The phylogeny of Chinese indigenous pig breeds inferred from microsatellite markers

Abstract

A genetic study of 32 local Chinese, three foreign pig breeds [Duroc (DU), Landrace and Yorkshire], and two types of wild boar (Hainan and Dongbei wild boar) based on 34 microsatellite loci was carried out to clarify the phylogeny of Chinese indigenous pig breeds. The allele frequencies, effective numbers of alleles, and the average heterozygosity within populations were calculated. The results showed that the genetic variability of the Lingao pig was the largest, while the Jiaxing pig was the lowest. The greatest distance between domestic pigs was found between Shanggao and DU pig and the shortest was found between Wuzhishan and Lingao pig, respectively. A neighbour-joining tree constructed from Modified Cavalli-Sforza genetic distances divided Chinese pigs into two clusters; four subclusters were also identified. Our results only partly agree with the traditional types of classification and also provide a new relationship among Chinese local pig breeds. Our data also confirmed that Chinese pig breeds have a different origin from European/American breeds and can be utilized in programmes that aim to maintain Chinese indigenous pig breeds.

Biodiversity of pig breeds from China and Europe estimated from pooled DNA samples: differences in microsatellite variation between two areas of domestication

“…This observation was congruent with Fang et al [12] and Kim et al [22] and was in line with the biogeography of the wild boar, that occurs throughout Eurasia but is absent in the desert areas in the Gobi and at high altitudes in the Himalayas [31]. This effectively presented a barrier for dispersion in what is currently the central Asian part of China (i.e.…”

“…The 45 sampled Chinese breeds show a very good representation of all six recognized types [49], including the Tibetan (Plateau) type. Names of European breeds are according to Porter [34], Chinese breeds mainly according to Zhang [49], Zhang et al [50], and Fang et al [12]. DNA was isolated from individual samples using standard phenol-chloroform protocols [32].…”

“…[2,12,50]) Nei D a measure [30,35,45], and it seems superior in tree building performance particularly for intra-species phylogenies [45]. D s seems less appropriate for our current study since it cannot cope well with fluctuating populations sizes [14], which is something that is likely to have been common in most breeds.…”

“…Although undoubtedly Chinese pig breeders have sought to use animals from other than the local breeds to enhance their breeding practice [12], this has apparently been much less pronounced than in Europe. The result is that China has more pig breeds than any other country in the world by far; the World Watch List for Domestic Animal Diversity [41] lists 118 distinct breeds.…”

“…A comprehensive, global assessment of pig diversity would give better insight into the genetic relationships and distinctiveness of pigs from different parts of the world, and may aid in preservation of worldwide livestock diversity. Recent papers have reported on relations between pigs using microsatellite markers [12,22,26,28,40,47,50], but mainly between pig breeds from either China or Europe. For instance, Zhang et al [50] concluded that a number of major groups could be discerned, in part congruent with previous classification schemes.…”