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A feedback mechanism converts individual cell features into a supracellular ECM structure in Drosophila trachea.

Öztürk-Çolak A, Moussian B, Araújo SJ, Casanova J - Elife (2016)

Bottom Line: Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM.Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions.Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation.

View Article: PubMed Central - PubMed

Affiliation: Institut de Biologia Molecular de Barcelona, Parc Cientific de Barcelona, Barcelona, Spain.

ABSTRACT
The extracellular matrix (ECM), a structure contributed to and commonly shared by many cells in an organism, plays an active role during morphogenesis. Here, we used the Drosophila tracheal system to study the complex relationship between the ECM and epithelial cells during development. We show that there is an active feedback mechanism between the apical ECM (aECM) and the apical F-actin in tracheal cells. Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM. Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions. Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation.

No MeSH data available.


Related in: MedlinePlus

Kkv co-localises with F-actin and chitin rings at embryonic and larval stages.(A) Detail of stage 16 wild-type embryos expressing a kkvGFP transgene in tracheal cells and stained with phalloidin to reveal the F-actin rings; Kkv is detected in rings that resemble the F-actin rings (arrowhead in A’). (B) DT zoomed detail of an L3 larva expressing a kkvGFP transgene in tracheal cells and stained with anti-GFP antibody to detect KkvGFP localisation and fluostain to reveal the chitin filament. (C) Zoomed detail of the apical membrane of the tracheal cells of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (D) Zoomed detail of the DT of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (E) Quantification of the number of KkvGFP dots that overlap within the taenidium (mean of 24.8 ± 1.4, n = 24) in comparison to the dots localised outside the taenidium (mean of 14.8 ± 1.2, n = 24). Error bars represent ± SEM and p-value is 3.1E-6 by two-tailed unpaired Student’s t-test.DOI:http://dx.doi.org/10.7554/eLife.09373.007
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fig3s1: Kkv co-localises with F-actin and chitin rings at embryonic and larval stages.(A) Detail of stage 16 wild-type embryos expressing a kkvGFP transgene in tracheal cells and stained with phalloidin to reveal the F-actin rings; Kkv is detected in rings that resemble the F-actin rings (arrowhead in A’). (B) DT zoomed detail of an L3 larva expressing a kkvGFP transgene in tracheal cells and stained with anti-GFP antibody to detect KkvGFP localisation and fluostain to reveal the chitin filament. (C) Zoomed detail of the apical membrane of the tracheal cells of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (D) Zoomed detail of the DT of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (E) Quantification of the number of KkvGFP dots that overlap within the taenidium (mean of 24.8 ± 1.4, n = 24) in comparison to the dots localised outside the taenidium (mean of 14.8 ± 1.2, n = 24). Error bars represent ± SEM and p-value is 3.1E-6 by two-tailed unpaired Student’s t-test.DOI:http://dx.doi.org/10.7554/eLife.09373.007

Mentions: KkvGFP showed a highly punctated accumulation in tracheal cells, which makes it difficult to distinguish clear spatial patterns. However, we did detect linear arrangements perpendicular to the tube length that resembled the actin rings detected by phalloidin and the chitin rings detected by fluostain (Figure 3B and C and Figure 3—figure supplement 1). We have quantified the number of times these KkvGFP dots overlap with the fluostain rings and observed that they are indeed more frequent within each ring (on average, 25 dots per taenidium in contrast to 15 dots outside, n = 24, Figure 3—figure supplement 1E). Interestingly, we also found that these KkvGFP dots are larger when they overlap with the fluostain rings than when they are present outside (Figure 3—figure supplement 1D). These findings support the notion that actin organisation, which dictates taenidial fold organization, participates in the distribution of the Kkv chitin synthase. Interestingly, we did not observe the same arrangements upon driving kkvGFP expression in a tal/pri mutant background (100%, n = 30, Figure 3D). Instead, we found that Kkv dots are more aligned with the disrupted actin fibers. In tal/pri mutants, actin fiber organisation is disrupted and taenidia are not properly formed, reinforcing the idea of a functional role for Kkv distribution.10.7554/eLife.09373.006Figure 3.Kkv co-localises with F-actin rings during tracheal maturation.


A feedback mechanism converts individual cell features into a supracellular ECM structure in Drosophila trachea.

