Macrophylogenetic analyses of the gain and loss of self-incompatibility in the Asteraceae.
ABSTRACT The self-incompatibility (SI) status of 571 taxa from the Asteraceae was identified and the taxa were scored as having SI, partial SI or self-compatibility (SC) as their breeding system. A molecular phylogeny of the internal transcribed spacer (ITS) region was constructed for 211 of these taxa. Macrophylogenetic methods were used to test hypotheses concerning the ancestral state of SI in the Asteraceae, the gain and loss of SI, the irreversibility of the loss of SI and the potential for partial SI or SC to be terminal states. The ancestral breeding system in the family could not be resolved. Both maximum likelihood and parsimony analyses indicated that transitions among all breeding system states provide the best fit to the data and that neither partial SI nor SC is a terminal state. Furthermore, the data indicated that the loss of SI is not irreversible, although breeding system evolution has been more dynamic in some clades than in others. These results are discussed within the context of evidence for the gain and loss of SI, the evolutionary role of partial SI and methodological assumptions of tests of breeding system evolution.
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ABSTRACT: The program MODELTEST uses log likelihood scores to establish the model of DNA evolution that best fits the data. AVAILABILITY: The MODELTEST package, including the source code and some documentation is available at http://bioag.byu. edu/zoology/crandall_lab/modeltest.html.Bioinformatics 02/1998; 14(9):817-8. · 5.32 Impact Factor
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ABSTRACT: Flowering plants have evolved various stratagems to prevent inbreeding and promote outcrosses. One such mechanism, gametophytic self-incompatibility, provides a genetic barrier to self-fertilization, and in the simplest cases is controlled by the highly polymorphic S locus. Growth of a pollen tube in the style is arrested when the S allele carried by the pollen matches one of the two S alleles carried by the pistil. Putative S allele proteins of the pistil have been identified in several solanaceous species based on their co-segregation with S alleles, and they have been shown to be ribonucleases. So far, there has been only correlative or indirect evidence for the claim that these S allele-associated proteins (S proteins) are involved in recognition and rejection of self pollen. Here we show that inhibition of synthesis of S3 and S2 proteins in Petunia inflata plants of S2S3 genotype by the antisense S3 gene resulted in failure of the transgenic plants to reject S3 and S2 pollen. We further show that expression of the transgene encoding S3 protein in P. inflata plants of S1S2 genotype confers on the transgenic plants the ability to reject S3 pollen. The self-incompatibility behaviour of the pollen was not affected by the transgene in either set of experiments. Taken together, these findings provide direct in vivo evidence that S proteins control the self-incompatibility behaviour of the pistil.Nature 03/1994; 367(6463):560-3. · 38.60 Impact Factor
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ABSTRACT: Computer programs for phylogenetic analysis have been important tools in systematics and evolutionary biology, but most have been designed primarily for the reconstruction of phylogenetic trees and not the interpretation of patterns of character evolution. Described here is the computer program MacClade, designed for interactive analysis of character evolution and phylogeny. For a given tree and a matrix of character data, MacClade displays its reconstruction of character evolution by shading the branches of the tree to indicate ancestral states. Trees can be manipulated for instance by picking up and moving branches. Assumptions underlying the reconstruction of character evolution can be varied extensively. With these manipulations and MacClade's graphical feedback, one can explore the relationships among phylogenetic trees, character data, assumptions and interpretations of character evolution. MacClade has extensive facilities for editing data, displaying various summaries of character evolution in charts and diagrams, and printing.Folia Primatologica 02/1989; 53(1-4):190-202. · 1.04 Impact Factor