Abstract The number of plant species with genomic and transcriptomic data has been increasing rapidly. The grasses—Poaceae—have been well represented among species with published reference genomes. However, as a result the genomes of wild grasses are less frequently targeted by sequencing efforts. Sequence data from wild relatives of crop species in the grasses can aid the study of domestication, gene discovery for breeding and crop improvement, and improve our understanding of the evolution of C4photosynthesis. Here, we used long‐read sequencing technology to characterize the transcriptomes of three C3panicoid grass species:Dichanthelium oligosanthes,Chasmanthium laxum, andHymenachne amplexicaulis. Based on alignments to the sorghum genome, we estimate that assembled consensus transcripts from each species capture between 54.2% and 65.7% of the conserved syntenic gene space in grasses. Genes co‐opted into C4were also well represented in this dataset, despite concerns that because these genes might play roles unrelated to photosynthesis in the target species, they would be expressed at low levels and missed by transcript‐based sequencing. A combined analysis using syntenic orthologous genes from grasses with published reference genomes and consensus long‐read sequences from these wild species was consistent with previously published phylogenies. It is hoped that these data, targeting underrepresented classes of species within the PACMAD grasses—wild species and species utilizing C3photosynthesis—will aid in future studies of domestication and C4evolution by decreasing the evolutionary distance between C4and C3species within this clade, enabling more accurate comparisons associated with evolution of the C4pathway.
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Generating high-quality plant and fish reference genomes from field-collected specimens by optimizing preservation
Abstract Sample preservation often impedes efforts to generate high-quality reference genomes or pangenomes for Earth’s more than 2 million plant and animal species due to nucleotide degradation. Here we compare the impacts of storage methods including solution type, temperature, and time on DNA quality and Oxford Nanopore long-read sequencing quality in 9 fish and 4 plant species. We show 95% ethanol largely protects against degradation for fish blood (22 °C, ≤6 weeks) and plant tissue (4 °C, ≤3 weeks). From this furthest storage timepoint, we assemble high-quality reference genomes of 3 fish and 2 plant species with contiguity (contig N50) and completeness (BUSCO) that achieve the Vertebrate Genome Project benchmarking standards. For epigenetic applications, we also report methylation frequency compared to liquid nitrogen control. The results presented here remove the necessity for cryogenic storage in many long read applications and provide a framework for future studies focused on sampling in remote locations, which may represent a large portion of the future sequencing of novel organisms.
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- Award ID(s):
- 2011004
- PAR ID:
- 10488456
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- Communications Biology
- Volume:
- 6
- Issue:
- 1
- ISSN:
- 2399-3642
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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