Social status and reproductive success of male Macaca fascicularis

Dominant males of nonseasonally breeding species should have more opportunity than seasonal breeders to monopolize access to estrous females and thus enhance their reproductive success. They may also use other strategies for maximizing reproductive success such as producing offspring by relatively high ranking females. To test these hypotheses, the paternity of 35 (80%) of 44 Macaca fascicularis offspring, born over a 28-month period, was established using electrophoretically and serologically defined genetic markers. The social ranks of each of the seven potential fathers and 26 potential mothers were determined by recording outcomes of dyadio agonistic interactions. No evidence could be found to support either hypothesis. Further, in view of previously reported significant, positive correlations between male social rank and sexual activity rates in this study group, sexual activity rates do not appear to predict the number of offspring a male sires in this species.     

Chromosomal location and cloning of the gene (trmD) responsible for the synthesis of tRNA (m1G) methyltransferase in Escherichia coli K-12

Summary The trmD gene, which governs the formation of 1-methyl-guanosine (m¹G) in transfer ribonucleic acid (tRNA), has been located by phage P1 transduction at 56 min on the chromosomal map of Escherichia coli. Cotransduction to tyrA at 56 min is 80%. From the Clarke and Carbon collection a ColE1-tyrA ⁺ hybrid plasmid was isolated, which carried the trmD ⁺ gene and was shown to over-produce the tRNA (m¹G)methyltransferase. By subcloning restriction enzyme fragments in vitro, the trmD ⁺ gene was located to a 3.4 kb DNA fragment 6.5 kb clockwise from the tyrA ⁺ gene. The mutation trmD1, which renders the tRNA (m¹G) methyltransferase temperaturesensitive both in vivo and in vitro could be complemented by trmD ⁺ plasmids. These results suggest that the gene trmD ⁺ is the structural gene for the tRNA (m¹G)methyltransferase (EC 2.1.1.3.1).     

Predicting Carriers of Ongoing Selective Sweeps without Knowledge of the Favored Allele

Methods for detecting the genomic signatures of natural selection have been heavily studied, and they have been successful in identifying many selective sweeps. For most of these sweeps, the favored allele remains unknown, making it difficult to distinguish carriers of the sweep from non-carriers. In an ongoing selective sweep, carriers of the favored allele are likely to contain a future most recent common ancestor. Therefore, identifying them may prove useful in predicting the evolutionary trajectory—for example, in contexts involving drug-resistant pathogen strains or cancer subclones. The main contribution of this paper is the development and analysis of a new statistic, the Haplotype Allele Frequency (HAF) score. The HAF score, assigned to individual haplotypes in a sample, naturally captures many of the properties shared by haplotypes carrying a favored allele. We provide a theoretical framework for computing expected HAF scores under different evolutionary scenarios, and we validate the theoretical predictions with simulations. As an application of HAF score computations, we develop an algorithm (PreCIOSS: Predicting Carriers of Ongoing Selective Sweeps) to identify carriers of the favored allele in selective sweeps, and we demonstrate its power on simulations of both hard and soft sweeps, as well as on data from well-known sweeps in human populations.     

Two Penicillium camembertii mutants affected in the production of cyclopiazonic acid.

Penicillium camembertii was mutated and screened for cyclopiazonic acid-negative mutants. With a simple and rapid mini-extraction method for detection of cyclopiazonic acid production, we were able to isolate two strains which were affected in the production of this metabolite. One strain had completely lost the ability to synthesize detectable amounts of this secondary metabolite, whereas the other mutant produced 50 to 100 times less cyclopiazonic acid than the wild type. Also, the former strain had a changed morphology compared with the wild type. This morphological alteration appears to be coupled to the inability to produce cyclopiazonic acid because morphological revertants were able to synthesize cyclopiazonic acid to a level comparable to the wild type. The second mutant accumulated a new metabolite which was detectable by two-dimensional thin-layer chromatography. This new metabolite, however, appears not to be a direct precursor of cyclopiazonic acid.     

