High level of divergence of male-reproductive-tract proteins, between Drosophila melanogaster and its sibling species, D. simulans

We compared male-reproductive-tract polypeptides of Drosophila melanogaster and D. simulans by using two-dimensional gel electrophoresis. Approximately 64% of male-reproductive-tract polypeptides were identical between two randomly chosen isofemale lines from these two species, compared with 83% identity for third-instar imaginal wing-disc polypeptides. Qualitatively similar differences were found between reproductive tracts and imaginal discs when D. sechellia was compared with D. melanogaster and with D. simulans. When genic polymorphism was taken into account, approximately 10% of male- reproductive-tract polypeptides were apparently fixed for different alleles between D. melanogaster and D. simulans; this proportion is the same as that found for soluble enzymes by one-dimensional gel electrophoresis. Strikingly, approximately 20% of male-reproductive- tract polypeptides of either D. melanogaster or D. simulans had no detectable homologue in the other species. We propose that proteins of the Drosophila male reproductive tract may have diverged more extensively between species than have other types of proteins and that much of this divergence may involve large changes in levels of polypeptide expression.      

Genetic polymorphism of complement component C8

Summary Extensive genetic polymorphism of complement component C8 was demonstrated by isoelectric focusing of serum or plasma samples followed by immunoblotting procedures. Using these methods, we could detect both - (C81) and (C82) chain polymorphisms in the same gel. Two-dimensional (2D) electrophoresis of C8 immunoprecipitates was used to obtain further information of the C8 patterns. Evidence was obtained that the C81 polymorphism resides in the structural gene of the C8 chain. Both C8 systems show autosomal, chiefly codominant inheritance, and the distribution of phenotypes agrees with the Hardy-Weinberg equilibrium. Our findings suggest at least five different alleles in the C81 system; the gene frequencies of the two most common ones, C81 ^*A and C81 ^*B being 0.59 and 0.39, respectively. In C82 we found evidence for at least three codominant alleles, the gene frequencies for the two most common ones, C82 ^*B and C82 ^*A being 0.94 and 0.05, respectively. In addition, family studies disclosed the existence of a null allele, C82 ^* Q0.     

Bioleaching of manganese (IV) oxide and application to its recovery from ores

Summary Bioleaching of manganese (IV) oxide with Thiobacillus thiooxidans has been studied in media with and without sulfur, ferrous sulfide and ferrous sulfate. The knowledge of the role played by the bacteria and the reducing substances suggest that the leaching of manganese (IV) ores through the use of thiobacteria is only justified when suitable amounts of sulfur or metal sulfides are present.     

Action of Thiobacillus thiooxidans on Sulphur in the Presence of a Surfactant Agent and its Application in the Indirect Dissolution of Phosphorus

The addition of a surfactant agent (Tween 80) to a medium containing sulphur and a culture of Thiobacillus thiooxidans increased the attachment of bacteria to sulphur, the rate of sulphur oxidation and sulphuric acid production. This acid was used to dissolve phosphorus from calcium phosphate. The yield was higher than reported for other microorganisms although dissolution was not increased significantly by Tween addition.     

Early detection of cell metabolism with a silicon microsensor

A silicon microsensor (ISFET — Ion Sensitive Field Effect Transistor) has been used to detect the metabolism of a cell population cultured on a coverslip and positioned close to the sensor surface. The system output is analyzed as a function of cell density.     

The Philadelphia variant of galactokinase.

We have previously reported the existence of a polymorphism that causes black populations to have lower mean RBC galactokinase activity than comparable white populations. We have designated this allele the Philadelphia variant, GALKP, and have suggested that it is common in blacks and rare in whites. GALKP individuals have normal WBC GALK activity, in contrast to the half normal WBC GALK activities of heterozygotes for the allele (GALKG) that causes the galactokinase-deficient form of galactosemia. In one family, we have presented evidence for the existence of two sisters heterozygous for both GALKG and GALKP alleles. These individuals have 50% normal WBC GALK activity and less than 50% normal red cell activity. The latter finding indicates that the two variant GALK alleles additively affect RBC activity. The WBC results suggest that the low activity of GALK in RBC of individuals with the GALKP allele is due to its relative instability. We could obtain no evidence for such instability from studies of high reticulocyte bloods or RBC fractionation. Furthermore, we could not demonstrate that the GALK in WBC from GALKP individuals has altered electrophoretic migration.     

Pre-induction priming of the uterine cervix with oral prostaglandin E2 and a placebo

A double blind study was undertaken to determine the effectiveness or oral prostaglandin E2 as a means of improving the pelvic score prior to induction of labour. 48 patients who were greater than 37 were gestation and who had Bishop scores of less than 6 entered the study. Ten tablets were given on an hourly regime. Of 25 patients in the prostaglandin group, 17 were considered successes (68.0%), whereas of 23 patients who received a placebo, 9 were successes (39.1%). No adverse effects were recorded. Prostaglandin E2 is therefore considered a safe and effective method for priming the unfavourable cervix prior to induction of labour.     

Monoclonal antibodies to rabbit liver cytochrome P-448

Cytochrome P-448 (mol wt 55,000 Daltons) from rabbit liver was purified to a specific content of 16.6 nmol/mg. Mice were immunised with this preparation, their spleens removed and dissociated lymphocytes hybridised with myeloma cells. Four monoclonal antibodies against cytochrome P-448 were raised and partially characterised. All four antibodies interacted with cytochrome P-448 in intact microsomal fractions and selectively immunoadsorbed cytochrome P-448 from solubilised microsomal preparations. One of the antibodies inhibited benzo[a] pyrene hydroxylase activity in a reconstituted system, one had no effect on activity and two increased activity. The possible applications of such antibodies are discussed.