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Biology subjects

Dowland, S.

Publications and source records attributed to Dowland, S..

3 recordsLinked to original sources

Synchrotron phase contrast micro-CT of prostate tissue

Formalin-fixed prostate tissue samples were imaged by propagation-based synchrotron phase contrast micro computed tomography ({micro}CT) with a 3D spatial resolution of ca. 3 {micro}m. Post-{micro}CT, samples were prepared for histology with sections close to coplanar with the transverse {micro}CT image planes. Haematoxylin and eosin stained sections were examined by an expert prostate histopathologist and compared qualitatively with corresponding {micro}CT-visible microstructure features. There is potential for {micro}CT to provide complimentary information to conventional histology and light microscopy without the need for preparation of stained thin sections. For the imaging conditions and spatial resolution of our study, {micro}CT may provide tissue architectural features similar to those used in Gleason grading, albeit without clear subcellular microstructure detail. At the spatial resolution of our study {micro}CT may provide novel 3D microstructure information for validation of diffusion weighted magnetic resonance imaging (MRI) methods. As an example, we demonstrate a qualitative correlation between {micro}CT-derived stromal fibre orientation and preferential water diffusion direction measured by diffusion tensor MRI microscopy of the same sample.

cancer biology↗

Developmental stage-dependent decoupling of molecular and phenotypic responses to heat in wheat grain

Heatwaves during flowering and grain development threaten global wheat production, yet the extent to which developmental stage shapes molecular and phenotypic responses remains unclear. Here, we investigated whether heat stress (36/29{degrees}C for 48 h) imposed at closely spaced developmental stages surrounding anthesis generates stage-specific molecular responses that are associated with subsequent effects on grain properties. Heat exposure increased floret abortion most strongly when it was imposed at the trinucleate stage (TN; [~]48%) compared with the binucleate (BN) and early post-anthesis stages. Methylation levels were largely unaffected by prior heat treatments; however, heat induced stage- and locus-specific methylation changes, particularly at BN. Spatial RNA-seq revealed tissue-specific heat responses that were distinctively different in BN and TN. Integrated metabolomic analyses revealed stage-dependent metabolic reprogramming, including shifts towards stress-associated pathways. Despite heat stress at BN generating broader molecular reprogramming in developing grain, exposure at TN produced stronger effects on grain set and composition, revealing a decoupling between the magnitude of responses and phenotypic outcomes. Together, these findings demonstrate that subtle differences in developmental stage influence the complex molecular responses to heat and subsequent grain properties.

plant biology↗

Extracellular vesicles, syntaxin 2 and SNAP23 collectively play a role in the receptive uterine microenvironment

Uterine luminal fluid (ULF) composition plays a major role in cell-to-cell communication between the receptive endometrium and an invading blastocyst. ULF is made up of secretions from the uterine glands and uterine epithelial cells (UEC). However, the cellular mechanisms regulating these exocytotic secretions are not yet understood. This study investigated the role of extracellular vesicles (EVs) during early pregnancy using Transmission Electron Microscopy (TEM). TEM analysis at time of fertilisation (TOF) Day 1 and at time of receptivity (TOR) Day 5.5 revealed EVs present, with an abundance at TOR. Exocytosis signalling in UECs, by SNARE proteins syntaxin 2 (syn2) and SNAP23, was also examined. Immunofluorescence microscopy showed both syn2 and SNAP23 to be present in the apical area of UECs at TOR. Western blot and immunofluorescence quantification revealed a significant increase in syn2 and SNAP23 at TOR compared to TOF. SNAP23 colocalization with apical actin showed SNAP23 was in the luminal space contributing to ULF. Overall, this data shows EVs, syn2 and SNAP23 (potential receptivity marker) are present in ULF and may together create a favourable microenvironment for blastocyst implantation. Summary statementDuring uterine receptivity SNAREs participate in the secretion of ULF. EVs and SNAP23 are present in the uterine luminal space during uterine receptivity. SNAP23 has the potential to be used as a receptivity marker.

cell biology↗