Male and female mice derived from the same embryonic stem cell clone by tetraploid embryo complementation

Area of Science:

• Genetics
• Developmental Biology
• Animal Models

Background:

• Generating genetically modified animal models is crucial for understanding gene function.
• Traditional methods for creating mutant mouse lines can be time-consuming and resource-intensive.
• Efficient production of specific sex genotypes is often required for research.

Purpose of the Study:

• To establish a streamlined strategy for producing female mice from male embryonic stem (ES) cells.
• To facilitate the generation of gene-targeted mutant mouse lines.
• To reduce the time and cost associated with creating experimental animal models.

Main Methods:

• Derivation of 39,X0 ES cell lines from male 40,XY ES cell lines through Y chromosome loss.
• Utilizing tetraploid embryo complementation for generating chimeric mice from both 40,XY and 39,X0 ES cells.
• Employing a single intercross to produce homozygous mutant offspring.

Main Results:

• Y chromosome loss occurred in 2% of subclones from 40,XY ES cell lines, enabling routine identification of 39,X0 derivatives.
• Successful generation of male and female mice carrying targeted mutations via tetraploid embryo complementation.
• Demonstrated that inherent karyotypic instability of ES cells does not impede the production of adult tetraploid mice.

Conclusions:

• The developed strategy efficiently produces female mice from male ES cells, simplifying the generation of gene-targeted mutant lines.
• This method significantly reduces the time and expense for creating experimental mutant animals by avoiding outcrossing.
• The approach is robust, even with the inherent karyotypic instability observed in ES cells.