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Organisms Commons

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Cell and Developmental Biology

Himmelfarb Health Sciences Library, The George Washington University

Articles 1 - 3 of 3

Full-Text Articles in Organisms

High-Sensitivity Mass Spectrometry For Probing Gene Translation In Single Embryonic Cells In The Early Frog (Xenopus) Embryo, Camille Lombard-Banek, Sally Ann Moody, Peter Nemes Aug 2016

High-Sensitivity Mass Spectrometry For Probing Gene Translation In Single Embryonic Cells In The Early Frog (Xenopus) Embryo, Camille Lombard-Banek, Sally Ann Moody, Peter Nemes

Anatomy and Regenerative Biology Faculty Publications

Direct measurement of protein expression with single-cell resolution promises to deepen the understanding of basic molecular processes during normal and impaired development. High-resolution mass spectrometry provides detailed coverage of the proteomic composition of large numbers of cells. Here we discuss recent mass spectrometry developments based on single-cell capillary electrophoresis that extend discovery proteomics to sufficient sensitivity to enable the measurement of proteins in single cells. The single-cell mass spectrometry system is used to detect a large number of proteins in single embryonic cells in blastomeres in the 16-cell embryo of the South African clawed frog (Xenopus laevis) that give rise …


Localized Jnk Signaling Regulates Organ Size During Development., Helen Rankin Willsey, Xiaoyan Zheng, José Carlos Pastor-Pareja, A Jeremy Willsey, Philip A Beachy, Tian Xu Mar 2016

Localized Jnk Signaling Regulates Organ Size During Development., Helen Rankin Willsey, Xiaoyan Zheng, José Carlos Pastor-Pareja, A Jeremy Willsey, Philip A Beachy, Tian Xu

Anatomy and Regenerative Biology Faculty Publications

A fundamental question of biology is what determines organ size. Despite demonstrations that factors within organs determine their sizes, intrinsic size control mechanisms remain elusive. Here we show that Drosophila wing size is regulated by JNK signaling during development. JNK is active in a stripe along the center of developing wings, and modulating JNK signaling within this stripe changes organ size. This JNK stripe influences proliferation in a non-canonical, Jun-independent manner by inhibiting the Hippo pathway. Localized JNK activity is established by Hedgehog signaling, where Ci elevates dTRAF1 expression. As the dTRAF1 homolog, TRAF4, is amplified in numerous cancers, these …


Single-Cell Mass Spectrometry For Discovery Proteomics: Quantifying Translational Cell Heterogeneity In The 16-Cell Frog (Xenopus) Embryo, Camille Lombard-Banek, Sally Ann Moody, Peter Nemes Jan 2016

Single-Cell Mass Spectrometry For Discovery Proteomics: Quantifying Translational Cell Heterogeneity In The 16-Cell Frog (Xenopus) Embryo, Camille Lombard-Banek, Sally Ann Moody, Peter Nemes

Anatomy and Regenerative Biology Faculty Publications

We advance mass spectrometry from a cell population-averaging tool to one capable of quantifying the expression of diverse proteins in single embryonic cells. Our instrument combines capillary electrophoresis (CE), electrospray ionization, and a tribrid ultrahigh-resolution mass spectrometer (HRMS) to enable untargeted (discovery) proteomics with ca. 25 amol lower limit of detection. CE-μESI-HRMS enabled the identification of 500–800 nonredundant protein groups by measuring 20 ng, or <0.2% of the total protein content in single blastomeres that were isolated from the 16-cell frog (Xenopus laevis) embryo, amounting to a total of 1709 protein groups identified between n=3 biological replicates. By quantifying ≈150 nonredundant protein groups between all blastomeres and replicate measurements, we found significant translational cell heterogeneity along multiple axes of the embryo at this very early stage of development when the transcriptional program of the embryo has yet to begin.