title: Unique transducins expressed in long and short photoreceptors of lamprey Petromyzon marinus.
abstract: Lampreys represent the most primitive vertebrate class of jawless fish and serve as an evolutionary model of the vertebrate visual system. Transducin-alpha (G alpha(t)) subunits were investigated in lamprey Petromyzon marinus in order to understand the molecular origins of rod and cone photoreceptor G proteins. Two G alpha(t) subunits, G alpha(tL) and G alpha(tS), were identified in the P. marinus retina. G alpha(tL) is equally distant from cone and rod G proteins and is expressed in the lamprey's long photoreceptors. The short photoreceptor G alpha(tS) is a rod-like transducin-alpha that retains several unique features of cone transducins. Thus, the duplication of the ancestral transducin gene giving rise to rod transducins has already occurred in the last common ancestor of the jawed and jawless vertebrates.
authors.affiliation: Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA. Hakim-Muradov@uiowa.edu
authors.forename: Hakim
authors.initials: H
authors.lastname: Muradov
authors.forename: Vasily
authors.initials: V
authors.lastname: Kerov
authors.forename: Kimberly K
authors.initials: KK
authors.lastname: Boyd
authors.forename: Nikolai O
authors.initials: NO
authors.lastname: Artemyev
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D055537:Light Signal Transduction / Q000502:physiology; D008969:Molecular Sequence Data; D055355:Opsins / Q000378:metabolism; D048428:Petromyzon / Q000235:genetics / Q000378:metabolism*; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D010802:Phylogeny; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism; D015293:Transducin / Q000235:genetics / Q000378:metabolism*
chemical_list: D055355:Opsins; D015293:Transducin