By ANNELIESE MOLL
for the UAS Whalesong
On December 9, 2015 Cornell University published a study in which they were able to successfully sire a litter of puppies by in vitro fertilization. In vitro fertilization (IVF) is a pretty complex process that is utilized when treating individuals with genetic or fertility trouble. During the procedure mature eggs are taken from a female and sperm from a male and then the egg is fertilized within a laboratory. To add another level to this experiment, researchers decided to cryopreserve (preserve though freezing) the eggs and sperm of the dogs since the majority of eggs and sperm collected from humans is stored this way (Nagashima et al. 2015).
Surprisingly, prior to this study there has been very little work done in regards to canine species. Which is interesting because there are currently over 300 known heritable disorders or traits present in dogs that are very similar to conditions observed within humans. Since their domestication humans have selected for specific traits both aesthetically and behaviorally.
Earlier this month researchers at the University of California Los Angeles published a study where the complete genome of 19 wolves, 25 wild dogs, and 46 domesticated dogs from 34 various breeds (Marsden et al. 2016). The results indicated that domestication may have gradually led to an increase of harmful genetic changes. Researchers speculate that this is a result of reductions in population sizes which led to a bottleneck situation. Kirk Lohmueller, senior author of the research and assistant professor of ecology and evolutionary biology in the UCLA, mentioned that “[within] selective breeding programs, particularly those aimed at conserving rare and endangered species, may need to include and maintain large populations to minimize the inadvertent enrichment of harmful genetic changes.”
The research from Cornell University regarding in vitro fertilization of dogs combined with gene editing tools, such as CRIPSER, could lead to beneficial changes regarding heritable genetic disorders within not only dogs, but other domesticated animals. Stepping even further this could easily have a large impact on how we approach the conservation of endangered species.
Marsden, C. D., Ortega-Del Vecchyo, D., O’Brien, D. P., Taylor, J. F., Ramirez, O., Vilà, C., … & Lohmueller, K. E. (2016). Bottlenecks and selective sweeps during domestication have increased deleterious genetic variation in dogs. Proceedings of the National Academy of Sciences, 113(1), 152-157.
Nagashima JB, Sylvester SR, Nelson JL, Cheong SH, Mukai C, Lambo C, et al. (2015) Live Births from Domestic Dog (Canis familiaris) Embryos Produced by In Vitro Fertilization. PLoS ONE 10(12): e0143930. doi:10.1371/journal.pone.0143930
University of California – Los Angeles. (2016, January 11). Dog domestication may have increased harmful genetic changes, biologists report. ScienceDaily. Retrieved January 19, 2016 from http://www.sciencedaily.com/releases/2016/01/160111162701.htm