SLC4A2 and osteopetrosis: The gross and histological features observed in Ae2-/- mice are similar to those observed in osteopetrosis-affected calves; Ae2-/- mice exhibit improper bone marrow cavity formation [24-26], growth retardation[24-26,34], early lethality (typically by age of weaning) [26,34], abnormal mandibles [25] and impaired tooth development [25,34].