Related Experiment Video
Updated: Aug 10, 2026
Dissection and Staining of Drosophila Larval Ovaries
Published on: May 13, 2011
Pole cells of Drosophila paulistorum: embryologic differentiation with symbionts
Abstract:
The pole cells of young D. paulistorum embryos are destined to form the germinal cells of both male and female imagoes. In addition, specialized portions of the midgut may be derived from pole cell progenitors. In this initial study of their embryogenesis by means of electron microscopy, various stages of pole cell development are shown in both non-hybrid (potentially fertile) and intersemispecific hybrid (potentially sterile as males) materials. Originally, approximately 5 or 6 cells emerge to form the early polar cap and subsequently divide asynchronously until the 35-50 cells of the late polar cap are derived. Unlike other Drosophila species, however, mycoplasma-like symbionts, apparently an hereditary infection, have been traced to locations within the cytoplasm of these pole cells. They are depicted as arriving there after transmission via the egg cytoplasm, implicating this as their probable route of entry into the future germinal tissues of adult flies. It is postulated that these microorganisms function as an infectious reproductive isolating mechanism fostering hybrid male sterility between D. paulistorum semispecies.
Insights
Drosophila paulistorum pole cells form germ cells and may contribute to the midgut. Mycoplasma-like symbionts within pole cells are linked to hybrid male sterility in this species.
Area of Science:
- Developmental Biology
- Microbiology
- Genetics
Background:
- Pole cells in Drosophila paulistorum embryos are precursors to germline cells and potentially midgut tissues.
- Hybrid male sterility is observed in intersemispecific crosses of D. paulistorum.
Purpose of the Study:
- To investigate the embryogenesis of D. paulistorum pole cells using electron microscopy.
- To identify the role of mycoplasma-like symbionts in pole cell development and hybrid sterility.
Main Methods:
- Electron microscopy was used to examine pole cell development in D. paulistorum embryos.
- Stages of pole cell division and the presence of symbionts were analyzed in both hybrid and non-hybrid embryos.
Main Results:
- Pole cells originate from an early polar cap and undergo asynchronous division.
- Mycoplasma-like symbionts were identified within the cytoplasm of D. paulistorum pole cells, transmitted via egg cytoplasm.
- These symbionts are hypothesized to cause reproductive isolation and hybrid male sterility.
Conclusions:
- The study elucidates the early development of D. paulistorum pole cells and their interaction with microbial symbionts.
- Mycoplasma-like symbionts are implicated as a potential infectious mechanism for reproductive isolation and hybrid male sterility in D. paulistorum.
