Molecular and behavioural characterisation of ovine dermal papilla cells performed in this study indicate they synthesise a highly specialised extracellular matrix (ECM). This is conserved between different species and distinguishes papilla cells from dermal fibroblasts with which they have a common origin. The composition of the dermal papilla ECM is temporally and spatially regulated during wool follicle development. It was shown that the ECM associated with dermal papilla cells in foetal sheep skin becomes specialised in regard to chondroitin sulphate synthesis prior to the appearance of follicle primordia. Chrondroitin sulphate and fibronectin were present in the ECM of dermal papilla cells throughout follicle development and during fibre production. Cellular differentiation antigen 44 was present in the ECM od papilla cells exclusively during the formation of dermal papilla, while laminin was present in the dermal papilla ECM of fibre producing follicles only. Co-operation between chondroitin sulphate, fibronectin, and CD44 in regulating the agrregative and proliferative behaviour of papilla cells was demonstrated in culture. Finally, the inhibition of proteoglycan synthesis in newborn mouse skin was found to disrupt the growth of existing follicles and the generation of new ones. Together these findings demonstrate that chondroitin sulphate is intimately associated with the earliest interactions between epithelial and mesenchymal cells during the formation of follicle primordia. It is likely that the interactions specifically involve fibronectin and CD44, and possibly other ECM molecules which have he effect of regulating the behaviour of papilla cells / Doctor of Philosophy (PhD)

Value of leather produced from sheep is determined by its quality and looseness is one of the quality attributes that determines the value of the leather. As of now, looseness in sheep skin can be determined only after the tanning process is done and it is a long and expensive process to treat the looseness in skins after the tanning process. An interdigital sensor based sensing system has been developed which works on the principle of sensing technique based on interaction of electric field with the materials under test. Finite element software has been used for analysis and design of sensors. It has been reported that a good correlation was found between the actual looseness values and calculated looseness values.