Characterization of Microsatellite Markers for the Siamese Crocodile and Amplification in the Closely Related Genus Crocodylus

Abstract

Twenty microsatellite markers from Crocodylus siamensis were characterized in 40 crocodiles: 29 C. siamensis, 4 C. porosus, 2 hybrids (C. siamensis + C. porosus) and 5 Caiman crocodilus crocodilus. Fourteen microsatellite markers that showed specific alleles were considered as specific markers for use in identifying the species of crocodile. These markers were: CS-25 for C. siamenis; CS-4, CS-26 and CS-30 for C. porosus; CS-2, CS-7, CS-10, CS-12, CS-14, CS-17, CS-22, CS-24 and CS-35 for C. c. crocodilus; and CS-20 for all species. Twelve microsatellite markers that had polymorphic alleles in the same species were considered as intra-specific markers. These markers were: CS-4, CS-5, CS-10, CS-12, CS-17, CS-18, CS-21, CS-24, CS-26, CS-30, CS-32 and CS-35. Seven microsatellite markers showed an absence of alleles in C. c. crocodilus and were considered as genus-specific markers. These markers were: CS-4, CS-5, CS-18, CS-21, CS-26, CS-30, and CS-32. The microsatellite markers mentioned above could be used for species testing and could also be evaluated to help determine parentage in situations where the maternity, paternity, or both were unknown. It was therefore recommended that more microsatellite markers be used in such situations. The use of the microsatellite markers involved in this study would broaden the scope of a breeding program, allowing progeny from adults maintained in large breeding lagoons to be tested for selection as future breeding animals.