Meeting Abstract
Viviparous reproduction is characterized by maternal retention of developing offspring within her reproductive tract during gestation, culminating in live birth. In some cases a mother will provide nutrition beyond that present in the yolk; this is known as matrotrophic viviparity. While this phenomenon is best associated with mammals, it is observed in insects such as the viviparous cockroach, Diploptera punctata. Female D. punctata carry developing embryos in the brood sac, a reproductive organ that acts as both a uterus and placenta by protecting and providing a nutritive secretion to the intrauterine developing progeny. While the basic physiology of D. punctata pregnancy has been characterized, little is known about the molecular mechanisms underlying this phenomenon. This study combines RNA-seq analysis, RNA interference, and other assays to characterize molecular changes associated with D. punctata reproduction and provides the most complete gene set to date for this species. A comparison of four stages of the female reproductive cycle revealed unique gene expression profiles corresponding to each stage. Differentially regulated transcripts of interest include the previously identified family of milk proteins, transcripts associated with juvenile hormone metabolism, and other reproduction-associated transcripts. RNA interference experiments reveal potential impacts of juvenile hormone breakdown in maintaining pregnancy in D. punctata. Additional experiments explore the potential use of DNA methylation as an epigenetic mechanism in D. punctata.
