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Wnt affects symmetry and morphogenesis during post-embryonic development in colonial chordates.

Di Maio A, Setar L, Tiozzo S, De Tomaso AW - Evodevo (2015)

Bottom Line: Modulation of the Wnt signaling in either process has shown to result in unusual body axis phenotypes.Chemical manipulation of the pathway resulted in atypical budding due to the duplication of the A/P axes, supernumerary budding, and loss of the overall cell apical-basal polarity.Our results suggest that Wnt signaling is used for equivalent developmental processes both during embryogenesis and asexual development in an adult organism, suggesting that patterning mechanisms driving morphogenesis are conserved, independent of embryonic, or regenerative development.

View Article: PubMed Central - PubMed

Affiliation: School of Bioscience, University of Birmingham, Edgbaston, Birmingham, B19 2TT UK ; Molecular Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106 USA.

ABSTRACT

Background: Wnt signaling is one of the earliest and most highly conserved regulatory pathways for the establishment of the body axes during regeneration and early development. In regeneration, body axes determination occurs independently of tissue rearrangement and early developmental cues. Modulation of the Wnt signaling in either process has shown to result in unusual body axis phenotypes. Botryllus schlosseri is a colonial ascidian that can regenerate its entire body through asexual budding. This processes leads to an adult body via a stereotypical developmental pathway (called blastogenesis), without proceeding through any embryonic developmental stages.

Results: In this study, we describe the role of the canonical Wnt pathway during the early stages of asexual development. We characterized expression of three Wnt ligands (Wnt2B, Wnt5A, and Wnt9A) by in situ hybridization and qRT-PCR. Chemical manipulation of the pathway resulted in atypical budding due to the duplication of the A/P axes, supernumerary budding, and loss of the overall cell apical-basal polarity.

Conclusions: Our results suggest that Wnt signaling is used for equivalent developmental processes both during embryogenesis and asexual development in an adult organism, suggesting that patterning mechanisms driving morphogenesis are conserved, independent of embryonic, or regenerative development.

No MeSH data available.


Related in: MedlinePlus

Ectopic secondary bud formation upon Wnt pathway alteration. B. schlosseri colonies treated with GSK-3β inhibitor (APL) are massively affected in their overall morphology. (A) Ventral views of a colony incubated with Wnt agonists showing ectopic budlets (highlighted with red dashed line) formations from the primary bud (N + 1, 9/8/3). (B) At stage 9/8/1, control colonies of the same genotype treated with DMSO do not show any morphological alteration. (C) Maximum projection of a z-stack of confocal image showing wnt2B expression by FISH. Note the high level of expression of wnt2B within the two ectopic budlets (b) at stage 9/8/3 (N + 1 cycle). The internal vasculature (asterisk) is also labeled with the probe. (D) A sub-clone of the animals in (C) was used as control for the same FISH experiment. The confocal z-stack image shows wnt2B expression located only on the secondary bud (b). Some background staining is visible on the apical side of the primary bud (B), not considered as true fluorescent signal. (E) Measurements of the A/P axes of primary buds at N + 1 cycle within treated colonies (blue) and control colonies (red). BARS: 1 mm (A and B); 200 μm (C and D).
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Fig5: Ectopic secondary bud formation upon Wnt pathway alteration. B. schlosseri colonies treated with GSK-3β inhibitor (APL) are massively affected in their overall morphology. (A) Ventral views of a colony incubated with Wnt agonists showing ectopic budlets (highlighted with red dashed line) formations from the primary bud (N + 1, 9/8/3). (B) At stage 9/8/1, control colonies of the same genotype treated with DMSO do not show any morphological alteration. (C) Maximum projection of a z-stack of confocal image showing wnt2B expression by FISH. Note the high level of expression of wnt2B within the two ectopic budlets (b) at stage 9/8/3 (N + 1 cycle). The internal vasculature (asterisk) is also labeled with the probe. (D) A sub-clone of the animals in (C) was used as control for the same FISH experiment. The confocal z-stack image shows wnt2B expression located only on the secondary bud (b). Some background staining is visible on the apical side of the primary bud (B), not considered as true fluorescent signal. (E) Measurements of the A/P axes of primary buds at N + 1 cycle within treated colonies (blue) and control colonies (red). BARS: 1 mm (A and B); 200 μm (C and D).

Mentions: Although during the first days of treatments with APL we did not observe any major signs of morphology alteration, 10 days after the beginning of the drug incubation (9/8/3 stage - N + 1 cycle), colonies showed increased pigmentation and abnormal organization of ampullae together with multiple ectopic secondary buds that were sometimes irregular in shape and size (outlined in red in Figure 5A). At that point, primary buds were smaller and rounded compared to control animals (Figure 5B). The source of the ectopic budlets was the first individual to receive treatment, suggesting that Wnt may be involved in budlet initiation or in early steps of budlet evagination.Figure 5


Wnt affects symmetry and morphogenesis during post-embryonic development in colonial chordates.

