Dissertation/Thesis Abstract

The expression of the transcription factor broad and RNA-binding factors in the midgut of the mosquito Aedes aegypti
by Ray, Kathryn, Ph.D., City University of New York, 2013, 144; 3612487
Abstract (Summary)

Transcription factors, microRNAs and RNA binding factors frequently interact to coordinate gene expression during development. The transcription factor BROAD (BR) is a global regulator of insect gene transcription and governs the timing of the commitment to pupate. I determined BR expression in the Ae. aegypti midgut by qPCR, and correlated its expression with that of nine miRNAs and three RNA-binding factors. During midgut metamorphosis the expression of these factors was dynamic and reproducible.

To better understand the changes in expression patterns, I evaluated the effects of hormone analogs on expression. Using this approach I uncovered concurrent up-regulation of BR, miR-34and miR-14 in the pupal midgut when treated with methoprene, and found that RH2485 accelerated expression of BR, BRAT, and microRNAs let-7 and miR-125. Treatment with each hormone analog resulted in a change in BR expression.

Finally, I evaluated the effect of nutrients on expression levels. Surprisingly, though most transcripts were down-regulated during starvation, the expression of BR did not decrease, while microRNAs miR-34 and miR-14 were elevated. This may identify a novel role for miR-34 during starvation in an invertebrate, and raises the possibility that miR-34 and miR-14 are part of a starvation-induced stress response in the mosquito midgut.

In summary, this expression analysis suggests that microRNA regulation plays an important role during midgut metamorphosis, and reveals a new layer of regulatory complexity in the control of development in Ae. aegypti .

Indexing (document details)
Advisor: Nishiura, James T.
Commitee: Bratu, Diana, Dubrovsky, Edward, Lipke, Peter, Studamire, Barbara
School: City University of New York
Department: Biology
School Location: United States -- New York
Subjects: Molecular biology
Keywords: Aedes aegypti, Midgut development, Mosquitos, RNA binding, miRNA
Publication Number: 3612487
ISBN: 978-1-303-74069-5