No abstract

One quantitative and nine qualitative genetic markers were investigated in some 200 individuals of the family Canidae, including 34 breeds and species. A high degree of homogeneity was observed and only one marker, transferrin, displayed marked variation. The consistent differences were: wolf (one sample), transferrin; jackal (one sample), transferrin and glucosephosphate isomerase; foxes, albumin, transferrin and glucosephsophate isomerase. Two abnormal transferrins were observed in two siblings among six German short-haired pointers. All other markers were homogeneous, usually single protein species or multiple forms dispersed randomly through the group. The results suggest that domestic dogs and dingoes share a common pool of genes and that all canids but the foxes possess many genes in common. There are indications that the jackal and wolf may differ from other canids in some marker systems.

SummaryThe levels of six glycolytic enzymes were studied in three different populations of M. robU8tU8. Significant interpopulation differences were found for five of the enzymes. Glucose-6-phosphate dehydrogenase levels are up to three times higher than those found in eutherians. Keto-I-phospha.te aldolase substrate specificity differs radically from that found in eutherians. The enzymes studied are independently regulated.

Richardson and Czuppon (1969) reported a cline in red blood cell glucose-6-phosphate dehydrogenase levels in a marsupial-the wallaroo Macropu8 robustu8 Gould, 1841. High dehydrogenase levels were found in animals from the dry inland areas of Australia, while animals from the wetter eastern coastal areas had lower levels. Richardson and Czuppon (1970) presented evidence to show that this phenomenon was inherited and not the result of direct environmental influences. The variation in dehydrogenase levels could be due to altered function of the enzyme, variations in the rate of production of the enzyme, or to a change in the half-life of the enzyme. This communication reports some biochemical properties of the enzyme. These properties were also determined for enzyme preparations from two related species-the grey kangaroo, Macropu8 giganteus Shaw, 1790, and the red kangaroo, Megaleia rufa (Desmarest, 1822).The methods used for purifying the enzyme and for determining Km values with glucose 6-phosphate and TPN as substrate were those recommended by Kirkman (1962). Utilization of the substrate analogue 2-deoxyglucose 6-phosphate relative to glucose 6-phosphate was determined for each animal. For the pH activity curves the standard assay procedure (Zinkham, Lenhard, and Childs 1958) was used with the pH of the Tris-HCI being altered to give the desired pH in the final solution.The results are summarized in Tables 1 and 2. The purified enzyme preparation contained less than 1% glucosephosphate isomerase and less than O· 01 % 6-phosphogluconate dehydrogenase.In the three species examined the Km values with glucose 6-phosphate and TPN are markedly higher than those reported for humans (Kirkman 1962). While the Km TPN values for the inland and coastal wallaroos are indistinguishable, a slight difference is apparent between the Km glucose 6-phosphate values. This variation, which would lead to a difference of about 1 unit of activity between inland and coastal animals under the normal assay conditions, is insufficient to explain the difference of 13 units found between the two forms.The pH activity curves for the dehydrogenases of the inland and coastal wallaroos and of the red kangaroo were similar. The grey kangaroo preparation was active over an even wider range of pH and the curve differed in shape from that of the other kangaroos, being biphasic.