Distribution of testosterone-estradiol binding globulin (TeBG) in the higher vertebrates

The presence of testosterone-estradiol binding globulin (TeBG) in a variety of higher vertebrate species has been investigated by an ammonium sulphate precipitation technique. TeBG has been demonstrated in significant amounts in primates, carnivora, marsupiala, and some artiodactyla, even in circumstances where previously electrophoretic studies failed to identify it. For the first time it has also been shown in trace amounts in certain rodents and birds. TeBG in the kangaroo substantiates the primitiveness of the protein in the mammal line and its absence in certain orders and species of eutherian mammals must represent a secondary loss.