Ossification in nude mice. 1. Macroscopical study.

Ossification was studied in cleared fetuses, newborns, 1- and 6-week-old nu/nu and nu/+ mice of the B 10 LP background. The same ossification pattern was observed in nu/nu and nu/+ in the embryonal period as well as in newborn animals and mice aged 1 or 6 weeks. On the other hand, 6-week-old nu/nu mice exhibited a lower X-ray density of the skeleton and a lower thickness of the proximal tibial growth plate than 6-week-old nu/+ litter mates. The results indicate the influence of postnatal factors on the skeletal development of nu/nu mice.