Abstract presented to the April 11-13 1997 Pennsylvania
Academy of Science meeting held in Malvern, PA.
Immunofluorescent localization of clathrin to Drosophila melanogaster
oocytes.
Debra M. Hollinshead* and David S. Richard. Department of Biology, Susquehanna
University, Selinsgrove PA 17870-1164.
During female reproductive development in Drosophila melanogaster
oocytes sequester yolk proteins (YP) from the hemolymph under the control
of the endocrine system. Receptor-mediated endocytosis involves several
non-specific proteins such as the clathrin heavy chain molecule. This 180kDa
protein forms interlocking triskelions on the cytoplasmic surface of membrane
endocytotic pits as these invaginate to internalize extracellular proteins.
Using commercial goat anti-clathrin (bovine) primary antibodies with FITC-conjugated
rabbit anti-goat second antibodies we show that immunopositive material
is localized to developing oocytes. Young oocytes (stages 1 to 7), which
are still growing and preparing to sequester YP from the hemolymph, display
more intense clathrin staining than older fully developed stage-14 oocytes.
Oocytes from diapausing females (in previtellogenic arrest when reared under
LD 12:12 photoperiod at 11oC) show intense clathrin
immuno-staining indicating a readiness to break diapause (following a temperature
upshift to 25oC) as demonstrated by the uptake of YP.