Genetic diversity in eight Swiss goat breeds was estimated using PCR amplification of 20 bovine microsatellites on 20-40 unrelated animals per breed. In addition, the Creole breed from the Caribbean and samples of Ibex and Bezoar goat were included. A total of 352 animals were tested. The bovine microsatellites chosen amplified well in goat. The average heterozygosity within population was higher in domestic goat (0.51-0.58) than in Ibex (0.17) and Bezoar goat (0.19). Twenty-seven per cent of the genetic diversity in the total population could be attributed to differences between the populations. However, with the exclusion of Ibex from the total population, this proportion dropped to 17%. Principal component analysis showed that all Swiss goat breeds are closely related, whereas the Creole breed, Ibex and Bezoar goat are clearly distinct from all eight Swiss breeds.

Introduction  First attempts at establishing the genetic relationships among cattle populations relied on archeological evidence (Epstein 1971; Epstein and Mason 1984) and protein polymorphisms (Baker and Manwell 1980, 1991). Loftus et al. (1994) examined mitochondrial DNA to determine the divergence time between Bos taurus and Bos indicus. Today most studies on genetic diversity are based on microsatellite analysis (Litt and Luty 1989; Tautz 1989; Weber and May 1989). Microsatellites were used in, e.g. man (Bowcock et al. 1994), canids (Roy et al. 1994; Fredholm and Winterø 1995) and sheep (Buchanan et al. 1994). Recent studies in cattle are also microsatellite based (e.g. Machugh et al. 1994; Ciampolini et al. 1995; Moazami‐Goudarzi et al. 1997) and aim at facilitating the development of management programs for endangered breeds (FAO 1981). Our microsatellite‐based investigation on the genetic diversity between and within Swiss cattle breeds included Original Swiss Brown, purebred Simmental, Holstein, Hérens and Evolènard. Previous studies in Swiss breeds made use of blood group systems (Reuse 1969), serum transferrin and hemoglobin (Krummen 1964), amylase (Buser 1970) and carboanhydrases (Kästli et al. 1980). The Hérens breed is endemic to the canton of Wallis. The Evolènard, which are very few in numbers and restricted to a single valley in the canton of Wallis, are phenotypically very similar to the Hérens with the exception of the coat colour. In the Aosta valley (Italy) which borders the canton of Wallis these two breeds find their counterparts. The phenotype of the Aosta Chestnut fits the Hérens and the Aosta Black Pied fits the Evolènard. The Holstein breed replaced the Fribourg breed which was a colour variant of the purebred Simmental breed (Engeler et al. 1961) and is now extinct. The Original Swiss Brown and the purebred Simmental are endemic to Switzerland.

No abstract

We established a set of 30 microsatellites of Bovidae origin for use in a biodiversity study in Swiss and Creole goats. Additional microsatellites located within or next to "candidate" genes of interest, such as cytokine genes (IL4, INF-gamma) and MHC class II genes (DRB, DYA) were tested in the caprine species in order to detect possible associations with two infectious caprine diseases. Microsatellite analysis was undertaken using automated sequencers (ABI373 & 3100). In the first study, a total of 82 unrelated Creole goats, 37 resistant and 45 susceptible to Heartwater disease (Cowdriosis) were analysed. In this study, the two microsatellite loci DRBP1 (MHCII) and BOBT24 (IL4) were positively associated with disease susceptibility, demonstrating a corrected P-value of 0.002 and 0.005, respectively. In a second investigation, we tested 36 goats, naturally infected with the nematode parasite Trichostrongylus colubriformis. These animals were divided into a "low" and "high" excreting group on the basis of two independently recorded fecal egg counts. For this nematode resistance study, we detected a significant association of one of the alleles of the microsatellite locus SPS113 with "low" excretion (resistance). The MHC class II locus DYA (P19), was weakly associated with susceptibility in both diseases (Pc = 0.05). In future experiments, we will extend the sample size in order to verify the described associations.

No abstract