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M Källersjö

Publications and source records attributed to M Källersjö.

6 recordsLinked to original sources
PubMed2001

Validating Livanow: molecular data agree that leeches, Branchiobdellidans, and Acanthobdella peledina form a monophyletic group of oligochaetes.

To investigate the phylogenetic relationships of leeches, branchiobdellidans, and acanthobdellidans, whole nuclear 18S rDNA and over 650 bp of mitochondrial cytochrome c oxidase subunit I were acquired from 101 annelids, including 36 leeches, 18 branchiobdellidans, Acanthobdella peledina, as well as 28 oligochaetes and combined with homologous data for 17 polychaete outgroup taxa. Parsimony analysis of the combined aligned dataset supported monophyly of leeches, branchiobdellidans, and acanthobdellidans in 100% of jackknife replicates. Monophyly of the oligochaete order Lumbriculida with Acanthobdellida, Branchiobdellida, and Hirudinea was supported in 84% of jackknife replicates. These results provide support for the hypotheses that leeches and branchiobdellidans are sister groups, that acanthobdellidans are sister to them, and that together with the family Lumbriculidae they all constitute a clade within Oligochaeta. Results support synonymy of the classes Clitellata and the more commonly used Oligochaeta. Leeches branchiobdellidans, and acanthobdellidans should be regarded as orders equal to their closest relatives, the order Lumbriculida.

Animals↗
PubMed2000

Generic realignment in primuloid families of the Ericales s.l.: a phylogenetic analysis based on DNA sequences from three chloroplast genes and morphology.

The phylogenetic interrelationships in Primulaceae, Myrsinaceae, and Theophrastaceae were investigated using DNA sequence data from the chloroplast genes atpB, ndhF, and rbcL. The three genes were analyzed separately, together, and in combination with morphology, using parsimony jackknifing. The sequence data are further explored by analyses of first and second codon position only, third positions only, and transversions only. The results show that all codon positions contribute group support to the ndhF tree, whereas third codon positions provide most of the structure in the atpB and rbcL trees. Analyzed separately, transversions in atpB and rbcL have little structure, whereas in ndhF they produce a well-resolved tree. We conclude that the most informative and robust results are obtained from analyses with all codon positions included and that the tree resulting from the combined analysis of all available data provides the best estimate of phylogeny.The results show that Maesa is sister to all other taxa from the three families. Theophrastaceae are well supported, but both Myrsinaceae and Primulaceae are paraphyletic. We conclude that four families should be recognized, Maesaceae, Theophrastaceae, Primulaceae, and Myrsinaceae. For all families to be monophyletic, Samolus was transferred to Theophrastaceae, and Lysimachia, Anagallis, Trientalis, Glaux, Asterolinon, and Pelletiera were moved to the Myrsinaceae together with the genera Coris, Ardisiandra, and Cyclamen.

Journal Article↗
PubMed1999

Sequence insertions and ITS data provide congruent information on Roccella canariensis and R. tuberculata (Arthoniales, Euascomycetes) phylogeny.

Four Roccella species, R. canariensis, R. fimbriata, R. montagnei, and R. tuberculata, were found to possess sequence insertions in up to four locations in the first half of the SSU rDNA. Insertions from one of these positions have been classified as group I introns, while the others may represent degenerative forms of group I introns or messenger RNA introns. Two of the insertion-containing taxa, R. canariensis and R. tuberculata, differ only in their dispersal strategy: R. canariensis is sexual, producing only fruiting bodies and R. tuberculata is sterile, producing only vegetative propagules, i.e., soredia. Because insertions occurred in specimens of both taxa, they were used to examine the phylogenetic relationships between and within the two species. The sequence insertions from each of the four positions were aligned and cladistically analyzed separately. Internal transcribed spacers (ITS) were additionally sequenced to study the phylogeny of all R. canariensis and R. tuberculata specimens. Three other Roccella species (R. babingtonii, R. fimbriata, and R. montagnei) and Dirina catalinariae were used as outgroups in this parsimony analysis. Sequence insertions were found to be potentially useful in phylogenetic studies, although due to the sequence dissimilarity, homology relations were difficult to establish above the species level and in some cases even within the species. The phylogenies obtained from the insertion matrices were totally consistent with the ITS data and the insertions were concluded to have been inherited. When the insertion and ITS data were combined for total evidence, R. canariensis and R. tuberculata did not form distinct lineages in the phylogenetic tree, but appeared mixed in well-supported groups containing both sorediate and fertile specimens.

Ascomycota↗
PubMed1999

Phylogenetic placement and circumscription of tribes Inuleae s. str. and Plucheeae (Asteraceae): evidence from sequences of chloroplast gene ndhF.

DNA sequences from chloroplast gene ndhF were investigated in 15 species in tribes Inuleae Cass. s. str., Plucheeae (Benth.) A. Anderb., and Gnaphalieae Benth. (Asteraceae) and combined with 90 ndhF sequences from GenBank to evaluate the circumscription of the putative sister tribes Inuleae and Plucheeae. The data were subjected to phylogenetic analysis using parsimony jackknifing. The results are presented in a cladogram and discussed in comparison to previous analyses of both molecular and morphological data. The interpretations of specific diagnostic characters are also discussed. The majority of genera from Inuleae s. str. and Plucheeae comprise a monophyletic group, sister to the Heliantheae s. l. -Blepharispermum-Athroisma group. The genera of the Gnaphalieae belong to a different monophyletic group within the family that also includes tribes Anthemideae, Astereae, and Calenduleae. Within the Inuleae-Plucheeae complex, two well-supported subclades were identified, one corresponding to the Inuleae s. str. and the second to the Plucheeae. Three genera, Antiphiona, Pegolettia, and Geigeria, were outside of both tribes and were part of an unresolved polytomy at the base of the Inuleae-Plucheeae clade. Anisopappus, hitherto considered a member of Inuleae s. str., was found to be part of the Heliantheae-Athroisma-Blepharispermum clade. As discussed, the results of previous phylogenetic analyses, presenting Anisopappus as the basalmost taxon of Inuleae s. str., may be due to inadequate sampling.

Asteraceae↗
PubMed1999

Variable sizes of introns in the SSU rDNA in three species of Roccella (Arthoniales, Euascomycetes).

Three species of the lichenized fungus Roccella (Arthoniales, Euascomycetes), R. canariensis, R. tuberculata and R. montagnei, were found to possess insertions in the first half of the nuclear SSU rDNA. Both the number and the type of these insertions varied between and within species. At position 516 the insertions belonged to group-IC1 introns with a characteristic secondary structure and conserved sequences. At three positions, 300, 330 and 393, the insertions were short and lacked the characteristic features of group-I introns. The splicing-site junctions of these short introns resembled those of mRNA introns. Furthermore, the conserved sequence flanking the branch-point A of mRNA introns was also present. Extraction of RNA and sequencing of cDNA confirmed that the insertions from positions 300, 330 and 516 had been spliced from the pre-rRNA during maturation. At position 393 the insertion had been spliced from R. canariensis, whereas in R. montagnei the insertion was still present in the rRNA.

Ascomycota↗