Disrupted developmental signaling induces novel transcriptional states

Aleena L Patel1,2, Vanessa Gonzalez3, Triveni Menon3,4

  • 1Department of Developmental Biology, Stanford University, Stanford, CA 94305.

Insights

This study introduces DAISEE, a new algorithm for analyzing single-cell RNA sequencing data from complex experiments. DAISEE effectively separates signaling pathway responses from batch effects in developing zebrafish embryos.

Area of Science:

  • Developmental Biology
  • Systems Biology
  • Genomics

Background:

  • Cellular differentiation during embryogenesis involves complex signaling pathways and transcriptional changes.
  • Understanding gene responses to signaling requires single-cell resolution due to cell state heterogeneity.
  • Experimental batch effects can confound the analysis of single-cell transcriptomic data.

Purpose of the Study:

  • To develop a novel algorithm, DAISEE, for integrating single-cell RNA sequencing datasets from complex experimental designs.
  • To accurately model and separate perturbation responses from confounding variations in single-cell data.
  • To investigate the effects of activating the extracellular signal-regulated kinase (ERK) pathway on zebrafish embryogenesis.

Main Methods:

  • Development of the Design-Aware Integration of Single Cell ExpEriments (DAISEE) algorithm.
  • Application of DAISEE to integrate single-cell RNA sequencing data from zebrafish embryos.
  • Utilizing photoswitchable MEK (psMEK) to globally activate the ERK pathway in zebrafish embryos.
  • Comparison of DAISEE with existing integrative nonnegative matrix factorization methods.

Main Results:

  • DAISEE effectively models perturbation responses in complex single-cell experimental designs.
  • The algorithm demonstrates improved separation of perturbation responses from confounding variation compared to previous methods.
  • Activation of the ERK pathway in zebrafish embryos induced novel cell states and altered gene expression, including early-acting endothelial genes.
  • Some cells exposed to ERK signals shifted toward wild-type states.

Conclusions:

  • DAISEE provides a robust framework for analyzing perturbed single-cell transcriptomic data from complex experiments.
  • Overactive signaling pathways, such as ERK, can lead to unexpected gene expression states and cell phenotypes during embryonic development.
  • Single-cell analysis is crucial for dissecting heterogeneous responses to signaling perturbations in vivo.

Related Concept Videos

Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
7.1K
Notch Signaling Pathway03:14

Notch Signaling Pathway

The Notch signaling pathway is a major intracellular signaling pathway that is highly conserved over a broad spectrum of metazoan species. It stands unique from other intracellular signaling mechanisms in animals because notch protein itself acts as the receptor as well as the primary signaling molecule.
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not...
6.3K
Role Of Notch Signalling In Intestinal Stem Cell Renewal01:12

Role Of Notch Signalling In Intestinal Stem Cell Renewal

Notch signaling was first discovered in Drosophila melanogaster, where it is involved in cell lineage differentiation. Notch signaling regulates the maintenance and differentiation of intestinal stem cells or ISCs by controlling the expression of atonal homolog 1 or Atoh1. Atoh1 directs cells to differentiate into secretory cells.
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
2.4K
Hedgehog Signaling Pathway02:33

Hedgehog Signaling Pathway

The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
9.7K
Regulation of Expression Occurs at Multiple Steps02:24

Regulation of Expression Occurs at Multiple Steps

3.8K
Regulation of Expression Occurs at Multiple Steps02:24

Regulation of Expression Occurs at Multiple Steps

Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
25.6K