A Trial of Oocyte Maturation and In Vitro Fertilization by Frozen-Thawed Spermatozoa in the Red-Bellied Tamarin (Saguinus labiatus)

Freezing of epididymal spermatozoa from red-bellied tamarins (Saguinus labiatus) was achieved by using a semen-diluting medium called TTE (Tes, Tris, egg-yolk base) containing 5% glycerol. When the frozen spermatozoa were suspended and incubated in m-TYH medium (TYH medium supplemented with 1mM caffeine and 1mM dibutyryl cyclic AMP), the frozen-thawed spermatozoa showed a good sperm survival rate and hyperactive movement after 30 min of incubation. A total of 59 germinal vesicle (GV) stage oocytes were collected from 4 ovaries of 4 female red-bellied tamarins regardless of their menstrual cycles. At 24, 48, and 72 h after incubation in TCM-199 medium containing 10% fetal calf serum (FCS), 30%, 53%, and 71% oocytes, respectively, either showed germinal vesicle breakdown (GVBD) or had extruded the first polar body. Although the oocytes matured in vitro were inseminated by frozen-thawed spermatozoa, no eggs became fertilized.