Functional heterogeneity of embryonic stem cells revealed through translational amplification of an early endodermal transcript

Maurice A. Canham, Alexei A. Sharov, Minoru Ko, Joshua M. Brickman

Research output: Contribution to journalArticle

165 Citations (Scopus)

Abstract

ES cells are defined as self-renewing, pluripotent cell lines derived from early embryos. Cultures of ES cells are also characterized by the expression of certain markers thought to represent the pluripotent state. However, despite the widespread expression of key markers such as Oct4 and the appearance of a characteristic undifferentiated morphology, functional ES cells may represent only a small fraction of the cultures grown under self-renewing conditions. Thus phenotypically ''undifferentiated'' cells may consist of a heterogeneous population of functionally distinct cell types. Here we use a transgenic allele designed to detect low level transcription in the primitive endoderm lineage as a tool to identify an immediate early endoderm-like ES cell state. This reporter employs a tandem array of internal ribosomal entry sites to drive translation of an enhanced Yellow Fluorescent Protein (Venus) from the transcript that normally encodes for the early endodermal marker Hex. Expression of this Venus transgene reports on single cells with low Hex transcript levels and reveals the existence of distinct populations of Oct4 positive undifferentiated ES cells. One of these cells types, characterized by both the expression of the Venus transgene and the ES cells marker SSEA-1 (V+S+), appears to represent an early step in primitive endoderm specification. We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self-renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts. Interestingly, while these subpopulations are equivalently and clonally interconvertible under self-renewing conditions, when induced to differentiate both in vivo and in vitro they exhibit different behaviours. Most strikingly when introduced back into morulae or blastocysts, the V+S+ population is not effective at contributing to the epiblast and can contribute to the extra-embryonic visceral and parietal endoderm, while the V2S+ population generates high contribution chimeras. Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo.

Original languageEnglish
JournalPLoS Biology
Volume8
Issue number5
DOIs
Publication statusPublished - 2010 May
Externally publishedYes

Fingerprint

embryonic stem cells
Embryonic Stem Cells
Stem cells
Cell culture
Amplification
CD15 Antigens
Cells
Endoderm
Transcription
Venus
cells
Specifications
blastocyst
Proteins
Blastocyst
Transgenes
Population
Embryonic Structures
Blastocyst Inner Cell Mass
Cell Culture Techniques

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Neuroscience(all)

Cite this

Functional heterogeneity of embryonic stem cells revealed through translational amplification of an early endodermal transcript. / Canham, Maurice A.; Sharov, Alexei A.; Ko, Minoru; Brickman, Joshua M.

In: PLoS Biology, Vol. 8, No. 5, 05.2010.

Research output: Contribution to journalArticle

@article{912df297da294bb3b033d7b161cd539e,
title = "Functional heterogeneity of embryonic stem cells revealed through translational amplification of an early endodermal transcript",
abstract = "ES cells are defined as self-renewing, pluripotent cell lines derived from early embryos. Cultures of ES cells are also characterized by the expression of certain markers thought to represent the pluripotent state. However, despite the widespread expression of key markers such as Oct4 and the appearance of a characteristic undifferentiated morphology, functional ES cells may represent only a small fraction of the cultures grown under self-renewing conditions. Thus phenotypically ''undifferentiated'' cells may consist of a heterogeneous population of functionally distinct cell types. Here we use a transgenic allele designed to detect low level transcription in the primitive endoderm lineage as a tool to identify an immediate early endoderm-like ES cell state. This reporter employs a tandem array of internal ribosomal entry sites to drive translation of an enhanced Yellow Fluorescent Protein (Venus) from the transcript that normally encodes for the early endodermal marker Hex. Expression of this Venus transgene reports on single cells with low Hex transcript levels and reveals the existence of distinct populations of Oct4 positive undifferentiated ES cells. One of these cells types, characterized by both the expression of the Venus transgene and the ES cells marker SSEA-1 (V+S+), appears to represent an early step in primitive endoderm specification. We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self-renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts. Interestingly, while these subpopulations are equivalently and clonally interconvertible under self-renewing conditions, when induced to differentiate both in vivo and in vitro they exhibit different behaviours. Most strikingly when introduced back into morulae or blastocysts, the V+S+ population is not effective at contributing to the epiblast and can contribute to the extra-embryonic visceral and parietal endoderm, while the V2S+ population generates high contribution chimeras. Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo.",
author = "Canham, {Maurice A.} and Sharov, {Alexei A.} and Minoru Ko and Brickman, {Joshua M.}",
year = "2010",
month = "5",
doi = "10.1371/journal.pbio.1000379",
language = "English",
volume = "8",
journal = "PLoS Biology",
issn = "1544-9173",
publisher = "Public Library of Science",
number = "5",

