The Role And Mechanism Of GADD45G In Lip Development

Growth arrest and DNA damage inducible protein 45(GADD45)family genes are important genes for DNA damage repair.The GADD45 family encodes three proteins(GADD45A,GADD45 B,and GADD45G),which are nuclear proteins that interact with various cell cycle-associated proteins,have very similar amino acid sequences,and have a protein homology of 55% to 58%.In recent years,with the continuous exploration of the GADD45 G gene by researchers,some genome-wide association studies indicated that the GADD45 G gene is closely related to the development of the lip/palate.However,there is no animal model to confirm the direct relationship between the gene and the lip/palate,and the mechanism is still uncertain.Therefore,it is extremely urgent to establish a better animal model of GADD45 G gene mutation and explore the relationship between gene and the lip/palate.At present,animal disease models such as mice and rabbits have been widely used to explore the pathogenesis of cleft lip and palate in humans.It is worth noting that rabbits are considered to be better disease models than mice in recapitulating human diseases because rabbits and humans are more similar than mice in terms of physiology,anatomy,and genetics.At present,CRISPR/Cas9 gene editing technology has become the mainstream gene editing tool,which has the advantages of simple design and convenient use,and has been successfully applied to genome editing of animals such as rats,pigs and zebrafish.In 2016,the David team took a programmable cytidine deaminase based on the CRISPR/Cas9 system has been shown to convert from C to T and G to A.The application of this technology can better simulate human diseases and has broad prospects for gene therapy.Although the GADD45 G mutant mouse model has been reported,no signs of cleft lip and palate have been found.Therefore,the experiment used rabbit as an animal model of disease to explore whether the GADD45 G gene is closely related to the development of the lip/palate.In this experiment,two gene editing technologies were used to construct the GADD45 G gene targeting vector,and the GADD45 G gene mutant rabbits were obtained by microinjection.The study showed that the GADD45 G mutant rabbit exhibited cleft lip and all died within three days due to sucking milk problems.By performing lip detection on the embryonic day 13 rabbits,it was found that cell proliferation,apoptosis and epithelial-mesenchymal transition were disordered during lip development.In summary,this study used CRISPR technology to successfully construct GADD45 G mutant rabbits,which can be used as an animal model to explore the relationship between GADD45 G and cleft lip and palate development.