Showing papers by "Christopher E. Lane published in 2007"

Diversity, nomenclature, and taxonomy of protists.

Abstract: the origin of echolocation and flight in bats. Nature 403:188– 192. van Rheede, T., T. Bastiaans, D. N. Boone, S. B. Hedges, W. W. de Jong, and O. Madsen. 2006. The platypus in its place: nuclear genes and indels confirm the sister group relation of monotremes and therians. Mol. Biol. Evol. 23:587–597. Waddell, P. J., H. Kishino, and R. Ota. 2001. A phylogenetic foundation for comparative mammalian genomics. Genome Informatics 12:141– 154. Waddell, P. J., N. Okada, and M. Hasegawa. 1999. Towards resolving the interordinal relationships of placental mammals. Syst. Biol. 48:1–5. Waddell, P. J., and S. Shelley. 2003. Evaluating placental inter-ordinal phylogenies with novel sequences including RAG1, γ -fibrinogen, ND6, and mt-tRNA, plus MCMC-driven nucleotide, amino acid, and codon models. Mol. Phylogenet. Evol. 28:197–224.

Nucleomorph genome of Hemiselmis andersenii reveals complete intron loss and compaction as a driver of protein structure and function

Abstract: Nucleomorphs are the remnant nuclei of algal endosymbionts that took up residence inside a nonphotosynthetic eukaryotic host. The nucleomorphs of cryptophytes and chlorarachniophytes are derived from red and green algal endosymbionts, respectively, and represent a stunning example of convergent evolution: their genomes have independently been reduced and compacted to <1 megabase pairs (Mbp) in size (the smallest nuclear genomes known) and to a similar three-chromosome architecture. The molecular processes underlying genome reduction and compaction in eukaryotes are largely unknown, as is the impact of reduction/compaction on protein structure and function. Here, we present the complete 0.572-Mbp nucleomorph genome of the cryptophyte Hemiselmis andersenii and show that it is completely devoid of spliceosomal introns and genes for splicing RNAs—a case of complete intron loss in a nuclear genome. Comparison of H. andersenii proteins to those encoded in the slightly smaller (0.551-Mbp) nucleomorph genome of another cryptophyte, Guillardia theta, and to their homologs in the unicellular red alga Cyanidioschyzon merolae reveal that (i) cryptophyte nucleomorph genomes encode proteins that are significantly smaller than those in their free-living algal ancestors, and (ii) the smaller, more compact G. theta nucleomorph genome encodes significantly smaller proteins than that of H. andersenii. These results indicate that genome compaction can eliminate both coding and noncoding DNA and, consequently, drive the evolution of protein structure and function. Nucleomorph proteins have the potential to reveal the minimal functional units required for basic eukaryotic cellular processes. endosymbiosis genome evolution genome reduction

Notes on the Marine Algae of the Bermudas. 8. Further Additions to the Flora, Including Griffithsia aestivana sp. nov. (Ceramiaceae, Rhodophyta) and an Update on the Alien Cystoseira compressa (Sargassaceae, Heterokontophyta)

Abstract: Griffithsia aestivana sp. nov. is described as an endemic from Bermuda. Vegetatively, it is most similar to G. capitata from the eastern Atlantic Ocean, but the two differ in overall size and in the tetrasporic state. Eleven other marine algal taxa are reported from Bermuda for the first time: Anadyomene howei, Struvea elegans, Cladophoropsis macromeres, Derbesia turbinata, Caulerpa racemosa var. lamourouxii, Halimeda discoidea, Chrysymenia nodulosa, Gloiocladia iyoensis, Dasya caraibica, Chondrophycus iridescens and Polysiphonia scopulorum. All except D. turbinata represent new northern limits of distribution in the North Atlantic Ocean. In addition, recent Bermuda collections of the alien Mediterranean Cystoseira compressa and the rarely found Womersleyella setacea are detailed.