Di Maio A, Setar L, Tiozzo S, De Tomaso AW - Evodevo (2015)

Ectopic secondary bud formation upon Wnt pathway alteration. B. schlosseri colonies treated with GSK-3β inhibitor (APL) are massively affected in their overall morphology. (A) Ventral views of a colony incubated with Wnt agonists showing ectopic budlets (highlighted with red dashed line) formations from the primary bud (N + 1, 9/8/3). (B) At stage 9/8/1, control colonies of the same genotype treated with DMSO do not show any morphological alteration. (C) Maximum projection of a z-stack of confocal image showing wnt2B expression by FISH. Note the high level of expression of wnt2B within the two ectopic budlets (b) at stage 9/8/3 (N + 1 cycle). The internal vasculature (asterisk) is also labeled with the probe. (D) A sub-clone of the animals in (C) was used as control for the same FISH experiment. The confocal z-stack image shows wnt2B expression located only on the secondary bud (b). Some background staining is visible on the apical side of the primary bud (B), not considered as true fluorescent signal. (E) Measurements of the A/P axes of primary buds at N + 1 cycle within treated colonies (blue) and control colonies (red). BARS: 1 mm (A and B); 200 μm (C and D).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4499891&req=5

Fig5: Ectopic secondary bud formation upon Wnt pathway alteration. B. schlosseri colonies treated with GSK-3β inhibitor (APL) are massively affected in their overall morphology. (A) Ventral views of a colony incubated with Wnt agonists showing ectopic budlets (highlighted with red dashed line) formations from the primary bud (N + 1, 9/8/3). (B) At stage 9/8/1, control colonies of the same genotype treated with DMSO do not show any morphological alteration. (C) Maximum projection of a z-stack of confocal image showing wnt2B expression by FISH. Note the high level of expression of wnt2B within the two ectopic budlets (b) at stage 9/8/3 (N + 1 cycle). The internal vasculature (asterisk) is also labeled with the probe. (D) A sub-clone of the animals in (C) was used as control for the same FISH experiment. The confocal z-stack image shows wnt2B expression located only on the secondary bud (b). Some background staining is visible on the apical side of the primary bud (B), not considered as true fluorescent signal. (E) Measurements of the A/P axes of primary buds at N + 1 cycle within treated colonies (blue) and control colonies (red). BARS: 1 mm (A and B); 200 μm (C and D).
Mentions: Although during the first days of treatments with APL we did not observe any major signs of morphology alteration, 10 days after the beginning of the drug incubation (9/8/3 stage - N + 1 cycle), colonies showed increased pigmentation and abnormal organization of ampullae together with multiple ectopic secondary buds that were sometimes irregular in shape and size (outlined in red in Figure 5A). At that point, primary buds were smaller and rounded compared to control animals (Figure 5B). The source of the ectopic budlets was the first individual to receive treatment, suggesting that Wnt may be involved in budlet initiation or in early steps of budlet evagination.Figure 5

Bottom Line: Modulation of the Wnt signaling in either process has shown to result in unusual body axis phenotypes.Chemical manipulation of the pathway resulted in atypical budding due to the duplication of the A/P axes, supernumerary budding, and loss of the overall cell apical-basal polarity.Our results suggest that Wnt signaling is used for equivalent developmental processes both during embryogenesis and asexual development in an adult organism, suggesting that patterning mechanisms driving morphogenesis are conserved, independent of embryonic, or regenerative development.

View Article: PubMed Central - PubMed

Affiliation: School of Bioscience, University of Birmingham, Edgbaston, Birmingham, B19 2TT UK ; Molecular Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106 USA.

ABSTRACT

Background: Wnt signaling is one of the earliest and most highly conserved regulatory pathways for the establishment of the body axes during regeneration and early development. In regeneration, body axes determination occurs independently of tissue rearrangement and early developmental cues. Modulation of the Wnt signaling in either process has shown to result in unusual body axis phenotypes. Botryllus schlosseri is a colonial ascidian that can regenerate its entire body through asexual budding. This processes leads to an adult body via a stereotypical developmental pathway (called blastogenesis), without proceeding through any embryonic developmental stages.

Results: In this study, we describe the role of the canonical Wnt pathway during the early stages of asexual development. We characterized expression of three Wnt ligands (Wnt2B, Wnt5A, and Wnt9A) by in situ hybridization and qRT-PCR. Chemical manipulation of the pathway resulted in atypical budding due to the duplication of the A/P axes, supernumerary budding, and loss of the overall cell apical-basal polarity.

Conclusions: Our results suggest that Wnt signaling is used for equivalent developmental processes both during embryogenesis and asexual development in an adult organism, suggesting that patterning mechanisms driving morphogenesis are conserved, independent of embryonic, or regenerative development.

No MeSH data available.


Related in: MedlinePlus