Nuclear bodies in bovine mammary gland in different physiological states

The frequency of nuclear bodies was determined in epithelial cells of mammary ductules or alveoli, milk cistern and teat sinus of virgin heifers, non-lactating cows and cows in early lactation. The determined frequency was within the range 12–16% with the single exception of the epithelial cells of secretory alveoli of lactating cows, in which the frequency was 3 %. These data support the concept that nuclear bodies are normal nuclear organelles which can respond to altered physiological conditions.