Guenons (tribe Cercopithecini) are one of the most diverse groups of primates. They occupy all of sub-Saharan Africa and show great variation in ecology, behavior, and morphology. This variation led to the description of over 60 species and subspecies. Here, using next-generation DNA sequencing (NGS) in combination with targeted DNA capture, we sequenced 92 mitochondrial genomes from museum-preserved specimens as old as 117 years. We infer evolutionary relationships and estimate divergence times of almost all guenon taxa based on mitochondrial genome sequences. Using this phylogenetic framework, we infer divergence dates and reconstruct ancestral geographic ranges. We conclude that the extraordinary radiation of guenons has been a complex process driven by, among other factors, localized fluctuations of African forest cover. We find incongruences between phylogenetic trees reconstructed from mitochondrial and nuclear DNA sequences, which can be explained by either incomplete lineage sorting or hybridization. Furthermore, having produced the largest mitochondrial DNA data set from museum specimens, we document how NGS technologies can “unlock” museum collections, thereby helping to unravel the tree-of-life. [Museum collection; next-generation DNA sequencing; primate radiation; speciation; target capture.]

Museums hold most of the world's most valuable biological specimens and tissues collected, including type material that is often decades or even centuries old. Unfortunately, traditional museum collection and storage methods were not designed to preserve the nucleic acids held within the material, often reducing its potential viability and value for many genetic applications. High‐throughput sequencing technologies and associated applications offer new opportunities for obtaining sequence data from museum samples. In particular, target sequence capture offers a promising approach for recovering large numbers of orthologous loci from relatively small amounts of starting material. In the present study, we test the utility of target sequence capture for obtaining data from museum‐held material from a speciose mammalian genus: the horseshoe bats (Rhinolophidae: Chiroptera). We designed a ‘bait’ for capturing > 3600 genes and applied this to 10 species of horseshoe bat that had been collected between 93 and 7 years ago and preserved using a range of methods. We found that the mean recovery rate per species was approximately 89% of target genes with partial sequence coverage, ranging from 3024 to 3186 genes recovered. On average, we recovered 1206 genes with ≥ 90% sequence coverage, per species. Our findings provide good support for the application of large‐scale bait capture across congeneric species spanning approximately 15 Myr of evolution. On the other hand, we observed no clear association between the success of capture and the phylogenetic distance from the bait model, although sample sizes precluded a formal test.

BackgroundRecent studies show that galling Hymenoptera and Diptera are able to synthesize the plant hormone indole-3-acetic acid (auxin) from tryptophan and that plant response to insect-produced auxin is implicated in gall formation. We examined the leaf transcriptome of galled and ungalled leaves of individuals of the Hawaiian endemic plant Metrosideros polymorpha (Myrtaceae) subject to infestation by psyllid (Hemiptera) gall-makers in the genus Trioza (Triozidae).ResultsTranscript libraries were sequenced using Illumina technology and the reads assembled de novo into contigs. Functional identification of contigs followed a two-step procedure, first identifying contigs by comparison to the completely sequenced genome of the related Eucalyptus, followed by identifying the equivalent Arabidopsis gene using a pre-computed mapping between Eucalyptus and Arabidopsis genes. This allowed us to use the rich functional annotation of the Arabidopsis genome to assess the transcriptional landscape of galling in Metrosideros. Comparing galled and ungalled leaves, we find a highly significant enrichment of expressed genes with a gene ontology (GO) annotation to auxin response in the former. One gene consistently expressed in all galled trees examined but not detected in any libraries from ungalled leaves was the Metrosideros version of SMALL AUXIN UPREGULATED (SAUR) 67 which appears to be a marker for leaf-galling in Metrosideros.ConclusionsWe conclude that an auxin response is involved in galling by Metrosideros psyllids. The possibility should therefore be considered that psyllids (like other insects examined) are able to synthesize auxin.

Recent genomic studies show that introgression can occur at a genome-wide scale among recently diverged lineages. However, introgression is difficult to distinguish from incomplete lineage sorting (ILS), and these processes are expected to occur together. Moreover, ncDNA introgression is less easily detected than mtDNA introgression, and as such its prevalence is less well understood. The Chinese horseshoe bat (Rhinolophus sinicus) occurs as three distinct forms on mainland China: the subspecies R. s. septentrionalis and two parapatric clades of R. s. sinicus (Central and East R. s. sinicus). Previous work suggested widespread mtDNA introgression between these subspecies, however, no ncDNA introgression was detected. In this new study we sampled the coding genomes of all three forms of R. sinicus in order to perform a more sensitive test for ncDNA introgression against an expected background of incomplete lineage sorting. We assembled 3548 nuclear protein-coding genes from these and three congeneric species, and built a high confidence species tree using Maximum Likelihood and Bayesian concordance methods. Phylogenetic analysis suggested a mosaic genome for Central R. s. sinicus derived from R. s. septentrionalis and East R. s. sinicus. Nuclear DNA introgression between Central R. s. sinicus and R. s. septentrionalis was supported by three different tests, whereas ILS could not be ruled out completely. Our findings, in line with other recent results, indicate that recently diverged taxa undergo large scale secondary introgression, and that this process likely operates alongside incomplete lineage sorting to give rise to phylogenomic discordances or even mosaic genomes.