Harvesting Monodelphis Embryos

Abstract

INTRODUCTIONMonodelphis domestica, the gray, short-tailed, or laboratory opossum, is the most commonly used laboratory marsupial. In addition to the factors that make it a convenient laboratory animal (small size, ease of care, nonseasonal breeding), it is the first marsupial whose genome has been sequenced. Monodelphis has proven useful as a model organism for studies on spinal cord regeneration, ultraviolet (UV)-induced melanoma, and genetic influences on cholesterol, as well as comparative studies of the immune system. In addition, Monodelphis has been used to understand the basic functions of the olfactory system and the role of various olfactory chemicals in social and reproductive behavior. Recently, Monodelphis has been used to understand fundamental aspects of marsupial development, anatomy, evolution, and evolutionary consequences of the derived marsupial mode of development and reproduction. Monodelphis embryos are easily harvested, as described in this protocol. Depending on the specific use for the embryo, there may be slight differences in euthanasia procedure, fixation, and embryo treatment. Most commonly, specimens will be used for anatomical or molecular (e.g., in situ hybridization) techniques, in which case they will be fixed in standard fixatives appropriate for the particular protocol.