BASKET AND BASAL-DUCT CELLS IN DOMESTIC-ANIMALS - DIFFERENT CYTOKERATIN EXPRESSION AND SHAPE

Cytokeratins (CKs) are a multigenic family of proteins constituting in termediate filaments in epithelia, indicated in humans by the numbers 1-20. Different cell-types can be immunocytochemically identified on t he grounds of their CK expression. This investigation was designed to study CK expression of basket cells (BCs) and basal-duct cells (BDCs) in some domestic animals. Frozen sections of mammary and major salivar y glands from cows, sheep, pigs and rabbits were treated using the imm unofluorescent method, using as monoclonal antibodies clones CK-E3, CK B1, KS-1A3, and LDS-68, respectively, revealing the human CKs 17, 14, 13, 7. BCs surrounding acini and BDCs were stained by CK 17 antibody o nly in the rabbit. CK 14 was detectable in both cell types in cows, sh eep and pigs, except in the case of bovine salivary BCs. CK 13 was rev ealed in BCs and BDCs of all mammary glands and also rabbit salivary g lands. In the salivary glands of the other species, only BDCs were sta ined. CK 7 gave unreliable results in all the species and cell types e xamined. Interestingly, in the rabbit, also BDCs are basketlike in sha pe. The antibodies employed showed different staining depending on spe cies and gland. On the grounds of immunoreactivity and shape, BCs and BDCs can be considered the same cell type in the rabbit. In the other species, they appear to be different, since BDCs may express additiona l CKs and are triangular-shaped, whereas BCs are truly basket-like. It is worth noting that clone KS-1A3 in the rabbit and CKB1 in the sheep and pig can be considered markers of the basket/basal system.