Environmental and Maternal Effects on Gene Expression and Life History in the Cricket Allonemobius sociusEPA Grant Number: F5D61327
Title: Environmental and Maternal Effects on Gene Expression and Life History in the Cricket Allonemobius socius
Investigators: Huestis, Diana L.
Institution: The University of Texas at Arlington
EPA Project Officer: Zambrana, Jose
Project Period: August 22, 2005 through August 15, 2008
Project Amount: $110,422
RFA: GRO Fellowships for Graduate Environmental Study (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Given that insects are both diverse and widespread, they are of general biological interest and serve as an ideal model system for studying many aspects of ecology and evolutionary biology. In particular, the induction of egg diapause is a very important life-history trait for insect species, as it enhances survival during inclement environmental conditions. However, the mechanism underlying egg diapause is not known for most species, and thus remains an exciting and interesting question. The proposed research will examine environmental, maternal, and genetic influences on diapause in the cricket Allonemobius socius.
Crickets will be collected from the field at several locations and screened using allozymes to confirm species status. Wild-caught crickets will be mated to produce a F 1 generation for use in all experiments. The F 1 will consist of diapause and non-diapause individuals which will be reared separately under controlled conditions. Once adulthood is reached, mating pairs will be established and randomly assigned to one of two experimental temperatures. This design enables the study of two main factors: parental diapause history and egg-laying/egg-incubation temperature. mRNA differential display will be utilized to screen the entire transcriptome for expression differences related to temperature and/or parental diapause history. Results will be confirmed with real-time PCR, and those genes which are consistently differentially expressed will be sequenced. Sequences will be analyzed and compared to other known sequences using available databases. Follow-up experiments to confirm that identified genes of interest are involved in the diapause pathway will be done using RNAi and injection technology.
Gene expression differences should be found with this design, and are expected to result from differences in temperature and/or parental diapause history between the individuals studied. These genes may be novel or similar to those identified in other species. Follow-up RNAi experiments are expected to confirm that genes found to be differentially expressed are part of the diapause pathway.