Electron Microscopy of the Morphology and Histology of Lymphoid and Immune tissue in Japanese Quail (Coturnix coturnix japonica)

Summary The goal of this study was to describe the morphology and histology of lymphoid and immune tissue in Japanese Quail (Coturix coturnix japonica). Specific systems that were examined include the blood (white blood cells and red blood cells), the spleen, an important lymphoid organ, as well as the Bursa of Fabricius, an organ found in avian species, important to immunological development and the site of B-cell production. This study is part of a larger endeavor to understand and explain the ontogeny of the immune system in avian species, as well as the energetic consequences of immune development and challenges. This study also tested the common belief that “you can’t overfix” as, contrary to the protocols followed, which called for overnight 2.5% glutaraldehyde fixation, all samples used were fixed for over 20 days. This study used both Transmission Electron Microscopy and Scanning Electron Microscopy. TEM was used to look at the buffy coats taken from blood samples spun for 10min in a microcentrifuge, and results showed that this method is effective in the study of Quail immune cells, and that Quail leukocytes are analogous, both in terms of size and appearance, to those of other avian species as well as those of well studied mammalian species. SEM photography revealed regions of the organs looked at based on the topography and diversity of cells. Furthermore, it was established that overfixation is not detrimental to the study of these systems with the methods utilized.