Chemical profiling of the single-cell metabolome offers unique insights into molecular processes as embryonic stem cells differentiate to form the normal vertebrate body. Capillary electrophoresis (CE)-mass spectrometry (MS) has recently allowed us to profile metabolites among dissected cells in the vertebrate embryo, but to minimize biological embryo-to-embryo variability, preferably multiple cells need analysis from the same embryo. Here, we combine microprobe sampling and CE-MS to quantify metabolites in cells within the same embryo, fated to develop into different tissue-types in the frog Xenopus laevis. We extracted ~10 nL cell extract from 4 adjacent dorsal and ventral cells of the 16-cell Xenopus embryo. The cell content was aspirated using fabricated microcapillaries, and immediately transferred into microvials containing 4 μL of an organic solvent to solvent to extract small molecules (metabolites). The extracts were measured in a laboratory-built CE-ESI system hyphenated to a high-resolution quadrupole-time-of-flight mass spectrometer. A total of ~250 molecular features (unique m/z and migration time) were detected among cells, 70 of which were identified as small molecules (metabolites) based on accurate mass measurements, tandem MS, and migration time comparison to standards and databases. Multivariate analysis (PCA and HCA) revealed metabolite concentration gradients among cells predetermined to give rise to distinct tissues during embryonic development. Additionally, we investigated the selective transfer of metabolites between dorsal–ventral cells in the 16-cell Xenopus embryo using heavy-isotope metabolites and fluorescent dyes. The presented work enabled in situ characterization of metabolites in the same embryo to profile metabolic activity of neighboring dorsal and ventral cells, and transjuctional transfer of metabolites during embryogenesis.

Single-cell mass spectrometry reveals metabolite gradients in the vertebrate frog embryo (Xenopus laevis)

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.