insignificant (P > 0.05) variation. In serum, Zn concentration showed significant (P < 0.05) results among all the tehsils of study district. Mean concentrations of Mn and Cu in serum were found inversely proportional to the mean egg count per gram of sheep faeces in tehsil Pasroor of the Sialkot district. Forages containing high concentrations of Mn and Cu can be used effectively against GI parasites. © 2021 Friends Science Publishers

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

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.

scholarly journals Seasonal dynamics and repeatability of gastrointestinal parasite burdens in wild Soay sheep

2021 ◽  
Author(s):  
Amy R. Sweeny ◽  
Yolanda Corripio-Miyar ◽  
Xavier Bal ◽  
Adam Hayward ◽  
Jill G. Pilkington ◽  
...  
Keyword(s):  
Seasonal Dynamics ◽  
Disease Ecology ◽  
Gastrointestinal Parasites ◽  
Reproductive Status ◽  
Gastrointestinal Parasite ◽  
Short Term ◽  
Soay Sheep ◽  
Long Term Study ◽  
Faecal Samples

AbstractSeasonality is a ubiquitous feature of wildlife disease ecology, but is determined by a complex interplay of environmental, parasitological and host factors. Gastrointestinal parasites often exhibit strong seasonal dynamics in wild vertebrate populations due to, for example, environmental influences on free-living or vectored life stages, and variation in the physiological and immune status of hosts across their annual cycle. At the same time, wild populations are typically infected with multiple parasites. The seasonal dynamics of co-infecting parasites may differ depending on age and reproductive status, and associations among parasites may be driven by short-term within-individual changes or longer-term interactions that are consistent among hosts. Here, we used faecal samples and egg counts collected repeatedly from individually marked and monitored wild Soay sheep that were part of a long-term study to investigate seasonal dynamics of six gastrointestinal parasite groups (strongyle nematodes, coccidian protozoa, Capillaria, Strongyloides, Nematodirus, and Moniezia). Prevalence and abundance generally tended to be higher spring and summer, and burdens were higher in lambs than adults. Within the highly prevalent strongyle nematode group, we found differences in seasonality of egg counts depending on adult reproductive status. Reproductive ewes had increased counts in spring around the time of birth followed by a drop in abundance in summer, while barren ewes showed little evidence of seasonality. Males showed a sustained rise in egg counts through spring and summer, and sex differences were only strongly apparent in summer. In contrast, in similarly prevalent coccidia we found a peak in faecal oocyst counts in spring but no differences in seasonality among males, barren and pregnant ewes. Using multivariate mixed-effects models, we went on to show that both strongyle and coccidia counts are moderately repeatable across seasons among individuals. We further show that apparent positive correlation between strongyle and coccidia counts was driven by short-term within-individual changes in both parasite burdens rather than long-term among-individual covariation. Overall, our results demonstrate that seasonality varies across demographic and parasite groups and highlight the value of investigating fluctuating susceptibility and exposure over time for understanding epidemiology of a population.

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

2013 ◽  
Vol 79 (7) ◽  
pp. 2240-2246 ◽  
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.

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

Genetics ◽  
2006 ◽  
Vol 173 (3) ◽  
pp. 1521-1537 ◽  
Author(s):  
Dario Beraldi ◽  
Allan F. McRae ◽  
Jacob Gratten ◽  
Jon Slate ◽  
Peter M. Visscher ◽  
...  
Keyword(s):  
Linkage Map ◽  
Ovis Aries ◽  
Free Living ◽  
Soay Sheep

scholarly journals Selection of lamb size and early pregnancy in Soay sheep (Ovies aries)

2020 ◽  
Author(s):  
Maria João Janeiro ◽  
Jonathan M. Henshaw ◽  
Josephine M. Pemberton ◽  
Jill G. Pilkington ◽  
Michael B. Morrissey
Keyword(s):  
Body Size ◽  
Early Pregnancy ◽  
Large Body ◽  
Ovis Aries ◽  
Direct Selection ◽  
Trade Off ◽  
Soay Sheep ◽  
Ewe Lamb ◽  
Slow Evolution ◽  
Selection Of

AbstractThe paradox of stasis – the unexpectedly slow evolution of heritable traits under direct selection – has been widely documented in the last few decades. This paradox is often particularly acute for body size, which is often heritable and where positive associations of size and fitness are frequently identified, but constraints to the evolution of larger body sizes are often not obvious. Here, we identify a trade-off between survival and size-dependent reproduction in Soay sheep (Ovis aries), contributes to selection against large body size. Using recently developed theory on non-linear developmental systems, then decompose total selection of ewe lamb mass along different causal paths to fitness. Larger lambs are more likely to become pregnant, which has a large viability cost. After controlling for this pathway, however, the association between lamb mass and subsequent lifetime fitness is positive. Thus this trade-off does not fully explain stasis of size in tis population, but it does substantially reduce the strength of positive directional selection of size that would otherwise occur. While selection currently favours reduced probability of early pregnancy, largely irrespective of body size, it is likely that the occurrence of early pregnancy could result from adaptation to conditions during a recent period during which population density was much lower.

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