@article{mallik_carlson_wcisel_fisk_yoder_dornburg_2023, title={A chromosome-level genome assembly of longnose gar, Lepisosteus osseus}, volume={4}, ISSN={["2160-1836"]}, url={https://doi.org/10.1093/g3journal/jkad095}, DOI={10.1093/g3journal/jkad095}, abstractNote={Holosteans (gars and bowfins) represent the sister lineage to teleost fishes, the latter being a clade that comprises over half of all living vertebrates and includes important models for comparative genomics and human health. A major distinction between the evolutionary history of teleosts and holosteans is that all teleosts experienced a genome duplication event in their early evolutionary history. As holostean genomes did not undergo a round of genome duplication, they have been heralded as a means to bridge teleost models to other vertebrate genomes. However, only three species of holosteans have been genome sequenced to date and sequencing of more species is needed to fill sequence sampling gaps and provide a broader comparative basis for understanding holostean genome evolution. Here we report the first high quality reference genome assembly and annotation of the longnose gar (Lepisosteus osseus). Our final assembly consists of 22,709 scaffolds with a total length of 945 bp with contig N50 of 116.6 kb. Using BRAKER2, we annotated a total of 30,068 genes. Analysis of the repetitive regions of the genome reveals the genome to contain 29.1% transposable elements, and the longnose gar to be the only other known vertebrate outside of the spotted gar to contain CR1, L2, Rex1, and Babar. These results highlight the potential utility of holostean genomes for understanding the evolution of vertebrate repetitive elements and provide a critical reference for comparative genomic studies utilizing ray-finned fish models. Significance Over half of all living vertebrates are teleost fishes, including numerous experimental models such as zebrafish (Danio rerio) and medaka (Oryzias latipes). However, translating research in teleost models to other organisms such as humans is often challenged by the fact that teleosts experienced a genome duplication event in their early evolutionary history. Recent genome sequencing of three holosteans, the sister lineage to teleosts that did not experience a genome duplication event, has revealed these taxa to be critical for linking homologs between teleosts and other vertebrates. Sequencing of holostean genomes remains limited, thereby impeding further comparative genomic studies. Here we fill this sampling gap through the genomic sequencing of the longnose gar (Lepisosteus osseus). This annotated reference genome will provide a useful resource for a range of comparative genomic applications that span fields as diverse as immunogenetics, developmental biology, and the understanding of regulatory sequence evolution.}, journal={G3-GENES GENOMES GENETICS}, author={Mallik, Rittika and Carlson, Kara B. and Wcisel, Dustin J. and Fisk, Michael and Yoder, Jeffrey A. and Dornburg, Alex}, editor={Whiteman, NEditor}, year={2023}, month={Apr} } @article{carlson_nguyen_wcisel_yoder_dornburg_2023, title={Ancient fish lineages illuminate toll-like receptor diversification in early vertebrate evolution}, volume={8}, ISSN={["1432-1211"]}, url={https://doi.org/10.1007/s00251-023-01315-7}, DOI={10.1007/s00251-023-01315-7}, abstractNote={Since its initial discovery over 50 years ago, understanding the evolution of the vertebrate RAG- mediated adaptive immune response has been a major area of research focus for comparative geneticists. However, how the evolutionary novelty of an adaptive immune response impacted the diversity of receptors associated with the innate immune response has received considerably less attention until recently. Here, we investigate the diversification of vertebrate toll-like receptors (TLRs), one of the most ancient and well conserved innate immune receptor families found across the Tree of Life, integrating genomic data that represent all major vertebrate lineages with new transcriptomic data from Polypteriformes, the earliest diverging ray-finned fish lineage. Our analyses reveal TLR sequences that reflect the 6 major TLR subfamilies, TLR1, TLR3, TLR4, TLR5, TLR7, and TLR11, and also currently unnamed, yet phylogenetically distinct TLR clades. We additionally recover evidence for a pulse of gene gain coincident with the rise of the RAG-mediated adaptive immune response in jawed vertebrates, followed by a period of rapid gene loss during the Cretaceous. These gene losses are primarily concentrated in marine teleost fish and synchronous with the mid Cretaceous anoxic event, a period of rapid extinction for marine species. Finally, we reveal a mismatch between phylogenetic placement and gene nomenclature for up to 50% of TLRs found in clades such as ray-finned fishes, cyclostomes, amphibians, and elasmobranchs. Collectively, these results provide an unparalleled perspective of TLR diversity and offer a ready framework for testing gene annotations in non-model species.