Science: The Mac experiment reveals human evolution! Human-specific genes can cause neocortex expansion

Introduction: Perhaps a coincidence of 6 million years ago, a human-specific gene separated people from chimpanzees, opening up the most magical evolutionary process in natural history: the evolution of the human brainBrain dilation is an important feature of human brain evolutionA new study in Science suggests that the gene causes the neocortex to grow larger and plays a key role in human evolutionprevious studies have shown that the human-specific gene ARHGAP11B causes the neocortex to become larger and the brain to grow in size in mice and ferrets, but its relevance to primate evolution is unclearTo study the role of the ARHGAP11B gene on primates, the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Germany, in collaboration with the Central Experimental Animal Research Institute (CIEA) in Kawasaki City, Japan, which produces genetically modified non-human primate technology, and Keio University in Tokyo, found that genetically modified macaques are developing a new cortex to express the human-specific gene ARHGAP11B, which is not commonly usedCombined with previous studies, it has been concluded that ARHGAP11B causes the neocortex to become larger, thus promoting the evolution of the human brainThey published their findings in the journal ScienceThe rise of human-specific genesthe ARHGAP11B gene played a key role in the evolution of the human brain
scientists believe that the human ancestors in the process of biological evolution must have a genetic mutation, stimulating brain growth2015, Wieland Huttner, head of the research team at the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Germany, and his team identified for the first time that the ARHGAP11B gene exists only in humans and is associated with theregeneration of the base brainstem cells that trigger the collapse of the cerebral cortexThe human-specific ARHGAP11B gene is a partial replication of the common ARHGAP11A gene, evolving with the evolutionary lineage of Neanderthals, Denisova and now humansChimpanzees were formed after the lineage was separated from the chimps ARHGAP11B causes more neurons to be produced during brain development, increasing the volume of the brain responsible for advanced cognitive abilities such as speech and thinking 2016, a study led by Wieland Huttner explains why the ARHGAP11B protein contains 47 amino acid sequences that are human-specific, not found in the ARHGAP11A protein, and are a prerequisite for ARHGAP11B's ability to increase brain stem cells Specifically, the discovery of a Base Replacement from C to G base in the ARHGAP11B gene results in the loss of 55 nucleotides in the ARHGAP11B messenger RNA, which causes the reading box to shift, resulting in a human-specific and functionally critical 47 amino acid sequences This point mutation is not uncommon, but in the case of ARHGAP11B, the advantage of forming a larger brain seems to immediately affect human evolution ARHGAP11B's Ethical Considerations Japan's ethical standards and regulations are similar to those in Germany in animal research and welfare Japan obtained the brain of the 101-day-old macaque fetus (50 days before the normal date of birth) and exported it to MPI-CBG in Dresden for detailed analysis A 101-day-old ARHGAP11B genetically modified fetal macaque brain sliced by a microscope image DAPI (white) shows the nucleus; the brains of wild (normal) and ARHGAP11B genetically modified fetuses (101 days) macaques Yellow line: cerebral cortex boundary; white line: developing cerebellum; arrow: folds researchers say the new cerebral cortex of ordinary macaques does get larger, and the surface of the brain folds and the cortex is thicker than normal In addition, an increase in the number of radial glia progenitors and upper neurons can be seen in the subvention area of the ventricle This type of neuron increases as primates evolve This study provides functional evidence that ARHGAP11B causes primates to have a larger neocortex Wieland Huttner added that their analysis was limited to macaque fetuses because they expected the expression of AGAPRH11B to affect the development of the macaque's neocortex Given the potentially unforeseen effects of ARHGAP11B on fetal brain function after birth, they believe that ethically, it is necessary to first determine the effect of ARHGAP11B on the development of the fetal macaque cortex