In vitro fertilization and development of llama (Lama glama ) oocytes using epididymal spermatozoa and oviductal cell co-culture.
A study was designed to determine the feasibility of developing in vitro maturation, fertilization and culture systems utilizing follicular oocytes and epididymal spermatozoa collected from llamas at slaughter. From a total of 1324 cumulus oocyte complexes (COCs) recovered, 972 were cultured in 50-ul drops of TCM-199 medium with 10% heat inactivated steer serum (DBS) and hormones for 30 h. After maturation, the oocytes were randomly allocated into 4 groups in a 2x2 factorial design: cumulus-enclosed oocytes, 2 ug/ml heparin (Group 1); cumulus-enclosed oocytes, 5 ug/ml heparin (Group 2); denuded oocytes, 2 ug/ml heparin (Group 3); and denuded oocytes, 5 ug/ml heparin (Group 4). Denuded oocytes were obtained for groups 3 and 4 by vortexing. Epididymides were also collected at slaugther and fresh spermatozoa (for each replicate) were obtained by mincing the cauda epididymis with a scalpel blade. A total of 721 oocytes were inseminated with 2-3 x 10(6) epididymal spermatozoa/ml in a 50-ul drop of FERT-TALP medium. After 18 h of in vitro insemination, 234 oocytes were placed in a llama oviductal epithelial cell (LLOEC) co-culture in TCM-199 for 9 d. All cultures were done at 38.5 degrees C under 5% CO(2) in air with high humidity. The rate of fertilization, initial cleavage and development in co-culture were evaluated and compared. Of 192 oocytes examined for signs of fertilization, 56 (29.2%) were penetrated by spermatozoa with 57.1% (32 56 ) of the penetrated oocytes having a male and female pronucleus. There were no differences among treatment groups in total fertilization. However, the frequency of oocytes fertilized normally tended to be higher in the denuded oocytes 67.7% (21 31 ) than the oocytes inseminated with cumulus cells 44.0% (11 25 ) independent of heparin concentration (P<0.06). The total embryo development rate to the 2 cells to blastocyst stage was 32.1% (75 234 ). There was no difference in development rate between groups. From the 234 oocytes co-cultured in LLOEC for 9 d, 15.8% developed into 2 to 16 cells, 5.6% into morulae, 6.0% into early/expanded blastocysts and 4.7% into hatching/hatched blastocysts. The results indicate that an in vitro fertilization system is possible in the llama utilizing slaughterhouse material and that llama oocytes can be fertilized in the presence of heparin and epididymal spermatozoa.
Del Campo
M R
MR
Department of Herd Medicine and Theriogenology, Western College of Veterinary Medicine University of Saskatchewan. Saskatoon, SK. Canada S7N OWO.
Del Campo
C H
CH
Donoso
M X
MX
Berland
M
M
Mapletoft
R J
RJ