Schärer Group
Evolutionary Biology
Zoological Institute
University of Basel
Vesalgasse 1
CH-4051 Basel
Switzerland

Elena Menéndez

email: elena.menendez-at-stud.unibas.ch

I am a Master student in the Schärer group. I am especially interested in research on the topic of sexual selection.

Current research

The free-living flatworms of the genus Macrostomum are a powerful model system for studying sexual selection in simultaneous hermaphrodites. Given their small size and transparent bod, the reproductive organs are well visible in living worms, which allows stem cell and regeneration experiments. Although the reason why these organisms regenerate is not clea,r they are highly efficient in doing so.
My Master thesis is focused on the regeneration capacity of the tail plate of several species of Macrostomum (i.e. M. lignano, M. hystrix, M. pusillum, M. sp. 84 and M. sp. 94), using the male copulatory organ (stylet) regeneration as a proxy. To do so, I cut the tail plate around the end of the gut of the organisms (Figure 1), then I measure the stylet by taking photos of the tail plate. On the days afterward amputation, I follow the regeneration process (Figure 2) by making squeeze preparations of the individuals and taking photos on the microscope of each one, until the stylet is completed. The duration required for regeneration varies depending on the species. Finally, I measure the stylet on the photos and I compared the measurements of the newly formed stylet and the original one.

Figure 1. Summarized representation of M. lignano. The dashed line is the cut level. (ph: pharynx, ts: testis, ov: ovaries, fo: female opening, st: stylet).

Figure 2. Photos following the stylet regeneration in M. lignano. a-d: day 3 to day 6 of the regeneration after the amputation.

Publications

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