Why are there people who are liked by mosquitoes and people who are not like that?
Technologies for eradicating mosquitoes are being developed as it will cause people to infect diseases such as malaria. On the other hand, even if they are in the same place, there are people who are easily bitten by mosquitoes and people who are not easily bitten by mosquitoes, why is this? About YouTube's science channel " Veritasium " is explained in an easy-to-understand manner.
Why Are Mosquitoes Attracted To You ?! - YouTube
Derek Alexander Muller, who is a self-proclaimed "mosquito friendly person" came, is New Mexico state in the United States. Why are there people who are likely to be mosquitoes and others who are not? Based on previous studies that have investigated, it is believed that part of DNA is related to whether mosquito-susceptible or not.
Muller came to see Professor Immo A. Hansen who conducts mosquito research at New Mexico State University.
A man of images who greeted me at the laboratory, Professor Hansen.
Professor Hansen keeps several kinds of mosquitoes in the laboratory, and there seems to be some species that gives Professor Hansen's blood as a food. I can not ask the students "Can you separate the blood?", So I was using my blood as a food.
Professor Hansen who will practice "putting your arms and waiting for a while" against the question "How do you give a food?"
Mosquitoes need proteins in blood because they lay eggs, so only female mosquitoes suck blood.
In the laboratory there was also a container for mosquito larvae to grow quickly.
"How do you know how mosquitoes are liked by mosquitoes?" Muller enters the subject.
In answer, Professor Hansen took out a Y type tube.
There were 20 mosquitoes tightly confined at the end opposite to that of Y. A fan is also attached to the tip, and when the mosquito is released, the mosquito is pushed out to the Y part of the tube by the power of the fan. We can use this device to ascertain whether myself is liked by mosquitoes.
First of all, you first stick your hands or move the sweat behind your neck to the palm of your hand.
Mosquitoes trapped are species specialized in sucking humans.
Move the dividing net and release the mosquito ... ...
A mosquito headed towards the hand held by Muller ahead of the Y - shaped tube. In a situation where 20 out of 20 mosquitoes are headed to Mr. Muller, "You seem to be very attractive", Professor Hansen.
Such an experiment was actually done in a study to investigate whether genes are involved in being liked by mosquitoes.
In the experiments with 18 monozygotic pairs and 19 diagonoidal twins as subjects, the results of the survey showed that "one of the twins is likely to be liked by mosquitoes, the other is also likely to be mosquito-susceptible". However, as the twins have grown up and their diet is the same, this result may be attributed to environmental factors.
When comparing the results of dizygotic twins and identical twins, it was shown that identical twins are stronger in correlation. It is evidence that it is strong evidence that genetic influence is exerted on "mosquito-susceptibility".
Next, in the laboratory, Mr. Muller and his wife Raquel will be comparing experiments.
Raquel's hand on one end of the Y letter and Muller's hand on the other side, there are only 5 mosquitoes headed towards Raquel. In other words, Muller was shown to be likable to mosquitoes even compared with other people.
Can this be genetically explained? That's why Mr. Muller and Raquel tested seven parts of DNA.
In the study of 2017, about 16,000 subjects "The mosquito-friendly taste?" Was examined by genome-wide association analysis , whereas people telling that "it is easy for mosquitoes" talks about "mosquitoes It is said that the difference was seen with people who talk about "It is not liked by."
It is believed that the difference between these seven DNAs is related to "likability for mosquitoes." So Muller and Raquel looked at each other's DNA.
As a result, it was said that the DNA of two people had the same shape in 4 out of 7 DNA sites related to 'mosquito-friendly person'. In other words, the difference between the two DNAs is in three places, Raquel has "not much like mosquitoes" DNA, that is, "protects you from mosquitoes" DNA, Muller also says "to protect yourself from mosquitoes" Although he had DNA, he said that it was not much different than Raquel. And Mr. Muller seems to have been shown "genetically more susceptible to mosquitoes" genetically than Raquel because of the large "DNA mismatchable to DNA" mutation in addition to that.
However, parts other than genes are also involved to "whether mosquitoes are likely to be liked". Carbon dioxide is one of them, metabolism is high, exercise is just finished, or body is bigger, it is more likely to be liked by mosquitoes.
Mosquitoes also react to volatile substances such as lactic acid, acetone, ammonia.
Also, substances such as octanal , nonanol , decanal , methyl heptenone make mosquitoes easier to find humans. Since mosquitoes are said to be the most killing human beings, it is considered very important to clarify these genetic relationships.
Professor Hansen who answers, "Mosquitoes are the worst creature for human beings" and "no doubt" "Malaria is killing far more human beings than the number of people killed by humans." There are people claiming that mosquitoes have killed more than half of human beings so far, and this proportion is argued as "too big", but still many people have been killed by diseases caused by mosquitoes It is a fact.
"Is there any possibility that humans are evolving in a manner that emits a smell that keeps mosquitoes away, or is it a coincidence that there are" people not liked by mosquitoes "? ....
"That is a very good question!" Professor Hansen answered, but there seemed to be no answer yet.