Journal of Molecular Evolution

, Volume 62, Issue 1, pp 42–52

Rate Variation as a Function of Gene Origin in Plastid-Derived Genes of Peridinin-Containing Dinoflagellates

  • Tsvetan R. Bachvaroff
  • M. Virginia Sanchez-Puerta
  • Charles F. Delwiche
Article

DOI: 10.1007/s00239-004-0365-4

Cite this article as:
Bachvaroff, T.R., Sanchez-Puerta, M.V. & Delwiche, C.F. J Mol Evol (2006) 62: 42. doi:10.1007/s00239-004-0365-4

Abstract

Peridinin-pigmented dinoflagellates contain secondary plastids that seem to have undergone more nearly complete plastid genome reduction than other eukaryotes. Many typically plastid-encoded genes appear to have been transferred to the nucleus, with a few remaining genes found on minicircles. To understand better the evolution of the dinoflagellate plastid, four categories of plastid-associated genes in dinoflagellates were defined based on their history of transfer and evaluated for rate of sequence evolution, including minicircle genes (presumably plastid-encoded), genes probably transferred from the plastid to the nucleus (plastid-transferred), and genes that were likely acquired directly from the nucleus of the previous plastid host (nuclear-transferred). The fourth category, lateral-transferred genes, are plastid-associated genes that do not appear to have a cyanobacterial origin. The evolutionary rates of these gene categories were compared using relative rate tests and likelihood ratio tests. For comparison with other secondary plastid-containing organisms, rates were calculated for the homologous sequences from the haptophyte Emiliania huxleyi. The evolutionary rate of minicircle and plastid-transferred genes in the dinoflagellate was strikingly higher than that of nuclear-transferred and lateral-transferred genes and, also, substantially higher than that of all plastid-associated genes in the haptophyte. Plastid-transferred genes in the dinoflagellate had an accelerated rate of evolution that was variable but, in most cases, not as extreme as the minicircle genes. Furthermore, the nuclear-transferred and lateral-transferred genes showed rates of evolution that are similar to those of other taxa. Thus, nucleus-to-nucleus transferred genes have a more typical rate of sequence evolution, while those whose history was wholly or partially within the dinoflagellate plastid genome have a markedly accelerated rate of evolution.

Keywords

Dinoflagellate Endosymbiosis Plastid Relative rate test Gene transfer 

Supplementary material

supp.pdf (170 kb)
Supplementary material

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Tsvetan R. Bachvaroff
    • 1
    • 2
  • M. Virginia Sanchez-Puerta
    • 1
  • Charles F. Delwiche
    • 1
  1. 1.Department of Cell Biology and Molecular GeneticsUniversity of Maryland College ParkCollege ParkUSA
  2. 2.Center of Marine BiotechnologyBaltimoreUSA

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