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1. Liftoff: an accurate gene annotation mapping tool

   https://doi.org/10.1101/2020.06.24.169680  

   Shumate, A.; Salzberg, S.L. (June 2020, bioRxiv)

   Improvements in DNA sequencing technology and computational methods have led to a substantial increase in the creation of high-quality genome assemblies of many species. To understand the biology of these genomes, annotation of gene features and other functional elements is essential; however for most species, only the reference genome is well-annotated. One strategy to annotate new or improved genome assemblies is to map or ‘lift over’ the genes from a previously-annotated reference genome. Here we describe Liftoff, a new genome annotation lift-over tool capable of mapping genes between two assemblies of the same or closely-related species. Liftoff aligns genes from a reference genome to a target genome and finds the mapping that maximizes sequence identity while preserving the structure of each exon, transcript, and gene. We show that Liftoff can accurately map 99.9% of genes between two versions of the human reference genome with an average sequence identity >99.9%. We also show that Liftoff can map genes across species by successfully lifting over 98.4% of human protein-coding genes to a chimpanzee genome assembly with 98.7% sequence identity. Availability The source code for Liftoff is available at https://github.com/agshumate/Liftoff 

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2. Liftoff: accurate mapping of gene annotations

   https://doi.org/10.1093/bioinformatics/btaa1016  

   Shumate, Alaina; Salzberg, Steven L (May 2021, Bioinformatics)

   Valencia, Alfonso (Ed.)

   Abstract Motivation Improvements in DNA sequencing technology and computational methods have led to a substantial increase in the creation of high-quality genome assemblies of many species. To understand the biology of these genomes, annotation of gene features and other functional elements is essential; however, for most species, only the reference genome is well-annotated. Results One strategy to annotate new or improved genome assemblies is to map or ‘lift over’ the genes from a previously annotated reference genome. Here, we describe Liftoff, a new genome annotation lift-over tool capable of mapping genes between two assemblies of the same or closely related species. Liftoff aligns genes from a reference genome to a target genome and finds the mapping that maximizes sequence identity while preserving the structure of each exon, transcript and gene. We show that Liftoff can accurately map 99.9% of genes between two versions of the human reference genome with an average sequence identity >99.9%. We also show that Liftoff can map genes across species by successfully lifting over 98.3% of human protein-coding genes to a chimpanzee genome assembly with 98.2% sequence identity. Availability and implementation Liftoff can be installed via bioconda and PyPI. In addition, the source code for Liftoff is available at https://github.com/agshumate/Liftoff. Supplementary information Supplementary data are available at Bioinformatics online. 

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3. The Complete Genome Sequence of Sarcoramphus papa (Cathartidae), the King Vulture

   https://doi.org/10.56179/001c.68132  

   Catanach, Therese A; Pirro, Stacy (January 2023, Biodiversity Genomes)

   Sarcoramphus papa is a New World Vulture found predominantly in tropical lowland forests stretching from southern Mexico to northern Argentina. We present the whole genome sequence of this species. Illumina paired-end reads were assembled by a de novo method followed by a finishing step. The raw and assembled data are publicly available via GenBank: Sequence Read Archive (SRR19167646) and assembled genome (GCA_027580115). 

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4. A Reference Genome Assembly of American Bison, Bison bison bison

   https://doi.org/10.1093/jhered/esab003  

   Oppenheimer, Jonas; Rosen, Benjamin D; Heaton, Michael P; Vander Ley, Brian L; Shafer, Wade R; Schuetze, Fred T; Stroud, Brad; Kuehn, Larry A; McClure, Jennifer C; Barfield, Jennifer P; et al (February 2021, Journal of Heredity)

   Koepfli, Klaus-Peter (Ed.)

   Abstract Bison are an icon of the American West and an ecologically, commercially, and culturally important species. Despite numbering in the hundreds of thousands today, conservation concerns remain for the species, including the impact on genetic diversity of a severe bottleneck around the turn of the 20th century and genetic introgression from domestic cattle. Genetic diversity and admixture are best evaluated at genome-wide scale, for which a high-quality reference is necessary. Here, we use trio binning of long reads from a bison–Simmental cattle (Bos taurus taurus) male F1 hybrid to sequence and assemble the genome of the American plains bison (Bison bison bison). The male haplotype genome is chromosome-scale, with a total length of 2.65 Gb across 775 scaffolds (839 contigs) and a scaffold N50 of 87.8 Mb. Our bison genome is ~13× more contiguous overall and ~3400× more contiguous at the contig level than the current bison reference genome. The bison genome sequence presented here (ARS-UCSC_bison1.0) will enable new research into the evolutionary history of this iconic megafauna species and provide a new tool for the management of bison populations in federal and commercial herds. 

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5. A complete mitochondrial genome for fragrant Chinese rosewood (Dalbergia odorifera, Fabaceae) with comparative analyses of genome structure and intergenomic sequence transfers

   https://doi.org/10.1186/s12864-021-07967-7  

   Hong, Zhou; Liao, Xuezhu; Ye, Yuanjun; Zhang, Ningnan; Yang, Zengjiang; Zhu, Weidong; Gao, Wei; Sharbrough, Joel; Tembrock, Luke R.; Xu, Daping; et al (December 2021, BMC Genomics)

   Abstract Background Dalbergia odorifera is an economically and culturally important species in the Fabaceae because of the high-quality lumber and traditional Chinese medicines made from this plant, however, overexploitation has increased the scarcity of D. odorifera . Given the rarity and the multiple uses of this species, it is important to expand the genomic resources for utilizing in applications such as tracking illegal logging, determining effective population size of wild stands, delineating pedigrees in marker assisted breeding programs, and resolving gene networks in functional genomics studies. Even the nuclear and chloroplast genomes have been published for D. odorifera , the complete mitochondrial genome has not been assembled or assessed for sequence transfer to other genomic compartments until now. Such work is essential in understanding structural and functional genome evolution in a lineage (Fabaceae) with frequent intergenomic sequence transfers. Results We integrated Illumina short-reads and PacBio CLR long-reads to assemble and annotate the complete mitochondrial genome of D. odorifera . The mitochondrial genome was organized as a single circular structure of 435 Kb in length containing 33 protein coding genes, 4 rRNA and 17 tRNA genes. Nearly 4.0% (17,386 bp) of the genome was annotated as repetitive DNA. From the sequence transfer analysis, it was found that 114 Kb of DNA originating from the mitochondrial genome has been transferred to the nuclear genome, with most of the transfer events having taken place relatively recently. The high frequency of sequence transfers from the mitochondria to the nuclear genome was similar to that of sequence transfer from the chloroplast to the nuclear genome. Conclusion For the first-time, the complete mitochondrial genome of D. odorifera was assembled in this study, which will provide a baseline resource in understanding genomic evolution in the highly specious Fabaceae. In particular, the assessment of intergenomic sequence transfer suggests that transfers have been common and recent indicating a possible role in environmental adaptation as has been found in other lineages. The high turnover rate of genomic colinearly and large differences in mitochondrial genome size found in the comparative analyses herein providing evidence for the rapid evolution of mitochondrial genome structure compared to chloroplasts in Faboideae. While phylogenetic analyses using functional genes indicate that mitochondrial genes are very slowly evolving compared to chloroplast genes. 

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