Abstract

iTRAQ-MS/MS for Quantitative Proteomics of Single Xenopus Embryos

Norman Dovichi, Professor, University of Notre Dame

We report the first comprehensive proteomic analysis of single Xenopus laevis embryos, an important model organism for early vertebrate development. Using stable isotopic labeling and tandem mass spectrometry, the abundance change of 3,983 proteins across four to six stages of development was obtained. Protein expression change was clustered into groups that mirror the major regulatory changes in transcription that occur during early Xenopus development. Proteins encoded by both maternal mRNA and zygotic mRNA can be discerned.  Post-transcriptional regulation controls expression of maternal mRNAs beyond the mid-blastula transition, which allows for a seamless progression into the more complex patterns of zygotic transcription. Finally, there is no evidence for significant protein heterogeneity between single embryos at the same stage of development.