Cell commitment and cell interactions in the ectoderm of Drosophila melanogaster

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 39-46 ◽  
Author(s):  
Isabella Stüttem ◽  
José A. Campos-Ortega
Keyword(s):  
Drosophila Melanogaster ◽  
Progenitor Cells ◽  
Epidermal Cells ◽  
Cellular Interactions ◽  
Heterotopic Transplantation ◽  
Anterior Pole ◽  
Neural Fate ◽  
Cell Commitment ◽  
Anterior Midgut

The separation of neural from epidermal progenitor cells in the ventral neuroectoderm of Drosophila is thought to be mediated by cellular interactions. In order to verify the occurrence of regulatory signals and to test the neurogenic capabilities of cells from various regions of the ectoderm, we have carried out homotopic and heterotopic transplantations of single ectodermal cells. We found that cells from any of the tested regions, with the exception of the proctodeal anlage, are capable of developing as neuroblasts following their transplantation into the ventral neuroectoderm. These neurogenic capabilities are gradually distributed. Cells from the procephalic and ventral neurogenic regions exhibit maximal capabilities, as shown by their behavior in heterotopic transplantations. However, the two neurogenic regions differ from each other in that no epidermalising signals can be demonstrated to occur within the procephalic neuroectoderm, whereas such signals are strong within the ventral neuroectoderm; in addition, neuralising signals from neighbouring cells seem to be necessary for neuroectodermal cells to develop as neuroblasts. Other ectodermal regions whose cells exhibit weaker neurogenic capabilities are, in decreasing order of capability, the dorsal epidermal anlage, the anterolateral region of the procephalic lobe, comprising the anlage of the pharynx, and the anterior pole of the embryo, corresponding to the anlagen of the stomodeum and ectodermal anterior midgut. We assume that, during development in situ, the neurogenic capabilities of all these cells are suppressed by inhibitory signals, which are released upon heterotopic transplantation into the neuroectoderm. A community effect which prevents groups of dorsal epidermal cells from taking on a neural fate upon their transplantation into the ventral neuroectoderm, is shown. Finally, we hypothesize that the lack of neurogenic capability in the cells from the proctodeal anlage is due to the absence of products of the proneural genes.

scholarly journals Conserved and Divergent Features of Mesenchymal Progenitor Cell Types within the Cortical Nephrogenic Niche of the Human and Mouse Kidney

2018 ◽  
Vol 29 (3) ◽  
pp. 806-824 ◽  
Author(s):  
Nils O. Lindström ◽  
Jinjin Guo ◽  
Albert D. Kim ◽  
Tracy Tran ◽  
Qiuyu Guo ◽  
...  
Keyword(s):  
Single Cell ◽  
Progenitor Cells ◽  
Kidney Development ◽  
Collecting Duct ◽  
Transcriptional Profiling ◽  
Cell Types ◽  
Transcriptional Profile ◽  
Cellular Interactions ◽  
Human And Mouse

Cellular interactions among nephron, interstitial, and collecting duct progenitors drive mammalian kidney development. In mice, Six2+ nephron progenitor cells (NPCs) and Foxd1+ interstitial progenitor cells (IPCs) form largely distinct lineage compartments at the onset of metanephric kidney development. Here, we used the method for analyzing RNA following intracellular sorting (MARIS) approach, single-cell transcriptional profiling, in situ hybridization, and immunolabeling to characterize the presumptive NPC and IPC compartments of the developing human kidney. As in mice, each progenitor population adopts a stereotypical arrangement in the human nephron-forming niche: NPCs capped outgrowing ureteric branch tips, whereas IPCs were sandwiched between the NPCs and the renal capsule. Unlike mouse NPCs, human NPCs displayed a transcriptional profile that overlapped substantially with the IPC transcriptional profile, and key IPC determinants, including FOXD1, were readily detected within SIX2+ NPCs. Comparative gene expression profiling in human and mouse Six2/SIX2+ NPCs showed broad agreement between the species but also identified species-biased expression of some genes. Notably, some human NPC-enriched genes, including DAPL1 and COL9A2, are linked to human renal disease. We further explored the cellular diversity of mesenchymal cell types in the human nephrogenic niche through single-cell transcriptional profiling. Data analysis stratified NPCs into two main subpopulations and identified a third group of differentiating cells. These findings were confirmed by section in situ hybridization with novel human NPC markers predicted through the single-cell studies. This study provides a benchmark for the mesenchymal progenitors in the human nephrogenic niche and highlights species-variability in kidney developmental programs.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

scholarly journals The Alcohol Dehydrogenase Gene Is Nested in the outspread Locus of Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 897-911 ◽  
Author(s):  
S McNabb ◽  
S Greig ◽  
T Davis
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Pcr Amplification ◽  
Transcription Unit ◽  
Adjacent Gene ◽  
Dehydrogenase Gene ◽  
Chromosomal Breakpoints ◽  
Splicing Patterns ◽  
Somatic Musculature

