A Preliminary Population Genetics Analysis of Feral Goats

from an Insular Environment

Tomas Hrbek

Yadira Ortiz

Capra aegagrus hircus

• Goats have played a key role throughout human history

• Most recent genetic and archeological evidence strongly supports the hypothesis that goats were domesticated in the Zagros Mountains and that domestication occurred 10,000 years before present

• Goat were possibly the first animals to be domesticated

Capra aegagrus hircus

• Subsequent to their domestication, goats have spread to other parts of Europe, Asia and Africa

• Goats arrived with European colonists to the Americas beginning in the 16th century

• In many places goats were purposely set loose to form feral populations

Feral Goat dilemma

• Feral goats have a tendency to heavily and negatively impact native vegetation

• They have caused the extinction of native vegetation

• They have caused the extinction of native animals

Feral Goat dilemma

Feral Goat dilemma

• On the other hand, feral goats are often derived from European breeds which no longer exist in Europe

• Feral goats are also adapted to a new set of often extreme environmental conditions

• Feral goats in insular environments are also subject to genetic bottlenecks and inbreeding

Feral Goat dilemma

• Being an invasive species on one hand, and a reservoir of potentially useful genic variation that can be used for commercial stock improvement

Mona Island

Mona Island

• Mona Island is an uplifted carbonate plateau that lies halfway between Puerto Rico and Hispaniola

• Mona Island is made of Miocene to Pliocene shallow water carbonates and is fringed on its western and southern sides by Pleistocene reef terraces

• Mona Island is a stressful xeric environment

Mona Island Goats

• What is the neutral genetic diversity and adaptive genetic variation in feral Mona goats compared with unimproved and improve breeds in Europe and Africa?

• How does individual genetic diversity correlate between neutral and selected loci?

• What are the origins of the feral Mona goats?

Mona Island Goat characterization

• 41 individuals of goat genotyped for 19 microsatellite markers

• 7 markers are monomorphic

• Miminum number of alleles was 2

• Maximum number of alleles was 5 (locus CSMM66)

• Observed heterozygosity was 0.372

Comparisons

• There are a number of published studies investigating population genetic parameters in goats, and the relationships of goat breeds or land races

• These studies are mainly the result of the European Union funded Econogene project

Comparisons

• Luikart et al. (1999):

• 22 markers from 4 distinct populations

• Spanish Murciana-Grenadina population (32 individuals) is polymorphic at all 22 loci, and heterozygosity is 0.570

Comparisons

• Ouafi et al. (2002):

• 5 markers from 8 distinct populations from two localized breeds of Morocco and the Pyrenees, and cosmopolitan Alpine breeds

• All markers are polymorphic in the 6335 individuals analyzed and heterozygosity varied between 0.630 to 0.729

Comparisons

• Serrano et al. (2009):

• 10 markers from 20 subpopulations of the threatened Spanish Guadarrama goats

• All markers are polymorphic in the 6335 individuals analyzed and heterozygosity varied between 0.587 and 0.744

Conclusions

• In general Mona goats have very low heterozygosities and gene diversities

• Many loci area also monomorphic

• The Mona Island goats are highly inbred with respect to European and North African goat breeds

Future Prospects

• Mona Island goats will be sampled in January 2010

• We are now in the process of developing a screen for MHC II complex

• We are in the process of developing microsatellite and MHC II complex markers for Mona Island pigs

• Geographic structure and demographic analyses planned