Abstract
Sheep wool fibres (fine hairs) have a complex architecture with para- and ortho-cortical cells being responsible for the curliness of wool fibres (1, 2). However, there is no definite explanation regarding the mechanism by which they dictate the curliness of the fibre and what drives one cortical cell type over the other to cause curl. We are using SBF-SEM to be able to model where the cortical cells sit in relation to the curl. Alongside modelling of the whole fibre, we aim to segment individual cortical cells to explore how internal variation in sub-cellular morphology (macrofibrils composed of keratin fibrils) relates to cell type (ortho- or para-) and distribution across fibres with different curvatures.
Investigation of the three-dimensional structure of hair fibres and follicles started in the 1960’s using sheep wool as a model. Pre-digital approaches to this included manually tracing of cell outlines from projected serial sections onto rolls of paper to line up cells. New electron microscopy techniques, automation and big-data handling allow a more efficient workflow, enabling spatial reconstructions that revolutionise how we visualize cell changes within the three-dimensional context of hair structures and during hair growth within follicles. Serial block-face scanning electron microscope (SBF-SEM) is one of the new microscopic techniques employed to determine how sheep wool and the cells within a fibre can chance along the length of the fibre.