Ascidian genome

The draft sequence of a sea squirt genome sheds light on vertebrate evolution.

Written byJonathan Weitzman
| 1 min read

Register for free to listen to this article
Listen with Speechify
0:00
1:00
Share

Ascidians are sea squirts — hermaphrodite marine invertebrates that live in shallow ocean waters, and which are thought to exhibit characteristics of the evolutionary ancestors of chordates and vertebrates. In the December 13 Science, Paramvir Dehal and colleagues report a draft sequence of the genome of the ascidian Ciona intestinalis, one of the smallest of the chordates (Science, 298:2157-2167, December 13, 2002).

Most of the DNA came from a single individual in Half Moon Bay, California, and was sequenced using a whole-genome shotgun approach. Dehal et al. observed a high rate of allelic polymorphism, nearly 15-fold higher than that seen in humans. The genome assembly spans 116.7 Mb and contains 95% of the protein coding genes. Japanese researchers have also collected over 480,000 ESTs (expressed sequence tags) that were used to find genes in the Ciona genome sequence. An annotation workshop came up with a prediction of around 16,000 coding ...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member? Login Here

Meet the Author

Share
Illustration of a developing fetus surrounded by a clear fluid with a subtle yellow tinge, representing amniotic fluid.
January 2026

What Is the Amniotic Fluid Composed of?

The liquid world of fetal development provides a rich source of nutrition and protection tailored to meet the needs of the growing fetus.

View this Issue
Human-Relevant In Vitro Models Enable Predictive Drug Discovery

Advancing Drug Discovery with Complex Human In Vitro Models

Stemcell Technologies
Redefining Immunology Through Advanced Technologies

Redefining Immunology Through Advanced Technologies

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Beckman Coulter Logo
Conceptual multicolored vector image of cancer research, depicting various biomedical approaches to cancer therapy

Maximizing Cancer Research Model Systems

bioxcell

Products

Refeyn logo

Refeyn named in the Sunday Times 100 Tech list of the UK’s fastest-growing technology companies

Parse Logo

Parse Biosciences and Graph Therapeutics Partner to Build Large Functional Immune Perturbation Atlas

Sino Biological Logo

Sino Biological's Launch of SwiftFluo® TR-FRET Kits Pioneers a New Era in High-Throughout Kinase Inhibitor Screening

SPT Labtech Logo

SPT Labtech enables automated Twist Bioscience NGS library preparation workflows on SPT's firefly platform