A Preliminary Study On Screening,Identification And Function Of Imprinted Genes In Mouse Mammary Gland

Genomic imprinting refers to an epigenetic phenomenon in which the specific gene,gene cluster or whole chromosome of the offspring only express the allele of one side of the parent,and the other side is silent.The expression of the affected gene in this phenomenon is called the Imprinted gene.The Imprinted genes play different roles in different tissues,which can affect the speed of embryo development and the weight of the embryo during embryonic development.In addition to neurodevelopmental function,Imprinted genes can regulate the metabolic activity of the whole organism through the nervous system.In addition,the Imprinted genes play an important role in each adult tissue,in which liver,pancreas,fat and other metabolic related tissues can detect the active expression of the Imprinted gene.Thus,the Imprinted gene has an important effect on the regulation of energy metabolism,taking into account that the mammary gland is another energy supply organ in addition to the placenta,and the mammary gland is the only vegetative organ that provides the necessary energy material for the offspring after birth,while the current lack of breast tissue study of the imprinted gene,so the study of mouse mammary gland tissue to carry out imprinted gene research.We first identified the Imprinted genes in the mouse mammary gland.In order to capture the Imprinted genes more fully,the study selected two mouse strains with different nucleotide polymorphic loci(SNP)differences(C57BL/6 and PWK/PhJ)for this work.Using the F1 hybrid mice obtained from the reciprocal strategy,we obtained mammary gland tissue and used for transcriptional sequencing.Combined with the imprinted gene analysis process,the study detected and identified the Imprinted genes in the mammary gland.The results showed that the mammary gland tissues had two tissue-specific Imprinting genes(Gm30189 and,Slc22al),and the other 18 breast Imprinted gene were consistent with the embryonic stage.The The temporal and spatial specificity of Imprinted gene expression is an important scientific problem in the field of genetic.Our data support the dynamic distribution of Imprinted genes in different mammary glands,and also indicate that the imprinted genes are not as a trend that is traditionally reduced.Secondly,the functional characteristics of the Imprinted genes were studied.Previous studies have found that Imprinting genes can be regulated between each other,and Imprinted genes may form a unique Imprinted gene regulation network(IGN).The Imprinted genes are able to regulate the level of self-expression and interact with other non-Imprinted genes through this network regulation,which contributes to numerous important physiological functions,including the regulation of energy metabolism.Based on the above-mentioned mouse mammary gland tissue transcript data,we identified the gene expression profiles of other lactating species(a total of more than 600 chip samples).We conducted a correlation study by co-expression network analysis(WGNCA)Indicating that the liver tissue enriched three IGNs.The mammary gland gene regulates membrane integrity and fatty acid metabolism in co-expression networks.In order to verify the presence of this network,we knock down the network members(Peg3,Ndn,Cdknlc)by lentivirus(shRNA system),and the results showed that the gene expression of IGN was affected.These results show that Imprinted genes in the Imprinted gene network can affect IGN.This part of the results further supports early preliminary data in the field:Imprinted genes interact with each other to form a co-expression network,and use the network to control other non-Imprinted genes to exercise similar biological functions.A large number of experimental studies have shown that many Imprinted genes can regulate embryonic development and nutrient supply.In order to confirm the function of Imprinted genes in mammary gland tissue,the study used lentiviral knockdown genes(Peg3,Cdkn1c,Ndn,H19,Sgce)in mammary epithelial cells to analyze their role in mammary gland development.The results of clonal assay showed that knockdown of the above gene expression levels reduced the ability of breast stem cells to self-renew.Milk-like unit formation experiments showed that lactation was also significantly disturbed.These results show that imprinted genes play an important role in mammary gland development.In order to better analyze the function of the imprinted gene in the mammary gland,we compared the expression profile in this study with the published gene expression profile,suggesting that the marker gene in the mammary gland regulates the energy supply during lactation,which provides for subsequent studies important basis.This study first identified the number of mammary gland Imprinted genes and the effects of mammary gland Imprinted genes on mammary gland development and energy metabolism,and further enhanced the understanding of Imprinted genes on mammary gland development and mammary gland function.