QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Goff, D. J. Articles by Morisato, D. Search for Related Content PubMed PubMed Citation Articles by Goff, D. J. Articles by Morisato, D. Social Bookmarking                         What's this?

Establishment of dorsal-ventral polarity of the Drosophila egg requires capicua action in ovarian follicle cells

¹ Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
² Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal QC H3A 1B1, Canada

View larger version (68K): [in a new window]   Fig. 1. Reduction of fet function produces a dorsalized maternal effect phenotype and zygotic wing defect. (A,B) Eggshell produced by wild-type and fetU6/fetE11 female (dorsal view). The fet egg is shorter than wild type, with broader dorsal appendages that are shifted laterally and appendage base material encircling the anterior circumference. In all panels depicting an eggshell or embryo, anterior is towards the left. (C,D) Cuticle of embryo produced by wild-type and fetU6/fetE11 female. The fet embryo is dorsalized, and lacks ventral and lateral denticle bands. (E,F) Expression of zen RNA in blastoderm embryo produced by wild-type and fetT6/fetE11 female (lateral view, dorsal side upwards). The domain of this dorsal marker is expanded along the entire DV axis in the fet embryo. (G,H) Expression of sog RNA in blastoderm embryo produced by wild-type and fetT6/fetE11 female. In this lateral view, only one of the two stripes expressed in the wild-type embryo is visible. No sog RNA is detected in the fet embryo except for a posterior spot. (I,J) Expression of Twist protein in blastoderm embryo produced by wild-type and fetT6/fetE11 female. This ventral marker is not detected in the fet embryo, except for expression at the termini, which is regulated independently of the DV pathway. (K,L) Wing blade of wild-type and fetU6/fetE11 fly. The fet wing is smaller than wild-type, and exhibits vein thickening and blistering.

View larger version (43K): [in a new window]   Fig. 2. fet is required in ventral follicle cells for normal DV pattern of the embryo. (A-C) Embryos produced by fet germline clones (GLC). The expression of Twist (A) and zen RNA (B) appear normal in fetE11 GLC embryos (lateral view, dorsal side upwards). The differentiated cuticle has normal DV polarity but shows a torso gain-of-function phenotype (C). (D) Embryo produced by unmarked fetU6 follicle cell clones (FCC). This cuticle of a FCC embryo is strongly dorsalized. (E,F) Embryos produced by dec-marked fetU6 FCC. (E) Two views of a single egg with a large dorsal clone. The dorsal follicle cells were mutant for fet, whereas the ventral follicle cells were wild type. The embryo within has a normal DV pattern. (F) A ventral posterior clone causes localized dorsalization, as evident by the loss of ventral denticle bands. The clone borders have been highlighted using Adobe Photoshop.

View larger version (92K): [in a new window]   Fig. 3. Egfr signaling appears normal in fet ovaries at stage 10. Early stage 10 (A-H) and late stage 10 (I,J) egg chambers from wild-type (A,C,E,G,I) and fetU6/fetE11 (B,D,F,H,J) ovaries. In early stage 10 fet ovaries, the expression of grk RNA (A,B), the kek1 enhancer trap line 15A6 (C,D), the mirror enhancer trap line mirr6D1 (E,F) and fringe RNA (G,H) appear normal. During late stage 10, mirror expression expands in fet ovaries (I,J). (Lateral view, dorsal side upwards.)

View larger version (110K): [in a new window]   Fig. 4. fet acts downstream of Egfr in patterning the embryo. (A,B) Egfr1/Egfr1; fetT6/+ females lay eggs with a ventralized embryo (A) and ventralized eggshell (B). (C,D) Egfr1/+; fetT6/fetE11 females lay eggs with a dorsalized embryo (C) and dorsalized eggshell (D). (E,F) Egfr1/Egfr1; fetT6/fetE11 double mutant females lay eggs with a dorsalized embryo (E) and an eggshell (F) that shows a combination of Egfr and fet phenotypes.

View larger version (100K): [in a new window]   Fig. 5. fet is required for pipe expression in ventral follicle cells. Stage 9 and stage 10B egg chambers from wild-type (A,C) and fetU6/fetE11 (B,D) ovaries were detected for pipe RNA expression. The oocyte nucleus is visible in the dorsal anterior corner.

View larger version (40K): [in a new window]   Fig. 6. fet is allelic to cic. (A-C) In the wild-type embryo (A), tll RNA expression is confined to the termini of the embryo. In embryos produced by fetT6/fetE11 females (B) and fetE11 GLC embryos (C), tll RNA expression is derepressed towards the center of the embryo. (Lateral view, dorsal side upwards). (D) Cuticle of embryo produced by fetU6/cic1 transheterozygote shows a torso gain-of-function phenotype. (E) RNA blot probed with cic cDNA probe. Each lane was loaded with 1 µg poly(A)+ ovarian RNA isolated from females with the indicated genotypes. Mobilities of DNA markers are indicated on left. The arrow points to the 5.7 kb cic transcript. (F) The intron/exon organization of the cic transcript, with black boxes representing the 13 exons. The HMG box lies within exon 3, and the conserved C-terminal domain is located within exons 11 and 12. The positions of mutations fetT6, fetU6, and fetE11 are indicated above the boxes. The location of the cic1 hobo insertion has been described to be in the 5' untranslated region (Jiménez et al., 2000).

View larger version (138K): [in a new window]   Fig. 7. Fet/Cic protein is expressed in follicle cell nuclei. (A,B) Stage 10A (A) and stage 10B (B) wild-type egg chamber showing expression of Fet/Cic protein in follicle cell nuclei (lateral view, dorsal side upwards). In the older chamber, Cic is downregulated on the dorsal side. (C,D) Egg chamber cross-section at the plane of the oocyte nucleus shows a subtle reduction of Cic protein on the dorsal side at stage 10A (C) and a complete absence of Cic on the dorsal side at stage 10B (D) (dorsal side upwards). (E,F) Cic protein is expressed in egg chambers from cic1 females (E) and absent in egg chambers from fetE11/fetU6 females (F) (lateral view, dorsal side upwards).

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

Twitter