They were collected from Saliega and another female -- both sterilized and retired from the breeding program -- by Berlin 's Leibniz Institute for Zoo and Wildlife Research and stored in liquid nitrogen at the Museo Nacional de Ciencias Naturales de Madrid for possible future breeding .
They were collected from Saliega and another female -- both sterilized and retired from the breeding program -- by Berlin 's Leibniz Institute for Zoo and Wildlife Research and stored in liquid nitrogen at the Museo Nacional de Ciencias Naturales de Madrid ( CSIC ) for possible future breeding .