De novotranscriptome assembly and genome annotation of the fat-tailed dunnart (Sminthopsis crassicaudata)

Abstract

Marsupials exhibit highly specialized patterns of reproduction and development, making them uniquely valuable for comparative genomics studies with their sister lineage, eutherian (also known as placental) mammals. However, marsupial genomic resources still lag far behind those of eutherian mammals, limiting our insight into mammalian diversity. Here, we present a series of novel genomic resources for the fat-tailed dunnart (Sminthopsis crassicaudata), a mouse-like marsupial that, due to its ease of husbandry andex-uterodevelopment, is emerging as a laboratory model. To enable wider use, we have generated a multi-tissuede novotranscriptome assembly of dunnart RNA-seq reads spanning 12 tissues. This highly representative transcriptome is comprised of 2,093,982 assembled transcripts, with a mean transcript length of 830 bp. The transcriptome mammalian BUSCO completeness score of 93% is the highest amongst all other published marsupial transcriptomes. Additionally, we report an improved fat-tailed dunnart genome assembly which is 3.23 Gb long, organized into 1,848 scaffolds, with a scaffold N50 of 72.64 Mb. The genome annotation, supported by assembled transcripts andab initiopredictions, revealed 21,622 protein-coding genes. Altogether, these resources will contribute greatly towards characterizing marsupial biology and mammalian genome evolution.