Analysis of Microsatellites and Parentage Testing in Saltwater Crocodiles

Fifteen microsatellite loci were evaluated in farmed saltwater crocodiles for use in parentage testing. One marker (C391) could not be amplified. For the remaining 14, the number of alleles per locus ranged from two to 16, and the observed heterozygosities ranged from 0.219 to 0.875. The cumulative exclusion probability for all 14 loci was.9988. The 11 loci that showed the greatest level of polymorphism were used for parentage testing, with an exclusion probability of.9980. With these 11 markers on 107 juveniles from 16 known-breeding pairs, a 5.6% pedigree error rate was detected. This level of pedigree error, if consistent, could have an impact on the accuracy of genetic parameter and breeding value estimation. The usefulness of these markers was also evaluated for assigning parentage in situations where maternity, paternity, or both may not be known. In these situations, a 2% error in parentage assignment was predicted. It is therefore recommended that more microsatellite markers be used in these situations. The use of these microsatellite markers will broaden the scope of a breeding program, allowing progeny to be tested from adults maintained in large breeding lagoons for selection as future breeding animals.