TRANSPLANTATION OF FROZEN - THAWED MOUSE PRIMORDIAL FOLLICLES

Primordial follicles were isolated from juvenile mouse ovaries and cry opreserved by slow freezing with dimethylsulphoxide as the cryoprotect ant. After thawing, approximately 80% of the oocytes and 65% of the so matic cells excluded Trypan Blue dye, indicating that cell membranes w ere still intact. Frozen-thawed cells were suspended in plasma dots an d transplanted to the ovarian bursas of host animals that had been ste rilized by oophorectomy. The grafts of frozen-thawed cells reorganized into morphologically distinguishable ovaries which produced signs of oestrogenic activity. After natural mating, host females produced norm al offspring that were demonstrated by genetic markers to be derived f rom the transplanted frozen-thawed primordial follicles.