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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

Wnt pathway over-activation induces A/P axes duplication and elongation. (A) Upon chemical treatments with Wnt pathway agonist (LiCl), in some cases, single individuals within a colony showed signs of axes duplication (double arrows). At N + 2 cycle, next to the adult bifurcated individual, only primary buds are visible (single arrows). (B) Dorsal view enlargement of one of the zooids in (A) showing a double oral siphon. (C) Toluidine blue staining of semi-thick sections (150 μm) from control colony indicating the A/P axes orientation on primary (B - blue) and secondary (b - yellow) buds. (D) The same preparation on drug-treated colony shows bifurcated peribranchial epithelium within the budding region. BAR: 1 mm (A); 200 μm (B); 500 μm (C and D).
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Fig6: Wnt pathway over-activation induces A/P axes duplication and elongation. (A) Upon chemical treatments with Wnt pathway agonist (LiCl), in some cases, single individuals within a colony showed signs of axes duplication (double arrows). At N + 2 cycle, next to the adult bifurcated individual, only primary buds are visible (single arrows). (B) Dorsal view enlargement of one of the zooids in (A) showing a double oral siphon. (C) Toluidine blue staining of semi-thick sections (150 μm) from control colony indicating the A/P axes orientation on primary (B - blue) and secondary (b - yellow) buds. (D) The same preparation on drug-treated colony shows bifurcated peribranchial epithelium within the budding region. BAR: 1 mm (A); 200 μm (B); 500 μm (C and D).

Mentions: In addition to ectopic budlet formation and changes in A/P polarity, we also observed a duplication of the main A/P axis in either APL- or LiCl-treated animals. In about 20% of cases (n = 22) at N + 2 cycle, the surviving zooids showed axes duplication with two oral and one atrial siphon (Figure 6A and B). Histological sections of control and drug-treated colonies (Figure 6C and D, respectively) show a bifurcated peribranchial epithelia in the presumptive budding region demonstrating that duplicated axes appeared during budlet initiation, at N + 1 cycle.Figure 6


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

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

Wnt pathway over-activation induces A/P axes duplication and elongation. (A) Upon chemical treatments with Wnt pathway agonist (LiCl), in some cases, single individuals within a colony showed signs of axes duplication (double arrows). At N + 2 cycle, next to the adult bifurcated individual, only primary buds are visible (single arrows). (B) Dorsal view enlargement of one of the zooids in (A) showing a double oral siphon. (C) Toluidine blue staining of semi-thick sections (150 μm) from control colony indicating the A/P axes orientation on primary (B - blue) and secondary (b - yellow) buds. (D) The same preparation on drug-treated colony shows bifurcated peribranchial epithelium within the budding region. BAR: 1 mm (A); 200 μm (B); 500 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

Fig6: Wnt pathway over-activation induces A/P axes duplication and elongation. (A) Upon chemical treatments with Wnt pathway agonist (LiCl), in some cases, single individuals within a colony showed signs of axes duplication (double arrows). At N + 2 cycle, next to the adult bifurcated individual, only primary buds are visible (single arrows). (B) Dorsal view enlargement of one of the zooids in (A) showing a double oral siphon. (C) Toluidine blue staining of semi-thick sections (150 μm) from control colony indicating the A/P axes orientation on primary (B - blue) and secondary (b - yellow) buds. (D) The same preparation on drug-treated colony shows bifurcated peribranchial epithelium within the budding region. BAR: 1 mm (A); 200 μm (B); 500 μm (C and D).
Mentions: In addition to ectopic budlet formation and changes in A/P polarity, we also observed a duplication of the main A/P axis in either APL- or LiCl-treated animals. In about 20% of cases (n = 22) at N + 2 cycle, the surviving zooids showed axes duplication with two oral and one atrial siphon (Figure 6A and B). Histological sections of control and drug-treated colonies (Figure 6C and D, respectively) show a bifurcated peribranchial epithelia in the presumptive budding region demonstrating that duplicated axes appeared during budlet initiation, at N + 1 cycle.Figure 6

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