Complementation of null CF mice with a human CFTR YAC transgene

Area of Science:

• Genetics
• Molecular Biology
• Physiology

Background:

• Cystic Fibrosis (CF) is a genetic disorder caused by mutations in the CFTR gene.
• CFTR gene dysfunction leads to severe health issues, including respiratory and digestive problems.
• Animal models are crucial for understanding CFTR function and developing therapeutic strategies.

Purpose of the Study:

• To create and characterize transgenic mice expressing the intact human CFTR gene.
• To assess the functional restoration of CFTR activity in a CF mouse model.
• To investigate the expression patterns of the human CFTR transgene in vivo.

Main Methods:

• Construction of a large yeast artificial chromosome (YAC) containing the full human CFTR gene.
• Generation of transgenic mice carrying the human CFTR YAC.
• Breeding transgenic mice with CFTR-null mice to achieve transgene expression without endogenous gene function.
• Assessment of physiological function, including chloride secretion.
• Analysis of transgene expression patterns in various tissues.

Main Results:

• Transgenic mice expressing the human CFTR gene were successfully generated.
• Mice lacking endogenous CFTR but expressing the human transgene exhibited normal physiology and reproductive capacity.
• Chloride secretory responses in these mice were comparable to or greater than wild-type levels.
• Transgene expression was cell-type specific, largely mirroring endogenous mouse CFTR patterns in gut and salivary glands.
• Expression differences were observed in certain tissues, with the transgene adhering to the mouse expression pattern.

Conclusions:

• A large DNA fragment containing the human CFTR gene can direct physiological expression in relevant cell types.
• This transgenic model provides a valuable tool for studying CFTR function and potential gene therapies.
• The study demonstrates the feasibility of using YACs for delivering large, intact genes to restore function in genetic disorders.