title: A full suite of histone and histone modifying genes are transcribed in the dinoflagellate Lingulodinium.
abstract: BACKGROUND
  Dinoflagellates typically lack histones and nucleosomes are not observed in DNA spreads. However, recent studies have shown the presence of core histone mRNA sequences scattered among different dinoflagellate species. To date, the presence of all components required for manufacturing and modifying nucleosomes in a single dinoflagellate species has not been confirmed.
  
  
  RESULTS
  Analysis of a Lingulodinium transcriptome obtained by Illumina sequencing of mRNA shows several different copies of each of the four core histones as well as a suite of histone modifying enzymes and histone chaperone proteins. Phylogenetic analysis shows one of each Lingulodinium histone copies belongs to the dinoflagellate clade while the second is more divergent and does not share a common ancestor. All histone mRNAs are in low abundance (roughly 25 times lower than higher plants) and transcript levels do not vary over the cell cycle. We also tested Lingulodinium extracts for histone proteins using immunoblotting and LC-MS/MS, but were unable to confirm histone expression at the protein level.
  
  
  CONCLUSIONS
  We show that all core histone sequences are present in the Lingulodinium transcriptome. The conservation of these sequences, even though histone protein accumulation remains below currently detectable levels, strongly suggests dinoflagellates possess histones.
authors.affiliation: Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Sougata
authors.initials: S
authors.lastname: Roy
authors.forename: David
authors.initials: D
authors.lastname: Morse
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D002478:Cells, Cultured; D019295:Computational Biology; D004247:DNA / Q000235:genetics; D004141:Dinoflagellida / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D015151:Immunoblotting; D009707:Nucleosomes / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers; D006657:Histones; D009707:Nucleosomes; D015800:Protozoan Proteins; D012333:RNA, Messenger; D004247:DNA; D011495:Histone-Lysine N-Methyltransferase