An Electron Microscope Study of Fibril : Matrix Arrangements in High- and Low-Crimp Wool Fibres

Abstract

The crimped structure of [Merino sheep] wool fibers is generally associated with a bilateral arrangement of ortho- and paracortical cells. The most obvious difference between these cell types is in the arrangement and relative proportions of microfibril and matrix proteins that constitute the fiber cortex. In the low-crimp fibers examined there was a poorer expression of bilateral cortical asymmetry compared with the high-crimp wools together with a higher proportion of intermediate-staining mesocortical cells. These mesocortical cells exhibited much more regular arrays of microfibrils than paracortical cells. The packing arrangement of microfibrils in all 3 cell types was basically hexagonal, and the variation observed in mature cells was a function of the fibril:matrix ratio.