Submitted to: Reproductive Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 2005
Publication Date: July 1, 2005
Citation: Lawrence, J.L., Schrick, F., Hopkins, F.M., Welborn, M.G., Mccracken, M.D., Sonstegard, T.S., Wilson, T.J., Edwards, J. 2005. Fetal losses and pathologic findings of clones derived from serum-starved versus serum-fed bovine ovarian granulosa cells. Reproductive Biology. 5(2):171-184.
Interpretive Summary: This manuscript compares the viability differences of cloned embryos derived from either serum starved or fed bovine ovarian/granulose cells. Embryonic loss was greater in the first trimester for clones derived from serum-starved cells. Only one fetus derived from serum fed cells developed to term. However, both methods of cell feeding were equally inefficient at generating clones that were viable for the full term of pregnancy. The clonal origin of the one calf successfully generated from this study was validated by comparing marker genotypes generated from 12 bovine microsatellite markers.
The objective was to evaluate development of cloned embryos constructed with serum-starved versus fed ovarian/granulosa cells. Fusion of somatic cells with cytoplasts (50.7 and 50.7%; SEM=5.5), development of cloned embryos to 8-16-cell (59.4 and 62.6%; SEM=6.4), and compact morula/blastocyst-stages (24.9 and 26.5%; SEM=8.5) was similar. More heifers were confirmed pregnant with clones derived from serum-starved cells. However, embryonic loss between 29-50 days was greater for clones constructed with serum-starved (88.9%) versus fed (36.4%) cells. Development of clones derived from serum fed cells through placentation and differentiation was not predictive of competency to term. Fetal deaths occurred in the majority of late term pregnancies as a result of complications from hydrallantois. Only one fetus derived from serum fed ovarian/granulosa cells developed to term (278 days). At birth and for consecutive months thereafter, routine veterinary checks confirmed expected growth patterns. Cumulatively, results indicate use of serum starved versus fed ovarian/granulosa cells work inefficiently well for somatic cell nuclear transfer. The high incidence of third trimester losses raised concern with the use of serum fed ovarian/granulosa cells to construct cloned embryos.