Testis-specific Arf promoter expression in a transposase-aided BAC transgenic mouse model

Area of Science:

• Genetics and Molecular Biology
• Developmental Biology
• Cancer Research

Background:

• The CDKN2A gene encodes p16Ink4a and p19Arf proteins involved in tumor suppression, aging, and development.
• While protein functions are known, Cdkn2a transcript expression control remains unclear.
• Genetically engineered mouse models have elucidated protein functions, but not gene regulation in situ.

Purpose of the Study:

• To investigate the coordinate and transcript-specific expression of Cdkn2a.
• To generate a novel BAC transgenic mouse model for studying Cdkn2a regulation.
• To identify regulatory elements controlling Cdkn2a expression during development.

Main Methods:

• Utilized a transposase-aided approach to create BAC transgenic mice.
• Replaced first exons of Arf and Ink4a with fluorescent reporters.
• Analyzed reporter gene expression in mouse embryo fibroblasts (MEFs) and developing tissues.

Main Results:

• Transgenic reporters accurately reflected endogenous Cdkn2a expression in cultured MEFs.
• Arf reporter expression was observed in the normal mouse testis.
• TGFβ-2-dependent Arf reporter induction in the eye, crucial for development, was notably absent.

Conclusions:

• BAC transgenesis is valuable for mapping regulatory elements of genes like Cdkn2a.
• Identified genomic DNA regions required for Cdkn2a induction in cultured cells and the testis.
• Revealed the absence of specific regulatory elements driving Cdkn2a expression in the developing eye.