Mechanical role of the spatial patterns of contractile cells in invagination of growing epithelial tissue

The amnioserosa is an extraembryonic, epithelial tissue that covers the dorsal side of the Drosophila embryo. The initial development of the amnioserosa is controlled by the dorsoventral patterning genes. Here we show that a group of genes, which we refer to as the U-shaped-group (ush-group), is required for maintenance of the amnioserosa tissue once it has differentiated. Using several molecular markers, we examined amnioserosa development in the ush-group mutants: u-shaped (ush), hindsight (hnt), serpent (srp) and tail-up (tup). Our results show that the amnioserosa in these mutants is specified correctly and begins to differentiate as in wild type. However, following germ-band extension, there is a premature loss of the amnioserosa. We demonstrate that this cell loss is a consequence of programmed cell death (apoptosis) in ush, hnt and srp, but not in tup. We discuss the role of the ush-group genes in maintaining the amnioserosa's viability. We also discuss a possible role for the amnioserosa in germ-band retraction in light of these mutants' unretracted phenotype.

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The Role of Cell-Cell Adhesion in Epithelial Tissue Mechanics and Morphogenesis

10.1115/1.0004742v ◽

2021 ◽

Author(s):

Xun Wang ◽

Christian Cupo ◽

Karen Kasza

Keyword(s):

Cell Adhesion ◽

Tissue Mechanics ◽

Epithelial Tissue ◽

Cell Cell

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Incidence of visceral leishmaniasis in the Vaishali district of Bihar, India: spatial patterns and role of inland water bodies

Geospatial health ◽

10.4081/gh.2011.173 ◽

2011 ◽

Vol 5 (2) ◽

pp. 205 ◽

Cited By ~ 18

Author(s):

Gouri Sankar Bhunia ◽

Shreekant Kesari ◽

Nandini Chatterjee ◽

Dilip Kumar Pal ◽

Vijay Kumar ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Spatial Patterns ◽

Water Bodies ◽

Inland Water ◽

Inland Water Bodies

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The role of time and species identities in spatial patterns of species richness and conservation

Conservation Biology ◽

10.1111/cobi.12716 ◽

2016 ◽

Vol 30 (5) ◽

pp. 1080-1088 ◽

Cited By ~ 12

Author(s):

Judi E. Hewitt ◽

Simon F. Thrush ◽

Kari E. Ellingsen

Keyword(s):

Species Richness ◽

Spatial Patterns

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Palate Morphogenesis

Development ◽

10.1242/dev.53.1.75 ◽

1979 ◽

Vol 53 (1) ◽

pp. 75-90

Author(s):

Elizabeth L. Wee ◽

Bruce S. Babiarz ◽

Stephen Zimmerman ◽

Ernest F. Zimmerman

Keyword(s):

Embryo Culture ◽

Posterior Region ◽

Anterior Region ◽

Serotonin Antagonists ◽

A Cell ◽

Pharmacologic Agents ◽

Muscle Contractile ◽

Contractile Cells

Previous studies have localized non-muscle contractile systems in the posterior (region 2) and the anterior (region 3) ends of mouse palates at the time of shelf movement. In order to determine whether these contractile systems function in shelf rotation, effects of pharmacologic agents have been analyzed in embryo culture. First, it was shown that the posterior end of the palate rotates before the anterior end, and its rotation in culture was proportionally greater as development of the embryo progressed. Generally, the posterior end of the palate was more easily inhibited in embryo culture than the anterior end. Serotonin at 10–−8 M to 10–−5 M was shown to significantly stimulate rotation atthe anterior end of the palate after 2 h in embryo culture. The effect on the posterior palate was less pronounced. To investigate further the role of this neurotransmitter on palate shelf rotation, serotonin antagonists were employed. Methysergide (10–−4 M) inhibited anterior shelf rotation to 12% of control values (P < 0·005), while not significantly affecting the posterior end. Ergotamine (10–−6 M) significantly inhibited the stimulation induced by 10–−5 M serotonin (P < 0·025). Cyproheptadine (10–−9 M) partially inhibited anterior and posterior shelf rotation in embryo culture. When injected into the pregnant dam, cyproheptadine partially inhibited shelf rotation and fusion. The palate was examined histologically after embryo culture. In the presence of 10–−4 M methysergide, the elongated contractile cells in region 3 at the anterior and midpalatal mesenchyme were prevented from rounding. Thus, serotonin may be regulating rotation of the anterior end of the palate by an effect on a cell-mediated process.

