The Evolutionary Origins and Presence of Eosinophils in Extant Species

摘要: Amoeboid cells containing acidophilic cytoplasmic granular structures are found in the hemolymph and eventually blood circulatory system of representative, if not all, metazoan species. Though an stain quality is hardly sufficient to assert homology, comparability granule ultrastructure, developmental similarities, some functions contribute consideration that alleged eosinophil granulocyte at least primordially existent many primitive invertebrates (representative several phyla) all vertebrate This possible ubiquity suggestive a prevailing function significant survival confers favorable advantage process natural selection. The adaptive metamorphosis considered preference host defense mechanisms. Also suggested evolutionary ongoing. As such, granulocytes may still be contributing species survival.