From Cell Biology to Tissue Engineering


Comparative study of the eyelids and orbital glands morphology in the okapi (Okapia johnstoni, Giraffidae), Père David's deer (Elaphurus davidianus, Cervidae) and the Philippine mouse-deer (Tragulus nigricans, Tragulidae)

Joanna Elżbieta Klećkowska-Nawrot1, Karolina Goździewska-Harłajczuk1 and Karolina Barszcz2

1Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw and 2Department of Morphological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland

Offprint requests to: Joanna Elżbieta Klećkowska-Nawrot or Karolina Goździewska-Harłajczuk, Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, 1 Kozuchowska, Wroclaw, Poland. e-mail: k.gozdziewska.wroc@gmail.com or lestat_v@poczta.onet.pl

Summary. The accessory organs of the eye represent part of the protective system of the eyeball. In the present study, an examination of the accessory organs of the eye of three species of captive ruminants was performed using light microscopy. In the okapi, the superficial gland of the third eyelid and lacrimal gland were complex branched multilobar tubular glands formed by mucous units with tubular secretory portions and no plasma cells. The deep gland of the third eyelid was absent in the okapi and present in both the Père David's deer and the Philippine mouse-deer. In the Philippine mouse-deer, the deep gland had a very thick connective capsule and thick interlobar septae. It contained fewer lobes forming the gland parenchyma compared to Père David's deer and other ruminants. Organized lymphoid follicles were present within the upper and lower eyelids only in the okapi and Père David's deer, while diffuse lymphocytes were observed in the Philippine mouse-deer. The orbital glands in the Père David's deer had a multilobar tubuloacinar structure with numerous plasma cells and a mucoserous character. In contrast to the Philippine mouse-deer, these glands had a serous character. The presence of several macroscopic and microscopic structural differences of the examined accessory organs of the eye in the three captive ruminant species may be understood within an ecological context and may be associated with different habitat-specific environmental conditions. Histol Histopathol 35, 185-202 (2020)

Key words: Morphology, Histology, Histochemistry, Accessory organs of the eye, Ruminants

DOI: 10.14670/HH-18-144