Fetal erythropoiesis and hemoglobin ontogeny in tail-short (Ts/+) mutant mice.

Mutant Ts/+ fetuses are developmentally retarded as compared to normal +/+ littermates. Mutant fetuses have less total hemoglobin than do normal fetuses of the same gestational age. However, when compared to +/+ fetuses of similar body weight, Ts/+ fetuses have the appropriate amount of total hemoglobin, suggesting that the apparent anemia observed in mutant fetuses is most likely the result of delay in growth and development. Changes in …