title: Cell-type specific light-mediated transcript regulation in the multicellular alga Volvox carteri.
abstract: BACKGROUND
  The multicellular green alga Volvox carteri makes use of none less than 13 photoreceptors, which are mostly expressed in a cell-type specific manner. This gives reason to believe that trasncriptome pattern of each cell type could change differentially in response to environmental light. Here, the cell-type specific changes of various transcripts from different pathways in response to blue, red and far-red light were analyzed.
  
  
  RESULTS
  In response to different light qualities, distinct changes in transcript accumulation of genes encoding proteins involved in chlorophyll and carotenoid biosynthesis, light-harvesting complexes, circadian clock and cell cycle control were observed. Namely, blue light tends to be effective to accumulate transcripts in the somatic cells; while red light leads to accumulate transcripts predominantly in the reproductive cells. Blue light also induced marked accumulation of two components of circadian rhythms only in the somatic cells, indicating that these clock-relevant components are affected by blue light in a cell-type specific manner. Further, we show that photosynthetic associated genes are regulated distinctly among cell types by different light qualities.
  
  
  CONCLUSIONS
  Our results suggest that Volvox uses different sophisticated cell-type specific light signaling pathways to modulate expression of genes involved in various cellular and metabolic pathways including circadian rhythms and photosynthesis in response to environmental light.
authors.affiliation: Department of Cellular and Developmental Biology of Plants, University of Bielefeld, Universitätsstr, 25, D-33615 Bielefeld, Germany. kianian@uni-bielefeld.de.
authors.forename: Arash
authors.initials: A
authors.lastname: Kianianmomeni
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis; D002453:Cell Cycle / Q000235:genetics; D002734:Chlorophyll / Q000378:metabolism; D057906:Circadian Clocks / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D008027:Light; D053858:Metabolic Networks and Pathways; D009928:Organ Specificity / Q000235:genetics; D010786:Photoreceptor Cells / Q000378:metabolism; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D044446:Volvox / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D010940:Plant Proteins; D002734:Chlorophyll; D002338:Carotenoids