Female turtles are capable of storing sperm from multiple males, potentially enabling offspring from a single clutch to be fathered by several males. Multiple paternity may provide turtles with adaptive advantages, but how widespread multiple paternity is among turtle species is debated. To accurately assess multiple paternity in a species, it is necessary to examine representative samples of different populations. In this study, multiple paternity was examined in a clutch (n = 31) of the Colombian giant Amazon river turtle, Podocnemis expansa, using seven microsatellite loci. Microsatellites are tandem repeats of a nucleotide motif (1-6 base pairs long). They are stably inherited and accumulate mutations in the number of repeats, causing variation and making them good tools for the study of multiple paternity. Genomic DNA containing the microsatellite region was amplified with fluorochrome labeled primers and genotyped to score the paternal alleles present in each egg. By analyzing the number of alleles at any given locus and across loci, we established the incidence of multiple paternity, with a minimum number of three fathers being represented in this single clutch.
Pavla Brachova, ’09 Ames, IA
Majors: Biochemistry and Molecular Biology, Spanish
Sponsor: S. Andrew McCollum