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Genetic diversity, breed composition and admixture of Kenyan domestic pigs
PloS ONE
  • Fidalis Denis Mujibi, Nelson Mandela Africa Institution of Science and Technology
  • Edward Okoth, International Livestock Research Institute, Nairobi, Kenya
  • Evans K. Cheruiyot, USOMI Limited
  • Cynthia Onzere, Washington State University
  • Richard P. Bishop, Washington State University
  • Eric M. Fèvre, International Livestock Research Institute, Nairobi, Kenya
  • Lian Thomas, University of Edinburgh
  • Charles Masembe, Makerere University
  • Graham Plastow, University of Alberta
  • Max Rothschild, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
1-22-2018
DOI
10.1371/journal.pone.0190080
Abstract

The genetic diversity of African pigs, whether domestic or wild has not been widely studied and there is very limited published information available. Available data suggests that African domestic pigs originate from different domestication centers as opposed to international commercial breeds. We evaluated two domestic pig populations in Western Kenya, in order to characterize the genetic diversity, breed composition and admixture of the pigs in an area known to be endemic for African swine fever (ASF). One of the reasons for characterizing these specific populations is the fact that a proportion of indigenous pigs have tested ASF virus (ASFv) positive but do not present with clinical symptoms of disease indicating some form of tolerance to infection. Pigs were genotyped using either the porcine SNP60 or SNP80 chip. Village pigs were sourced from Busia and Homabay counties in Kenya. Because bush pigs (Potamochoerus larvatus) and warthogs (Phacochoerus spp.) are known to be tolerant to ASFv infection (exhibiting no clinical symptoms despite infection), they were included in the study to assess whether domestic pigs have similar genomic signatures. Additionally, samples representing European wild boar and international commercial breeds were included as references, given their potential contribution to the genetic make-up of the target domestic populations. The data indicate that village pigs in Busia are a non-homogenous admixed population with significant introgression of genes from international commercial breeds. Pigs from Homabay by contrast, represent a homogenous population with a “local indigenous’ composition that is distinct from the international breeds, and clusters more closely with the European wild boar than African wild pigs. Interestingly, village pigs from Busia that tested negative by PCR for ASFv genotype IX, had significantly higher local ancestry (>54%) compared to those testing positive, which contained more commercial breed gene introgression. This may have implication for breed selection and utilization in ASF endemic areas. A genome wide scan detected several regions under preferential selection with signatures for pigs from Busia and Homabay being very distinct. Additionally, there was no similarity in specific genes under selection between the wild pigs and domestic pigs despite having some broad areas under similar selection signatures. These results provide a basis to explore possible genetic determinants underlying tolerance to infection by ASFv genotypes and suggests multiple pathways for genetically mediated ASFv tolerance given the diversity of selection signatures observed among the populations studied.

Comments

This article is published as Mujibi, Fidalis Denis, Edward Okoth, Evans K. Cheruiyot, Cynthia Onzere, Richard P. Bishop, Eric M. Fèvre, Lian Thomas, Charles Masembe, Graham Plastow, and Max Rothschild. "Genetic diversity, breed composition and admixture of Kenyan domestic pigs." PloS one 13, no. 1 (2018): e0190080. doi: 10.1371/journal.pone.0190080.

Rights
This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Language
en
File Format
application/pdf
Citation Information
Fidalis Denis Mujibi, Edward Okoth, Evans K. Cheruiyot, Cynthia Onzere, et al.. "Genetic diversity, breed composition and admixture of Kenyan domestic pigs" PloS ONE Vol. 13 Iss. 1 (2018) p. e0190080
Available at: http://works.bepress.com/max-rothschild/171/