Essential elements of radical pair magnetosensitivity in Drosophila.

Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation1. The favoured mechanism for magnetosensitivity involves a blue-light-activated electron-transfer reaction between flavin adenine dinucleotide (FAD) and a chain of tryptophan residues within the photoreceptor protein CRYPTOCHROME (CRY). The spin-state of the resultant radical pair, and therefore the concentration of CRY in its active state, is influenced by the geomagnetic field2. However, the canonical CRY-centric radical-pair mechanism does not explain many physiological and behavioural observations2-8. Here, using electrophysiology and behavioural analyses, we assay magnetic-field responses at the single-neuron and organismal levels. We show that the 52 C-terminal amino acid residues of Drosophila melanogaster CRY, lacking the canonical FAD-binding domain and tryptophan chain, are sufficient to facilitate magnetoreception. We also show that increasing intracellular FAD potentiates both blue-light-induced and magnetic-field-dependent effects on the activity mediated by the C terminus. High levels of FAD alone are sufficient to cause blue-light neuronal sensitivity and, notably, the potentiation of this response in the co-presence of a magnetic field. These results reveal the essential components of a primary magnetoreceptor in flies, providing strong evidence that non-canonical (that is, non-CRY-dependent) radical pairs can elicit magnetic-field responses in cells.

Ongoing transposition in cell culture reveals the phylogeny of diverse Drosophila S2 sublines.

Cultured cells are widely used in molecular biology despite poor understanding of how cell line genomes change in vitro over time. Previous work has shown that Drosophila cultured cells have a higher transposable element content than whole flies, but whether this increase in transposable element content resulted from an initial burst of transposition during cell line establishment or ongoing transposition in cell culture remains unclear. Here, we sequenced the genomes of 25 sublines of Drosophila S2 cells and show that transposable element insertions provide abundant markers for the phylogenetic reconstruction of diverse sublines in a model animal cell culture system. DNA copy number evolution across S2 sublines revealed dramatically different patterns of genome organization that support the overall evolutionary history reconstructed using transposable element insertions. Analysis of transposable element insertion site occupancy and ancestral states support a model of ongoing transposition dominated by episodic activity of a small number of retrotransposon families. Our work demonstrates that substantial genome evolution occurs during long-term Drosophila cell culture, which may impact the reproducibility of experiments that do not control for subline identity.

The droso4schools project: Long-term scientist-teacher collaborations to promote science communication and education in schools.

Science communication is becoming an increasingly important part of a scientist's remit, and engaging with primary and secondary schools is one frequently chosen strategy. Here we argue that science communication in schools will be more effective if based on good understanding of the realities of school life, which can be achieved through structured participation and/or collaboration with teachers. For example, the Manchester Fly Facility advocates the use of the fruit fly Drosophila as an important research strategy for the discovery processes in the biomedical sciences. To communicate this concept also in schools, we developed the 'droso4schools' project as a refined form of scientist-teacher collaboration that embraces the expertise and interests of teachers. Within this project, we place university students as teaching assistants in university partner schools to collaborate with teachers and develop biology lessons with adjunct support materials. These lessons teach curriculum-relevant biology topics by making use of the profound conceptual understanding existing in Drosophila combined with parallel examples taken from human biology. By performing easy to implement experiments with flies, we bring living organisms into these lessons, thus endeavouring to further enhance the pupil's learning experience. In this way, we do not talk about flies but rather work with flies as powerful teaching tools to convey mainstream curriculum biology content, whilst also bringing across the relevance of Drosophila research. Through making these lessons freely available online, they have the potential to reach out to teachers and scientists worldwide. In this paper, we share our experiences and strategies to provide ideas for scientists engaging with schools, including the application of the droso4schools project as a paradigm for long-term school engagement which can be adapted also to other areas of science.

The Manchester Fly Facility: Implementing an objective-driven long-term science communication initiative.

