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A functional genomic screen combined with time-lapse microscopy uncovers a novel set of genes involved in dorsal closure of Drosophila embryos.

Jankovics F, Henn L, Bujna Á, Vilmos P, Kiss N, Erdélyi M - PLoS ONE (2011)

Bottom Line: Morphogenesis, the establishment of the animal body, requires the coordinated rearrangement of cells and tissues regulated by a very strictly-determined genetic program.We show that pbl regulates actin accumulation and protrusion dynamics in the leading edge of the migrating epithelial cells.Finally, we provide evidence that pbl is involved in closure of the adult thorax, suggesting its general requirement in epithelial closure processes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary. jankovic@brc.hu

ABSTRACT
Morphogenesis, the establishment of the animal body, requires the coordinated rearrangement of cells and tissues regulated by a very strictly-determined genetic program. Dorsal closure of the epithelium in the Drosophila melanogaster embryo is one of the best models for such a complex morphogenetic event. To explore the genetic regulation of dorsal closure, we carried out a large-scale RNA interference-based screen in combination with in vivo time-lapse microscopy and identified several genes essential for the closure or affecting its dynamics. One of the novel dorsal closure genes, the small GTPase activator pebble (pbl), was selected for detailed analysis. We show that pbl regulates actin accumulation and protrusion dynamics in the leading edge of the migrating epithelial cells. In addition, pbl affects dorsal closure dynamics by regulating head involution, a morphogenetic process mechanically coupled with dorsal closure. Finally, we provide evidence that pbl is involved in closure of the adult thorax, suggesting its general requirement in epithelial closure processes.

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Related in: MedlinePlus

Abnormal thorax closure generated by RNAi.(A) Control thorax with pnr-Gal4/+ genotype. (B–C) Thoracic cleft phenotypes induced by pnr-Gal4-driven expression of UAS-RNAi constructs. (B) Silencing of N. (C) Silencing of pbl. The transformant ID of the UAS-RNAi constructs are KK100002 for N and GD35350 for pbl. Figures show dorsal views of adult thoraxes with anterior to the left.
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pone-0022229-g005: Abnormal thorax closure generated by RNAi.(A) Control thorax with pnr-Gal4/+ genotype. (B–C) Thoracic cleft phenotypes induced by pnr-Gal4-driven expression of UAS-RNAi constructs. (B) Silencing of N. (C) Silencing of pbl. The transformant ID of the UAS-RNAi constructs are KK100002 for N and GD35350 for pbl. Figures show dorsal views of adult thoraxes with anterior to the left.

Mentions: Closure of the adult thorax during metamorphosis has been shown to share many signaling and structural elements with the dorsal closure of the embryonic epithelium [38]. To test the conservation of our candidate genes between these closure processes, their involvement was also tested in thorax closure. In a genome-wide screen, specific dsRNAs of all Drosophila genes has been expressed by Mummery-Widmer et al. in a tissue-specific manner at the dorsal midline during metamorphosis using the Pnr-GAL4 driver, and the loss-of-function RNAi phenotypes of the adults have been determined [39]. In this experiment – of our candidate genes – only pbl has been shown to be required for thorax closure. Since coexpression of dicer2 has been demonstrated to enhance the RNAi-phenotype, we simultaneously expressed dicer2 with dsRNAs for our candidate genes in the thorax [40]. Under these conditions, silencing of five of the ten tested genes exhibited a phenotype. Silencing of three genes (scb, Bx42, ptc) led to lethality, while silencing of two genes (N and pbl) caused abnormal thorax closure and resulted in the formation of a thorax cleft, suggesting the general requirement of these genes in epithelial closure processes (Figure 5).


A functional genomic screen combined with time-lapse microscopy uncovers a novel set of genes involved in dorsal closure of Drosophila embryos.

Jankovics F, Henn L, Bujna Á, Vilmos P, Kiss N, Erdélyi M - PLoS ONE (2011)

Abnormal thorax closure generated by RNAi.(A) Control thorax with pnr-Gal4/+ genotype. (B–C) Thoracic cleft phenotypes induced by pnr-Gal4-driven expression of UAS-RNAi constructs. (B) Silencing of N. (C) Silencing of pbl. The transformant ID of the UAS-RNAi constructs are KK100002 for N and GD35350 for pbl. Figures show dorsal views of adult thoraxes with anterior to the left.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3140500&req=5

pone-0022229-g005: Abnormal thorax closure generated by RNAi.(A) Control thorax with pnr-Gal4/+ genotype. (B–C) Thoracic cleft phenotypes induced by pnr-Gal4-driven expression of UAS-RNAi constructs. (B) Silencing of N. (C) Silencing of pbl. The transformant ID of the UAS-RNAi constructs are KK100002 for N and GD35350 for pbl. Figures show dorsal views of adult thoraxes with anterior to the left.
Mentions: Closure of the adult thorax during metamorphosis has been shown to share many signaling and structural elements with the dorsal closure of the embryonic epithelium [38]. To test the conservation of our candidate genes between these closure processes, their involvement was also tested in thorax closure. In a genome-wide screen, specific dsRNAs of all Drosophila genes has been expressed by Mummery-Widmer et al. in a tissue-specific manner at the dorsal midline during metamorphosis using the Pnr-GAL4 driver, and the loss-of-function RNAi phenotypes of the adults have been determined [39]. In this experiment – of our candidate genes – only pbl has been shown to be required for thorax closure. Since coexpression of dicer2 has been demonstrated to enhance the RNAi-phenotype, we simultaneously expressed dicer2 with dsRNAs for our candidate genes in the thorax [40]. Under these conditions, silencing of five of the ten tested genes exhibited a phenotype. Silencing of three genes (scb, Bx42, ptc) led to lethality, while silencing of two genes (N and pbl) caused abnormal thorax closure and resulted in the formation of a thorax cleft, suggesting the general requirement of these genes in epithelial closure processes (Figure 5).

Bottom Line: Morphogenesis, the establishment of the animal body, requires the coordinated rearrangement of cells and tissues regulated by a very strictly-determined genetic program.We show that pbl regulates actin accumulation and protrusion dynamics in the leading edge of the migrating epithelial cells.Finally, we provide evidence that pbl is involved in closure of the adult thorax, suggesting its general requirement in epithelial closure processes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary. jankovic@brc.hu

ABSTRACT
Morphogenesis, the establishment of the animal body, requires the coordinated rearrangement of cells and tissues regulated by a very strictly-determined genetic program. Dorsal closure of the epithelium in the Drosophila melanogaster embryo is one of the best models for such a complex morphogenetic event. To explore the genetic regulation of dorsal closure, we carried out a large-scale RNA interference-based screen in combination with in vivo time-lapse microscopy and identified several genes essential for the closure or affecting its dynamics. One of the novel dorsal closure genes, the small GTPase activator pebble (pbl), was selected for detailed analysis. We show that pbl regulates actin accumulation and protrusion dynamics in the leading edge of the migrating epithelial cells. In addition, pbl affects dorsal closure dynamics by regulating head involution, a morphogenetic process mechanically coupled with dorsal closure. Finally, we provide evidence that pbl is involved in closure of the adult thorax, suggesting its general requirement in epithelial closure processes.

Show MeSH
Related in: MedlinePlus