A preliminary electrophoretic stury on Bangia vermicularis Harvey (Rhodophyta) populations of British Columbia

A preliminary electrophoretic study on Bangia vermicularis Harvey (Rhodophyta) along the coast of British Columbia was undertaken to determine whether enzyme banding patterns could be used to identify the relatedness of the populations which varied in chromosome number (3, 6 or 4) and life history (asexual or sexual). Material from nineteen sites was tested for seven enzymes: glutamate dehydrogenase (GDH); malate dehydrogenase (MDH); lactate dehydrogenase (LDH); superoxide dismutase (SOD), glucose 6-phosphate dehydrogenase (G6PDH); phosphoglucoisomerase (PGI); and phosphoglucomutase (PGM). Unlike higher plants, some of the banding patterns obtained in Bangia could only be explained if the enzymes SOD, GDH, LDH and PGI are monomers and the enzymes PGM, SOD, GDH, PGI, and G6PDH have only one cellular location. Generally, with the exception of two enzymes, PGI and G6PDH, which were highly polymorphic, only one to three bands were evident. Considerable amounts of variation in the mobility of the isoenzymes were detected between populations independent of chromosome number or sexuality. Contrary to expectations, often populations with three chromosomes or six ' chromosomes had the same number of loci and many of the three chromosome populations had some banding patterns indicative of diploids. Consequently, if there had been a polyploid origin of the six chromosome populations then there must also have been many gene duplications in the three chromosome populations. Alternatively, if the three chromosome populations arose by aneuploid reduction within a six chromosome population then there must also have been gene silencing and/or the formation of null alleles. Populations that were very close geographically differed to a large extent suggesting that there may be little gene flow between populations. The variability between populations could be explained by isolation over long periods of time during which changes could have occurred in the structure and regulation of the enzymes tested.Science, Faculty ofBotany, Department ofGraduat