Summary
The Drosophila oocyte develops within a cyst of 16 germline cells interconnected by ring canals. Polarized, microtubule-based transport of unknown determinants is required for oocyte formation, but whether polarity is established during or after cyst formation is not clear. We have analyzed how polarity develops in stem cells and dividing cysts by following the growth of the fusome, a vesiculated cytoplasmic organelle. Our studies show that the fusome grows by a regular, polarized process throughout the stem cell and cyst cell cycles. Each polarization cycle begins in mitosis, when the fusome segregates to a single daughter cell of each pair. Following mitosis, a ‘plug’ of fusomal material forms in each nascent ring canal and gradually fuses with the pre-existing fusome. In stem cells, the ring canal is transient and closes down after the fusome is partitioned through it. In dividing cysts, as the fusome plugs move toward the pre-existing fusome, their associated ring canals also move, changing the geometry of the cyst. At the end of each cycle of cyst growth, the fusome remains asymmetrically distributed within the cyst; one of the two cells with four ring canals retains a bigger piece of fusome than any other cell, including the other cell with four ring canals. Based on these observations, we argue that the oocyte is specified at the first cyst division.
Article navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
An interview with Swathi Arur
Swathi Arur joined the team at Development as an Academic Editor in 2020. Her lab uses multidisciplinary approaches to understand female germline development and fertility. We met with her over Zoom to hear more about her life, her career and her love for C. elegans.
Jim Wells and Hanna Mikkola join our team of Editors
We are pleased to welcome James (Jim) Wells and Hanna Mikkola to our team of Editors. Jim joins us a new Academic Editor, taking over from Gordan Keller, and Hanna joins our team of Associate Editors. Find out more about their research interests and areas of expertise.
New funding scheme supports sustainable events
As part of our Sustainable Conferencing Initiative, we are pleased to announce funding for organisers that seek to reduce the environmental footprint of their event. The next deadline to apply for a Scientific Meeting grant is 26 March 2021.
Read & Publish participation continues to grow
“I’d heard of Read & Publish deals and knew that many universities, including mine, had signed up to them but I had not previously understood the benefits that these deals bring to authors who work at those universities.”
Professor Sally Lowell (University of Edinburgh) shares her experience of publishing Open Access as part of our growing Read & Publish initiative. We now have over 150 institutions in 15 countries and four library consortia taking part – find out more and view our full list of participating institutions.
Upcoming special issues
Imaging Development, Stem Cells and Regeneration
Submission deadline: 30 March 2021
Publication: mid-2021
The Immune System in Development and Regeneration
Guest editors: Florent Ginhoux and Paul Martin
Submission deadline: 1 September 2021
Publication: Spring 2022
Both special issues welcome Review articles as well as Research articles, and will be widely promoted online and at key global conferences.
Development presents...
Our successful webinar series continues into 2021, with early-career researchers presenting their papers and a chance to virtually network with the developmental biology community afterwards. Here, Michèle Romanos talks about her new preprint, which mixes experimentation in quail embryos and computational modelling to understand how heterogeneity in a tissue influences cell rate.
Save your spot at our next session:
10 March
Time: 9:00 (GMT)
Chaired by: Thomas Lecuit
Join our mailing list to receive news and updates on the series.