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).     

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.     

Problems of body-weight estimation in fossil primates

Body-weight estimates of fossil primates are commonly used to infer many important aspects of primate paleobiology, including diet, ecology, and relative encephalization. It is important to examine carefully the methodologies and problems associated with such estimates and the degree to which one can have confidence in them. New regression equations for predicting body weight in fossil primates are given which provide body-weight estimates for most nonhominid primate species in the fossil record. The consequences of using different subgroups (evolutionary “grades”) of primate species to estimate fossil-primate body weights are explored and the implications of these results for interpreting the primate fossil record are discussed. All species (fossil and extant) were separated into the following “grades”: prosimian grade, monkey grade, ape grade, anthropoid grade, and all-primates grade. Regression equations relating lower molar size to body weight for each of these grades were then calculated. In addition, a female-anthropoid grade regression was also calculated for predicting body weight infernales of extinct, sexually dimorphic anthropoid species. These equations were then used to generate the fossil-primate body weights. In many instances, the predicted fossil-primate body weights differ substantially from previous estimates.     

A water-soluble fraction from adult bone stimulates the differentiation of cartilage in explants of embryonic muscle

A water-soluble fraction of a 4 M guanidine HCl extract of demineralized adult bovine bone stimulated the differentiation of cartilage in explants of minced skeletal muscle from embryonic chick legs; cartilage was also induced by a semipurified protein preparation. Cartilage could be identified in treated cultures at 1 week with muscle from day-9 embryos, not before 2 weeks with muscle from day-12 embryos, and not before 3 weeks with muscle from day-19 embryos. The ability to respond to this water-soluble fraction by exhibiting cartilage differentiation was dose-dependent, but not confined to any particular muscle region of the day-12 embryonic leg. These observations indicate that bone-derived soluble chondroinductive agents act on cells in minced embryonic muscle preparations. The induction of cartilage is dependent upon the accessibility of the responding cells to the agents, on the concentration of inductive agents, and on the developmental age of the responsive tissue.     

Laboratory investigations of mars: Chemical and spectroscopic characteristics of a suite of clays as Mars Soil Analogs

Two major questions have been raised by prior explorations of Mars. Has there ever been abundant water on Mars? Why is the iron found in the Martian soil not readily seen in the reflectance spectra of the surface? The work reported here describes a model soil system of Mars Soil Analog Materials, MarSAM, with attributes which could help resolve both of these dilemmas. The first set of MarSAM consisted of a suite of variably iron/calcium-exchanged montmorillonite clays. Several properties, including chemical composition, surface-ion composition, water adsorption isotherms, and reflectance spectra, of these clays have been examined. Also, simulations of the Viking Labeled Release Experiment using the MarSAM were performed. The results of these studies show that surface iron and adsorbed water are important determinants of clay behavior as evidenced by changes in reflectance, water absorption, and clay surface reactions. Thus, these materials provide a model soil system which reasonably satisfies the constraints imposed by the Viking analyses and remote spectral observations of the Martian surface, and which offers a sink for significant amounts of water. Finally, our initial results may provide insights into the mechanisms of reactions that occur on clay surfaces as well as a more specific approach to determining the mineralogy of Martian soils.     

Floral-specific polypeptides of the Japanese morning glory

Polypeptides from stems, leaves, sepals, corollas, stamens and pistils of the Japanese morning glory (Ipomoea nil Roth (Pharbitis nil Chois.)) were separated by one- and two-dimensional gel electrophoresis and visualized by silver staining. The majority of polypeptides were expressed in two or more organs, while those specific to only one organ were comparatively rate. Among the polypeptides of the former class were two which appeared to be floral-specific. A 46-kDa (kilodalton) polypeptide was expressed in corollas, stamens and pistils, whereas a 32-kDa polypeptide was observed only in extracts prepared from reproductive organs. Polypeptide spots from the various organs were compared with those from leaves, and it was found that sepals and stems shared 40–50% of their polypeptides with leaves, whereas corollas, stamens and pistils shared 20% or less. The latter organs shared 120 polypeptides or roughly 15% of those identified in the floral extracts. Floralorgan-specific polypeptides comprised nearly 10% of the total floral polypeptides identified.Abbreviations kDa kilodalton - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecylsulfate     

Somatic embryogenesis and plant regeneration from zygotic embryo explants in mexican weeping bamboo,Otatea acuminata aztecorum

An efficient protocol has been developed for the in vitro propagation of Mexican Weeping Bamboo through somatic embryogenesis from zygotic embryo explants. Mature seeds and excised embryos were cultured in the light or in the dark on both Murashige and Skoog's and Gamborg's B5 basal media with various supplements. Optimal somatic embryogenesis and plant regeneration were obtained by culture in the dark on Murashige and Skoog's basal medium supplemented with 3 mg/1 2,4-dichlorophenoxyacetic acid, 0.5 mg/1 6-benzylaminopurine and 2.0% sucrose. More than 95% of the germinating somatic embryos developed shoots and roots, and were transferred to soil with 85% success.