Abstract Detail
Phylogenomics Roberts, Wade [1], Alverson, Andrew [1]. Phylogenomic analysis of the centric diatom order Thalassiosirales based on genome and transcriptome data. Diatoms (Bacillariophyta) are one of the most species-rich lineages of microbial eukaryotes and contribute significantly to global primary production. The Thalassiosirales is a large and diverse order of centric diatoms that is widespread in both marine and freshwater environments. Previous phylogenetic studies of the Thalassiosirales used only two nuclear and two chloroplast markers. We broadly sampled the diversity within the order and undertake the first phylogenomic analysis of the Thalassiosirales based on a combined dataset of genomes and transcriptomes. We generated 42 low-coverage draft genomes and 11 transcriptomes. These data were combined with 34 other genomes or transcriptomes for a combined dataset of 87 taxa. We inferred orthogroups from protein sequences and used them to estimate gene trees, which were subsequently trimmed and filtered. We then estimated species trees using both multi-labeled (orthologs and paralogs) and single-copy (orthologs only) gene trees. The majority of branches in the species trees were well-supported but exhibited high levels of discordance, particularly along the backbone of rapidly diverging marine clades. We further explored the patterns and causes of the gene tree discordance in both protein and coding nucleotide sequences using a variety of approaches. The phylogenomic hypothesis presented here will a useful starting point for further understanding of genome evolution in diatoms and the genetic basis of freshwater adaptation by diatoms.
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1 - University of Arkansas, Department of Biological Sciences, 1 University of Arkansas, Fayetteville, AR, 72701, USA
Keywords:
Diatoms
Genome skimming
Transcriptome
phylogenomics
Genome Assembly.
Presentation Type: Oral Paper
Session: PHYLOI, Phyogenomics I
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 10:30 AM(EDT)
Number: PHYLOI003
Abstract ID:153
Candidate for Awards:None | 