| Dean Croshaw 's Projects |  |
Microsatellite Primer Development and Cross Amplification in Salamanders
With Mandy Schable and Travis Glenn, I have used an enrichment technique to isolate, clone, and sequence microsatellites in four species of salamander that occur on the SRS (Notophthalmus viridescens, Desmognathus auriculatus, Ambystoma opacum, Ambystoma talpoideum). We designed and optimized several primer pairs for each species. Also, I tested the congeneric primers developed by Shannon Julian and Tim King for cross amplification in A. opacum and A. talpoideum with moderate success.
Multiple Paternity in Marbled Salamanders
With the help of a summer REU student, Maureen Peters, we are genotyping mothers and hatchlings of field-collected marbled salamander (Ambystoma opacum) clutches at four polymorphic microsatellite DNA loci. I searched for nesting females at two Carolina bays (Okie's and Ginger's) during the fall breeding season of 2002. I brought the clutches into the lab to develop and preserved them upon hatching. With much more genotyping and analysis to be done, we already know that a high proportion of clutches were sired by multiple males.
Mating Order and Fertilization Success in Mole Salamanders
I am doing laboratory experiments in which small groups of females receive access to an ordered series of males in courtship and oviposition arenas. After reproduction, eggs will be allowed to develop and hatch before preservation. Microsatellite genotyping and parentage exclusion will allow a look at sperm precedence and the importance of mating order for fertilization success of competing males.
The Importance of Polyandry to Individual Female Fitness and Population Ecology
With field enclosure experiments, I am comparing the performance of polyandrous and monandrous clutches to determine if multiple mating affects the success of individual females. Also, with post-metamorphic parentage exclusion, I will explore the possible links between female mating behavior, population ecology, and effective population size.