Amazing news, my international exchange project to work with Sylvain Pincebourde (CNRS, France) was funded in May 2023! Sylvain and I have started working on linking microclimate (his expertise) and butterfly fertility (me). As a start, Sylvain visited Lincoln in June 2023 and we trialled two different thermal imaging cameras to measure temperature on wild and domesticated cabbages as well as eggs, caterpillars and pupae of the large white butterfly, Pieris brassicae. The wild black mustard, Brassica nigra, plants came from seeds that Nina Fatouros, Wageningen University, shared with me, while we grew kale (Brassica oleracea spp.) from organic seeds. The two thermal imaging cameras (FLIR E54 and FLIR T540) worked well, with the FLIR T540 comfortably outperforming the FLIR E54. No surprise there, as the price tag of the FLIR T540 is almost double that of the FLIR E54! The good news is that we can pick out the temperature differences across the leaves. This work was also done thanks to Teun's efforts - Teun is my summer Erasmus research intern for 2023. I look forward to developing this collaboration over the course of the next few years.
0 Comments
It all started with an email in late August 2022. I wrote to Nina Fatouros at Wageningen University and Research (WUR), to ask her for some images (SEMs) of Pieris brassicae eggs. Over a few brief email exchanges, we discovered that we both shared an interest on insect eggs, and that we could learn from each other's different angles (mine on the evolution of reproductive traits, Nina's on plant-insect interactions). Nina invited me to apply for a Visiting Scientist Fellowship at WUR and then fast forward to 30th January 2023, I found myself on a train crossing the Channel heading for Wageningen, the Netharlands. I spent four intense (and fun) weeks at the Biosystematics Group, WUR. Nina, her PhD student Liana Greenberg, and I, drafted some hypotheses on latitudinal and climatic gradients effects on eggs of populations of Pieris spp. Nina and Liana have collected Pieris napi from across Europe, from Wageningen to Spain. Nina also has two stable populations of Pieris rapae and brassicae, which she has kept in the lab for a number of generations. I then spent several days in the company of Marcel Giesbers, a very knowledgeable SEM technician, to image Pieris eggs using Cryo SEM, which was a lot of fun (oh, and talking of Dutch cheeses with Marcel...). I have learnt a lot about plant-insect interactions (and dusted off my two botany exams taken decades ago), started a collaboration with an amazing colleague, and visited the Netherlands for the first time! I was made to feel at home by every member of the Biosystematics group, and I am indebted to Nina, Klaas, Eric, Liana, Wilma, Marcel, Patrick, Jordy, and everyone else at WUR + WEES for inviting me to give a talk. I really hope to be able to come back soon. A few months back, I was working on a manuscript (soon to be published) about work I have been doing during my Back to Science Fellowship. We ran different experimental treatments for our Indian meal moth cultures, heating them during their development and up to the point when, as adults, they were ready to mate. We found that sperm got shorter the higher the temperature we subjected the insect cultures to. This is interesting in itself because it is important to know how species will be affected by rising temperatures as the climate is changing. However, as I was reading the literature, I was surprised to learn that this pattern wasn't unique. I mean, I have been working on reproduction since my PhD, so I have done a fair bit of reading on the topic in general and yet, I had not noticed this pattern before. Let me explain. It is well known that male mammals are unable to produce sperm at body temperature, hence the reason why mammalian testes are usually located outside the body cavity - there are some exceptions to this pattern, for example in marine mammals, but these species have developed adaptations to cool the testes. However, what I was reading in the literature, was that when subjected to heat stress, male mammals and some male insects too, become infertile - and this is the interesting part - before the females do. So, you can mate females who have also been heat stressed to non-stressed males - and they can produce offspring but the reverse doesn't work, heat-stressed males are infertile. Somehow, spermatogenesis (the production of sperm) - and more generally gametogenesis (the production of gametes) too, as plants show the same trend - appears more sensitive to heat stress than oogenesis (the production of eggs). Then, in January, an opinion article came out that summarised exactly what I had been thinking. As I read it excitedly, I noticed that the authors had not picked up on the male/female differences on heat-stress sensitivity, so I wrote a comment. It is not only intriguing that males and females show different sensitivity to temperature stress, it may also tell us something about how species will be affected by climate change and how we might buffer or tackle these sensitivities. I am very keen to explore this further. So if you are a student, and this sounds interesting, please contact me. In search of micropylesWhen I arrived at the University of Lincoln in 2015, I started a project on a topic I had not worked on before: micropyles. These intriguing structures found on insect eggs (but analogous structures are also found in ovules of seeds in plants and on the eggs of fishes, among other organisms), are the point of sperm entry. Literally micropyle (from the Greek mikro- pule) means small gate: what a wonderful word!
My model species was the Indian meal moth, Plodia interpunctella, which proved rather difficult because of the size of its eggs, about half a millimetre long, or about the size of a dot on this page! It followed a year and a half of trying to image Plodia's micropyles with a variety of imaging techniques, to no avail. Recently, however, I have started collaborating with Professor Johanna Mappes on her model species, the wood tiger moth, Arctia plantaginis, an aposematic moth with larger eggs. Thanks to new Alicona 3D imaging microscope, just installed at our department, Sarah Aldridge (also a new collaborator) has captured this amazing image of a micropylar plate on A. plantaginis. Enjoy. |
AuthorGraziella Iossa Archives
August 2023
Categories
All
|