Potential of the opossum in oral research.

Abstract

The OpOSSUin (Didelphis virginiana) is the only marsupial native to North America. The young migrate from the vagina into the pouch after 12.5 days of gestation. The stomatodeum attaches to a teat, and the young become firmly anchored as the teats swell. The ermbryo resnains in the pouch for the next 60 to 70 days. This phenomenon has given the opossum a recent and important place in research. Reports have been made of its research values in areas Such as aUtoimmune mechanisms, genetics, endocrine behavior, growth development, wound healing, and blood problems (S.E. KAILMUTZ Nature 193:851 853, 1962; J.F.A.D. MIrtrIR, ET Al.: Proc Soc Exp Biol Med 118:916 921, 1965; M. GRAY: Amer J Physiol 68:149-152, 1924). In his article on the embryology of the opossumr, however, McGrady (Amer Anat Mem, No. 16, 1938) did not inclttde oral and odontogenic histogenesis. A review of the use of the opossum for research has been reported (J.H. KRUPP and R. QUILLIN, Lab Anim Care 1463: 189-94, 1964). The purpose of this annotation is to illustrate some of the early odontogenic embryology and to stress the potential of the opossum in oral research. Figure 1 illustrates the morphologic structure of the embryonal odontogenic apparatus at the dental lamina stage. It is estimated that the dental age of the newx born opossum is about