Abstract This report describes the structure and expression of the outspread (osp) gene of Drosophila melanogaster. Previous work showed that chromosomal breakpoints associated with mutations of the osp locus map to both sides of the alcohol dehydrogenase gene (Adh), suggesting that Adh and the adjacent gene Adh' are nested in osp. We extended a chromosomal walk and mapped additional osp mutations to define the maximum molecular limit of osp as 119 kb. We identified a 6-kb transcript that hybridizes to osp region DNA and is altered or absent in osp mutants. Accumulation of this RNA peaks during embryonic and pupal periods. The osp cDNAs comprise two distinct classes based on alternative splicing patterns. The 5′ end of the longest cDNA was extended by PCR amplification. When hybridized to the osp walk, the 5′ extension verifies that Adh and Adh' are nested in osp and shows that osp has a transcription unit of ≥74 kb. In situ hybridization shows that osp is expressed both maternally and zygotically. In the ovary, osp is transcribed in nurse cells and localized in the oocyte. In embryos, expression is most abundant in the developing visceral and somatic musculature.

scholarly journals Effect of wing scalloping mutations on cut expression and sense organ differentiation in the Drosophila wing margin.

Genetics ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 353-363 ◽  
Author(s):  
J Jack ◽  
Y DeLotto
Keyword(s):  
Sense Organ ◽  
Epidermal Cells ◽  
Additive Effect ◽  
Mutant Phenotype ◽  
Wing Margin ◽  
Transcriptional Enhancer ◽  
Organ Differentiation ◽  
Notch Activity ◽  
Neural Fate ◽  
Drosophila Wing

Abstract A number of wing scalloping mutations have been examined to determine their effects on the mutant phenotype of cut mutations and on the expression of the Cut protein. The mutations fall into two broad classes, those which interact synergistically with weak cut wing mutations to produce a more extreme wing phenotype than either mutation alone and those that have a simple additive effect with weak cut wing mutations. The synergistically interacting mutations are alleles of the Notch, Serrate and scalloped genes. These mutations affect development of the wing margin in a manner similar to the cut wing mutations. The mutations inactivate the cut transcriptional enhancer for the wing margin mechanoreceptors and noninnervated bristles and prevent differentiation of the organs. Surprisingly, reduction of Notch activity in the wing margin does not have the effect of converting epidermal cells to a neural fate as it does in other tissues of ectodermal origin. Rather, it prevents the differentiation of the wing margin mechanoreceptors and noninnervated bristles.

scholarly journals The Possible Origin of miRNAs Differentially Regulated in Leiomyoma Progenitors

2021 ◽  
Author(s):  
Mariangela Di Vincenzo ◽  
Concetta De Quattro ◽  
Marzia Rossato ◽  
Raffaella Lazzarini ◽  
Giovanni Delli Carpini ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Progenitor Cells ◽  
Clustering Analysis ◽  
Adherens Junction ◽  
Receptor Interaction ◽  
Embryonic Cells ◽  
Tgfβ Signaling ◽  
Mirna Profiling ◽  
Kegg Pathways ◽  
Cell Commitment

Abstract Background: Leiomyoma are the most common indication for hysterectomy in the world and have a strong economic impact on health care systems; many different mechanisms have been considered for their aetiology, such as inflammation, dysregulated progenitor cells or different regulation of miRNAs. After performing a whole genome miRNA profiling in progenitor cells (PCs) derived from healthy myometrium (MPCs) and from leyomioma (LPCs), only 15 miRNAs were identified as differentially expressed between MPCs and LPCs. Progenitor cells from Amniotic Fluid (AFPCs) are considered the most undifferentiated cells after the embryonic ones. Here we try to clarify if the miRNAs differently regulated between leiomyoma and myometrium cells arise as a conversion of MPCs along the differentiation process or if they may originate from a divergent cell commitment. To track the origin of the dysregulation, miRNA expression was analyzed in AFPCs (considered as surrogate for embryonic cells), MPCs and LPCs.Methods: MPCs, LPCs and AFPCs were isolated and subjected to whole genoma miRNA profiling; the expression of the 15 miRNAs previously identified as differentially regulated in MPCs and LPCs was compared to that detected in AFPCs.Results: Clustering analysis sub-grouped the 15 miRNAs into 4 major clusters that converge to the KEGG pathways: Adherens junction, ECM-receptor interaction, TGFβ signaling and cell cycle. miRNAs are differentially regulated in MPCs and LPCs compared to AFPCs and 10/15 of them show statistically significant variations between MPCs and LPCs. Conclusion(s): Our results seem to point that a linear physiological differentiation axis exists from AFPCS to MPCs that, under particular insults, pathologically continues toward LPCs. Clustering analysis sub-grouped the 15 miRNAs into 4 major clusters that converge to the KEGG pathways: Adherens junction, ECM-receptor interaction, TGFβ signaling and cell cycle. miRNAs are differentially regulated in MPCs and LPCs compared to AFPCs and 10/15 of them show statistically significant variations between MPCs and LPCs. Our results seem to point that a linear physiological differentiation axis exists from AFPCS to MPCs that, under particular insults, pathologically continues toward LPCs.

