The Ephemeroptera (mayflies) is considered to be among the first group of organisms to have ever taken flight and also are unique among all insects by having a non-reproductive winged stage that molts (subimago). Despite these peculiarities, the phylogenetic relationships among mayfly families remains debatable and in some groups is unknown. Recent cladistic studies based on morphology have provided resolution in some ephemeropteran groups, however, there has yet to be a comprehensive analysis of familial level relationships.
We have begun an exciting, novel, and much needed project to address the higher-level phylogeny for Ephemeroptera using DNA sequence information combined with morphological data. Our goal is to sequence a wide range of exemplar taxa for multiple genes, combine this information with morphological data, and use these data to gain new insights into ephemeropteran systematics and evolution.
I am currently using data based on five genes (18S rDNA, 28S rDNA, 16S, 12S, and histone 3) and morphology to look at these relationships. I plan on adding several more genes in the near future.
A critical component of this research is to obtain a wide range of ephemeropteran taxa (and odonate taxa), and this project will not succeed without the collaboration of investigators throughout the world. Consequently I am seeking assistance from any investigators who can provide us with material for DNA analysis, and I am also seeking input on interesting questions in ephemeropteran systematics. I currently have over 200 genera deposited in the genomic tissue bank. Check my taxon sampling list to see taxa that have been acquired. Material can be collected into 95-100% ethanol, and specimens up to 2 years provide good results. In addition, I am organizing the material into the first genomic tissue bank of Ephemeroptera, where specimens will be stored at -80° C. All tissue will be available for any future studies and collaborations.
This material is based upon work supported by the National Science Foundation under Grant No. 0206505. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Principal Investigator: Heath Ogden
View the entire spreadsheet.
If you have fresh material of genera that are not in the list (or on the list and you have extra specimens), please contact me in order to collaborate. The final goal is to include tissue from all genera (and species) of Ephemeroptera in a Centalized Genomic Tissue Library. We have funding to establish tissue libraries for a number of insect orders, so please help out in this endeavor so that future research by all interested investigators may benifit.
18S rDNA Entire Region (˜ 2000 bp): The 18S sequence has proven to be useful for addressing higher level relationships in insects (divergence times of ~300MYA) (Pashley, MCPheron et al., 1993; Campbell, Steffen-Campbell et al., 1995; Whiting, Carpenter et al., 1997). Complete 18S sequences have been obtained from 40 taxa. In this study 18S will be used primarily to properly determine ordinal relationships of basal pterygotes and higher level relationships within Ephemeroptera. Some regions of 18S are hypervariable and may also provide resolution at deeper nodes. 18s will also play an important role in the polarization character states.
28S rDNA Entire Region (˜ 2300 bp): Portions of 28S r DNA have been used in insect phylogenetics, however it tends to show higher levels of variation at the ordinal level than (Whiting, Carpenter et al., 1997; Yeates and Weigmann, 1999). Complete 28S sequences have been obtained from 25 taxa. As with 18S, portions of this gene are hypervariable and pose obstacles for alignment, but may also provide resolution at the lower phylogenetic levels.
Histone 3 (H3; 376 bp): Histone H3 is part of the histone family of genes and forms the basic structural unit of the nucleosome (Maxson, Cohn et al., 1983; Adams, Knowler et al., 1992). H3 is organized in tandem repeats and is highly expressed, but has been shown to undergo concerted evolution between copies (Hood et al., 1975; Zernick et al., 1980). H3 has been successfully used in insect phylogenetics (Colgan, McLauchlan et al., 1998), and congruence between the H3 topology and other molecular markers supports the use of the gene in this study. Sequence has been obtained for 39 taxa. H3 should provide further support for more terminal relationships.
Elongation Factor 1-µ(EF-1µ; ˜ 1200 bp): EF-1µ codes for a key protein used in the translational elongation process and has a well conserved amino acid sequence making alignment straightforward. This gene has paralogous copies in some insects (Danforth and Ji, 1998) and so one must be careful to use ortholgous copies. It has been used to resolve higher level arthropod relationships (Regier and Shultz, 1997) and higher level insect relationships (Yang, Wiegmann et al., 2000). Preliminary PCR and sequencing have shown that this is a viable marker that can be used for this study.
Cytochrome Oxidase II (COII; ˜ 600 bp): COII is a common mitochodrial gene used in insect phylogenetics. The conservation of the codon reading frame makes the alignment straightforward. As with EF-1µ, COII has amplified well and appears to give good levels of divergence.
I am currently collaborating with Dr. Michel Sartori, Dr. Arnold Staniczek, Dr. Thomas Soldan, and Jean-Luc Gattolliat, who are creating a morphology matrix across all families. We recognize that this will be a difficult task, however, we believe that it is also a crucial part in understanding mayfly phylogeny and evolution. Please contact me if you would like to participate in this endeavor at: email@example.com
Here is a preliminary list of the taxa we are trying to code. The morphology data will be combined with the molecular data in order to infer phylogentic relationships.
As coded characters, at the family level, are sent to me I will post them here in matrix format.
The topology below is based on an analysis of a data set size of over 90 genera of mayflies for 5 molecular markers (12S, 16S, 18S, 28S, and Histone 3). The final results of this analysis has been accepted and will be published soon in Molecular Phylogenetics and Evolution. However, you are welcome to take a look at the phylogeny and any comments would be welcomed.
Topology 1 (Direct optimization via POY, Parsimony)
Topology 2 (Direct optimization via POY, Likelihood)
Character optimizations (Ancestral state character reconstructions for three morphological character systems)
In collaboration with Sartori et al, we are currently constructing a morphology matrix across all major lineages.