}

TY - JOUR

T1 - Functional heterogeneity of embryonic stem cells revealed through translational amplification of an early endodermal transcript

AU - Canham, Maurice A.

AU - Sharov, Alexei A.

AU - Ko, Minoru

AU - Brickman, Joshua M.

PY - 2010/5

Y1 - 2010/5

N2 - ES cells are defined as self-renewing, pluripotent cell lines derived from early embryos. Cultures of ES cells are also characterized by the expression of certain markers thought to represent the pluripotent state. However, despite the widespread expression of key markers such as Oct4 and the appearance of a characteristic undifferentiated morphology, functional ES cells may represent only a small fraction of the cultures grown under self-renewing conditions. Thus phenotypically ''undifferentiated'' cells may consist of a heterogeneous population of functionally distinct cell types. Here we use a transgenic allele designed to detect low level transcription in the primitive endoderm lineage as a tool to identify an immediate early endoderm-like ES cell state. This reporter employs a tandem array of internal ribosomal entry sites to drive translation of an enhanced Yellow Fluorescent Protein (Venus) from the transcript that normally encodes for the early endodermal marker Hex. Expression of this Venus transgene reports on single cells with low Hex transcript levels and reveals the existence of distinct populations of Oct4 positive undifferentiated ES cells. One of these cells types, characterized by both the expression of the Venus transgene and the ES cells marker SSEA-1 (V+S+), appears to represent an early step in primitive endoderm specification. We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self-renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts. Interestingly, while these subpopulations are equivalently and clonally interconvertible under self-renewing conditions, when induced to differentiate both in vivo and in vitro they exhibit different behaviours. Most strikingly when introduced back into morulae or blastocysts, the V+S+ population is not effective at contributing to the epiblast and can contribute to the extra-embryonic visceral and parietal endoderm, while the V2S+ population generates high contribution chimeras. Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo.

AB - ES cells are defined as self-renewing, pluripotent cell lines derived from early embryos. Cultures of ES cells are also characterized by the expression of certain markers thought to represent the pluripotent state. However, despite the widespread expression of key markers such as Oct4 and the appearance of a characteristic undifferentiated morphology, functional ES cells may represent only a small fraction of the cultures grown under self-renewing conditions. Thus phenotypically ''undifferentiated'' cells may consist of a heterogeneous population of functionally distinct cell types. Here we use a transgenic allele designed to detect low level transcription in the primitive endoderm lineage as a tool to identify an immediate early endoderm-like ES cell state. This reporter employs a tandem array of internal ribosomal entry sites to drive translation of an enhanced Yellow Fluorescent Protein (Venus) from the transcript that normally encodes for the early endodermal marker Hex. Expression of this Venus transgene reports on single cells with low Hex transcript levels and reveals the existence of distinct populations of Oct4 positive undifferentiated ES cells. One of these cells types, characterized by both the expression of the Venus transgene and the ES cells marker SSEA-1 (V+S+), appears to represent an early step in primitive endoderm specification. We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self-renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts. Interestingly, while these subpopulations are equivalently and clonally interconvertible under self-renewing conditions, when induced to differentiate both in vivo and in vitro they exhibit different behaviours. Most strikingly when introduced back into morulae or blastocysts, the V+S+ population is not effective at contributing to the epiblast and can contribute to the extra-embryonic visceral and parietal endoderm, while the V2S+ population generates high contribution chimeras. Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo.

UR - http://www.scopus.com/inward/record.url?scp=77952915049&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77952915049&partnerID=8YFLogxK

U2 - 10.1371/journal.pbio.1000379

DO - 10.1371/journal.pbio.1000379

M3 - Article

VL - 8

JO - PLoS Biology

JF - PLoS Biology

SN - 1544-9173

IS - 5

ER -