Öztürk-Çolak A, Moussian B, Araújo SJ, Casanova J - Elife (2016)

Kkv co-localises with F-actin and chitin rings at embryonic and larval stages.(A) Detail of stage 16 wild-type embryos expressing a kkvGFP transgene in tracheal cells and stained with phalloidin to reveal the F-actin rings; Kkv is detected in rings that resemble the F-actin rings (arrowhead in A’). (B) DT zoomed detail of an L3 larva expressing a kkvGFP transgene in tracheal cells and stained with anti-GFP antibody to detect KkvGFP localisation and fluostain to reveal the chitin filament. (C) Zoomed detail of the apical membrane of the tracheal cells of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (D) Zoomed detail of the DT of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (E) Quantification of the number of KkvGFP dots that overlap within the taenidium (mean of 24.8 ± 1.4, n = 24) in comparison to the dots localised outside the taenidium (mean of 14.8 ± 1.2, n = 24). Error bars represent ± SEM and p-value is 3.1E-6 by two-tailed unpaired Student’s t-test.DOI:http://dx.doi.org/10.7554/eLife.09373.007
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4764556&req=5

fig3s1: Kkv co-localises with F-actin and chitin rings at embryonic and larval stages.(A) Detail of stage 16 wild-type embryos expressing a kkvGFP transgene in tracheal cells and stained with phalloidin to reveal the F-actin rings; Kkv is detected in rings that resemble the F-actin rings (arrowhead in A’). (B) DT zoomed detail of an L3 larva expressing a kkvGFP transgene in tracheal cells and stained with anti-GFP antibody to detect KkvGFP localisation and fluostain to reveal the chitin filament. (C) Zoomed detail of the apical membrane of the tracheal cells of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (D) Zoomed detail of the DT of an L3 larva expressing a KkvGFP showing how the larger KkvGFP units overlap with the taenidia. (E) Quantification of the number of KkvGFP dots that overlap within the taenidium (mean of 24.8 ± 1.4, n = 24) in comparison to the dots localised outside the taenidium (mean of 14.8 ± 1.2, n = 24). Error bars represent ± SEM and p-value is 3.1E-6 by two-tailed unpaired Student’s t-test.DOI:http://dx.doi.org/10.7554/eLife.09373.007
Mentions: KkvGFP showed a highly punctated accumulation in tracheal cells, which makes it difficult to distinguish clear spatial patterns. However, we did detect linear arrangements perpendicular to the tube length that resembled the actin rings detected by phalloidin and the chitin rings detected by fluostain (Figure 3B and C and Figure 3—figure supplement 1). We have quantified the number of times these KkvGFP dots overlap with the fluostain rings and observed that they are indeed more frequent within each ring (on average, 25 dots per taenidium in contrast to 15 dots outside, n = 24, Figure 3—figure supplement 1E). Interestingly, we also found that these KkvGFP dots are larger when they overlap with the fluostain rings than when they are present outside (Figure 3—figure supplement 1D). These findings support the notion that actin organisation, which dictates taenidial fold organization, participates in the distribution of the Kkv chitin synthase. Interestingly, we did not observe the same arrangements upon driving kkvGFP expression in a tal/pri mutant background (100%, n = 30, Figure 3D). Instead, we found that Kkv dots are more aligned with the disrupted actin fibers. In tal/pri mutants, actin fiber organisation is disrupted and taenidia are not properly formed, reinforcing the idea of a functional role for Kkv distribution.10.7554/eLife.09373.006Figure 3.Kkv co-localises with F-actin rings during tracheal maturation.

Bottom Line: Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM.Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions.Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation.

View Article: PubMed Central - PubMed

Affiliation: Institut de Biologia Molecular de Barcelona, Parc Cientific de Barcelona, Barcelona, Spain.

ABSTRACT
The extracellular matrix (ECM), a structure contributed to and commonly shared by many cells in an organism, plays an active role during morphogenesis. Here, we used the Drosophila tracheal system to study the complex relationship between the ECM and epithelial cells during development. We show that there is an active feedback mechanism between the apical ECM (aECM) and the apical F-actin in tracheal cells. Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM. Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions. Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation.

No MeSH data available.


Related in: MedlinePlus