title: Elephants and human color-blind deuteranopes have identical sets of visual pigments.
abstract: Being the largest land mammals, elephants have very few natural enemies and are active during both day and night. Compared with those of diurnal and nocturnal animals, the eyes of elephants and other arrhythmic species, such as many ungulates and large carnivores, must function in both the bright light of day and dim light of night. Despite their fundamental importance, the roles of photosensitive molecules, visual pigments, in arrhythmic vision are not well understood. Here we report that elephants (Loxodonta africana and Elephas maximus) use RH1, SWS1, and LWS pigments, which are maximally sensitive to 496, 419, and 552 nm, respectively. These light sensitivities are virtually identical to those of certain "color-blind" people who lack MWS pigments, which are maximally sensitive to 530 nm. During the day, therefore, elephants seem to have the dichromatic color vision of deuteranopes. During the night, however, they are likely to use RH1 and SWS1 pigments and detect light at 420-490 nm.
authors.affiliation: Department of Biology, Emory University, Atlanta, Georgia 30322, USA. syokoya@emory.edu
authors.forename: Shozo
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Naomi
authors.initials: N
authors.lastname: Takenaka
authors.forename: Dalen W
authors.initials: DW
authors.lastname: Agnew
authors.forename: Jeheskel
authors.initials: J
authors.lastname: Shoshani
mesh_terms: D000818:Animals; D002335:Carnivora / Q000378:metabolism; D002415:Cats; D002417:Cattle; D003117:Color Vision Defects / Q000235:genetics*; D004285:Dogs; D004606:Elephants / Q000235:genetics* / Q000378:metabolism; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D012168:Retinal Pigments / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017299:Rod Opsins / Q000235:genetics; D013053:Spectrophotometry
chemical_list: D012168:Retinal Pigments; D017299:Rod Opsins