NGS-Indel Coder v2.0: A Streamlined Pipeline to Code Indel Characters in Phylogenomic Data.

Hypothesized evolutionary insertions and deletions in nucleic acid sequences (indels) contain significant phylogenetic information and can be integrated in phylogenomic analyses. However, assemblies of short reads obtained from next-generation sequencing (NGS) technologies can contain errors that result in falsely inferred indels that need to be detected and omitted to avoid inclusion in phylogenetic analysis. Here, we detail the commands that comprise a new version of the NGS-Indel Coder pipeline, which was developed to validate indels using assembly read depth.

Settling a family feud: a high-level phylogenomic framework for the Gentianales based on 353 nuclear genes and partial plastomes.

Premise: Comprising five families that vastly differ in species richness-ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species-members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several alternative topologies for family-level relationships within Gentianales have been presented in previous studies.

Methods: Here we present a phylogenomic analysis based on nuclear genes targeted by the Angiosperms353 probe set for approximately 150 species, representing all families and approximately 85% of the formally recognized tribes.

Enabling evolutionary studies at multiple scales in Apocynaceae through Hyb-Seq.

Premise: Apocynaceae is the 10th largest flowering plant family and a focus for study of plant-insect interactions, especially as mediated by secondary metabolites. However, it has few genomic resources relative to its size. Target capture sequencing is a powerful approach for genome reduction that facilitates studies requiring data from the nuclear genome in non-model taxa, such as Apocynaceae.

A draft genome and transcriptome of common milkweed () as resources for evolutionary, ecological, and molecular studies in milkweeds and Apocynaceae.

Milkweeds () are used in wide-ranging studies including floral development, pollination biology, plant-insect interactions and co-evolution, secondary metabolite chemistry, and rapid diversification. We present a transcriptome and draft nuclear genome assembly of the common milkweed, . This reconstruction of the nuclear genome is augmented by linkage group information, adding to existing chloroplast and mitochondrial genomic resources for this member of the Apocynaceae subfamily Asclepiadoideae.

NGS-Indel Coder: A pipeline to code indel characters in phylogenomic data with an example of its application in milkweeds (Asclepias).

Targeted genome sequencing approaches allow characterization of evolutionary relationships using a considerable number of nuclear genes and informative characters. However, most phylogenomic analyses only utilize single nucleotide polymorphisms (SNPs). Studies at the species level, especially in groups that have recently radiated, often recover low amounts of phylogenetically informative variation in coding regions, and require non-coding sequences, which are richer in indels, to resolve gene trees.

Repeated translocation of a gene cassette drives sex-chromosome turnover in strawberries.

Turnovers of sex-determining systems represent important diversifying forces across eukaryotes. Shifts in sex chromosomes-but conservation of the master sex-determining genes-characterize distantly related animal lineages. Yet in plants, in which separate sexes have evolved repeatedly and sex chromosomes are typically homomorphic, we do not know whether such translocations drive sex-chromosome turnovers within closely related taxonomic groups.

PacBio-Based Mitochondrial Genome Assembly of Leucaena trichandra (Leguminosae) and an Intrageneric Assessment of Mitochondrial RNA Editing.

Reconstructions of vascular plant mitochondrial genomes (mt-genomes) are notoriously complicated by rampant recombination that has resulted in comparatively few plant mt-genomes being available. The dearth of plant mitochondrial resources has limited our understanding of mt-genome structural diversity, complex patterns of RNA editing, and the origins of novel mt-genome elements. Here, we use an efficient long read (PacBio) iterative assembly pipeline to generate mt-genome assemblies for Leucaena trichandra (Leguminosae: Caesalpinioideae: mimosoid clade), providing the first assessment of non-papilionoid legume mt-genome content and structure to date.

Evolution on the backbone: Apocynaceae phylogenomics and new perspectives on growth forms, flowers, and fruits.

Premise Of The Study: We provide the largest phylogenetic analyses to date of Apocynaceae in terms of taxa and molecular data as a framework for analyzing the evolution of vegetative and reproductive traits.

Methods: We produced maximum-likelihood phylogenies of Apocynaceae using 21 plastid loci sampled from 1045 species (nearly 25% of the family) and complete plastomes from 73 species. We reconstructed ancestral states and used model comparisons in a likelihood framework to analyze character evolution across Apocynaceae.

Evolution at the tips: Asclepias phylogenomics and new perspectives on leaf surfaces.

Premise Of The Study: Leaf surface traits, such as trichome density and wax production, mediate important ecological processes such as anti-herbivory defense and water-use efficiency. We present a phylogenetic analysis of Asclepias plastomes as a framework for analyzing the evolution of trichome density and presence of epicuticular waxes.

Methods: We produced a maximum-likelihood phylogeny using plastomes of 103 species of Asclepias.

Evolution of pyrrolizidine alkaloid biosynthesis in Apocynaceae: revisiting the defence de-escalation hypothesis.

Plants produce specialized metabolites for their defence. However, specialist herbivores adapt to these compounds and use them for their own benefit. Plants attacked predominantly by specialists may be under selection to reduce or eliminate production of co-opted chemicals: the defence de-escalation hypothesis.

Mimosoid legume plastome evolution: IR expansion, tandem repeat expansions, and accelerated rate of evolution in clpP.

The Leguminosae has emerged as a model for studying angiosperm plastome evolution because of its striking diversity of structural rearrangements and sequence variation. However, most of what is known about legume plastomes comes from few genera representing a subset of lineages in subfamily Papilionoideae. We investigate plastome evolution in subfamily Mimosoideae based on two newly sequenced plastomes (Inga and Leucaena) and two recently published plastomes (Acacia and Prosopis), and discuss the results in the context of other legume and rosid plastid genomes.

