Image by Michael Frankenstein from Pixabay
Tencent made a big oolong a few days ago: originally intended to sue Lao Ganma for not paying advertising fees, but found that he was deceived, not only lost face, but also lost 16 million.
For this reason, the little penguin looked at the old godmother in his hand and found it unscented:
Source: Bilibili
They even sent a video for this, saying that they ate chili sauce…
Wait! My blind student found a Chinese point!
Do penguins eat chili sauce? Then we will give you today…
Then I saw the fruit shells gathered together and gave the answer:
Picture Source: Weibo
Ah, for the hot spot, we are always slower…
But! As a professional biological science, adhering to the spirit of not giving up and giving up, we decideIt’s still going to be more in-depth with everyone. What determines what penguins and other birds can’t taste the taste of chili, and what other animals can’t experience the spiciness(In other words, it is very spicy).
Penguin: Actually I can’t taste a few flavors
If you read the above article, you must know that spicy taste is not a taste sensation, but a sensation that causes people and animals to feel hot, and it is more like a feeling of pain.
Tencent penguins don’t only taste spicy, as the fruit shell juju said, they don’t even taste a few “five flavors”: it can only taste sour and salty, but sweet and bitter. And umami are lost.
There is no taste in my mouth, and I am also desperate (Source: unsplash)
In fact, this study looks very “simple and rough”:
Scientists have studied several genes related to taste in the past ten years, such as Tas1r2 determines sweetness, Tas1r1 determines umami, Tas1r3 affects sweetness and umami, Tas2r determines bitterness…< /p>
And looking for these genes in the genomes of different animals, I found that none of the penguin genomes have (Accurately, they can’t be expressed), it means that penguins do not have these tastes.
Make an analogy, it is like you have to look up the words sweetness, umami, and bitterness, and you have a Chinese dictionary, an English dictionary, and a Martian dictionary in front of you, then after searching, you find that these three are not in the Martian dictionary. Words, we can speculate that the Martians may not be able to taste these flavors. (However, genes are more accurate than dictionaries)
The genomes of several species used by the researchers, and judging whether the number is seated has this taste (Source: Zhao H, et al.)
But why? In fact, our taste formation can be explained by Darwin’s theory of evolution: tasting sweet, umami, and salty tastes helps us recognize and supplement the glucose, amino acids, and salt that our bodies need, while tasting bitter and sour tastes. Most of them are poisonous or spoiled food. Therefore, such “five flavors” will be formed.
So for the same reason, we can speculate whether the change in environment caused the penguin to taste nothing:
For example, the study actually tested other birds and found that most birds have lost their sweetness;
While living in the icy and snowy ground like Antarctica, penguins like bitterness and umami may not be able to eat it, and it will degenerate over time;
In addition, when we watched the documentary, we can see that penguins like to swallow the food in a bite when eating, which may be the same as pig bajie eating ginseng fruit-no taste at all.
A penguin used in analysis, Papua penguin (Source: Zhang Jianzhi)
So if we follow this correspondence, we suggest that it’s best not to have too deep guacamole with condiments such as sweet sauce, monosodium glutamate, etc. It may be good to have a salty mouth like bean paste. (Funny.jpg)
So why are birds not afraid of spiciness?
In front of the fruit shells, it was mentioned that “birds cannot perceive capsaicin”, so the curious people should not only ask one more question: why are they unable to perceive? In other words, how do organisms perceive capsaicin?
In fact, similar to the previous taste, capsaicin also needs to be recognized, and this gene that senses thermal stimulation and pain has been discovered by scientists as early as 1997-TRPV1, which we will simply refer to as “capsaicin receptor” below. “Well.
(Otherwise, you can’t remember a string of English, but it is related to heat sensing and pain in addition to the perception of capsaicin, so it is not accurate to call it like this Of)
TRPV1 protein model (Source: Wikipedia)
When the capsaicin receptor binds capsaicin, it releases a signal to the brain, which makes you feel “pleased” of pain.
Scientists have found that the capsaicin receptor of chicken is even at a concentration of 100μM capsaicin(Converted according to the definition of hotness of hot sauce, it is probably Sichuan’s medium spicy, The feeling of nibbling the peppers directly) It’s not stimulatedThe response also explains why birds are indifferent to capsaicin.
The main reason is that the structure of this protein has changed, resulting in poor recognition of capsaicin.
And it is such a change in the receptor that the undigested chili seeds after the birds eat the chili can be spread around with the birds flying, which gives the capsaicin-containing plants a broad reproduction space.
You are Sichuan people and I am not afraid (but Guangdong people come to you, you are a white-cut chicken, source: unsplash)
In addition, scientists will use various methods to study the specific structure of proteins and how these structures work,
Combined with such research, it can be speculated that what changes in gene loci affect the recognition of capsaicin by capsaicin receptors.
Are only birds invincible in eating spicy food?
Through the vertebrate subphylum, there are really few who can break the wrist when eating spicy food. The capsaicin receptors of fish and reptiles are far less resistant to spicy food than birds. .
This light is evident from the ability of different animals’ capsaicin receptors to withstand temperature (Source: Gracheva EO, et al.)
Most mammals are naturally more spicy than non-winners. (Humans are more of the result of “training” the day after tomorrow)< /span>, but there are always exceptions.
At the earliest when studying the structure of capsaicin receptors, scientists discovered that the rabbit’s capsaicin receptor also had certain site mutations and was not very sensitive to capsaicin, and even transferred the rabbit’s capsaicin receptor to mice. In the past, it was found that the anti-chili ability of mice biubiu rose.
My Lord Rabbit is also a spicy little expert (Source: unsplash)
And recent research has also discovered a particularly spicy animal:
Tree shrew(qu, second tone, Tupaia belangeri chinensis)
Tree Shrew (Source: Kunming Primate ResearchResearch Center)
This little guy looks like a squirrel, but in fact it is a species that is very close to the primates to which humans belong. Therefore, it has been used as an important experimental animal to assist in the research of many human diseases.
And the experimenters who grow tree shrews found that when they feed peppers to tree shrews, they will take the initiative to eat, and they will eat with relish.
In contrast, if you add chili to the food of the mice, the mice will eat less and less(like me Cantonese who have no appetite for spicy foods.
The little guy is not afraid of red pepper (Source: Han Y, et al.)
Checking the genome, it turned out that this capsaicin receptor is too greasy. A mutation at one of these sites caused the tree shrew to be less sensitive to capsaicin.
In other words, the gene mutation caused the tree shrew to “change from Cantonese to Sichuanese.”
But the problem has arisen again. Tree shrews are mainly distributed in Southeast Asia, and chili peppers have only been in Asia for 300 years. No matter how powerful natural selection is, there is no way to make tree shrews “change from Cantonese to Sichuan in 300 years.” people”.
Further exploration scientists discovered that it was originally tree shrews who liked to eat a pepper plant that grows widely in Southeast Asia, reed vine (Piper boehmeriaefolium). This plant contains a capsaicin-like substance that promotes the rapid evolution of tree shrews in eating spicy talents.