Comparison of Peritrophic Matrix-Associated Gene Expression within Tsetse Species of Varying Vector Competence

Marleah Knights*, Miguel Medina Munoz, and Rita V.M. Rio

Department of Biology, West Virginia University, Morgantown, WV 26506

Presentation Category: Biological & Biochemical Sciences (Poster Presentation #107)

Student’s Major: Biology

Tsetse flies are the obligate vector of African trypanosomes, which cause fatality in animals if left untreated. Due to difficulties in vaccine design and the lack of pharmaceuticals, vector control remains the best option for impeding disease transmission. However, tsetse species differ in vector competence (i.e. the capacity to sustain and transmit the parasite). Therefore, it is critical to understand how vector competence is determined. Here, we compare the midgut gene expression of tsetse fly species focusing on components of the peritrophic matrix (PM). The PM is a chitinous structure that acts as a protective barrier between the blood meal and the gut epithelium. We hypothesize that tsetse species exhibit significant differences in PM-related gene expression, likely resulting in PM distinctions that will consequently impact their susceptibility to trypanosome infections. To test this hypothesis, the midguts of teneral (newly eclosed adults) G. morsitans (high vector competence), and G. brevipalpis (low vector competence) species were dissected. RNA was isolated, DNase treated, and reverse transcribed to produce cDNA libraries. These libraries, representing global midgut gene expression, were subsequently sequenced with Illumina HiSeq technology. Orthologous genes between tsetse species were identified and heat maps constructed through R. Significant differences in gene expression between species pertaining to PM synthesis and structure were identified. In understanding these genetic differences between species, we enhance our knowledge of biological factors driving vector competence which may ultimately be used in the design of novel interventions towards tsetse control.

Funding: National Institute of Health

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course, KY-WV LSAMP