spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online 15 March 2006
doi: 10.1242/dev.02318

Development 133, 1467-1475 (2006)
Published by The Company of Biologists 2006
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in Development
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shapiro, R. S.
Right arrow Articles by Anderson, K. V.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shapiro, R. S.
Right arrow Articles by Anderson, K. V.

Drosophila Ik2, a member of the I{kappa}B kinase family, is required for mRNA localization during oogenesis

Risa S. Shapiro1,2 and Kathryn V. Anderson1,*

1 Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10021, USA.
2 Biochemistry, Cell and Molecular Biology Program, Weill Graduate School of Medical Sciences, Cornell University, 445 East 69th Street, New York, NY 10021, USA.


Figure 1
View larger version (84K):

[in a new window]
  		Fig. 1. Defects in anteroposterior embryonic patterning caused by loss of ik2 in the female germline. (A-C) Dark-field views of larval cuticle preparations at the end of embryogenesis from (A) wild-type and (B,C) bicaudal embryos from an ik21 germline clone female. (D-G) bicoid mRNA is localized to the anterior pole of wild-type embryos (D), ik2alice (E) and ik21 (F) mutant germline-derived embryos, and BicD1/BicD2 (G) embryos. (H-K) oskar mRNA localization at the posterior pole of a wild-type embryo (H), and at both the anterior and posterior poles of embryos produced by an ik2alice germline clone female (I), an ik21 germline clone female (J), and a BicD1/BicD2 mutant female (K). (L-N) nanos mRNA localization at the posterior pole of a wild-type embryo (L), and at both the anterior and posterior poles of embryos produced by an ik2alice germline clone female (M), and an ik21 germline clone female (N). Anterior to the left.

 

Figure 2
View larger version (74K):

[in a new window]
  		Fig. 2. Defects in dorsoventral patterning caused by loss of ik2 in the female germline. (A-C) Dark-field views of larval cuticle preparations at the end of embryogenesis from (A) wild type, (B) a weakly ventralized embryo from an ik2alice germline clone female and (C) a ventralized embryo from an ik21 germline clone female. (D-F) Eggshells produced by (D) wild type, (E) an ik2alice germline clone female and (F) an ik21 germline clone female. Wild-type eggshells have two dorsal chorionic appendages, whereas the eggs in E and F have a single or no dorsal appendages, respectively. (G-I) Twist expression. Twist is expressed in the ventral 25% of cells of the wild-type blastoderm embryo (G), but is expressed in an expanded domain in embryos produced by ik21 germline clone females (H,I). Anterior to the left; dorsal is up in G-I.

 

Figure 3
View larger version (88K):

[in a new window]
  		Fig. 3. Defects in mRNA localization and expression during oogenesis caused by loss of ik2 in the female germline. (A-C) Fluorescent in situ hybridization shows that osk mRNA is localized to the posterior pole of a stage 9 wild-type oocyte (A), but is also found at the lateral cortex of an ik2alice oocyte (B), and at the anterior and lateral cortex of an ik21 oocyte (C). (D-F) In situ hybridization shows that grk mRNA is localized to the dorsoanterior corner of the wild-type oocyte at stage 8-9 (D), but is also found along the anterior border of an ik2alice oocyte (E), and is not enriched dorsally in an ik21 oocyte (F). (G-I) pipe mRNA is expressed in the follicle cells on the ventral side of the wild-type stage 10 egg chamber (G), but can also be detected in dorsal follicle cells of an ik2alice egg chamber (H), and is expressed at high levels both ventrally and dorsally in an ik21 egg chamber (I). pipe and grk in situ hybridizations were performed in parallel with wild-type controls, and all samples were developed for equal lengths of time. Anterior to the left, dorsal up.

 

Figure 4
View larger version (63K):

[in a new window]
  		Fig. 4. Epistasis analysis with pipe reveals that ik2 acts upstream of the Toll-Dorsal pathway during oogenesis. (A-D) Dark-field views of larval cuticle preparations at the end of embryogenesis from (A) wild type, (B) a bicaudal embryo from an ik21 germline clone female, (C) a dorsalized embryo from a pipe1 mutant female and (D) a dorsalized embryo from a ik21; pipe1 double homozygous mutant female.

 

Figure 5
View larger version (76K):

[in a new window]
  		Fig. 5. Effects of the loss of ik2 on microtubule organization in the oocyte. (A,B) Expression of Tau-GFP in wild-type (A) and ik21 (B) stage 7-8 egg chambers. An abnormal enrichment of Tau-GFP is seen around the oocyte nucleus in ik21 (arrow). Tau-GFP is also seen at higher levels in the nurse cells of the mutant than in wild type. (C,D) Localization of Kinesin-ß-gal, as assayed by antibodies to ß-galactosidase, in wild-type (C) and ik2alice (D) stage 9 oocytes, shows that the plus-ends of microtubules in ik2alice show the normal posterior enrichment. (E,F) The localization of dynein heavy chain (DHC) in wild-type (E) and ik21 (F) stage 9 oocytes; DHC is seen throughout the lateral cortex of ik21 oocytes, in contrast to its posterior localization in wild type. (G-J) Nod-ß-gal as assayed with antibodies to ß-galactosidase in wild-type (G,I) and ik21 (H,J) oocytes. In contrast to the dorsal anterior localization of Nod-ß-gal in wild-type stage 8 oocytes (G, arrow), Nod-ß-gal is ectopically localized at the posterior and lateral cortex of the ik21 (H) oocyte. By stage 10, Nod-ß-gal was not detected in the ik21 oocyte (J), whereas it was localized at the anterior of the wild-type oocyte (I). Nuclei are stained with DAPI (blue). Anterior to the left, dorsal up.

 

Figure 6
View larger version (102K):

[in a new window]
  		Fig. 6. Abnormal bristles in ik2 adult escapers, analyzed by scanning electron microscopy. (A-F) Bristles in the eye. The ommatidia of the wild-type compound eye are arranged in an orderly pattern (A), whereas the compound eyes of ik2 escaper adults (B) appear rough. At higher magnification, the interommatidial bristles can be seen at alternating vertices of wild type (C), but ik2 bristles are often duplicated at a single vertex (D). The wild-type interommatidial bristle is a long, tapered, actin-based structure (E), whereas the ik2 interommatidial bristles are misshapen and kinked (F). (G,H) Humeral bristles from wild type (G) and from an ik21 homozygous adult escaper (H).

 

Figure 7
View larger version (119K):

[in a new window]
  		Fig. 7. Ectopic F-actin colocalizes with ectopic Gurken protein in ik2 mutant oocytes. (A,B) Grk protein (red) is localized in the dorsoanterior region of the wild-type stage 10 oocyte (A), but is found at the anterior of the ik21 oocyte (B). (C-E) Grk (red; C) colocalizes with F-actin, visualized by phalloidin staining (green; D) in a wild-type stage 8/9 egg chamber; a merged image is shown in E. (F-H) In some ik21 germline clones, Grk (red) is present in aggregates (F) that colocalize with F-actin (green; G); a merged image is shown in H. Nuclei are stained with DAPI (blue). Anterior to the left, dorsal up.

 




© The Company of Biologists Ltd 2006