The Effect And Mechanism Of SUPT16H Gene On Developmental Delay

Developmental delay is a disease in which the intelligence and ability of adapting to society during the development of minors are significantly lower than the average level of their peers.The occurrence of stunting will significantly reduce the quality of life of children and their families,and will also bring heavy mental and economic pressure to the family and society.The disease is mainly caused by genetic factors,but its pathogenesis-related genes and mechanisms are still unclear.This experiment conducted qualitative and mechanism exploration on the genetic factors of disease,and the results are as follows:(1)Through cooperating with the hospital,we sequenced the patient's genome and found that a mutation in the SUPT16H gene caused developmental delay.The patient had a conversion mutation at the position 14:21826154.(2)In animal experiments,in order to verify the relationship between genes and diseases,we constructed related heterozygous mice,and after various behavioral verifications,we determined the relationship between the gene and developmental delay.The learning and memory ability of heterozygous mice is significantly lower than that of control mice,especially the conditioned memory ability.Not only are there obvious differences in the two tests between young and old,but the patterns of the differences are also the same,both showing the lack of learning ability and memory ability has little effect.In addition,there were some unexpected discoveries in data such as the breeding of the strains and the recording of physical signs.First of all,the abnormally reduced litter size and genotype identification results indicate that there is a homozygous lethal phenomenon.Then there was a significant drop in blood sugar in heterozygous mice,indicating that the metabolic process of the mice was affected.(3)The microscopic experiment is divided into two aspects:expression pattern exploration and cell function.In order to explore the expression pattern of this gene,we used immunofluorescence,immunohistochemistry and other methods to slice and stain the extracted mouse brain.The results showed that the expression of this gene in the mouse brain has no obvious preference.Combined with the known functional analysis of this gene in organisms related to cell transcription and replication,it is biased towards housekeeping genes,so it is normal.In addition,the results of immunofluorescence staining related to the development of the corpus callosum showed that the corpus callosum of heterozygous mice was larger and wider.The corpus callosum is an important place to connect the left and right hemispheres.Distortion may directly cause the brain function to deviate from normal.In order to explore the specific effects of this gene on the nervous system,we extracted primary neural stem cells and used small interfering RNA to inhibit the expression of SUPT16H in the cells.The results showed that the proliferation ability of neural stem cells in the treatment group was significantly affected,and the proliferation speed was significantly slowed down.The cell migration ability has an upward trend after treatment,but it has not yet reached a significant level.The differentiation direction of neural stem cells is also affected by the deletion of this gene.After treatment,the differentiation of neurons in the direction of neurons is obviously reduced,and the number of stem cells that differentiate into astrocytes increases.(4)In terms of gene expression patterns,in order to further explore the underlying causes of molecular and cellular phenotypes,we extracted the hippocampal structures of two groups of mice for transcriptome sequencing and analysis.The results show that the expression patterns of the two groups of mice are quite different,and the numerous differential genes are mainly enriched in three functionally related pathways.The most relevant trend is the process of neuron synapse formation,growth,and neurotransmitter transmission.Among them,glutamatergic neuron synapses have the highest degree of enrichment.The second is the pathways related to oxidative phosphorylation,especially the protein expression related to NADH dehydrogenase(electron transport chain complex I).Finally,the largest number reads involved is the cannabinoid retrograde signaling pathway.We believe that the changes in the above three pathways and their interactions have led to the above phenomenon.To sum up,the current research has confirmed that human chromosome 14 is related to developmental delay,but there is no research to locate a certain gene.We have not only established a connection between developmental delay and specific genes for the first time,but also explored the role of SUPT16H in this disease.The degree of action and the mechanism of the drug lay the foundation for the follow-up treatment of developmental delay and the exploration of brain development.