Nuclear segmentation, ultrastructure, and cytochemistry of blood cells from dogs with Pelger-Huët anomaly.

Nuclear segmentation, ultrastructural features and cytochemical staining reactions of blood cells from 7 dogs with the heterozygous form of Pelger-Huët (P-H) anomaly were investigated. Significant nuclear hyposegmentation of granulocytes, monocytes and megakaryocytes was found, indicating a common stem cell defect in the nuclear segmentation or lobulation process. Neutrophils and eosinophils from female P-H dogs lacked sex chromatin drumsticks. Other than the suggestion of nuclear hyposegmentation and the presence of coarse heterochromatin, no ultrastructural abnormalities were discerned. Cytochemical staining by a-naphthyl acetate esterase, alkaline phosphatase, naphthol ASD chloroacetate esterase, periodic acid-Schiff, peroxidase and Sudan black B techniques gave similar results for P-H and control dog leukocytes and platelets.