A transgenic mouse line with specific Cre recombinase expression in the adrenal cortex

Area of Science:

• Genetics and Molecular Biology
• Endocrinology
• Developmental Biology

Background:

• The Cre-loxP system is a powerful tool for conditional gene manipulation.
• Targeted gene inactivation in specific tissues is crucial for understanding gene function.
• Existing Cre driver lines often lack specificity or exhibit off-target expression.

Purpose of the Study:

• To develop a novel mouse model for achieving adrenal cortex-specific gene recombination in vivo.
• To utilize the 5'-flanking region of the akr1b7 gene to drive Cre expression in the adrenal cortex.
• To assess the specificity and efficacy of Cre expression in the adrenal cortex and other organs.

Main Methods:

• Generation of transgenic mice (0.5 akr1b7-Cre) using a 0.5-kb fragment of the akr1b7 5'-flanking region.
• In vivo assessment of Cre recombinase activity using the ROSA26R reporter locus.
• Histological analysis to determine Cre expression patterns in the adrenal cortex, gonads, and kidneys.

Main Results:

• The 0.5 akr1b7-Cre mice exhibited Cre expression in all steroidogenic zones of the adrenal cortex.
• Cre expression was notably absent in the gonads, demonstrating improved specificity.
• Cre activity was also detected in kidney collecting ducts and maturing glomeruli.

Conclusions:

• The 0.5 akr1b7-Cre mouse line provides specific Cre expression in the adrenal cortex, a significant advancement.
• This model is the first to show adrenal cortex-specific Cre expression without gonadal activity.
• This transgene represents a valuable tool for targeted gene manipulation in the adrenal cortex and kidney.