| 91. |
- Olsson, Urban, 1954, et al.
(författare)
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Non-monophyly of the avian genus Seicercus (Aves : Sylviidae) revealed by mitochondrial DNA
- 2004
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Ingår i: Zoologica Scripta. - Gothenburg Univ, Dept Zool, SE-40530 Gothenburg, Sweden. Uppsala Univ, Evolutionary Biol Ctr, Dept Systemat Zool, SE-75236 Uppsala, Sweden. : Wiley. - 0300-3256 .- 1463-6409. ; 33:6, s. 501-510
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Tidskriftsartikel (refereegranskat)abstract
- The phylogeny of all species and nearly all subspecies of Seicercus and representatives of all subgenera in Phylloscopus was estimated based on two mitochondrial genes. According to the gene tree, and supported by non-molecular data, Seicercus belongs in three separate clades. Two of these include only taxa currently classified as Seicercus, while the third comprises S. xanthoschistos and P. occipitalis. These results suggest that both Seicercus and Phylloscopus are paraphyletic. The gene tree suggests two more cases of non-monophyly: (1) the 'S. burkii complex' is separated into two different clades, one of which also includes S. affinis and S. poliogenys; (2) two populations of S. affinis intermedius are more closely related to S. affinis ocularis than to a third population of intermedius. A recent proposal to split the 'S. burkii complex' into six species is corroborated, as is the recognition of the taxon cognitus as a colour morph of S. affinis intermedius. Our study also revealed unexpectedly large genetic divergences between three different populations of the monotypic S. poliogenys, indicating the presence of cryptic species. Our results underscore the importance of dense sampling at the specific and infraspecific levels in intrageneric phylogenetic studies.
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| 92. |
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| 93. |
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| 94. |
- McArthur, A.G., et al.
(författare)
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Phylogenetic analysis of the Cytochrome P450 3 (CYP3) gene family
- 2003
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Ingår i: Journal of Molecular Evolution. - : Springer Science and Business Media LLC. - 0022-2844 .- 1432-1432. ; 57:2, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Cytochrome P450 genes (CYP) constitute a superfamily with members known from the Bacteria, Archaea, and Eukarya. The CYP3 gene family includes the CYP3A and CYP3B subfamilies. Members of the CYP3A subfamily represent the dominant CYP forms expressed in the digestive and respiratory tracts of vertebrates. The CYP3A enzymes metabolize a wide variety of chemically diverse lipophilic organic compounds. To understand vertebrate CYP3 diversity better, we determined the killifish (Fundulus heteroclitus) CYP3A30 and CYP3A56 and the ball python (Python regius) CYP3A42 sequences. We performed phylogenetic analyses of 45 vertebrate CYP3 amino acid sequences using a Bayesian approach. Our analyses indicate that teleost, diapsid, and mammalian CYP3A genes have undergone independent diversification and that the ancestral vertebrate genome contained a single CYP3A gene. Most CYP3A diversity is the product of recent gene duplication events. There is strong support for placement of the guinea pig CYP3A genes within the rodent CYP3A diversification. The rat, mouse, and hamster CYP3A genes are mixed among several rodent CYP3A subclades, indicative of a complex history involving speciation and gene duplication. Phylogenetic analyses suggest two CYP3A gene duplication events early in rodent history, with the rat CYP3A9 and mouse Cyp3a13 clade having a sister relationship to all other rodent CYP3A genes. In primate history, the human CYP3A43 gene appears to have a sister relationship to all other known primate CYP3A genes. Other, more recent gene duplications are hypothesized to have occurred independently within the human, pig, rat, mouse, guinea pig, and fish genomes. Functional analyses suggest that gene duplication is strongly tied to acquisition of new function and that convergent evolution of CYP3A function may be frequent among independent gene copies.
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| 95. |
- Nygren, Arne, 1971, et al.
(författare)
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Phylogeny and evolution of reproductive modes in Autolytinae (Syllidae, Annelida).
- 2003
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Ingår i: Molecular phylogenetics and evolution. - 1055-7903. ; 29:2, s. 235-49
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Tidskriftsartikel (refereegranskat)abstract
- The phylogeny of 31 autolytine taxa (Syllidae, Polychaeta, and Annelida) was estimated based on 16S rDNA and 18S rDNA sequences. Outgroups included 12 non-autolytine syllids and four other annelids from related groups. The phylogeny was used to trace the evolution of the various reproductive strategies (i.e., epigamy, anterior and posterior scissiparity, and gemmiparity) within the group, and it will also serve as a basis for a forthcoming revision of autolytine taxonomy. The two genes were analysed both separately and in combination using parsimony, maximum likelihood, and Bayesian inference. Regardless of method used the combined analysis supported a division of Autolytinae into three major clades: one with epigamous Autolytus; a second comprising Autolytus and Myrianida with posterior scissiparity and gemmiparity; and a third containing Proceraea, Procerastea, and Virchowia with anterior scissiparity. The relationship between these three groups is uncertain. Ancestral reproductive states were reconstructed with parsimony and maximum likelihood, and the results unequivocally support epigamy as the plesiomorphic reproductive mode in Syllidae, and that schizogamy in Syllinae and Autolytinae are separate events. The evolution of reproductive traits is ambiguous within Autolytinae, and either of the different reproductive modes could represent the ancestral state.
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| 96. |
- Sundberg, Per, 1950
(författare)
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Evolution and systematics.
- 2003
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Ingår i: Grizimek´s Animal Life Encyclopedia, 2nd edition. ; 2, s. 7-14
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 97. |
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| 98. |
- Sundberg, Per, 1950
(författare)
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Phylum Nemertea. Class Anopla
- 2003
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Ingår i: Grizimek´s Animal Life Encyclopedia, 2nd edition. ; 1, s. 245-251
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 99. |
- Sundberg, Per, 1950
(författare)
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Phylum Nemertea. Class Enopla.
- 2003
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Ingår i: Grizimek´s Animal Life Encyclopedia, 2nd edition. ; 1, s. 253-257
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 100. |
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