Format

Send to

Choose Destination
Genome Biol Evol. 2019 May 1;11(5):1440-1450. doi: 10.1093/gbe/evz067.

The Genome and mRNA Transcriptome of the Cosmopolitan Calanoid Copepod Acartia tonsa Dana Improve the Understanding of Copepod Genome Size Evolution.

Author information

1
Department of Science and Environment, Roskilde University, Denmark.
2
Department of Environmental Science - Environmental Microbiology and Biotechnology, Aarhus University, Roskilde, Denmark.
3
Natural History Museum of Denmark, University of Copenhagen, Denmark.
4
Centre of Excellence for Omics-Driven Computational Biodiscovery (COMBio), Faculty of Applied Sciences, AIMST University, Kedah, Malaysia.
5
Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.
6
Department of Integrative Biology, University of California, Berkeley.
7
National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa.
8
Estuary and Ocean Science Center, San Francisco State University, Tiburon, California.

Abstract

Members of the crustacean subclass Copepoda are likely the most abundant metazoans worldwide. Pelagic marine species are critical in converting planktonic microalgae to animal biomass, supporting oceanic food webs. Despite their abundance and ecological importance, only six copepod genomes are publicly available, owing to a number of factors including large genome size, repetitiveness, GC-content, and small animal size. Here, we report the seventh representative copepod genome and the first genome and the first transcriptome from the calanoid copepod species Acartia tonsa Dana, which is among the most numerous mesozooplankton in boreal coastal and estuarine waters. The ecology, physiology, and behavior of A. tonsa have been studied extensively. The genetic resources contributed in this work will allow researchers to link experimental results to molecular mechanisms. From PCR-free whole genome sequence and mRNA Illumina data, we assemble the largest copepod genome to date. We estimate that A. tonsa has a total genome size of 2.5 Gb including repetitive elements we could not resolve. The nonrepetitive fraction of the genome assembly is estimated to be 566 Mb. Our DNA sequencing-based analyses suggest there is a 14-fold difference in genome size between the six members of Copepoda with available genomic information. This finding complements nucleus staining genome size estimations, where 100-fold difference has been reported within 70 species. We briefly analyze the repeat structure in the existing copepod whole genome sequence data sets. The information presented here confirms the evolution of genome size in Copepoda and expands the scope for evolutionary inferences in Copepoda by providing several levels of genetic information from a key planktonic crustacean species.

KEYWORDS:

calanoid copepod genome; comparative genomics; genome assembly; genome size evolution; invertebrate genomics; repetitive DNA

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center