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Data from: Repurposing population genetics data to discern genomic architecture: a case study of linkage cohort detection in mountain pine beetle (Dendroctonus ponderosae)
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Trevoy, Stephen A.L.; Janes, Jasmine K.; Muirhead, Kevin; Sperling, Felix A.H. — 2019-02-06 Genetic surveys of the population structure of species can be used as resources for exploring their genomic architecture. By adjusting filtering assumptions, genome-wide single nucleotide polymorphism (SNP) datasets can be reused to give new insights into the genetic basis of divergence and speciation without targeted re-sampling of specimens. Filtering only for missing data and minor allele frequency, we used a combination of principle components analysis and linkage disequilibrium network analysis to distinguish three cohorts of variable SNPs in the mountain pine beetle in western Canada, including one that was sex-linked and one that was geographically associated. These marker cohorts indicate genomically localized differentiation, and their detection demonstrates an accessible and intuitive method for discovering potential islands of genomic divergence without a priori knowledge of a species’ genomic architecture. Thus, this method has utility for directly addressing the genomic architecture of species and generating new hypotheses for functional research.
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Data from: Comparison of five methods for delimitating species in Ophion Fabricius, a diverse genus of parasitoid wasps (Hymenoptera, Ichneumonidae)
Schwarzfeld, Marla D.; Sperling, Felix A. H.; Sperling, Felix A.H. — 2015-08-11 DNA taxonomy has been proposed as a method to quickly assess diversity and species limits in highly diverse, understudied taxa. Here we use five methods for species delimitation and two genetic markers (COI and ITS2) to assess species diversity within the parasitoid genus, Ophion. We searched for compensatory base changes (CBC’s) in ITS2, and determined that they are too rare to be of practical use in delimiting species in this genus. The other four methods used both COI and ITS2, and included distance-based (threshold analysis and ABGD) and tree-based (GMYC and PTP) models. We compared the results of these analyses to each other under various parameters and tested their performance with respect to 11 Nearctic species/morphospecies and 15 described Palearctic species. We also computed barcode accumulation curves of COI sequences to assess the completeness of sampling. The species count was highly variable depending on the method and parameters used, ranging from 47 to 168 species, with more conservative estimates of 89–121 species. Despite this range, many of the Nearctic test species were fairly robust with respect to method. We concluded that while there was often good congruence between methods, GMYC and PTP were less reliant on arbitrary parameters than the other two methods and more easily applied to genetic markers other than COI. However, PTP was less successful at delimiting test species than was GMYC. All methods, as well as the barcode accumulation curves, indicate that several Palearctic species remain undescribed and that we have scarcely begun to appreciate the Nearctic diversity within this genus.
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Data from: Cross-platform compatibility of de novo-aligned SNPs in a non-model butterfly genus
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Campbell, Erin O.; Davis, Corey S.; Dupuis, Julian R.; Muirhead, Kevin; Sperling, Felix A.H.; Sperling, Felix A. H. — 2017-06-20 High-throughput sequencing methods for genotyping genome-wide markers are being rapidly adopted for phylogenetics of non-model organisms in conservation and biodiversity studies. However, the reproducibility of SNP genotyping and degree of marker overlap or compatibility between datasets from different methodologies have not been tested in non-model systems. Using double-digest restriction site associated DNA sequencing, we sequenced a common set of 22 specimens from the butterfly genus Speyeria on two different Illumina platforms, using two variations of library preparation. We then used a de novo approach to bioinformatic locus assembly and SNP discovery for subsequent phylogenetic analyses. We found a high rate of locus recovery despite differences in library preparation and sequencing platforms, as well as overall high levels of data compatibility after data processing and filtering. These results provide the first application of NGS methods for phylogenetic reconstruction in Speyeria, and support the use and long-term viability of SNP genotyping applications in non-model systems.
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Data from: Would an RRS by any other name sound as RAD?
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Campbell, Erin O.; Brunet, Bryan M.T.; Dupuis, Julian R.; Sperling, Felix A.H.; Brunet, Bryan M. T.; Sperling, Felix A. H. — 2019-06-11 1. Sampling markers throughout a genome with restriction enzymes emerged in the 2000s as reduced representation shotgun sequencing (RRS). Rapid advances in sequencing technology have since spurred modifications of RRS, giving rise to many derivatives with unique names, such as restriction site-associated DNA sequencing (RADseq). But naming conventions have often been more creative than consistent and criteria for recognizing unique methods have been unclear, resulting in a proliferation of names characterized by ambiguity. 2. We give an overview of methodological and etymological relationships among 36 restriction enzyme-based methods, and survey the consistency of references to five prominent methods in the literature. 3. We identified several instances of methodological convergence, and note that many published derivatives have modified only minor elements of parent protocols. Misattribution through ambiguous or inconsistent literature references was observed in 8.4% of journal articles citing the original one and two-enzyme RADseq and GBS, as well as SBG publications. 4. The rapid expansion of names associated with derivative protocols is confusing and, in many cases, unwarranted. We urge greater restraint in naming derivative methods and suggest general guidelines for naming that promote a balance between clarity, descriptiveness, and recognition of scientific innovation.

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(Author: Sperling, Felix A.H.)

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