Laboratory of Molecular Biology and Physiology of Mosquitoes (Marcela Nouzová)
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Laboratory of molecular biology and physiology of mosquitoes takes an integrative approach that combines experiments at the organismal, cellular, and molecular levels to understand the synthesis, signaling, and role of juvenile hormone in mosquitoes. Juvenile hormone (JH) is an important hormonal regulator in insects. In females of Aedes aegypti, JH signals the completion of ecdysis to the adult stage and initiates reproductive processes. Our research, integrating metabolomics, genomics, and proteomics tools, shows that regulation of JH synthesis in mosquitoes has unique features related to adaptation to blood feeding and cyclic regulation of ovarian development. These unique features provide potential research opportunities to identify targets for new specific chemical and/or genetic strategies to control mosquitoes.
We used CRISPR/Cas9 to generate mosquitoes lacking one of the two enzymes that catalyze the final steps of MF /JH biosynthesis and epoxidation, respectively: the methyltransferase JHAMT and the P450 epoxidase CYP15 (EPOX). jhamt-/- larvae lacking both MF and JH die at the onset of metamorphosis. Strikingly, epox-/- mutants that synthesized MF, but not JH, went through the entire life cycle. While epox-/- adults were fertile, reproductive output of both sexes was drastically reduced.
We are using the following experimental approaches in our work on these projects:
- Maintenance of colonies of wild-type and mutant mosquitoes. Artificial ex vivo membrane feeding.
- Basic molecular biology techniques. Real-time PCR.
- Immunodetection of proteins in mosquito tissues by confocal microscopy and transmission electron microscopy.
- Manipulation of gene expression by CRISPR/Cas9 and RNA interference.
- Measurement of juvenile hormones by mass spectrometry.
- Transcriptome analysis.
As part of our research, we offer the following topics for undergraduate and graduate students.
Research projects
Investigate the role of JH during mosquito development.
Hypothesis: in the absence of JH, MF is able to activate regulatory pathways that control development and metamorphosis. Transcriptomic analysis of whole larvae from two null mutant lines and wild-type mosquitoes are currently being used to identify a set of differentially expressed genes that will be tested for function through a combination of RNAi and physiological experiments.
We aim to understand how the absence of JH affects reproduction.
JH regulates nutritional homeostasis, and the absence of epoxidized JH leads to loss of reproductive capacity in female and male mosquitoes. Transcriptomic analysis of ovaries from adult females of our mutant line and wild-type mosquitoes are currently being used to identify a set of differentially expressed genes that will be functionally tested.
Investigate the regulation of JH biosynthesis in the corpora allata gland of mosquitoes (CA).
We are combining microscopic imaging and various molecular and biochemical techniques to investigate the role and mechanism of action of various factors that control the activity of CA.
