Ocelloid

Not to be confused with the ocellus (pl. ocelli), a simple light-sensitive structure found in invertebrates.
An image of a single cell featuring a large nucleus and an ocelloid, which is composed of a roundish "lens" and a darkly pigmented disc-shaped retinal body.
A light micrograph of an ocelloid-containing dinoflagellate. The nucleus is marked n, the ocelloid is indicated with a double arrowhead, and a posterior cell extension is indicated with an arrow; scale bar = 10 μm.[1]

An ocelloid is a subcellular structure found in the family Warnowiaceae (warnowiids), which are members of a group of unicellular organisms known as dinoflagellates. The ocelloid is analogous in structure and function to the eyes of multicellular organisms, which focus, process and detect light. The ocelloid is much more complex than the eyespot, a light-sensitive structure also found in unicellular organisms, and is in fact one of the most complex known subcellular structures.[2] It has been described as a striking example of convergent evolution.[3]

  1. ^ Cite error: The named reference hoppenrath was invoked but never defined (see the help page).
  2. ^ Gregory S. Gavelis; Shiho Hayakawa; Richard A. White III; Takashi Gojobori; Curtis A. Suttle; Patrick J. Keeling; Brian S. Leander (2015). "Eye-like ocelloids are built from different endosymbiotically acquired components". Nature. 523 (7559): 204–7. Bibcode:2015Natur.523..204G. doi:10.1038/nature14593. hdl:10754/566109. PMID 26131935. S2CID 4462376.
  3. ^ Richards, Thomas A.; Gomes, Suely L. (1 July 2015). "Protistology: How to build a microbial eye". Nature. 523 (7559): 166–167. Bibcode:2015Natur.523..166R. doi:10.1038/nature14630. PMID 26131934.