New components of the Drosophila fusome suggest it plays novel roles in signaling and transport.
The fusome plays an essential role in prefollicular germ cell development within insects such as Drosophila melanogaster. Alpha-spectrin and the adducin-like protein Hu-li tai shao (Hts) are required to maintain fusome integrity, synchronize asymmetric cystocyte mitoses, form interconnected 16-cell germline cysts, and specify the initial cell as the oocyte. By screening a library of protein trap lines, we identified 14 new fusome-enriched proteins, including many associated with its characteristic vesicles. Our studies reveal that fusomes change during development and contain recycling endosomal and lysosomal compartments in females but not males. A significant number of fusome components are dispensable, because genetic disruption of tropomodulin, ferritin-1 heavy chain, or scribble, does not alter fusome structure or female fertility. In contrast, rab11 is required to maintain the germline stem cells, and to maintain the vesicle content of the spectrosome, suggesting that the fusome mediates intercellular signals that depend on the recycling endosome.
Lighthouse
Daniel V
DV
Howard Hughes Medical Institute Research Laboratories, Department of Embryology, Carnegie Institution, Baltimore, MD 21218, USA.
Buszczak
Michael
M
Spradling
Allan C
AC
D000818:Animals; D001052:Apoferritins / Q000378:metabolism; D001692:Biological Transport; D004330:Drosophila / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D005260:Female; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D015388:Organelles / Q000737:chemistry* / Q000378:metabolism*; D012727:Sex Characteristics; D015398:Signal Transduction; D013234:Stem Cells / Q000378:metabolism; D051348:Tropomodulin / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
D001052:Apoferritins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D051348:Tropomodulin; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C404683:Scrib protein, Drosophila