}, journal={IMMUNOGENETICS}, author={Carlson, Kara B. and Nguyen, Cameron and Wcisel, Dustin J. and Yoder, Jeffrey A. and Dornburg, Alex}, year={2023}, month={Aug} } @article{carlson_wcisel_ackerman_romanet_christiansen_niemuth_williams_breen_stoskopf_dornburg_et al._2022, title={Transcriptome annotation reveals minimal immunogenetic diversity among Wyoming toads, Anaxyrus baxteri}, volume={4}, ISSN={["1572-9737"]}, url={https://doi.org/10.1007/s10592-022-01444-8}, DOI={10.1007/s10592-022-01444-8}, abstractNote={Briefly considered extinct in the wild, the future of the Wyoming toad (Anaxyrus baxteri) continues to rely on captive breeding to supplement the wild population. Given its small natural geographic range and history of rapid population decline at least partly due to fungal disease, investigation of the diversity of key receptor families involved in the host immune response represents an important conservation need. Population decline may have reduced immunogenetic diversity sufficiently to increase the vulnerability of the species to infectious diseases. Here we use comparative transcriptomics to examine the diversity of toll-like receptors and major histocompatibility complex (MHC) sequences across three individual Wyoming toads. We find reduced diversity at MHC genes compared to bufonid species with a similar history of bottleneck events. Our data provide a foundation for future studies that seek to evaluate the genetic diversity of Wyoming toads, identify biomarkers for infectious disease outcomes, and guide breeding strategies to increase genomic variability and wild release successes.}, journal={CONSERVATION GENETICS}, author={Carlson, Kara B. and Wcisel, Dustin J. and Ackerman, Hayley D. and Romanet, Jessica and Christiansen, Emily F. and Niemuth, Jennifer N. and Williams, Christina and Breen, Matthew and Stoskopf, Michael K. and Dornburg, Alex and et al.}, year={2022}, month={Apr} } @article{bunch_carlson_hoogakker_plough_evans_2021, title={Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus Mitchill, 1815) early life stage consumption evidenced by high-throughput DNA sequencing}, volume={37}, ISSN={["1439-0426"]}, DOI={10.1111/jai.14153}, number={1}, journal={JOURNAL OF APPLIED ICHTHYOLOGY}, author={Bunch, Aaron J. and Carlson, Kara B. and Hoogakker, Frederick J. and Plough, Louis V. and Evans, Heather K.}, year={2021}, month={Feb}, pages={12–19} } @article{evans_bunch_schmitt_hoogakker_carlson_2021, title={High-throughput sequencing outperforms traditional morphological methods in Blue Catfish diet analysis and reveals novel insights into diet ecology}, volume={11}, ISSN={["2045-7758"]}, DOI={10.1002/ece3.7460}, abstractNote={Abstract Blue Catfish Ictalurus furcatus are an invasive, yet economically important species in the Chesapeake Bay. However, their impact on the trophic ecology of this system is not well understood. In order to provide in‐depth analysis of predation by Blue Catfish, we identified prey items using high‐throughput DNA sequencing (HTS) of entire gastrointestinal tracts from 134 samples using two genetic markers, mitochondrial cytochrome c oxidase I (COI) and the nuclear 18S ribosomal RNA gene. We compared our HTS results to a more traditional “hybrid” approach that coupled morphological identification with DNA barcoding. The hybrid study was conducted on additional Blue Catfish samples (n = 617 stomachs) collected from the same location and season in the previous year. Taxonomic representation with HTS vastly surpassed that achieved with the hybrid methodology in Blue Catfish. Significantly, our HTS study identified several instances of at‐risk and invasive species consumption not identified using the hybrid method, supporting the hypothesis that previous studies using morphological methods may greatly underestimate consumption of critical species. Finally, we report the novel finding that Blue Catfish diet diversity inversely correlates to daily flow rates, perhaps due to higher mobility and prey‐seeking behaviors exhibited during lower flow.}, number={10}, journal={ECOLOGY AND EVOLUTION}, author={Evans, Heather K. and Bunch, Aaron J. and Schmitt, Joseph D. and Hoogakker, Frederick J. and Carlson, Kara B.}, year={2021}, month={May}, pages={5584–5597} }