From owner-drosophila@net.bio.net Sun Apr 07 23:00:00 1996 Path: biosci!PSU.EDU!gxt5 From: gxt5@PSU.EDU (Graham Thomas) Newsgroups: bionet.drosophila Subject: role of dorsal appendages Date: 8 Apr 1996 08:23:17 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 43 Sender: daemon@net.bio.net Distribution: world Message-ID: NNTP-Posting-Host: net.bio.net Dear Fly People, I am curious about the function of the dorsal appendages on the chorion of Drosophila eggs. I have always been told that they are/might be 'for respiration' but the knowledge always seems anecdotal and never first hand knowledge. What is actually known about the role of these structures? This is not really my area of specific interest, but I am motivated to ask after leaving a grape plate in the fridge over the weekend and noticing that the flattened area at the end of the appendages seems to be a very efficient condensation nucleus for water vapour. The plates were moved from 25C to 4C with a petri dish lid in place; conditions that presumably favour condensation of moisture evaporating from the dish. (We are all familiar with the 'misting' of a petri dish lid when put a 4C). However, most of the eggs nucleated (and held) a neat drop of water at the end of both dorsal appendages. Is water condensation a known/speculated function for these objects? Just curious. Graham Thomas FliesFliesFliesFliesFliesFliesFliesFliesFliesFliesFliesFliesFliesFliesFlies We have a new graduate program in Cell and Developmental Biology. Please PASS ON THIS URL to any aspiring graduate students: http://www.bmb.psu.edu/thomas/cdb/cdbhome.htm Graham Thomas, Departments of Biology and Biochemisty/Molecular Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802 Email GXT5@PSU.EDU Telephone (814)-863-0716 Fax (814)-865-9131 WWW http://www.bmb.psu.edu/thomas Spectrin Spectrin Spectrin Spectrin Spectrin Spectrin Spectrin Spectrin .