Abstract
The giant, single-celled organism Stentor coeruleus has a long history as a model system for studying pattern formation and regeneration in single cells. Stentor [1, 2] is a heterotrichous ciliate distantly related to familiar ciliate models, such as Tetrahymena or Paramecium. The primary distinguishing feature of Stentor is its incredible size: a single cellis 1mm long. Early developmental biologists, including T.H. Morgan [3], were attracted to the system because of its regenerative abilities-if large portions of a cell are surgically removed, the remnant reorganizes into a normal-looking but smaller cell with correct proportionality [2, 3]. These biologists were also drawn to Stentor because it exhibits a rich repertoire of behaviors, including light avoidance, mechanosensitive contraction, food selection, and even the ability to habituate to touch, a simple form of learning usually seen in higher organisms [4]. While early microsurgical approaches demonstrated a startling array of regenerative and morphogenetic processes in this single-celled organism, Stentor was never developed as a molecular model system. We report the sequencing of the Stentor coeruleus macronuclear genome and reveal key features of the genome. First, we find that Stentor uses the standard genetic code, suggesting that ciliate-specific genetic codes arose after Stentor branched from other ciliates. We also discover that ploidy correlates with Stentor's cell size. Finally, in the Stentor genome, we discover the smallest spliceosomal introns reported for any species. The sequenced genome opens the door to molecular analysis of single-cell regeneration in Stentor.
Highlights
Out of 248 genes in the standard core set, fully completed ciliate genomes, such as Tetrahymena or Oxytricha, typically contain 220–230
We further investigated the distribution of chromosome sizes using a clamped homogeneous electric
We found that $135,165 open reading frames (ORFs) translated with the standard code had peptide support, compared to $139,929 ORFs translated with the primary ciliate code, $136,488 ORFs translated with the Blepharisma code, and $139,076 with the UAR-glutamate ciliate code
Summary
Out of 248 genes in the standard core set, fully completed ciliate genomes, such as Tetrahymena or Oxytricha, typically contain 220–230. Of Stentor’s 34,506 gene models, 21,602 were grouped into 7,676 ortholog groups shared with other species, including both curated ortholog groups in OrthoMCL and ciliate-specific ortholog groups (see Mendeley Data, http://dx.doi.org/10.17632/ 37gp2djcst.1).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