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Range-wide spatial mapping reveals convergent character displacement of bird song

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0443 ◽

2019 ◽

Vol 286 (1902) ◽

pp. 20190443 ◽

Cited By ~ 11

Author(s):

Alexander N. G. Kirschel ◽

Nathalie Seddon ◽

Joseph A. Tobias

Keyword(s):

Spatial Patterns ◽

Evolutionary Biology ◽

Environmental Gradients ◽

Empirical Studies ◽

Remote Sensing Data ◽

Character Displacement ◽

Similar Species ◽

Interspecific Territoriality ◽

Coexisting Species

A long-held view in evolutionary biology is that character displacement generates divergent phenotypes in closely related coexisting species to avoid the costs of hybridization or ecological competition, whereas an alternative possibility is that signals of dominance or aggression may instead converge to facilitate coexistence among ecological competitors. Although this counterintuitive process—termed convergent agonistic character displacement—is supported by recent theoretical and empirical studies, the extent to which it drives spatial patterns of trait evolution at continental scales remains unclear. By modelling the variation in song structure of two ecologically similar species of Hypocnemis antbird across western Amazonia, we show that their territorial signals converge such that trait similarity peaks in the sympatric zone, where intense interspecific territoriality between these taxa has previously been demonstrated. We also use remote sensing data to show that signal convergence is not explained by environmental gradients and is thus unlikely to evolve by sensory drive (i.e. acoustic adaptation to the sound transmission properties of habitats). Our results suggest that agonistic character displacement driven by interspecific competition can generate spatial patterns opposite to those predicted by classic character displacement theory, and highlight the potential role of social selection in shaping geographical variation in signal phenotypes of ecological competitors.

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Unexpected mutual regulation underlies paralogue functional diversification and promotes epithelial tissue maturation in Tribolium

Communications Biology ◽

10.1038/s42003-020-01250-3 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Daniela Gurska ◽

Iris M. Vargas Jentzsch ◽

Kristen A. Panfilio

Keyword(s):

Feedback Loop ◽

Single Species ◽

Epithelial Tissue ◽

Rna Seq ◽

Developmental Progression ◽

Late Embryogenesis ◽

Mutual Regulation ◽

Transcriptional Landscape

Abstract Insect Hox3/zen genes represent an evolutionary hotspot for changes in function and copy number. Single orthologues are required either for early specification or late morphogenesis of the extraembryonic tissues, which protect the embryo. The tandemly duplicated zen paralogues of the beetle Tribolium castaneum present a unique opportunity to investigate both functions in a single species. We dissect the paralogues’ expression dynamics (transcript and protein) and transcriptional targets (RNA-seq after RNAi) throughout embryogenesis. We identify an unexpected role of Tc-Zen2 in repression of Tc-zen1, generating a negative feedback loop that promotes developmental progression. Tc-Zen2 regulation is dynamic, including within co-expressed multigene loci. We also show that extraembryonic development is the major event within the transcriptional landscape of late embryogenesis and provide a global molecular characterization of the extraembryonic serosal tissue. Altogether, we propose that paralogue mutual regulation arose through multiple instances of zen subfunctionalization, leading to their complementary extant roles.

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Inferring Processes from Spatial Patterns: The Role of Directional and Non–Directional Forces in Shaping Fish Larvae Distribution in a Freshwater Lake System

PLoS ONE ◽

10.1371/journal.pone.0050239 ◽

2012 ◽

Vol 7 (11) ◽

pp. e50239 ◽

Cited By ~ 22

Author(s):

Andrea Bertolo ◽

F. Guillaume Blanchet ◽

Pierre Magnan ◽

Philippe Brodeur ◽

Marc Mingelbier ◽

...

Keyword(s):

Spatial Patterns ◽

Fish Larvae ◽

Freshwater Lake ◽

Lake System

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Unexpected mutual regulation underlies paralogue functional diversification and promotes maturation of a protective epithelial tissue

10.1101/427245 ◽

2018 ◽

Cited By ~ 1

Author(s):

Daniela Gurska ◽

Iris M. Vargas Jentzsch ◽

Kristen A. Panfilio

Keyword(s):

Feedback Loop ◽

Single Species ◽

Epithelial Tissue ◽

Rna Seq ◽

Developmental Progression ◽

Late Embryogenesis ◽

Mutual Regulation ◽

Transcriptional Landscape

ABSTRACTInsect Hox3/zen genes represent an evolutionary hotspot for changes in function and copy number. Single orthologues are required either for early specification or late morphogenesis of the extraembryonic tissues, which protect the embryo. The tandemly duplicated zen paralogues of the beetle Tribolium castaneum present a unique opportunity to investigate both functions in a single species. We dissect the paralogues’ expression dynamics (transcript and protein) and transcriptional targets (RNA-seq after RNAi) throughout embryogenesis. We identify an unexpected role of Tc-Zen2 in repression of Tc-zen1, generating a negative feedback loop that promotes developmental progression. Tc-Zen2 regulation is dynamic, including within co-expressed multigene loci. We also show that extraembryonic development is the major event within the transcriptional landscape of late embryogenesis and provide a global molecular characterization of the extraembryonic serosal tissue. Altogether, we propose that paralogue mutual regulation arose progressively and drove multiple instances of zen subfunctionalization, leading to complementary extant roles.

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