荔枝视频

Picture the scariest animal that you can think of. Lion? Tiger? Bear? Mosquito?

Mosquito? Really? Mosquitoes often don't play a significant role in northerners' lives in our cold climate, aside from the itch of their bite. For most of the global population though, mosquitoes are a very different story 鈥� one of illness and death.

Soon enough, that could be the case here as well. Recently, invasive mosquitoes that carry West Nile virus  so it may be high time that us northerners start thinking more about these little pests.

And U荔枝视频 Faculty of Veterinary Medicine鈥檚 (UCVM) Dr. John Soghigian, PhD (Biology), couldn鈥檛 agree more. 鈥淢osquitoes are among the deadliest animals on earth owing to the pathogens they transmit when blood-feeding, so their study is immensely important to human and veterinary health,鈥� Soghigian explains.

Soghigian鈥檚 recently published paper, "Phylogenomics Reveals the History of Host Use in Mosquitoes"  explores how mosquitoes are related to each other. By using a phylogenetic approach, in which the genome of an organism is reconstructed, rather than the usual morphological approach which looks at structural differences such as size or shape, researchers can gain significantly more data, leading to more robust and accurate results.

鈥淭his previous reliance on analyzing their morphology has resulted in contentious and often confusing ways of classifying mosquitoes, and hindered us from really using their evolutionary history to understand aspects of their biology related to disease transmission,鈥� says Soghigian.

Why does it matter how mosquitoes are related to each other?

鈥淢osquitoes that are more closely related to each other are a greater risk of disease transmission. There are more than 3,500 species of mosquitoes, and relatively few transmit pathogens to humans,鈥� Soghigian explains.

鈥淲e can use the evolutionary relationships among mosquitoes to help us better understand when, where, and why mosquitoes might transmit disease, because often, mosquitoes can be vastly different from one another. Different mosquitoes use different larval habitats for their young, bite at different times of day, and even live at different times of year.鈥�

An ounce of prevention is worth a pound of cure. 鈥淢any mosquito-borne diseases have no true cure, and while some vaccines are available, that isn鈥檛 the case for all pathogens mosquitoes transmit. So, quite often, we control mosquito-borne disease through combating mosquitoes themselves,鈥� Soghigian points out.

Understanding their habits and preferences is often our only form of preventive action against their bites. Knowing when they are active advises us when to cover up or stay inside. Knowing where they lay eggs advises us of areas to avoid.

In the tangled web that is mosquito phylogeny, there are species that don鈥檛 bite at all, 鈥渋nstead eating other mosquitoes, or dancing with ants for food,鈥� Soghigian says.

One of Soghigian鈥檚 favourite species, Toxorhynchites, offer us a look into a beautiful world that could be.

鈥淭oxorhynchites are among the coolest mosquitoes. For one, they鈥檙e featured in Jurassic Park! And not to ruin the movie for you, but even if dinosaur DNA could be found in mosquito fossils, there鈥檚 no way it鈥檇 be in Toxorhynchites 鈥� that鈥檚 because these guys are just pollinators as adults.

鈥淗owever, because they鈥檙e so different, it has been hard to understand how exactly they鈥檙e related to other mosquitoes. Our use of genomic data helped us out there. What鈥檚 cool about this is that there are only a handful of other mosquitoes that never bite at all 鈥� and almost all of those are in the group we found as 鈥榮ister鈥� to Toxorhynchites!

鈥淐ould this mean there are some common aspects of the genetics of these mosquitoes that, through evolutionary time, can lead to mosquitoes that don鈥檛 bite?鈥� Soghigian questions.

Alas, we are not living in a world with only Toxorhynchites, but also with the disease-carrying species. It鈥檚 these ones that have had big impacts on human history. For example, malaria-carrying mosquitoes have been around for a very long time, and in places with lots of malaria, people tend to have genetic traits that help protect them from the disease, like sickle cell trait.

Then there's our foe, Aedes aegypti. It's famous for spreading diseases like dengue and yellow fever today, but it caused big problems in the past. 鈥淚n 1793, it caused a deadly yellow fever outbreak in Philadelphia, and it was so bad that the U.S. Congress had to leave the city to stay safe,鈥� Soghigian says. So not only have these disease-carrying mosquitoes left their mark on our genes, but also in our history.

Much like the flutter of wings in the butterfly effect, it can also be the sting of a simple mosquito bite that can have the most profound impact on our lives.