Project description:The ascidia Halocynthia roretzi (Phylum: Chordata, Subphylum: Tunicata, Class: Ascidiacea) have been used as model species in development biology for over a century. It offers attractive experimental features, including a compact genome, invariant embryonic cell lineages, small embryonic cell number, and translucent embryos, which allow the description of developmental processes with a cellular level of resolution. Staged RNA-seq data has been already deposited in DDBJ (accessiton number DRA005714 and DRA005711). In the present study, we sequenced genome of H. roretzi of a southwestern Japanese population using RNA-Seq data. These RNA-Seq data covers expressions in 8 cell and 110 cell embryos of Animal(A), Vegetal(V) and whole-embryo regions. These genome assembly, transcript assembly, and transcript models are incorporated into the ANISEED (https://www.aniseed.cnrs.fr/) for genome browsing and blast searches. The genome and transcriptome resources will be useful datasets for developmental biology, evolutionary biology and molecular ecology using this model organism.