Mosquitoes are good at suckling blood and having babies | FIU news


The secret to the reproductive success of the world’s deadliest animal could result in fewer baby mosquitos. That could mean improved pest control.

Researchers at the FIU Biomolecular Sciences Institute worked with an international team to study juvenile hormone, a molecule that regulates development, reproduction, and behavior in insects. They produced genetically modified Aedes aegypti mosquitoes – carriers of deadly diseases such as yellow fever, dengue fever and Zika – that cannot produce the juvenile hormone. The mutants could still mate and have babies. Just not as many as their juvenile hormone producing counterparts. The researchers say a better understanding of how hormones work could unleash a new generation of mosquito control tools.

“It is important to understand why the juvenile hormone is so important so that we can use this information to better control insects and pests,” said FIU Biological Sciences Professor Fernando G. Noriega, the corresponding author of the study.

All insects – from bees and butterflies to mosquitoes – produce the hormone in question. It plays a crucial role in their development, controls various functions and dictates certain behaviors. It helps mosquito larvae complete metamorphosis into an adult when they are ready. It works in a similar way to the hormones that people depend on for puberty and reaching sexual maturity.

Mosquitoes and their distant relatives – crabs and lobsters – both have methyl farnesoate (MF). In crustaceans, MF regulates reproduction. Insects have the ability to convert MF to juvenile hormones, which gives them an evolutionary reproductive advantage by producing more and more offspring.

The team of biologists and chemists – including Noriega, Marcela Nouzova, Francisco Fernandez Lima, and Matthew DeGennaro from the FIU – worked together to move the mosquitoes back in time, when it seemed like they never evolved to be To produce juvenile hormones.

Nouzova and Noriega

Nouzova is the lead author of the study and the mastermind behind this project. She designed the experiments and directed the genome editing process to create the mutant mosquitoes for the experiments.

“To investigate the evolutionary importance of the two hormones, we used CRISPR / Cas9-mediated mutagenesis to create Aedes aegypti mosquitoes that lack the enzymes needed to synthesize either juvenile hormone or both methylfarnesoate also catalyze juvenile hormone, ”said Nouzova.

While the mutants who only had MF successfully reached adulthood, they lacked reproductive skills. They couldn’t keep up with the stronger, non-mutated males. The mutated females were also affected. Usually a female can lay up to 100 eggs after mating. In their short lifespan, they can lay three different sets that make hundreds of eggs. However, the mutants laid 50 percent fewer eggs.

The other mutants lost the ability to completely produce MF. They died as a larva and never reached adulthood. This means that the juvenile hormone is a major regulator of mosquito reproduction, DeGennaro said.

This information about mosquito reproductive biology can help control populations of insects that we want less of, such as mosquitos. It can also help us improve reproductive success and increase the populations of insects that we need more of.

The results were published in the Proceedings of the National Academy of Sciences of the United States of America.

Ayleen Barbel Fattal and Chrystian Tejedor contributed to this story.

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