Copulatory vocalizations of female macaques (Macaca fascicularis): Variability factors analysis

In 234 copulations, male and female behavioural patterns were collected, especially the vocal pattern for the female. Moreover quantitative structural analysis was performed on 38 of these female copulatory vocalizations. A multifactorial analysis, ANAFAC, was performed to seek relations between (1) utterance of female copulatory call and male and female copulatory behaviour and (2) these patterns and the great variability of female calls. Utterance of female copulatory vocalizations is essentially due to the female’s own copulatory behaviour in periods of intense sexual activity. Long female calls are related to male ejaculation, and those “rich” in harmonics are related to visual and tactile communicatory signals exchanged by the male and the female during a mount. This analysis strongly confirms the tied bond between quality of a call and internal state of the emitter. Long calls, rich in harmonics, may serve as signals maintaining or strengthening the possibly temporary preferential relation between male and sexually receptive female.     

Nuclear cytochrome-deficient mutants of Neurospora crassa: isolation, characterization, and genetic mapping.

Summary We have isolated twenty-six nuclear, singlegene cytochrome-deficient mutants of Neurospora crassa as an initial step toward the study of the structural components and regulatory mechanisms involved in the biogenesis of the mitochondrial cytochrome system. These mutants, together with two previously described mutants, cyt-1 and cyt-2, have been classified into six distinct groups on the basis of cytochrome phenotype: a) cytochrome aa ₃ deficiency (due to mutations affecting loci designated cya); b) cytochrome b deficiency (cyb-1 locus); c) cytochrome b deficiency with a partial deficiency of cytochrome aa ₃ (cyb-2 locus); d) deficiency of both cytochromes aa ₃ and b (cyt loci); e) deficiency of both cytochromes aa ₃ and c (cyt-2 locus); and f) partial deficiency of cytochromes aa ₃ and c (cyt-12 locus).Four of seven mutations affecting cya loci have been mapped and are located on linkage groups I, II, V, and VI. It is not yet known whether these genes code for structural components of cytochrome oxidase or have a regulatory function that affects synthesis or assembly of the enzyme. The cyb-1 and cyb-2 genes are located on linkage groups V and VI, respectively, and appear to code for regulatory elements that control the biogenesis of cytochromes b and aa ₃ . The positions of the cyt mutations that cause a simultaneous deficiency of cytochromes aa ₃ and b are dispersed throughout the genome, except for two gene clusters on the left arm of linkage group I. Some of these mutants may be deficient in mitochondrial protein synthesis. Two mutations, cyt-2 and cyt-12, are located on linkage groups VI and II, respectively, and appear to affect genes that code for components of a regulatory system that controls the biogenesis of cytochromes aa ₃ and c.     

Analysis of Escherichia coli TonB membrane topology by use of PhoA fusions.

Alkaline phosphatase (PhoA) fusions to TonB amino acids 32, 60, 125, 207, and 239 (the carboxy terminus) all showed high PhoA activity; a PhoA fusion to TonB amino acid 12 was inactive. The full-length TonB-PhoA fusion protein was associated with the cytoplasmic membrane and retained partial TonB function. These results support a model in which TonB is anchored in the cytoplasmic membrane by its hydrophobic amino terminus, with the remainder of the protein, including its hydrophobic carboxy terminus, extending into the periplasm.     

Marinobacter hydrocarbonoclasticus gen. nov., sp. nov., a new, extremely halotolerant, hydrocarbon-degrading marine bacterium.

On the basis of phenotypical characteristics and analysis of 16S rRNA sequence, a new species belonging to a new genus is described, and the name Marinobacter hydrocarbonoclasticus is proposed. This organism, isolated from Mediterranean seawater near a petroleum refinery, is a gram-negative, aerobic, rod-shaped bacterium. It grows at NaCl concentrations of 0.08 to 3.5 M and uses various hydrocarbons as the sole source of carbon and energy. Its DNA has a guanine-plus-cytosine content of 52.7 mol%. The 16S rRNA analysis shows a clear affiliation between M. hydrocarbonoclasticus and the gamma group of the phylum Proteobacteria. A close phylogenetic relationship appears among the species Marinomonas vaga, Oceanospirillum linum, Halomonas elongata, and Pseudomonas aeruginosa. Because of the impossibility of finding a single most closely related species, we suggest that this bacterium be assigned to a new genus, at least temporarily. The possibility of a revision of this status when new data appear is, however, not excluded. The type strain is M. hydrocarbonoclasticus SP.17 (= ATCC 49840).     

Radiolabeling of DNA can induce its fragmentation in HL-60 human promyelocytic leukemic cells.

Incorporation of radiolabeled thymidine is commonly used to investigate DNA damage. Using a filter-binding assay, we observed that the addition of various doses of [methyl-3H]thymidine (0.2 and 2 microCi/ml) or [2-14C]thymidine (0.02 and 0.2 microCi/ml) in the culture medium for 2 days, a standard method for cell-labeling, induces DNA fragmentation in HL-60 human promyelocytic cells. This effect was dose- and time-dependent and the DNA fragments were not protein-linked since the levels of DNA fragmentation were identical in the presence and in the absence of proteinase K (0.5 mg/ml). Radiolabeled thymidine-induced DNA fragmentation was associated with an inhibition of cell growth, but cells remained able to exclude trypan blue, suggesting that plasma membrane integrity was conserved, except at very high doses of [methyl-3H]thymidine (2 microCi/ml). By agarose-gel electrophoresis, the DNA-fragmentation was demonstrated to be internucleosomal with a typical ladder pattern. Addition of unlabeled thymidine to the culture medium prevented DNA fragmentation in a dose-dependent manner, indicating that radiolabeled thymidine incorporation in DNA was directly responsible for DNA fragmentation. We conclude that radiolabeling of DNA using thymidine incorporation can induce DNA fragmentation in some cell lines such as HL-60. This observation must be taken into account in methods using radiolabeling to study DNA damage in these cells.     

Cloning and expression of a cardiac/brain beta subunit of the L-type calcium channel.

The skeletal muscle dihydropyridine receptor/Ca2+ channel is composed of five protein components (alpha 1, alpha 2 delta, beta, and gamma). Only two such components, alpha 1 and alpha 2, have been identified in heart. The present study reports the cloning and expression of a novel beta gene that is expressed in heart, lung, and brain. Coexpression of this beta with a cardiac alpha 1 in Xenopus oocytes causes the following changes in Ca2+ channel activity: it increases peak currents, accelerates activation kinetics, and shifts the current-voltage relationship toward more hyperpolarized potentials. It also increases dihydropyridine binding to alpha 1 in COS cells. These results indicate that the cardiac L-type Ca2+ channel has a similar subunit structure as in skeletal muscle, and provides evidence for the modulatory role of the beta subunit.