NONGENERIC VARIATION, GENETIC-ENVIRONMENTAL INTERACTIONS AND ALTERED GENE-EXPRESSION .1. TEMPERATURE, PHOTOPERIOD, DIET, PH AND SEX-RELATEDEFFECTS

The use of protein electrophoretic data for determining the relationsh ips among species or populations is widespread and generally accepted. However, many confounding factors may alter the results of an electro phoretic study in such a way as to allow erroneous conclusions to be d rawn in taxonomic, systematic or population studies. Such variables as temperature, photoperiod, salinity, pH and diet have been shown to in fluence enzymes and proteins both quantitatively and qualitatively. Pr oduction of distinct ''cold'' and ''warm'' isozymes or ''seasonal'' is ozymes have been found In a variety of organisms. The factors that are or may be responsible for the appearance of these isozymes is discuss ed. Most studies that have demonstrated some apparent form of environm entally induced genetic expression have not determined the mechanisms responsible. However, proteolytic modification has been shown to produ ce seasonal isozymes of fructose 1,6-bisphosphatase in rabbit liver an d may account for other seasonal isozymes. Acclimating organisms to va rious conditions may actually allow detection oi cryptic genetic varia tion and provide valuable data. There are many aspects to consider in designing acclimation experiments, and the conditions used will vary a ccording to the aim of the research. Polyploidy may contribute to the genesis 31 environmentally regulated isozymes. A review of this litera ture follows with additional hypotheses and conclusions. Recommendatio ns are given for the resolution of real and potential problems. (C) 19 97 Elsevier Science Inc.