PNAS: Scientists screen new genes that protect the body against dementia

2018/09/28 23:29
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The survival of the fittest, the survival of the fittest is the most misunderstood term in the biological world. Recently, a research report published in the international journal PNAS, researchers from the University of California said through research that natural selection may be more inclined for humans. In order to protect the grandparents from genetic protection against dementia, maintaining good cognitive and memory skills in the old age may promote the elderly to spread their wisdom, and care for the children, while the elderly with dementia need to take care of themselves. .
This grandmother's hypothesis is more in line with the rules of relative selection (blood elimination), that is, individuals can continue their genes, not only through future generations, but also through the easy survival of the offspring sharing the genetic mutation. The way to accomplish this, it seems to be altruism, such as why ants build a bridge while their relatives can pass through obstacles, or why squirrels will scream to express warnings; for humans, grandparents pass by to teach future generations Certain survival skills to increase the likelihood of survival for future generations of children.
Humans and toothed whales are the only remaining mammals in the past breeding era. Killer whales can survive in the post-menopause period, probably because they can use the environment to teach young whales how to survive and survive; and humans also experience The same evolutionary path until the emergence of Alzheimer's disease, this disease can damage the cognitive ability of the elderly. In the article, researchers searched for a novel gene mutation that can neutralize the trend of dementia. Finally, they first discovered a gene called CD33, which encodes a receptor that maintains inflammatory and immune responses. This "C", etc. The gene is associated with early dementia, but the "A" allele protects the body's cognitive ability by promoting the absorption of excess amyloid beta by microglia.
In this study, the researchers identified 10 mutant genes that protect the body against vascular forms of dementia, which are APOE, AGT, SCG2, CAPN10, TCF7L2, EBF1, COX-2, CYP3A5, PPARG, and PON1, vascular dementia often block blood flow, and these 10 genes can protect the body against high blood pressure, type 2 diabetes and cardiovascular disease. Researchers have also discovered these derivatives in modern African organisms. The protective alleles indicate that these genes have existed for at least 100,000 years.
The final researcher, Ganeux, said that our study did not demonstrate that these factors are involved in the selective screening process of CD33, APOE and other gene protective mutants, but they can help to speculate on the possibility of this phenomenon; Care and communication of information are important factors in the survival of young offspring in the family and are critical to a wide range of social networks and tribes. Later researchers are also happy to develop new genetic markers to help detect new genes that can resist dementia. (奇健生物
Human-specific derived alleles of CD33 and other genes protect against postreproductive cognitive decline
Flavio Schwarza, b, c, d, 1, Stevan A. Springera, b, d, 1, Tasha K. Altheidea, b, c, d, Nissi M. Varkia, b, e, Pascal Gagneuxa, b, e, 2 , and Ajit Varkia,b,c,d,2
The individuals of most vertebrate species die when they can no longer reproduce. Humans are a rare exception, having evolved a prolonged postreproductive lifespan. Elders contribute to cooperative offspring care, assist in foraging, and interact important ecological and cultural knowledge, increasing the survival of Younger individuals. Age-related deterioration of cognitive capacity in humans compromises these benefits and also burdens the group with socially costly members. We investigated the contribution of the immunoregulatory receptor CD33 to a uniquely human postreproductive disease, Alzheimer's dementia. Surprisingly, even though selection at Advanced age is expected to be weak, a CD33 allele protective against Alzheimer's disease is derived and unique to humans and favors a functional molecular state of CD33 resembling that of the chimpanzee. Thus, derived alleles may be compensatory and restore interactions altered as a consequence of Human-specific brain evolut We found several other examples of derived alleles at other human loci that protect against age-related cognitive deterioration arising from neurodegenerative disease or cerebrovascular insufficiency. Selection by inclusive fitness may be adequate enough to favor alleles sealing specifically against cognitive decline in postreproductive humans. Such selection would operate by maximizing the contributions of postreproductive individuals to the fitness of younger kin.