Uptake and oxidation of aromatic substrates by Rhizobium leguminosarum MNF 3841 and Rhizobium trifolii TA1

Abstract Rhizobium trifolii TA1 and Rhizobium leguminosarum MNF 3841 grow on a range of aromatic substrates. R. trifolii TA1 possesses enzymes of both the catechol and protocatechuate pathways, whereas R. leguminosarum MNF 3841 only has enzymes of the latter pathway. The pathways are induced by growth on benzoate or 4-hydroxybenzoate, respectively, but they are not cross-inducible. 4-Hydroxybenzoate permease and hydroxylase are induced by growth on 4-hydroxybenzoate but not on protocatechuate, suggesting that they are regulated separately from protocatechuate dioxygenase. The uptake systems for both benzoate and 4-hydroxybenzoate are inhibited by azide, carbonyl cyanide m -chlorophenyl hydrazone and N , N '-dicyclohexylcarbodiimide but are insensitive to arsenate. Salicylate and protocatechuate interfere with benzoate and 4-hydroxybenzoate uptake, respectively.     

Photoaffinity labelling of juvenile hormone binding proteins in the cockroach Leucophaeamaderae

The synthesis and testing of several diazocarbonyl JH analogs (diazo JHA) which act as photoaffinity labels for insect juvenile hormone binding proteins are described. The best competitor, 10,11-epoxyfarnesyl diazoacetate, has been shown to irreversibly reduce [³H]-JH III binding to both ovarian and hemolymph JHBP from Leucophaeamaderae after irradiation at 254 nm for 20 seconds. No loss of activity was observed after incubation of JHBP and diazo JHA without irradiation. Protection from photoinactivation by diazo JHA II was achieved by the presence of an equimolar amount of JH III during the photolysis. Photoaffinity labeled proteins show loss of binding capacity without alteration of the binding affinity. This is the first example of the use of a photoaffinity label in the study of JH action on a molecular level, and may become a valuable tool in the elucidation of JH-receptor-chromatin interactions.     

The apical lamina of the sea urchin embryo: Major glycoproteins associated with the hyaline layer

The hyaline layer (HL) surrounding the sea urchin blastula appears to dissolve in 1 M glycine. However, after this treatment, there persists over the surfaces of the blastomeres a layer of material, referred to here as the apical lamina (AL), that sloughs off as an adhesive convoluted bag upon gradual dissociation of the embryo. Isolated hyaline layers, referred to as HL-AL complexes, were analyzed by urea-SDS-polyacrylamide gel electrophoresis. A major protein of the HL-AL complex, hyalin, bands or precipitates in the stacking gel. Two other major proteins, both strongly PAS positive, migrate with apparent molecular weights of 175K and 145K daltons. As with intact embryos, the glycine wash removes the hyalin protein from the isolated HL-AL complex, leaving the undissolved AL which consists primarily of the 175K- and 145K-dalton proteins. The embryo's own perivitelline-localized cortical granule peroxidase heavily radioiodinates the proteins of the HL-AL complex, further verifying their apical, extracellular location. Unlike hyalin, the AL proteins do not precipitate with calcium ions. Compared to the entire HL-AL complex, the AL contains a greater percentage of carbohydrate. No sialic acid is associated with the HL-AL complex, but the AL contains some sulfate. In contrast to a published report based on ultrastructural staining, no biochemical evidence was found in this study for the presence of collagen or significant glycosaminoglycan within the HL-AL complex. No developmental differences were observed in AL proteins from 1-hr-old embryos compared to those from blastulae. However, there is evidence suggesting heterogeneity and developmental differences in hyalin. The possible organization of hyalin and the AL proteins into separate layers surrounding the embryo is discussed. The influence of the AL proteins in morphogenesis and cell adhesion is considered, and hypothetical roles attributed to the HL and hyalin are critically questioned.     

An improved medium for the detection of Aspergillus flavus and A. parasiticus

An effective selective medium for the enumeration of Aspergillus flavus and Aspergillus parasiticus has been developed by modification of Bothast and Fennell's Aspergillus Differential Medium. Results can be obtained with the new medium, Aspergillus flavus and parasiticus Agar (AFPA), after 42 h incubation at 30°C. The medium is thus suitable for use in quality control as a guide to the presence of A. flavus and, potentially, of aflatoxins. AFPA has been extensively tested on peanuts and soils. Results were reproducible and comparable with those on standard fungal enumeration media incubated for much longer periods. A very low percentage of false positives or negatives was found.