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


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

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 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 Google Scholar
Google Scholar
Right arrow Articles by Peterson, C.
Right arrow Articles by White, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Peterson, C.
Right arrow Articles by White, K.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

reaper is required for neuroblast apoptosis during Drosophila development

Christian Peterson1, Ginger E. Carney2, Barbara J. Taylor2 and Kristin White1,*

1 CBRC, Massachusetts General Hospital/Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
2 Department of Zoology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA



View larger version (51K):

[in a new window]
  		Fig. 1. Generating a rpr–specific mutation. (A) Previously characterized deletions in the 75C1,2 region include H99, which removes rpr, grim and hid, X14, which deletes hid, and X25, which deletes hid and grim (White et al., 1994Go). Lines represent deleted DNA. Open boxes represent uncertainties in the location of the breakpoints. A deletion that removed rpr was generated by irradiating males carrying a marked P element 225 kb proximal to rpr. The progeny were scored for the loss of the eye color marker. As scored by single embryo PCR, one candidate line, XR38, showed a loss of rpr genomic sequences. (B) An example of single embryo PCR on the progeny of XR38/TM6B parents. Each lane represents the DNA of a single embryo. Primers from an unrelated gene, doom, are used as an internal control (lower band). Lanes with two bands indicate the embryo has both rpr (upper band) and doom. Lanes with no bands indicate insufficient DNA. Lanes with only the lower band indicate a loss of rpr DNA. (C) grim genomic sequences are not affected by this deletion. All embryos from XR38/+ parents show both grim (upper) and doom (lower) PCR products. (D-G) In situ hybrizations show that grim (D,E) and hid (F,G) expression is not detectably altered in XR38/XR38 embryos (E,G). (D,F) wild-type embryos.

 


View larger version (34K):

[in a new window]
  		Fig. 2. Most apoptosis is not detectably altered by loss of rpr. (A,B) No overall defects were seen in embryonic apoptosis as detected by AO, or by TUNEL (data not shown). (A) Wild-type embryo, (B) XR38 homozygous embryo.

 


View larger version (97K):

[in a new window]
  		Fig. 3. The role of rpr in DNA-damage-induced death. (A,B) The absence of rpr does not suppress the ability of p53 to induce apoptosis when overexpressed in the eye. (A,C) GMR-gal4/UAS-p53 (B,D) GMR-gal4/UAS-p53; XR38/H99. (C,D) AO staining of third instar eye discs detects similar levels of ectopic apoptosis. (E-G) X-ray-induced apoptosis is suppressed in rpr nulls. Third instar larvae were irradiated with 4,000 rads and wing discs were dissected 4 hours later and stained with AO to visualize apoptotic cells. Expression of dominant-negative p53 has been shown to block X-ray-induced apoptosis under these conditions (Brodsky et al., 2000Go; Ollmann et al., 2000Go) (E) Wild-type unirradiated disc, (F) wild-type irradiated disc, (G) XR38/H99 irradiated disc.

 


View larger version (91K):

[in a new window]
  		Fig. 4. Central nervous system defects in rpr nulls. (A-D) Anti-CCAP staining reveals persistent neurons in XR38/H99 adults. A and B are ventral views; C and D are dorsal views. (A,C) Ventral ganglia of a 2- to 6-day old XR38/TM6B adult, stained with anti-CCAP. An average of 3 CCAP-positive cells are present in these ganglia. (B,D) Ventral ganglia from 2- to 6-day old rpr null XR38/H99 adult. Black lines delineate the boundaries of the abdominal ganglion that are greatly enlarged in XR38/H99. About 20 CCAP-positive cells are present in these enlarged abdominal ganglia. (E,F) EcR-A-expressing neurons also persist in XR38/H99 adults. Ventral view of the T3 thoracic neuromere and abdominal neuromere of a 1- to 2-day old XR38/TM6B (E) and XR38/H99 adult (F). Black lines delineate the boundaries of the abdominal ganglion. All photos are taken at the same magnification.

 


View larger version (71K):

[in a new window]
  		Fig. 5. rpr is required to eliminate neuroblasts. (A-D) Anti-Grainyhead staining labels persistent neuroblasts throughout the abdominal neuromeres of rpr mutant larvae. (A) Very few neuroblasts are found in the abdominal neuromeres in the VNC of wild-type larvae. The white arrow indicates the boundary between the thoracic and abdominal neuromeres. (B) Many neuroblasts are present in the abdominal neuromeres of rpr mutant larvae (XR38/H99). (C) No ectopically surviving neuroblasts are seen in hid mutant larvae, even when one copy of grim and rpr are also deleted (hid05014/H99). (D) Mutation of dark, an Apaf1 homolog, also results in a few ectopically surviving neuroblasts in the abdominal neuromeres. (E-H) BrdU labeling reveals ectopic cell division in the abdominal neuromeres of the ventral nerve cord of rpr mutant larvae. (E) CNS from a wild-type third instar larva fed continuously on BrdU-containing food. Very little division is seen in the abdominal neuromeres. H99/+ animals also appear wild type (data not shown). (F) In the rpr mutant (XR38/H99), the abdominal region is filled with dividing cells. (G) A few cells labeled with BrdU during larval life are present in the small condensed abdominal neuromeres of wild-type adults. (H) Many cells labeled with BrdU during larval life are found in the enlarged abdominal neuromeres of the XR38/H99 adult.

 


View larger version (84K):

[in a new window]
  		Fig. 6. The progeny of ectopic neuroblast divisions differentiate as neurons. Wild-type (A-C) and rpr null (XR38/H99) (D-F) larvae were fed continuously on BrdU-containing food, and dissected nervous systems were double labeled with anti-BrdU (A,D) and anti-Elav (B,E). The Elav protein is expressed in the nuclei of all neurons. C and F are the merged images of A,B and D,E. Most BrdU-labeled cells in both wild-type and rpr null nervous systems label with Elav.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2002