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 .
|Advisor:||Nishiura, James T.|
|Commitee:||Bratu, Diana, Dubrovsky, Edward, Lipke, Peter, Studamire, Barbara|
|School:||City University of New York|
|School Location:||United States -- New York|
|Source:||DAI-B 75/06(E), Dissertation Abstracts International|
|Keywords:||Aedes aegypti, Midgut development, Mosquitos, RNA binding, miRNA|
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