The Embryonic Transcriptome of the Red-Eared Slider Turtle (Trachemys scripta)

PLoS One. 2013 Jun 19;8(6):e66357. doi: 10.1371/journal.pone.0066357. Print 2013.

Abstract

The bony shell of the turtle is an evolutionary novelty not found in any other group of animals, however, research into its formation has suggested that it has evolved through modification of conserved developmental mechanisms. Although these mechanisms have been extensively characterized in model organisms, the tools for characterizing them in non-model organisms such as turtles have been limited by a lack of genomic resources. We have used a next generation sequencing approach to generate and assemble a transcriptome from stage 14 and 17 Trachemys scripta embryos, stages during which important events in shell development are known to take place. The transcriptome consists of 231,876 sequences with an N50 of 1,166 bp. GO terms and EC codes were assigned to the 61,643 unique predicted proteins identified in the transcriptome sequences. All major GO categories and metabolic pathways are represented in the transcriptome. Transcriptome sequences were used to amplify several cDNA fragments designed for use as RNA in situ probes. One of these, BMP5, was hybridized to a T. scripta embryo and exhibits both conserved and novel expression patterns. The transcriptome sequences should be of broad use for understanding the evolution and development of the turtle shell and for annotating any future T. scripta genome sequences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Evolution
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation, Developmental
  • Gene Regulatory Networks
  • High-Throughput Nucleotide Sequencing / methods*
  • Sequence Analysis, RNA / methods*
  • Turtles / embryology*
  • Turtles / genetics

Grant support

This work was funded by Swarthmore College (Swarthmore.edu). KL and MS were supported by grant SF0180019s11 from Estonian Ministry of Education and Research (http://www.hm.ee/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.