Phylogenetic marker development for target enrichment from transcriptome and genome skim data: the pipeline and its application in southern African Oxalis (Oxalidaceae).

Phylogenetics benefits from using a large number of putatively independent nuclear loci and their combination with other sources of information, such as the plastid and mitochondrial genomes. To facilitate the selection of orthologous low-copy nuclear (LCN) loci for phylogenetics in nonmodel organisms, we created an automated and interactive script to select hundreds of LCN loci by a comparison between transcriptome and genome skim data. We used our script to obtain LCN genes for southern African Oxalis (Oxalidaceae), a speciose plant lineage in the Greater Cape Floristic Region.

Intragenomic polymorphisms among high-copy loci: a genus-wide study of nuclear ribosomal DNA in Asclepias (Apocynaceae).

Despite knowledge that concerted evolution of high-copy loci is often imperfect, studies that investigate the extent of intragenomic polymorphisms and comparisons across a large number of species are rarely made. We present a bioinformatic pipeline for characterizing polymorphisms within an individual among copies of a high-copy locus. Results are presented for nuclear ribosomal DNA (nrDNA) across the milkweed genus, Asclepias.

Hyb-Seq: Combining target enrichment and genome skimming for plant phylogenomics.

Premise Of The Study: Hyb-Seq, the combination of target enrichment and genome skimming, allows simultaneous data collection for low-copy nuclear genes and high-copy genomic targets for plant systematics and evolution studies. •

Methods And Results: Genome and transcriptome assemblies for milkweed (Asclepias syriaca) were used to design enrichment probes for 3385 exons from 768 genes (>1.6 Mbp) followed by Illumina sequencing of enriched libraries.

Phylogenetic signal detection from an ancient rapid radiation: Effects of noise reduction, long-branch attraction, and model selection in crown clade Apocynaceae.

Crown clade Apocynaceae comprise seven primary lineages of lianas, shrubs, and herbs with a diversity of pollen aggregation morphologies including monads, tetrads, and pollinia, making them an ideal group for investigating the evolution and function of pollen packaging. Traditional molecular systematic approaches utilizing small amounts of sequence data have failed to resolve relationships along the spine of the crown clade, a likely ancient rapid radiation. The previous best estimate of the phylogeny was a five-way polytomy, leaving ambiguous the homology of aggregated pollen in two major lineages, the Periplocoideae, which possess pollen tetrads, and the milkweeds (Secamonoideae plus Asclepiadoideae), which possess pollinia.

Molecular phylogenetics of Amorpha (Fabaceae): an evaluation of monophyly, species relationships, and polyploid origins.

Amorpha L. (false indigos and lead plants) is a North American legume genus of 16 species of shrubs, which is most diverse in the southeastern United States and distinctive due to the reduction of the corolla to a single petal. Most species have limited distributions, but the tetraploid A.

Horizontal transfer of DNA from the mitochondrial to the plastid genome and its subsequent evolution in milkweeds (apocynaceae).

Horizontal gene transfer (HGT) of DNA from the plastid to the nuclear and mitochondrial genomes of higher plants is a common phenomenon; however, plastid genomes (plastomes) are highly conserved and have generally been regarded as impervious to HGT. We sequenced the 158 kb plastome and the 690 kb mitochondrial genome of common milkweed (Asclepias syriaca [Apocynaceae]) and found evidence of intracellular HGT for a 2.4-kb segment of mitochondrial DNA to the rps2-rpoC2 intergenic spacer of the plastome.

Navigating the tip of the genomic iceberg: Next-generation sequencing for plant systematics.

Premise Of The Study: Just as Sanger sequencing did more than 20 years ago, next-generation sequencing (NGS) is poised to revolutionize plant systematics. By combining multiplexing approaches with NGS throughput, systematists may no longer need to choose between more taxa or more characters. Here we describe a genome skimming (shallow sequencing) approach for plant systematics.

Development of microsatellite markers in Lupinus luteus (Fabaceae) and cross-species amplification in other lupine species.

Premise Of The Study: Microsatellite primers were developed in Lupinus luteus L., an emerging temperate protein crop, to investigate genetic diversity, population structure, and to facilitate the generation of better yellow lupine varieties. •

Methods And Results: Thirteen polymorphic primer sets were evaluated in a European and Eastern European accession collection of L.

Building a model: developing genomic resources for common milkweed (Asclepias syriaca) with low coverage genome sequencing.

Background: Milkweeds (Asclepias L.) have been extensively investigated in diverse areas of evolutionary biology and ecology; however, there are few genetic resources available to facilitate and compliment these studies. This study explored how low coverage genome sequencing of the common milkweed (Asclepias syriaca L.

Conservation genetics of Amorpha georgiana (Fabaceae), an endangered legume of the Southeastern United States.

Amorpha georgiana (Fabaceae) is an endangered legume species found in longleaf pine savannas in the Southeastern United States. Approximately 900 individuals and 14 populations remain, most of which are concentrated in North Carolina. Eleven microsatellite loci were used to explore genetic diversity, population structure and recent population bottlenecks using genotypic data from 132 individuals collected at ten different localities.

Characterization of 12 polymorphic microsatellite markers for Georgia false indigo (Amorpha georgiana Wilbur var. georgiana), an endangered species, and their utility in other dwarf Amorpha L. species.

In order to facilitate the addition of a genetic component to conservation management plans for Georgia false indigo (Amorpha georgiana var. georgiana), a rare legume of the southeastern USA, 12 polymorphic microsatellite markers were developed. No gametic disequilibrium was detected among locus pairs, but observations for five of the loci significantly deviated from expected Hardy-Weinberg proportions.