Sex-reversed and Female Mouse (image) The Francis Crick Institute Share Print E-Mail Caption From left: male (XY) mouse with female genitalia and female (XX) mouse. Credit Greta Keenan, Francis Crick Institute Usage Restrictions With credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.