Regulation of salt gland activity in the estuarine crocodile: phenotypic plasticity and control mechanisms. The estuarine crocodile excretes excess sodium and chloride ions through salt glands located on the tongue, enabling the crocodile to live in seawater. This study will investigate the regulation of salt gland secretory capacity and activity, by examining both the phenotypic plasticity of the gland to changes in environmental salinity and diet, and by determining the neural/humoral mech ....Regulation of salt gland activity in the estuarine crocodile: phenotypic plasticity and control mechanisms. The estuarine crocodile excretes excess sodium and chloride ions through salt glands located on the tongue, enabling the crocodile to live in seawater. This study will investigate the regulation of salt gland secretory capacity and activity, by examining both the phenotypic plasticity of the gland to changes in environmental salinity and diet, and by determining the neural/humoral mechanisms controlling secretory rate. In vivo measurements of blood flow and salt gland secretory rate, together with perfused gland preparations will reveal extrinsic and intrinsic factors controlling salt gland activity and the degree of coupling between blood flow and secretory rate.Read moreRead less
FERTILIZATION IN VIVO AND IN VITRO IN AUSTRALIAN MARSUPIALS. Using reproductive technology previously undeveloped in Australian marsupials this study addresses the most significant question still unresolved in marsupial reproductive biology - 'How does fertilization occur?' We propose to investigate the morphological and functional characteristics of fertilisation and its roles in early development in marsupials, the uniqueness of these events and their evolutionary significance. These findings ....FERTILIZATION IN VIVO AND IN VITRO IN AUSTRALIAN MARSUPIALS. Using reproductive technology previously undeveloped in Australian marsupials this study addresses the most significant question still unresolved in marsupial reproductive biology - 'How does fertilization occur?' We propose to investigate the morphological and functional characteristics of fertilisation and its roles in early development in marsupials, the uniqueness of these events and their evolutionary significance. These findings will not only further our knowledge of reproduction in marsupials and shed light on the evolutionary factors underlying sperm and egg design but will provide tools for assisted breeding programs for threatened wildlife and for the regulation of over abundant species.Read moreRead less
What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increa ....What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increased daily treadmill exercise. Rates of bone growth and secondary remodelling are determined by histological analysis, and correlated with T3 and bone strain levels. The study tests the hypothesis that evolution of endothermy can be inferred from bone microstructure of fossil bones.Read moreRead less