A highly conserved nuclear gene for low-level phylogenetics: elongation factor-1 alpha recovers morphology-based tree for heliothine moths

Molecular systematists need increased access to nuclear genes. Highlyconserved, low copy number protein-encoding nuclear genes have attractivefeatures for phylogenetic inference but have heretofore been applied mostlyto very ancient divergences. By virtue of their synonymous substitutions,such genes should contain a wealth of information about lower-leveltaxonomic relationships as well, with the advantage that amino acidconservatism makes both alignment and primer definition straightforward. Wetested this postulate for the elongation factor-1 alpha (EF-1 alpha) genein the noctuid moth subfamily Heliothinae, which has probably diversifiedsince the middle Tertiary. We sequenced 1,240 bp in 18 taxa representingheliothine groupings strongly supported by previous morphological andallozyme studies. The single most parsimonious gene tree and theneighbor-joining tree for all nucleotides show almost complete concordancewith the morphological tree. Homoplasy and pairwise divergence levels arelow, transition/transversion ratios are high, and phylogenetic informationis spread evenly across gene regions. The EF-1 alpha gene and presumablyother highly conserved genes hold much promise for phylogenetics ofTertiary age eukaryote groups.