Genetic Characterization of the “Chusca Lojana”, a Creole Goat Reared in Ecuador, and Its Relationship with Other Goat Breeds

SIMPLE SUMMARY: An individual from a population presents a series of characteristics that differ from the rest and that increase as the kinship relationships are lower; this leads to the fact that two populations that stop exchanging genetic material through mating eventually come to present characters common to all members of each, but different between the two. This was what happened with the animal populations brought to America more than 500 years ago from the Iberian Peninsula in the colonization period, resulting in Creole populations that inhabit the harshest environments of our immense geography. The Creole goat “Chusca Lojana” has adapted to live in the dry forest region of Southern Ecuador, where environmental conditions are warm-dry, with sparse vegetation and a rather irregular topography. In the present study, the intra-breed genetic diversity of this goat is analyzed as well as its genetic relationships with other breeds. Significant F(IS) and intra-breed structure show that there is some heterogeneity and structure within the breed. However, inter-breed structure results underline that this breed is differentiated from other Creole breeds, because crossbreeding with other breeds was not detected; therefore, we must take advantage of this valuable genetic resource, and ensure its conservation and selection. ABSTRACT: The largest population of goats (62%) in Ecuador is in the dry forest region in the south of the country. A Creole goat, named “Chusca Lojana”, has adapted to the dry forest region where environmental conditions are warm-dry, with sparse vegetation. Knowledge of the genetic information of the Creole goat is important to determine intra-racial diversity, the degree of genetic distance among other breeds of goats, and the possible substructure of the population, which is valuable for the conservation of such a species’ genetic resources. A total of 145 samples of the Creole goat was taken from the four biotypes previously identified. Genetic analyses were performed using 38 microsatellites recommended for studies of goat genetic diversity (FAO-ISAG). The results of within-breed genetic diversity showed a mean number of alleles per locus (MNA) of 8, an effective number of alleles (Ae) of 4.3, an expected heterozygosity (He) of 0.71, an observed heterozygosity (Ho) of 0.63, polymorphic information content (PIC) of 0.67, and an F(IS) value of 0.11. Between-breed genetic diversity among 43 goat populations (native of Spain, American Creole, Europeans, and Africans) showed the following values: F(IS) = 0.087, F(IT) = 0.176, and F(ST) = 0.098. Regarding the analysis of the population structure, the results showed that the Creole Chusca Lojana goat population is homogeneous and no genetic separation was observed between the different biotypes (F(ST) = 0.0073). In conclusion, the Chusca Lojana goat has a high genetic diversity, without exhibiting a genetic substructure. Therefore, it should be considered as a distinct population because crossbreeding with other breeds was not detected.