DEVELOPMENTAL POTENTIAL OF MICROBIOPSIED MURINE BLASTOCYSTS

Objective: To evaluate the frequency of mouse pups born following blas tocyst biopsy and embryo transfer compared to nonbiopsied controls. Me thods: ICR Swiss albino and C57B1/6 mice served as embryo donors. Preg nant mare serum gonadotropin treatment was followed 46-52 hours later by hCG, when donors were paired with fertile males. Mating was confirm ed the following day and embryos were collected on the afternoon of da y 4. After overnight culture, hatching trophoblast was excised by micr omanipulation with a fine-pulled glass pipette. Embryos (206 controls, 206 biopsied) were transferred to 26 pseudopregnant recipients. Alter nate mouse strains were used to identify pups born from control or bio psied embryos. Results: The end point was percentage of pups born ((nu mber born/number transferred) x 100), using angular transformation bef ore analysis. There was no significant difference (P > .1) between per cent live-born in control (27.7%) or biopsied (34.5%) embryos, nor wer e there any strain differences. Conclusion: These data support the hyp othesis that the developmental potential of murine blastocysts is not affected adversely by the biopsy procedure.