Recently, infection of early-stage embryos or blastocysts with lentiviral constructs, to either overexpress or “knock down” expression of specific genes, have been reported in cattle and sheep and have promise for more efficient genetic manipulation of livestock, at least for research purposes.
Advances in Biomedical Research
This brief synopsis of how cell and molecular biology technologies are interfacing with animal agriculture is not meant to be all-inclusive or exhaustive, but rather to highlight areas that have already or have the potential to impact livestock production. However, a discussion of this “interface” would not be complete without providing examples of how livestock species have helped to advance biomedical research.
For example, many assisted reproduction technologies, such as artificial insemination, cryopreservation of gametes and embryo transfer, initially were developed in livestock species before being applied to humans. There has been, and continues to be, a strong interface between efforts to improve human fertility and similar efforts in animal agriculture.
|The pregnant sheep has many attributes that make it a relevant experimental model. Photo credit: Carly Lesser and Art Drauglis.
Another example is the use of livestock, especially sheep, to investigate the physiology of gestation. The pregnant sheep has many attributes that make it a relevant experimental model: It is a long gestational mammal like the human; it often gives rise to a single offspring that has similar organ developmental maturity to the human newborn; and it can be manipulated surgically such that chronic instrumentation (vascular catheters, flow probes, etc.) of the fetus allows repetitive sampling on both sides of the placenta under nonanesthetized steady-state conditions. This animal model has provided considerable insight into placental nutrient transfer, fetal-nutrient utilization and the impaired fetal physiology associated with intrauterine growth restriction.
Additionally, swine provide a very relevant model for studying the development of cardiovascular disease, and chickens are being used as a natural model for ovarian cancer.
Clearly, animal agriculture has benefited and continues to benefit from advances made in cell and molecular biology and livestock species have served as valuable and relevant animal models for biomedical research. And, although the percentage of the U.S. work force involved with agriculture continues to decline, agriculture still is an important and required component of everyday life. The interface between cell and molecular biology and agriculture has been robust, and should continue to be, with both scientific disciplines benefiting from each other.
Russell V. Anthony (Russ.Anthony@Colostate.edu) is the Hill professor in the department of biomedical sciences at Colorado State University. Scott L. Pratt (firstname.lastname@example.org) is an assistant professor in the department of animal and veterinary science at Clemson University.