Prioritization for Conservation of Northern European Cattle Breeds Based on Analysis of Microsatellite Data

Abstract

Northern European indigenous cattle breeds are currently endangered and at a risk of becoming extinct. We analyzed variation at 20 microsatellite loci in 23 indigenous, 3 old imported, and 9 modern commercial cattle breeds that are presently distributed in northern Europe. We measured the breeds' allelic richness and heterozygosity, and studied their genetic relationships with a neighbor-joining tree based on the Chord genetic distance matrix. We used the Weitzman approach and the core set diversity measure of Eding et al. (2002) to quantify the contribution of each breed to the maximum amount of genetic diversity and to identify breeds important for the conservation of genetic diversity. We defined 11 breeds as a "safe set" of breeds (not endangered) and estimated a reduction in genetic diversity if all nonsafe (endangered) breeds were lost. We then calculated the increase in genetic diversity by adding one by one each of the nonsafe breeds to the safe set (the safe-set-plus-one approach). The neighbor-joining tree grouped the northern European cattle breeds into Black-and-White type, Baltic Red, and Nordic cattle groups. Väne cattle, Bohus Poll, and Danish Jersey had the highest relative contribution to the maximum amount of genetic diversity when the diversity was quantified by the Weitzman diversity measure. These breeds not only showed phylogenetic distinctiveness but also low within-population variation. When the Eding et al. method was applied, Eastern Finncattle and Lithuanian White Backed cattle contributed most of the genetic variation. If the loss of the nonsafe set of breeds happens, the reduction in genetic diversity would be substantial (72%) based on the Weitzman approach, but relatively small (1.81%) based on the Eding et al. method. The safe set contained only 66% of the observed microsatellite alleles. The safe-set-plus-one approach indicated that Bohus Poll and Väne cattle contributed most to the Weitzman diversity, whereas the Eastern Finncattle contribution was the highest according to the Eding et al. method. Our results indicate that both methods of Weitzman and Eding et al. recognize the importance of local populations as a valuable resource of genetic variation.

Relative breed contributions to neutral genetic diversity of a comprehensive representation of Iberian native cattle

“…Both methodological Table 5 Pairwise correlation coefficients between the contributions obtained with the different methods, in the same order as shown in Table 3 and Table 4 Core MEKs and field studies have been widely published in recent years (Bennewitz and Meuwissen, 2004;Fabuel et al, 2004;Mateus et al, 2004;Garcia et al, 2005;Bennewitz et al, 2006;European Cattle Genetic Diversity Consortium, 2006;Hayes et al, 2006;Tapio et al, 2006;Boettcher et al, 2010), and yet no consensus has been reached on how to appropriately account for the between-and within-population components of genetic variation (Meuwissen, 2009;Caballero et al, 2010). The choice between prioritising within-or between-breed diversity is not an easy task.…”

“…Both components should be taken into account, but how to weight them is not consensual. Favouring within-breed diversity allows for a better response to selection and adaptation, whereas weighting between-breed variation is useful to assess crossbreeding/ admixture and to create synthetic populations (Barker, 1999;Tapio et al, 2006). Inbred populations with low levels of genetic variability are less viable than those with large effective sizes and high He, but combining distant and eventually inbred populations, with different alleles segregating at high frequencies, leads to new populations with a high genetic variability due to the new heterozygotes.…”

Maternal and paternal genealogy of Eurasian taurine cattle (Bos taurus)

“…In previous studies for autosomal markers (Tapio et al, 2006a;Li et al, 2007a), the mean F ST for autosomal data was 0.0948.…”

“…For the other breeds, DNA was available from previous cattle genetic diversity studies (Bradley et al, 1996;Edwards et al, 2000;Tapio et al, 2006a).…”

“…We compared interpopulation F ST estimates of the Y-chromosomal microsatellites corrected for the four-times smaller effective population size (Pérez-Lezaun et al, 1997), with F ST estimates of 20 autosomal microsatellites. In the F ST calculations computed with FSTAT1.2 (Goudet, 1995), the data set comprised the 40 taurine breeds analysed here for the Y-chromosomal markers, plus previously published autosomal microsatellite data from Li et al (2007a) and Tapio et al (2006a). After the marker-based analyses, the allelic combinations of Y-chromosomal markers were recorded as haplotypes, and the number of haplotypes and haplotypic diversity (Nei, 1987) were calculated.…”