Cellular & Molecular Imaging

The Darwin Tree of Life project has the goal to sequence the genomes of 70,000 species of eukaryotic organisms in Britain and Ireland. This is a collection of photographs of the samples included in the study, provided by the National History Museum (NHM).

The Darwin Tree of Life project has the goal to sequence the genomes of 70,000 species of eukaryotic organisms in Britain and Ireland. This is a collection of photographs of the samples included in the study, provided by the National History Museum (NHM).

The Darwin Tree of Life project has the goal to sequence the genomes of 70,000 species of eukaryotic organisms in Britain and Ireland. This is a collection of photographs of the samples included in the study, provided by the National History Museum (NHM).

The chicken embryo has been a long-standing model for studying embryonic development. Its easy access for in vivo experiments, together with the development of ex ovo culture techniques, has made it a choice model system for elaborate experimental manipulations. Here we present a time-lapse imaging dataset of the developing chicken embryo in ex ovo culture covering a range of HH3 to HH14+ embryonic stages, with 3-6 min temporal resolution.

Background Microsporidia sp. MB, a microsporidian symbiont found naturally in Anopheles mosquitoes, has potential as a novel malaria control tool since it can inhibit Plasmodium development and transmission. The most feasible MB-based Plasmodium control strategy would involve dissemination through live mosquito releases, or release of spores infective to mosquito larvae. To implement either strategy, establishment of stable mosquito colonies carrying MB at a high frequency is likely to be essential. The progeny of field caught An. gambiae s.l from Burkina Faso were isolated for individual egg laying and tested for MB. The progeny of the MB positive females were pooled and this process was repeated for multiple generations. The relative density of MB in different life stages and tissues of the An. coluzzii host was examined using a novel duplex qPCR assay. We also examined the impact of MB on fecundity through individualization for egg laying and counting of eggs. Finally, we examined laid eggs for presence of MB spores. Results Three An. coluzzii colonies and one An. gambiae s.l hybrid colony were established with high prevalence and density of MB and were maintained for more than two years with minimal intervention. MB prevalence and density was highest in eggs and adult females and lowest in L4 larvae; in adults density was highest in the gonads. Additionally, MB density increased in ovary samples following blood feeding which was likely due to the activation of sporogony. The production of spores is the reason why MB-carrying females lay more white non-hatching eggs and show a small reduction in fecundity. Conclusions Establishment of several stable MB carrying An. gambiae s.l colonies and understanding the impact of spores on fecundity are significant steps forward in developing MB as a malaria control tool.

Polyphasic studies on cyanobacterial biodiversity are scarce in the Caribbean and have never been conducted in the Dominican Republic. In this study we analysed sixteen cyanobacterial isolates sampled from biofilms growing on rocks and related to freshwater, saline and thermal environments across the country. A polyphasic approach was employed, incorporating 16S rRNA gene phylogenetic analysis, molecular identity assessments (p-distance), 16S–23S ITS sequence comparison and secondary structure analysis, alongside morphological characterization and habitat comparison. The strains were distributed across the orders Nodosilineales, Oculatellales, Oscillatoriales and Nostocales. Eleven strains were identified as belonging to Almyronema, Euryhalinema, Salileptolyngbya, Nodosilinea, Reticulonema, Vacuolonema, Capilliphycus, Purpureonostoc, Violetonostoc, Desmonostoc and Hapalosiphon. Additionally, four strains formed three distinct clades and presented low 16S rRNA gene identities with their phylogenetically closest genera, suggesting the existence of three undescribed lineages pending comprehensive polyphasic study. At the species level, four strains were considered undescribed lineages pending comprehensive polyphasic study and one strain (LEGE 171504) was described as a new species of Salileptolyngbya. This study represents the first investigation into the cyanobacterial diversity of Dominican Republic expanding the distribution of the identified taxa. Moreover, this is the first report of Salileptolyngbya in the Caribbean region and in brackish waters, as well as the first newly described cyanobacterial species from the Dominican Republic.

Significance: CSF rhinorrhea (leakage of brain fluid from the nose) can be difficult to identify and currently requires invasive procedures such as intrathecal fluorescein which requires a lumbar drain placement. Fluorescein is also known to have rare but significant side effects including seizures and death. As the number of endonasal skull base cases increase, the number of CSF leaks have also increased for which an alternative diagnostic method would be highly advantageous to patients. Aim: To develop an instrument to identify CSF leaks based on water absorption in the SWIR without the need of intrathecal contrast agents. This device needed to be adapted to the anatomy of the human nasal cavity while maintaining low weight and ergonomic characteristics of current surgical instruments. Approach: Absorption spectra of CSF and artificial CSF were obtained to characterize the absorption peaks that could be targeted with SWIR light. Different illumination systems were tested and refined prior to adapting them into a portable endoscope for testing in 3D printed models and cadavers for feasibility. Results: We identified CSF to have an identical absorption profile as water. In our testing, a narrow band laser source at 1480nm proved superior to using a broad 1450 nm LED. Using a SWIR enabling endoscope set up, we tested the ability to detect artificial CSF in a cadaver model. Conclusions: An endoscopic system based on SWIR narrow band imaging can provide an alternative in the future to invasive methods of CSF leak detection.

microscopy images and Excel files of quantitations for main figures

We present a detailed analysis of gene expression in the 2-day (HH12) embryonic chick heart. RNA-seq of 13 micro-dissected regions reveals regionalised expression of 15,570 genes. Of these, 132 were studied by in situ hybridisation and a subset (38 genes) was mapped by Optical Projection Tomography or serial sectioning to build a detailed 3-dimensional atlas of expression. We display this with a novel interactive 3-D viewer and as stacks of sections, revealing the boundaries of expression domains and regions of overlap. Analysis of the expression domains also defines some sub-regions distinct from those normally recognised by anatomical criteria at this stage of development, such as a previously undescribed subdivision of the atria into two orthogonal sets of domains (dorsoventral and left-right). We also include a detailed comparison of expression in the chick with the mouse and other species.

1) Light-sheet movies of the surface of chick embryos treated with different chemicals at cellular resolution. Ideal to study individual cell behaviours and tissue flows in epithelial tissues. 2) Confocal images of SNAI2 and pMLC2 of chick embryos treated with different chemicals.