The complete amino acid sequence of human serum paraoxonase/arylesterase and the DNA sequence coding for that protein have recently been determined in two independent laboratories. There is now considerable evidence that the esterase exists in two genetically determined allozymic forms, and these A and B allozymes possess both paraoxonase and arylesterase activities. The B-type esterase has rel...

Two polymorphic systems impinging on alpha-amylase in Drosophila pseudoobscura have been studied in laboratory populations maintained on medium in which the only carbohydrate source was starch (the substrate of amylase) and replicas maintained on medium in which the only carbohydrate source was maltose (the product of amylase). The two polymorphic systems were alleles at the structural gene (Am...

We examined the adaptive importance of allozyme variation in wild barley (Hordeum spontaneum). The test involved a nested sampling design with four population groups, each representing a different environment, and a comparison of observed allozyme variation with that expected under the assumption that allozymes are not neutral. Measurements of plant fitness in indigenous and alien environments ...

The superfamily of sulfotransferase (SULT) enzymes catalyzes the sulfate conjugation of several pharmacologically important endo- and xenobiotics. SULT1A1 catalyzes the sulfation of small planar phenols such as neurotransmitters, steroid hormones, acetaminophen, and p-nitrophenol (PNP). Genetic polymorphisms in the human SULT1A1 gene define three alleles, SULT1A1*1, *2, and *3. The enzyme activ...

Unequal differentiation between two types of loci (allozyme and DNA markers) across a Mytilus hybrid zone has recently been claimed as evidence for direct selection on some allozyme loci. We provide here a counter-example: a noncoding DNA locus that exhibits as much differentiation as the incriminated allozymes do. The levels of genetic differentiation varied widely among both allozymes and non...