On completion of the module the student should be able to explain the significance of:
● Cellular aspects of reproduction and gamete formation
● The formative process of embryo development
To achieve on understanding of the essential aspects of animal development from gamete formation to maturity, reproduction, ageing and cancer in the context of cellular physiology.
The module provides the basic framework for understanding animal development, reproduction and ageing in the context of modern cell biology and evolution.
The introduction to cell structure and function given in Module BS12020 will be built upon to present a greater understanding of the relationship between cellular behaviour and reproduction, development, ageing and cancer.
The following topics will be studied:
● A broad discussion of the eukaryotic cell-cycle and its control mechanisms, including triggers for apoptosis or differentiation will serve as an introduction to the module. The nature of stem cells and control of their division will also be discussed.
● Gametogenesis, leading to fertilization mechanisms.
● The significance of cell adhesion and motility, in response to growth factors and the extracellular matrix will be discussed in relation to cellular movements within the embryo. Experimental examples will be discussed where in vitro experiments of cultured cells have revealed much about how cells respond to their immediate environment. The neural crest movements, characteristic of the vertebrate developmental pattern, will be described and discussed in terms of cellular behaviour.
● 'Classical' embryological development will be examined, including patterns of cleavage and gastrulation as well as the ooplasmic segregation in mosaic eggs of annelids and echinoderms. Vertebrate gastrulation and neurulation will be described using examples of amphibian and avian embryos.
● Developmental mechanisms such as induction (tissue communication) will be discussed. Interaction between ectoderm and mesoderm in chick limb development will be taken as an example, as will the development of the eye. Theories of how the pattern of development is controlled will be introduced, with particular analysis of the role of homeobox genes in chick limb development.
● Genetic aspects of the developmental process will be examined. The hierarchy of homeobox gene action in the development of Drosphila will be compared with their expression patterns in the development of the head and main body axis of vertebrates.
● The process of ageing will be examined, and related to aspects of cellular behaviour in the body. How the body deals with the agents that accelerate the ageing process as well as agents and conditions that cause oncogenesis will be discussed with reference to its evolutionary significance.
● Practical classes will deal with observation of cell adhesion in sponges, cell division and cleavage in a serpulid or nematode egg, methods of staining a developing chick embryo, amphibian development patterns and a comparison of normal and cancer cells. These will include the viewing of suitable video material, where appropriate.