Nature: The mechanism of "meal and lust" has been found!

Psychologist Maslow divides human needs into five levels, which are: physiological, safety, love and belonging, esteem, and self-actualization
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Food is the most basic need for people to survive.
Just like "being full and warm and thinking about lust" and "knowing etiquette when we have enough food and clothing," we can only consider higher-level needs when we are hungry.
In front, even love has to retreat
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Recently, the team of Professor Wang Jing from the University of California, USA, has clarified the physiological mechanism behind "meal and lust" through the fruit fly model - love and bread.
The hungry male fruit flies prefer bread, only after ingesting protein-rich food, Drosophila can turn to the pursuit of love, and the transition from eating to courtship depends on a neuropeptide, diuretic hormone 31 (Dh31), released by enteroendocrine cells
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The research was published in the top international journal Nature
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Two groups of male fruit flies, one starved for 24 hours, and one after eating and drinking, when the starved male flies were faced with food (protein-rich yeast) and female flies at the same time, the male flies First choose to fill the stomach, and then stroll around to find female fruit flies to court
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The other group was different, with full-fed male flies ignoring the food and heading straight for the females in an effort to create a mating opportunity
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Legend: Drosophila starved for 24 hours ab and satiated male Drosophila spent the time of feeding (blue), courtship (orange), and mating (black) during the observation period
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It is worth noting that the food that fills the stomach is also a bit particular.
It must be a food rich in protein/amino acids, and sucrose will not work.
Even if you are full of sucrose, the male fruit flies are also "sexually deficient", and they would rather rub Rubbing his hands and grooming, he didn't bother to get close to the female fruit fly (male fruit fly: no such worldly desires)
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The male fruit flies that eat high protein/amino acids are different.
The higher the amino acid concentration in the food, the more energetic they are, and the longer they spend on the female fruit flies, and the successful mating rate is as high as 74%.
Therefore, the study The staff joked in the article that "the protein is simply an aphrodisiac for fruit flies
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"
Legend: c.
Feeding different concentrations of sucrose, male Drosophila spends time in feeding and courtship
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d.
Feeding different concentrations of amino acids, the time spent by male Drosophila in feeding and courtship
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Next, the researchers tried to find the mechanism by which the male fruit flies switch between feeding and courtship behavior - why do male fruit flies stop eating and instead fly to female fruit flies for courtship after a few minutes of eating high-protein food? Some previous studies have shown that some hormones that produce satiety in the body can promote the occurrence of mating behavior
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The researchers found that when a high-protein diet was ingested, Dh31 release from Drosophila enteroendocrine cells increased, and Dh31 concentrations in the blood circulation increased
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After knocking out the Dh31 gene in Drosophila, even if they eat high-protein food, the probability of successful mating in Drosophila is greatly reduced, and when the Dh31 gene in enteroendocrine cells is activated, Drosophila quickly turns from eating to mating, proving that Dh31 is a feeding and courtship behavior.
key molecules in the conversion between
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Legend: 1 and 3 are high and low concentration protein groups, 2 sucrose group, 4 Dh gene knockout group, 5 Dh gene siRNA knockout group So how does Dh31 make Drosophila lust after fullness? Using three-photon microscopy to image neurons in the Drosophila brain, the researchers found that within minutes of injecting Dh31 into the Dh31 circulatory system, two groups of Dh31 receptor-positive neurons were activated—Crz+ neurons AstC+ neurons, Crz+ neurons secrete corazonin to promote courtship, while AstC+ neurons secrete allatostatin-C to inhibit feeding
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In a word: after ingesting high-protein food, enteroendocrine cells are activated to release Dh31, which acts on neurons with different functions in the brain, suppresses appetite, and promotes courtship.
Drosophila completes the transition from eating to courtship
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Professor Jing Wang, the corresponding author of the study, laments: "We have witnessed the transition from feeding to courtship in Drosophila, and it is surprising that a molecule can have such a significant impact on the animal's behavioral decision-making
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" : Lin HH, Kuang MC, Hossain I, et al.
A nutrient-specific gut hormone arbitrates between courtship and feeding [published online ahead of print, 2022 Feb 9].
Nature.
2022;10.
1038/s41586-022-04408-7.
doi:10.
1038/s41586-022-04408-7 Source | Edited by Four Five Seven |