Polyrhachis

Moreau, Corrie S. & Wray, Brian D., 2017, An Empirical Test of Reduced-Representation Genomics to Infer Species-Level Phylogenies for Two Ant Groups, Insect Systematics and Diversity 1 (2), pp. 1-8 : 6

Polyrhachis

All four subgenera for which we had multiple representative species were recovered as monophyletic. Recent work by Mezger and Moreau (2016) challenged the monophyly of several of the previously defined subgenera and reconfigured the genus-wide topology into four broad regions composed of multiple subgenera, numbered I through IV, based on the Sanger-based molecular phylogeny they generated. Our study did not include multiple species of any of the subgenera challenged in the Mezger and Moreau (2016) study; however, we were able to recover the three geographic regions of the tree included in this study as being monophyletic, as found in the previous study.

The topology of the GBS phylogeny generated for this study was congruent with the phylogeny from Mezger and Moreau (2016) with the exception of the relationships within the subgenus Cyrtomyrma (within region II). In both trees, the basal node of the group is highly supported, but the splits differ between the two trees. In the phylogeny of Mezger and Moreau (2016), the Cyrtomyrma subgenus

is inferred with Polyrhachis delecta as sister to the rest of the clade, however in our GBS topology the split is between Polyrhachis monteithi and the rest of the subgenus. There are also differences in other nodes, though none of those nodes are supported in either topology. For all species where we had multiple representatives, we recovered them as monophyletic with the exception of Polyrhachis senilis with Polyrhachis sokolova nested within this clade ( Figs. 1 and 3 ).

Figures

Fig. 1. ML molecular phylogenies generated for this study using the RRGS method GBS. On the left is a phylogeny of the ant genus Cephalotes and the outgroup Procryptocerus.This Cephalotes topology including all samples that had sufficient data generated for our analyses. On the right is the full phylogeny of all samples included for our analysis of the ant genus Polyrhachis, along with the outgroup Camponotus. Both phylogenies were inferred from Illumina data generated from GBS libraries and were inferred using RAxML. Nodes with ML bootstrap support>0.95 are represented by black dots on nodes.

Fig. 3. Comparison between phylogenetic topologies generated by different molecular methods for the spiny ant genus Polyrhachis. On the left is the tree inferred by Moreau et al. (in prep.), trimmed with the Mesquite prune clade tool to represent only the taxa represented in the present study.The Moreau et al. (in prep.) topology was inferred with Sanger DNA sequence data from two mitochondrial genes (1,995 bp) and six protein-coding nuclear genes (2,928 bp). On the right is the phylogeny inferred for this study, also pruned with the Mesquite prune clade tool to remove duplicate taxa.This GBS topology was inferred from a dataset that had on average 34,000 loci per sample, each 100 bp in length. In the middle are the subgenera, with taxonomic groups assigned from Mezger and Moreau (2016) in parentheses. Nodes in the Sanger phylogeny with ML bootstrap support>0.7 and nodes in the GBS phylogeny with ML bootstrap support>0.95 are represented by black dots on nodes.