scholarly journals Direct determination of retrotransposon transposition rates in Drosophila melanogaster

1994 ◽  
Vol 63 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Sergey V. Nuzhdin ◽  
Trudy F. C. Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Inbred Line ◽  
Copy Number ◽  
Direct Determination ◽  
Hybridization Analysis ◽  
Spontaneous Mutations ◽  
Insertion Sites

SummaryRates of transposition and excision of the Drosophila melanogaster retrotransposon elements mdg3, 297, Doc, roo and copia were estimated directly, by in situ hybridization analysis of their cytological insertion sites in 31 replicates of a highly inbred line that had accumulated spontaneous mutations for approximately 160generations. Estimated transposition rates of Doc, roo and copia were, respectively, 4·2 × 10−5, 3·1 × 10−3 and 1·3 − 10−3; no transpositions of 297 nor mdg3 were observed. Rates of transposition of copia varied significantly among sublines. Excisions were only observed for roo elements, at a rate of 9·0 × 10−6 per element per generation. Copy number averaged over these element families increased 5·9 %; therefore, in these lines the magnitude of the forces opposing transposable element multiplication were weaker than transposition rates.

A novel, tissue-specific integrin subunit, beta nu, expressed in the midgut of Drosophila melanogaster

Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 845-858 ◽  
Author(s):  
G.H. Yee ◽  
R.O. Hynes
Keyword(s):  
Drosophila Melanogaster ◽  
Matrix Proteins ◽  
Beta Subunits ◽  
Integrin Subunit ◽  
Integrin Receptor ◽  
Tissue Specific ◽  
Surface Receptors ◽  
Polymerase Chain ◽  
Maximal Expression

The integrins are a family of cell surface receptors for extracellular matrix proteins and counter-receptors on other cells. We have used the polymerase chain reaction to identify a novel integrin receptor beta subunit in Drosophila melanogaster. The deduced amino acid sequence of this subunit, which we have termed beta v (beta-neu), indicates that it has several unusual properties. The beta v subunit is roughly 33% identical with each of the previously sequenced vertebrate and Drosophila beta subunits and is lacking four of the 56 cysteine residues characteristic of most members of this protein family. The expression of the beta v gene is strikingly restricted. It is temporally regulated, with maximal expression occurring at 12–15 hours of embryonic development. In situ hybridization analyses and antibody localization on whole-mount embryos reveal that beta v expression is tissue-specific and confined to the developing midgut endoderm and its precursors during embryogenesis. Tissue specificity of expression is maintained through later stages of development as beta v transcripts are found exclusively in the larval midgut. Within this structure, beta v transcripts are especially concentrated in the cells of the midgut imaginal islands which give rise to the adult midgut.

Proneural clusters: equivalence groups in the epithelium of Drosophila

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 927-932 ◽  
Author(s):  
P. Simpson ◽  
C. Carteret
Keyword(s):  
Nervous System ◽  
Cell Lineage ◽  
Cellular Interactions ◽  
Equivalence Group ◽  
Neural Fate ◽  
Axonal Projections ◽  
The Central Nervous System ◽  
Neuronal Specificity ◽  
Proneural Cluster ◽  
Do So

The segregation of neural precursors from epidermal cells during development of the nervous system of Drosophila relies on interactions between cells that are thought to be initially equivalent. During development of the adult peripheral nervous system, failure of the cellular interactions leads to the differentiation of a tuft of sensory bristles at the site where usually only one develops. It is thus thought that a group of cells at that site (a proneural cluster) has the potential to make a bristle but that in normal development only one cell will do so. The question addressed here is do these cells constitute an equivalence group (Kimble, J., Sulston, J. and White, J. (1979). In Cell Lineage, Stem Cells and Cell Determination (ed. N. Le Douarin). Inserm Symposium No. 10 pp. 59–68, Elsevier, Amsterdam)? Within clusters mutant for shaggy, where several cells of a cluster follow the neural fate and differentiate bristles, it is shown that these display identical neuronal specificity: stimulation of the bristles evoke the same leg cleaning response and backfilling of single neurons reveal similar axonal projections in the central nervous system. This provides direct experimental evidence that the cells of a proneural cluster are developmentally equivalent.

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