Human, dogs, and other about 4,000 placental mammals are characterized by long -term cultivation of fetus in the body.This important adaptive ability makes the brain develop slowly.At present, a study of gene expression of early pregnancy, when embryo is implanted into the uterus, it shows that the placental mammalian has evolved and produced the ability to transform inflammatory attacks on embryos into an advantage.
"Transplantation looks like inflammation because it comes from inflammation," said Arun Chavan, an evolutionary biologist at Yale University.On January 5, he published the discovery at the comprehensive and comparative biology society of San Francisco, California."We do this study to understand how it becomes implanted."
Evolution biologists believe that ancient mammals will produce eggs, just like today’s duckbill beasts.There are bags, including negative mice and kangaroo, which were later evolved: their fetus hatched from a shell egg in the mother’s body, and was soon expelled from the mother.But the initial incubation process seemed to inspire the immune system.In an article published in the "Proceedings of the National Academy of Sciences", Cha Wan and his colleagues pointedWhen an inflammatory gene is started when the endometrium is started.Earlier research on placental mammals also shows that when embryos are attached to the uterus, there will be signs of immune response.
But among the placenta mammals, embryos are not just attached to the uterus.Instead, it destroys the endometrium of the uterine when it invades the tissue, causing a large amount of inflammatory protein.During the infection and injury, these proteins usually fight and repair the wounds.Some of these proteins may be harmful to germinated life forms, but research shows that inflammation is necessary for embryos.For example, the risk of women’s abortion in the early stages of pregnancy is higher, because embryos are not successfully implanted in the uterus.Reproductive biologists believe that in some aspects of inflammation, such as the growth of new blood vessels, it helps to obtain the required oxygen and nutrients in development.
In order to understand how the placental mammalian was against protein attacks in the early days, Chavan analyzed the inflammatory response of three of the animals: rabbits (unicorn), 犰狳 (unicorn) and hedgehogs (unicorn).A kind of inflammatory protein, leukocyte-17, exists in high-level negative rats, and seems to be unrealistic in the mammalian of the placenta, as if it was cut off.Protein usually sends a signal to white blood cells, killing them by digesting them or using enzymes.CHAVAN said: "It may be important to close them before they destroy the embryo."
His preliminary study found that the cells in the placental mammalian uterus inhibit the production of pantin-17.In other aspects of inflammation reactions in the later stages of pregnancy, although it is not clear what it is caused.The results show that the placenta mammals have a good inflammatory response during pregnancy, so their inflammatory reactions will change.Yale University’s evolutionary biologist, the senior researcher at the study, said: "mammals have found a way to retain certain aspects of inflammation process that is beneficial to the fetus, but also to stop it fromReaction to the harmful part of the fetus. "
Gil Mor, a reproductive immunologist at Yale University, said these discoveries are fascinating.He hoped that they could provide details and eventually help clinicians reduce abortion and increase the bed rate of fine women outside the body.Although inflammation seems necessary during implantation, it is the main cause of abortion and premature birth.Mor said: "We need to find a way to change from inflammatory state to anti -inflammatory state so that women can keep their children."