Eye-like ocelloids are built from different endosymbiotically acquired components

Abolishment of Spontaneous Flight Turns in Visually Responsive Drosophila

“…NP0212 > Shi ts flies at 34°C continued to make some sharp turns during optomotor stimuli (see NP0212 > Shi ts example trace in Figure 4C). Such turns, whose rate seems to be increased by optomotor stimuli and which have been noted previously [3, 29, 45], represent a potentially different class of flight maneuver from those blocked in NP0212 > Shi ts flies.…”

“…In this preparation flies perform frequent, sharp wing-steering movements, which likely represent saccadic attempts to turn left or right [2]. Like others before us [2, 3], we will refer to these attempted turns in tethered flight as saccades, although more work will be required to determine the exact relationship between free-flight maneuvers and any specific tethered-flight measurement made here [4, 5]. …”

“…In both tethered and free flight, saccades often occur at unpredictable times relative to any obvious external sensory event [1, 3–6]. Though some of these seemingly random turns may ultimately be shown to have some relationship to the time history of sensory experience [7, 8], we will operationally refer to such turns as spontaneous saccades .…”

How to build a microbial eye

“…But animals were not the only organisms to evolve such systemsanalogous structures and biochemical responses exist in cells of several eukaryotic microorganisms (cells that package most of their DNA in a nucleus), allowing these microbes to move in response to light 3 . In a paper published on Nature's website today, Gavelis et al 4 describe the subcellular features that make up the eye-like structures of warnowiid dinoflagellates, which in anatomical terms are remarkably similar to vertebrate eyes.…”

“…a, The eye-like ocelloids found in unicellular organisms known as warnowiid dinoflagellates have a 'camera-like' complexity that resembles that of animal eyes. Gavelis et al4 show that two of these components in warnowiids have arisen through the reconfiguration of membrane-bound organelles that are usually used for cellular energy transformation: the cornea is formed from a layer of mitochondria and the retinal body is derived from a network of plastids. b, c, Microorganisms from other branches of the tree of life also contain eye-like structures, although these are anatomically simpler.…”