Science communication is increasingly important for scientists, although research, teaching and administration activities tend to eat up our time already, and budgets for science communication are usually low. It appears impossible to combine all these tasks and, in addition, to develop engagement activities to a quality and impact that would make the efforts worth their while. Here we argue that these challenges are easier addressed when centering science communication initiatives on a long-term vision with a view to eventually forming outreach networks where the load can be shared whilst being driven to higher momentum. As one example, we explain the science communication initiative of the Manchester Fly Facility. It aims to promote public awareness of research using the model organism Drosophila, which is a timely, economic and most efficient experimental strategy to drive discovery processes in the biomedical sciences and must have a firm place in the portfolios of funding organisations. Although this initiative by the Manchester Fly Facility is sustained on a low budget, its long-term vision has allowed gradual development into a multifaceted initiative: (1) targeting university students via resources and strategies for the advanced training in fly genetics; (2) targeting the general public via science fairs, educational YouTube videos, school visits, teacher seminars and the droso4schools project; (3) disseminating and marketing strategies and resources to the public as well as fellow scientists via dedicated websites, blogs, journal articles, conference presentations and workshops - with a view to gradually forming networks of drosophilists that will have a greater potential to drive the science communication objective to momentum and impact. Here we explain the rationales and implementation strategies for our various science communication activities - which are similarly applicable to other model animals and other areas of academic science - and share our experiences and resources to provide ideas and readily available means to those who are actively engaging or intend to do so.

A novel electronic assessment strategy to support applied Drosophila genetics training in university courses.

The advent of "omic" technologies has revolutionized genetics and created a demand to focus classical genetics on its present-day applications (Redfield, 2012, PLoS Biol 10: e1001356). This demand can be met by training students in Drosophila mating scheme design, which is an important problem-solving skill routinely applied in many modern research laboratories. It promotes a thorough understanding and application of classical genetics rules and introduces to transgenic technologies and the use of model organisms. As we show here, such training can be implemented as a flexible and concise module (~1-day home study, ~8-hour course time) on university courses by using our previously published training package designed for fly researchers (Roote and Prokop, 2013, G3 (Bethesda) 3: 353-358). However, assessing this training to make it an accredited course element is difficult, especially in large courses. Here, we present a powerful assessment strategy based on a novel hybrid concept in which students solve crossing tasks initially on paper and then answer automatically marked questions on the computer (1.5 hours total). This procedure can be used to examine student performance on more complex tasks than conventional e-assessments and is more versatile, time-saving, and fairer than standard paper-based assignments. Our evaluation shows that the hybrid assessment is effective and reliably detects varying degrees of understanding among students. It also may be applicable in other disciplines requiring complex problem solving, such as mathematics, chemistry, physics, or informatics. Here, we describe our strategies in detail and provide all resources needed for their implementation.

Expression of CXC chemokine IP-10/Mob-1 by primary hepatocytes following heat shock.

OBJECTIVE: To examine the expression of chemokine IP-10/Mob-1 of hepatocytes in responses to the stress imposed during isolation by collagenase perfusion. METHODS: This study was performed in the Faculty of Life Sciences University of Manchester during 2001-2005. We employed western and northern blotting analysis to detect IP-10/Mob-1 in isolated and cultured hepatocytes in response to isolation stresses and under heat shock stimulation in this project. RESULTS: We showed that the ELR-CXC chemokine, IP-10/Mob-1 is secreted from isolated rat hepatocytes immediately after isolation and early during culture and IP-10/Mob-1, expression by hepatocytes was also stimulated in response to heat shock. CONCLUSION: It seems that hepatocytes mimic the experiences of liver injury in vivo such as during stress, trauma, or after insults, and therefore, produce stress related agents like IP-10/Mob-1 chemokine to overcome such a injurious condition following isolation and heat shock stimulation. This study also provides a useful model to study the regulation of expression of this chemokines in vitro.

Structure of the extracellular domain of Tie receptor tyrosine kinases and localization of the angiopoietin-binding epitope.

Angiogenesis is essential for tissue repair and regeneration during wound healing but also plays important roles in many pathological processes including tumor growth and metastasis. The receptor protein tyrosine kinase Tie2 and its ligands, the angiopoietins, have important functions in the regulation of angiogenesis. Here, we report a detailed structural and functional characterization of the extracellular region of Tie2. Sequence analysis of the extracellular domain revealed an additional immunoglobulin-like domain resulting in a tandem repeat of immunoglobulin-like domains at the N terminus of the protein. The same domain organization was also found for the Tie1 receptor that shares a high degree of homology with Tie2. Based on structural similarities to other receptor tyrosine kinases and cell adhesion molecules, we demonstrate that the N-terminal two immunoglobulin-like domains of Tie2 harbor the angiopoietin-binding site. Using transmission electron microscopy we furthermore show that the extracellular domain of Tie receptors consists of a globular head domain and a short rod-like stalk that probably forms a spacer between the cell surface and the angiopoietin-binding site. Mutational analysis demonstrated that the head domain consists of the three immunoglobulin-like domains and the three epidermal growth factor-like modules and that the stalk is formed by the three fibronectin type III repeats. These findings might be of particular interest for drug development because Tie receptors are potential targets for treatment of angiogenesis-associated diseases.