Browsing by Author "Zhu, Yong"

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    Evolution of trinucleotide microsatellite sequence variation across the Polistinae, a social wasp subfamily
    (1998) Zhu, Yong; Strassmann, Joan E.; Queller, David C.
    I examined sequences of 3 microsatellite loci that were derived from Polistes bellicosus investigated their evolution in 78 species from four tribes in the Polistinae subfamily of wasps. I found that the basic repeat structure of the microsatellite repeat region at these three loci was conserved across species at the subgenus level. Besides changes in the number of repeats, base substitutions were the dominant mutations in the repeat regions. The tribe from which the loci were isolated had longer repeat regions and more perfect repeats that the tribes at the same loci. At microsatellite flanking regions, I found that a high proportion of insertions duplicated 1-4 bases of their preceding sequences. Microsatellite repeats may originate from these such little insertions.
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    The origin of microsatellites and their application to the study of social evolution in the cellular slime mold, Dictyostelium discoideum
    (2000) Zhu, Yong; Strassmann, Joan E.; Queller, David C.
    Data from the Human Gene Mutation Database were used to contrast the alternative hypotheses that microsatellites arise through insertions or through substitutions. The results showed that a high percentage of small insertions created novel microsatellite repeats through the duplication of the adjacent sequences. However substitutions were still the dominant source of new microsatellites since they are so much more common than insertions. Although insertions contributed a minority of new repeat loci, their relative importance increased rapidly with repeat motif sizes. Microsatellite techniques were then applied to examine genetic conflicts in the cellular slime mold, Dictyostelium discoideum. Microsatellite genotyping showed that genetically distinct clones generally formed multicellular fruiting structures together in the mixing experiments. More interestingly, some clones were found to preferentially become reproductive spores instead of non-reproductive altruistic stalk cells. These conflicts of genetic interest make D. discoideum a potential excellent model system for social evolution.
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    The phylogeny of the social wasp subfamily Polistinae: evidence from microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters
    (BioMed Central, 2004) Arévalo, Elisabeth; Zhu, Yong; Carpenter, James M.; Strassmann, Joan E.
    Background: Social wasps in the subfamily Polistinae (Hymenoptera: Vespidae) have been important in studies of the evolution of sociality, kin selection, and within colony conflicts of interest. These studies have generally been conducted within species, because a resolved phylogeny among species is lacking. We used nuclear DNA microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters to generate a phylogeny for the Polistinae (Hymenoptera) using 69 species. Results: Our phylogeny is largely concordant with previous phylogenies at higher levels, and is more resolved at the species level. Our results support the monophyly of the New World subgenera of Polistini, while the Old World subgenera are a paraphyletic group. All genera for which we had more than one exemplar were supported as monophyletic except Polybia which is not resolved, and may be paraphyletic. Conclusion: The combination of DNA sequences from flanks of microsatellite repeats with mtCOI sequences and morphological characters proved to be useful characters establishing relationships among the different subgenera and species of the Polistini. This is the first detailed hypothesis for the species of this important group.