Genetic diversity of three donkey populations in the Croatian coastal region

Abstract

Genetic variation in three Croatian donkey populations, Istrian (IS), North Adriatic (NA) and Littoral-Dinaric (LD), was analysed using eight microsatellite loci and by sequence and SSCP analysis of the proximal portion of the mtDNA D-loop region. The analysis of microsatellite loci revealed observed heterozygosities in the range of 0.37 (MPZ002 in LD) to 0.85 (AHT21 in LD) and polymorphic information content values in the range of 0.36 (MPZ002 in NA) to 0.78 (AHT21 in LD). The overall probability of exclusion was 0.991. Two populations (IS and NA) were closely related (Fst=0.0034), whereas genetic distances between IS and LD (Fst=0.021) and NA and LD (Fst=0.027) were higher. Using AMOVA, 97.6% of the total genetic variance was portioned within populations, while 2.7% was portioned between the Littoral-Dinaric population and the Istrian/North Adriatic population group. Sequencing of the proximal part of the mtDNA D-loop region revealed 36 polymorphic sites representing 19 haplotypes which clustered into three haplotype groups (Y, W, Ws). Only the Y haplotype was found in the IS population which is characterized by a large body size. Haplotypes W and Ws were found in the NA and LD populations which include smaller animals. All three haplotypes were found in the LD population, indicating sporadic migration events from the IS into LD donkey population.

Genetic variability and efficiency of DNA microsatellite markers for paternity testing in horse breeds from the Brazilian Marajó archipelago

“…Jordana et al (2001) recorded a mean PIC equal to the value recorded here for the Puruca breed, although a slightly lower value for CPE1 (99.93%) than either recorded here. Ivankovic et al (2002) also recorded slightly lower mean values for PIC (61%) and CPE1 (99.1%) than the present study.…”

“…These values are considerably lower than those observed in European horses and asses, for which mean heterozygosity ranges from 60% to 66% (see Ivankovic et al, 2002;Cunningham et al, 2001;Jordana et al, 2001;Aberle et al, 2004;Achmann et al, 2004).…”

“…Inbreeding is common practice in many domestic animals (Oliveira and Kuabara, 2001), but it is especially intense in populations with reduced effective size, as is the case here, with regard to both Marajoara and Puruca populations. Jordana et al (2001) and Ivankovic et al (2002) also observed Hardy-Weinberg disequilibrium in their study populations. The Catalonian breed analyzed by Jordana et al (2001) is known to have a restricted distribution and a population of more or less 100 individuals.…”

“…The difference between the two breeds appears to be due to sample size, although the mean number of alleles per locus -9.1 and 7.0, respectively -were similar to those recorded for other horse breeds. Mean values of approximately seven alleles per locus have been recorded for a number of equine populations, including seven populations of Lipizzaner, which is common in southeastern Europe (Achmann et al, 2004), four horse breeds native to the Basque country (Solis et al, 2005) and four populations of domestic ass (Equus asinus), one from Catalonia (Jordana et al, 2001) and three from Croatia (Ivankovic et al, 2002). Values similar to our recorded here for the Marajoara breed were found in four Norwegian (Bjørnstad et al, 2000) six German (Aberle et al, 2004), and seven Celtic Spanish horse breeds (Cañon et al, 2000).…”

“…The Catalonian breed analyzed by Jordana et al (2001) is known to have a restricted distribution and a population of more or less 100 individuals. Similarly, the Croatian breed studied by Ivankovic et al (2002) is threatened with extinction, and also has a reduced number of individuals. By contrast, the populations studied by Achmann et al (2004), Cunningham et al (2001) and Aberle et al (2004) were all in Hardy-Weinberg equilibrium, although the breeds studied in these cases are all amply distributed and presumably have populations of large effective size, as is the case of the Lipizzaner in particular (Achmann et al, 2004).…”