[The development of newborn C 57 BL/KsJ-dbm mice produced from eggs fertilized in vitro]

The purpose of this study was to examine the development of newly born C57BL/KsJ-dbm mice produced from eggs fertilized in vitro. The embryos derived from fertilization in vitro (which was performed by using db/db eggs and adrenalectomized db/db (Adrex) spermatozoa,) were transferred to the oviduct of MRL/MpJ pseudopregnant recipients 30 hr after insemination. 376 of these embryos yielded 65 young. Weight gain and urine glucose, plasma glucose and insulin levels were measured in these young as well as in Adrex males. The young produced by fertilization in vitro showed hyperglycemia, hyperinsulinemia and obesity. The physiological abnormalities in these young were similar to those in db/db young produced by natural mating between heterozygote (db/+) males and females. Adrex males did not show hyperglycemia but did show hyperinsulinemia. These results indicate that in vitro fertilization and embryo transfer is an effective means of producing fetuses or newborns with an overt genotype in genetically diabetic obese (db) mice.