PacBio whole-genome sequencing and draft assembly of Stentor coeruleus
Data files
Jan 09, 2025 version files 3.33 GB
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1_scoelr001.hifireads.fastq.gz
1.29 GB
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2_scoelr001.hifireads.fastq.gz
1.98 GB
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assembly.fasta
63.46 MB
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README.md
885 B
Abstract
Stentor coeruleus is a giant, regenerating unicellular ciliate. These cells reach lengths upwards of 1 mm in length, and the compartmentalized macronucleus extends along the anterior-posterior axis of the cell. The reference genome for this species (Slabodnick et al 2017) was sequenced using short-read Illumina sequencing. Here, we are sharing raw PacBio sequencing data as well as a draft genome assembly. These data will be used to update the Stentor coeruleus reference genome and aid in future studies.
README: PacBio whole-genome sequencing and draft assembly of Stentor coeruleus
https://doi.org/10.5061/dryad.bzkh189kk
Description of the data and file structure
We combined both replicates into one fastq file and assembled the genome using Flye. This project is ongoing, thus we have not trimmed any sequences and are working to improve the assembly and add gene annotations.
Assembly information (12/12/2024 upload):
Total length: 62416934
Fragments: 371
Fragments N50: 373482
Largest frg: 1584040
Scaffolds: 1
Mean coverage: 66### Files and variables
File: 1_scoelr001.hifireads.fastq.gz
Description: PacBio Sequel II raw reads replicate 1
File: 2_scoelr001.hifireads.fastq.gz
Description: PacBio Sequel II raw reads replicate 2
File: assembly.fasta
Description: Draft genome assembly with Flye
Methods
Stentor husbandry
Stentor coeruleus cultures are kept in glass Pyrex tupperware dishes in approximately 200 mL of Pasteurized Spring Water (Carolina Biological), hereafter referred to as ciliate water. Cells are fed a lentil-sized amount of solid wild-type Chlamydomonas reinhardtii (Chlamy) two or three times a week as needed.
DNA extraction
Several hundred Stentor coeruleus were hand-picked from the culture with a micropipette and transferred to 3 different tissue culture plate wells containing ciliate water to rid the cells of algae and debris. Cells were starved overnight and washed again to ensure that no remaining Chlamy will contaminate the extraction. Cells were transferred into an eppendorf tube, allowed to settle, and as much ciliate water as possible was removed. DNA was phenol-chloroform extracted according to a PacBio protocol: https://www.pacb.com/wp-content/uploads/2015/09/SharedProtocol-Extracting-DNA-usinig-Phenol-Chloroform.pdf
Sequencing
Genewiz (formerly) Azenta prepared libraries for two runs on a PacBio Sequel II.
Assembly
Flye command: flye combined.fastq --out-dir 20240503_flye_out --genome-size 80m --threads 16