Male reproductive tactics in the threespine stickleback– an evaluation by DNA fingerprinting

A random sample of 17 threespine stickleback nests was analysed using DNA fingerprinting. DNA from the guardian male and a random subsample of 10 fry per nest was probed with pYNZ132, a human single–locus VNTR probe which detects a multilocus fingerprint pattern in sticklebacks. Band–sharing indices (BSIs, the proportion of bands shared by two individuals) between the guardian male and its fry were calculated. In 147 of a total of 170 pair–wise comparisons the BSIs varied between 0.40 and 0.77. The guardian male was thought to be the true father of all these fry (p < 0.10). For the remaining 23 fry the BSIs varied between 0.09 and 0.34, suggesting that these fry were fathered by a different male (P<0.06). Once the paternal bands in each legitimate fry were determined, the remaining (i.e. maternal) bands among these fry were compared. Based on the BSIs obtained, the minimum number of females that spawned per nest was determined, and the maternal DNA fingerprints of the legitimate fry were traced back. In one nest five eggs of the sample had been fertilized by a sneaker, in two nests the guardian male had stolen eggs from a rival male, and in another nest one of the eggs was fertilized by a sneaker and three were stolen eggs.     

Studies on a new metabolite and its oxidation in the presence of ascorbic acid

1. A number of tissues, in particular, brain, liver, and kidney, incubated aerobically in vitro as slices or ground suspensions produce a compound which combines with p-aminobenzoic acid in acid solution to form a yellow color. 2. A study of this reaction in rat brain has shown that this compound can be produced when washed boiled brain protein is incubated aerobically with ascorbic acid. The latter acts as a catalyst to break the linkage between the protein and the compound. Oxygen is taken up in the process. 3. A number of aromatic hydroxy compounds such as epinephrine and catechol inhibit the reaction. Cyanide has little or no effect. No reaction occurs anaerobically. 4. The occurrence of the reaction in some animals has been described.