The study of the regulatory region of the Drosophila melanogaster Notch gene by new methods of directed genome editing

The Notch gene plays a key role in the development of organs and tissues of neuroectodermic origin, including the nervous system. In eukaryotic organisms, the Notch pathway is involved in cell fate determination. The Notch gene was first discovered in Drosophila melanogaster. In mammals, the family of Notch receptors includes four homologues. In humans, mutations in the Notch gene cause several hereditary diseases and carcinogenesis. Studies of the regulatory zone of the Notch gene in D. melanogaster have been conducted for several decades. We review their results and methods. The regulatory zone of the Notch gene is in the region of open chromatin state that corresponds to the 3C6/3C7 interband on the cytological map of polytene chromosomes of D. melanogaster salivary glands. The development of new methods for directed genome editing made it possible to create a system for introducing directed changes into the regulatory zone of the gene. Using the CRISPR/Cas9 system, we obtained a directed 4-kilobase deletion including the 5’-regulatory zone, promoter, and the first exon of the Notch gene and introduced the attP site into the first intron of the Notch gene. This approach enabled targeted changes of the sequence of the regulatory and promoter regions of the gene. Thus, it provided a new powerful tool for studies of Notch gene regulation and the organization of the open chromatin state.

Drosophila melanogaster, Notch gene, CRISPR/Cas9 system, gene activity regulation, insulator protein, open chromatin state, interbands

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