OMIA 001694-9940 : Resistance/susceptibility to lentivirus in Ovis aries

In other species: domestic cat

Mendelian trait/disorder: no

Mode of inheritance: Multifactorial

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2012

Species-specific name: Resistance/susceptibility to Visna/Maedi virus (VMV); Resistance/susceptibility to ovine progressive pneumonia virus (OPPV)

Species-specific symbol: OPP

Mapping: Using the first-generation ovine 50K SNP chip, Heaton et al. (2012) conducted a GWAS in 69 matched pairs (infected/uninfected controls) of mixed-breed sheep from the USMARC (Nebraska) sheep population. Two SNPs in the same region of chromosome OAR17 showed the highest and third-highest genome-wide significance.

In a separate GWAS of "964 sheep from Rambouillet, Polypay, and Columbia breeds with serological status and proviral concentration phenotypes", White et al. (2012) confirmed the TMEM154 results of Heaton et al. (2012) and reported "12 additional genomic regions associated with odds of infection, and provided 13 regions associated with control of infection (all nominal P<1 × 10(-5))".

Markers: In a global survey of sheep breeds, Heaton et al. (2013) observed "The average frequency of TMEM154 E35 among 74 breeds was 0.51 [which] indicated that highly-susceptible alleles were present in most breeds around the world." They concluded that "The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks."

Molecular basis: Following up the results of their GWAS described above, Heaton et al. (2012) showed that the two OAR17 SNPs are located in "an ovine gene homologous to the human TMEM154 gene". Subsequent sequencing and association analysis showed that "Two TMEM154 haplotypes encoding glutamate (E) at position 35 were associated with infection. . . . The odds of infection for ewes with one copy of a full-length TMEM154 E35 allele were 28 times greater than the odds for those without (p-value<0.0001, 95% CI 5–1,100). In a combined analysis of nine cohorts with 2,705 sheep from Nebraska, Idaho, and Iowa, the relative risk of infection was 2.85 times greater for sheep with a full-length TMEM154 E35 allele (p-value<0.0001, 95% CI 2.36–3.43). Although rare, some sheep were homozygous for TMEM154 deletion mutations and remained uninfected despite a lifetime of significant exposure." Taken together, these results led to Heaton et al. (2012) concluding that "TMEM154 may play a central role in ovine lentivirus infection and removing sheep with the most susceptible genotypes may help eradicate OPP and protect flocks from reinfection". While the actual function of the membrane protein encoded by TMEM154 is still to be worked out, the apparent resistance of sheep homozygous for a mutant that results in no functional peptide strongly suggests a mechanism for resistance/susceptibility, namely that the lentivirus needs this peptide in order to infect cells.

Following up one of the most promising regions for control of infection from the GWAS of White et al. (2012), White et al. (2013) "identified a small insertion/deletion variant near [5' of] ZNF389 [OVA20; g.29500068_29500069delAT; GenBank NC_019477.1] that showed consistent association with proviral concentration in three animal sets . . . The best estimate of proviral concentration by genotype, obtained from all 1310 OvLV-positive animals tested, showed insertion homozygotes had less than half the proviral concentration of other genotypes (P < 0.0001). . . . To our knowledge, this is the first genetic variant consistently associated with host control of OvLV post-infection in multiple sheep flocks."

Clinical features: As reported by Heaton et al. (2013), "The first signs of disease typically appear after age two and often include the loss of body condition and indurative mastitis (hard udder). Disease progression is associated with severe clinical signs that include difficulty breathing, chronic wasting, loss of motor control, and arthritis."

Breeds: Rambouillet, Polypay.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
TMEM154 transmembrane protein 154 Ovis aries 17 NC_019474.2 (4836004..4887683) TMEM154 Homologene, Ensembl, NCBI gene


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Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
Rambouillet Polypay Resistance to lentivirus TMEM154 regulatory NC_019477.1 17 g.29500068_29500069delAT 2013 24303974


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2015 Bishop, S.C. :
Genetic resistance to infections in sheep. Vet Microbiol 181:2-7, 2015. Pubmed reference: 26260859. DOI: 10.1016/j.vetmic.2015.07.013.
Clawson, M.L., Redden, R., Schuller, G., Heaton, M.P., Workman, A., Chitko-McKown, C.G., Smith, T.P., Leymaster, K.A. :
Genetic subgroup of small ruminant lentiviruses that infects sheep homozygous for TMEM154 frameshift deletion mutation A4Δ53. Vet Res 46:22, 2015. Pubmed reference: 25756342. DOI: 10.1186/s13567-015-0162-7.
2013 Heaton, M.P., Kalbfleisch, T.S., Petrik, D.T., Simpson, B., Kijas, J.W., Clawson, M.L., Chitko-McKown, C.G., Harhay, G.P., Leymaster, K.A. :
Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep. PLoS One 8:e55490, 2013. Pubmed reference: 23408992. DOI: 10.1371/journal.pone.0055490.
White, S.N., Mousel, M.R., Reynolds, J.O., Herrmann-Hoesing, L.M., Knowles, D.P. :
Deletion variant near ZNF389 is associated with control of ovine lentivirus in multiple sheep flocks. Anim Genet :, 2013. Pubmed reference: 24303974. DOI: 10.1111/age.12107.
2012 Heaton, M.P., Clawson, M.L., Chitko-Mckown, C.G., Leymaster, K.A., Smith, T.P., Harhay, G.P., White, S.N., Herrmann-Hoesing, L.M., Mousel, M.R., Lewis, G.S., Kalbfleisch, T.S., Keen, J.E., Laegreid, W.W. :
Reduced lentivirus susceptibility in sheep with TMEM154 mutations. PLoS Genet 8:e1002467, 2012. Pubmed reference: 22291605. DOI: 10.1371/journal.pgen.1002467.
White, S.N., Mousel, M.R., Herrmann-Hoesing, L.M., Reynolds, J.O., Leymaster, K.A., Neibergs, H.L., Lewis, G.S., Knowles, D.P. :
Genome-wide association identifies multiple genomic regions associated with susceptibility to and control of ovine lentivirus. PLoS One 7:e47829, 2012. Pubmed reference: 23082221. DOI: 10.1371/journal.pone.0047829.

Edit History

  • Created by Frank Nicholas on 29 Jun 2012
  • Changed by Frank Nicholas on 29 Jun 2012
  • Changed by Frank Nicholas on 25 Apr 2013
  • Changed by Frank Nicholas on 08 Dec 2013