Sexual reproduction is a major source of the genetic diversity that is required for organisms to adapt to changing environments. Asexual reproduction is associated with lower diversity but confers its own advantages, allowing asexual lineages to produce offspring at a much higher rate than sexual lineages. These benefits of asexuality are so great that why sexual reproduction remains so common in nature is unclear and is considered one of the most important unanswered questions in biology. Species that contain both sexual and asexual individuals are ideally suited to apply to the question of why sex is so common, allowing direct comparisons between sexual and asexual individuals. Potamopyrgus Antipodarum, an ancestrally sexual New Zealand snail, is characterized by coexisting sexual and asexual individuals and thus provides an ideal model system with which to study sex. Here, we use an RNA-sequencing approach to quantify and compare gene expression across reproductive modes, sexes, and reproductive status in P. antipodarum. This approach will allow us to identify genes uniquely expressed in reproductively active sexual vs. asexual females, potentially revealing candidates for genes that influence transitions to asexual reproduction. This study revealed that there was a fair amount of differentially expressed genes between sexual female genes and sexual female genes that were reproductively active. We are current using Blast2GO in order to characterize the function of these differentially expressed genes. This information will help to illuminate the mechanisms that cause P. antipodarum to transition from sexual to asexual reproduction and the genomic consequences of asexuality. Future directions will include using methylation-sensitive genotyping to determine whether the differential expression that we observed is generated by differential methylation and evaluating the extent to which the patterns we found here are generalizable across the species.