Tuesday, 10 June 2014

The end of the beginning: Y10s and model organisms

This week marks the end of the first stage of our efforts to introduce the meal worm, Tenebrio molitor to  the UTC as our very own model organism. The objective, after being stimulated by a grant from the Royal Society, was to establish protocols that would enable us to develop a school friendly "omics" platform for the Innovation Lab programme. I am delighted to say that the students at Y10 and Y12 have exceeded all of my expectations.

The meal worm farm was established by the Y12 Greenland Biodesign team, and special mention should go to Jack Webster who has devoted a considerable amount of time to ensuring continuity of larvae (and recently adult beetle) supply through his housing and feeding project: we are in his debt! Thanks also to Matthew, Sarah, Rachel, Rigsby and Josie in the team and George for your guiding hand! The supply chain of live larvae and beetles, the methods for dealing with developmental stage segregation and eradication of mite infestation has been a key component of this project and this has all been achieved by the students.

Extraction methods have been the focus of the first lab phase of the project (which incidentally needs a name since project mealworm doesn't have much of a ring to it. Any suggestions?). The Y10 class have investigated the extraction of macromolecules from fresh larvae and lyophilised (freeze dried) larvae. We have explored the use of mortar and pestle, glass homgenisers and the conditions of buffering and temperature. In conclusion, we have found simple and rapid conditions for the extraction of proteins, lipids, insoluble outer skeleton and both DNA and RNA, in quantities suitable for all downstream analysis. I will concentrate on the proteomics aspect here.

Rapid homogenisation of two mealworm larvae in phosphate buffered saline, with care to keep everything cold (on ice) is sufficient to yield protein-rich extracts in volumes of 2-3ml. In turn these samples are suitable for downstream ion exchange chromatography. In our first experiments, samples were separated on 0.2ml Q Sepharose columns (thanks to Eden Biodesign (now Actavis (for the resin!) revealing an enrichment of a basic fraction comprising a high molecular weight protein in abundance and similarly a highly acidic protein, which eluted in 2M NaCl and had a molecular weight of around 15 000 (RHS). We chose to focus on the basic fraction (low salt wash) and acidic fraction as an exercise in identifying the major components by downstream mass spectrometry. The class pooled their extracts and we obtained the above fractions on a 10ml column during a student open evening! The samples are now with Dr. Mark Dickman in the Department of Chemical and Biological Engineering at the University of Sheffield, thanks to Michael and Alison two of my PhD students. 

What were the important lessons from this first phase? The potential of large scale research carried out by inexperienced, but competent and enthusiastic school students represents an untapped opportunity in education. With a suitable programme of skills and confidence building, school students can add significant value to their formal programme of education that is much sought after by Universities and Industry.  By bringing scientific discovery using contemporary methods into schools at an early stage, I am confident that we shall both empower students and raise the quality of future employees and graduates in Science.  On a final note, the sample recovery for gel electrophoresis (LHS) involved ammonium sulphate precipitation, centrifugation of the pellet, redissolving and dialysis. The samples of protein were visible for the basic fractions, but not for the acid fractions (from our lab preps). However, despite an apparent absence of acid material, the samples turned the blue gel loading buffer yellow, which was an added bonus for the students. (Make sure you explain this, Y10s in your write-ups!)

Last minute addition: I am away from the lab today, but Marcus Kennedy and Millie Keegan from the "Crick Bench" managed to get through the whole process from larvae to dialysis and then to gel, before all other students. A remarkable achievement!

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