Evidence map›Paper›PMID 34044021›Full record

ArticleDevelopmental biology2021

Merlin and expanded integrate cell signaling that regulates cyst stem cell proliferation in the Drosophila testis niche.

Bryan Johnson, Judith Leatherman

Open access · greenAbstract read
In one paragraph

Article in Developmental biology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.4field-weighted citation impact, top 44% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 5 citations in OpenAlex.

  1. Stem cell competition.Current topics in developmental biology · 2026
    Review
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Bryan JohnsonSchool of Biological Sciences, University of Northern Colorado, Greeley, CO, USA.
Judith LeathermanSchool of Biological Sciences, University of Northern Colorado, Greeley, CO, USA. Electronic address: Judith.leatherman@unco.edu.
University of Northern Colorado · US

Funding

The role of zfh-1 in stem cell self-renewal in the Drosophila testis nicheR15GM102828 · NIGMS · UNIVERSITY OF NORTHERN COLORADO · PI LEATHERMAN, JUDITH L · 2014 to 2014
$291k
NIGMS NIH HHS R15 GM102828
6 · The paper itself

Abstract

The Drosophila testis is a model organism stem cell niche in which two stem cell populations coordinate together to produce sperm; thus, these stem cells must be balanced in the niche. Merlin, a tumor-suppressor and human disease gene required for contact inhibition of proliferation, is known to limit the proliferation of the somatic cyst stem cells in the testis niche. Expanded encodes a protein that is structurally similar to Merlin in Drosophila, and is semi-redundant with Merlin in multiple tissues. We found that expanded depletion caused similar cyst lineage cell over-proliferation as observed with Merlin, and double mutants showed more severe phenotypes than either gene individually. Thus, these genes have partially redundant functions in the cyst lineage cells of this niche. We also expressed non-phosphorylatable constitutively "tumor suppressing" alleles of Merlin in cyst lineage cells, and surprisingly, we observed a similar cyst lineage over-proliferation phenotype. Merlin is known to impact multiple different signaling pathways to exert its effect on proliferation. We found that the Merlin loss of function phenotype was associated with an increase in MAPK/ERK signaling, consistent with Merlin's established role in transmembrane receptor inhibition. Constitutive Merlin displayed a reduction in both MAPK/ERK signaling and PI3K/Tor signaling. PI3K/Tor signaling is required for cyst cell differentiation, and inhibition of this pathway by Merlin activation phenocopied the Tor cyst lineage loss of function phenotype. Thus, Merlin impacts and integrates the activity of multiple signaling pathways in the testis niche. The ability of Merlin to dynamically change its activity via phosphorylation in response to local contact cues provides an intriguing mechanism whereby the signaling pathways that control these stem cells might be dynamically regulated in response to the division of a neighboring germ cell.

Indexed as

Signal TransductionAdult Stem CellsAnimalsCell LineageCell ProliferationDrosophilaDrosophila ProteinsErbB ReceptorsExtracellular Signal-Regulated MAP KinasesMaleMembrane ProteinsModels, BiologicalNeurofibromin 2Receptor Protein-Tyrosine KinasesReceptors, Invertebrate PeptideTestisDrosophila ProteinsEgfr protein, DrosophilaErbB Receptorsex protein, DrosophilaExtracellular Signal-Regulated MAP KinasesMembrane Proteinsmerlin, DrosophilaNeurofibromin 2Receptor Protein-Tyrosine KinasesReceptors, Invertebrate Peptidetor protein, DrosophilaDrosophilaExpandedMerlinNicheStem celltestis

Identifiers

PMID34044021
PMCPMC8277742
OpenAlexW3165193364

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.