Ebnet, Edeltraut and Fischer, Markus and Deininger, Werner and Hegemann, Peter (1999) Volvoxrhodopsin, a light-regulated sensory photoreceptor of the spheroidal green alga Volvox carteri. PLANT CELL, 11 (8). pp. 1473-1484. ISSN 1040-4651,
Full text not available from this repository. (Request a copy)Abstract
Somatic cells of the multicellular alga Volvox carteri contain a visual rhodopsin that controls the, organism's phototactic behavior via two independent photoreceptor currents. Here, we report the identification of an opsinlike gene, designated as volvoxopsin (vop). The encoded protein exhibits homologies to the opsin of the unicellular alga Chlamydomonas reinhardtii (chlamyopsin) and to the entire animal opsin family, thus providing new perspectives on opsin evolution. Volvoxopsin accumulates within the eyes of somatic cells. However, the vop transcript is detectable only in the reproductive eyeless gonidia and embryos. vop mRNA levels increase 400-fold during embryogenesis, when embryos develop in darkness, whereas the vop transcript does not accumulate when embryos develop in the light. An antisense transformant, T3, was generated. This transformant produces 10 times less volvoxopsin than does the wild type. In T3, the vop transcript is virtually absent, whereas the antisense transcript is predominant and light regulated. It follows that vop expression is under light-dependent transcriptional control but that volvoxopsin itself is not the regulatory photoreceptor. Transformant T3 is phototactic, but its phototactic sensitivity is reduced 10-fold relative to the parental wild-type strain HK10. Thus, we offer definitive genetic evidence that a rhodopsin serves as the photoreceptor for phototaxis in a green alga.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CHLAMYDOMONAS; RHODOPSIN; EXPRESSION; PHOTOTAXIS; EVOLUTION; INTRON; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie I |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 11 Jan 2023 15:22 |
| Last Modified: | 11 Jan 2023 15:22 |
| URI: | https://pred.uni-regensburg.de/id/eprint/49104 |
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