Polyandry restores female fertility and paternal effects diminished by inbreeding in Hippodamia convergens

1. The fertility restoration hypothesis posits that polyandry can evolve when female fertility is reduced by matings with related males, but restored by matings with unrelated ones. 2. Using a promiscuous ladybird, this hypothesis was tested by mating mature, virgin females twice with sib and non‐sib males in all four permutations and observing female fertility. The development of progeny from the first and 10th clutches was also followed to test for differences in paternal effects. 3. Mating treatment did not affect fecundity, but egg viability was reduced by sib matings, and restored by non‐sib matings, regardless of mating sequence. In addition, negative paternal effects of sib matings on progeny (lower survival) were compensated by non‐sib matings. 4. The survival of offspring in first clutches was sensitive to the paternal mating sequence and was higher if a sibling male was preceded by a non‐sib male, compared with the reverse, consistent with a time lag in response to male epigenetic signals. Offspring survival did not differ between these two treatments in the 10th clutch, suggesting a blending of paternal effects over time. 5. The results are indicative of interactions between the paternal effects contributed by different males, and between paternal and maternal effects, the latter causing faster development in later clutches. 6. Thus, the reproductive benefits of polyandry for H. convergens females are potentially both genetic and epigenetic, as both egg fertility and beneficial paternal effects were diminished by sib matings, but restored by matings with unrelated males.     

Isolation of purified copper protein from horse liver

1. A procedure is described for isolating a copper protein from horse liver in pure form, in a state that appears to be crystalline. 2. This copper protein is colored blue-green, and its copper content varied between 0.3 and 0.4 per cent. No indication of any catalytic properties was obtained in the limited number of tests made. Because of its variable copper content, the protein may function for the storage of copper in the body. 3. The copper could be removed partly from the protein by dialysis against cyanide, and a colorless crystalline protein was obtained by lowering the pH to 5.0, followed by dialysis. The original blue-green color of the protein could be restored by dialysis against copper acetate solution.     

Production of cloned cDNA from a Swedish barley yellow dwarf virus isolate

A cDNA library was produced from the RNA of a Swedish MAV-like isolate of barley yellow dwarf virus (BYDV). The procedure involved random priming and the ds cDNA was cloned into the EcoRl site of the plasmid pUC19. Among the clones obtained some hybridised specifically with MAV-like isolates whereas others also hybridised with PAV-like isolates. Only very weak hybridisation was observed with an RPV-like isolate. An Australian cDNA clone, reported to be PAV-specific (pBY82, Waterhouse, Gerlach & Miller, 1986), hybridised with Swedish MAV-like but not with PAV-like isolates. Probes prepared from the clones detected virus in plant extracts by dot-blot hybridisation with sensitivity greater than that of ELISA. Virus was also readily detected in extracts of viruliferous aphids.     

Chloroplast DNA phylogeography suggests a West African centre of origin for the baobab, Adansonia digitata L. (Bombacoideae, Malvaceae)

The African baobab ( Adansonia digitata L.) is an emblematic, culturally important, and physically huge tropical tree species whose natural geographical distribution comprises most of tropical Africa, but also small patches of southern Arabia, and several Atlantic and Indian Ocean islands surrounding the African continent, notably including Madagascar. We analysed the polymerase chain reaction–restriction fragment length polymorphism of five chloroplast DNA fragments obtained from 344 individuals of A. digitata collected from 74 populations covering the entire extant distribution range of the species. Our goal was to reconstruct the phylogeographical history of the species and, if possible, to identify its centre of origin, which has been a subject of controversy for many decades. We identified five haplotypes whose distribution is clearly geographically structured. Using several species of Adansonia and of closely related genera as outgroups, the haplotypes showed a clear phylogeographical pattern of three groups. Two are phylogenetically related to the outgroup taxa, and are distributed in West Africa. The third group is substantially more differentiated genetically from outgroup species, and it corresponds to southern and eastern Africa, Arabia and the Indian Ocean islands, including Madagascar. According to our results, the tetraploid A. digitata , or its diploid progenitor, probably originated in West Africa and migrated subsequently throughout the tropical parts of that continent, and beyond, by natural and human-mediated terrestrial and overseas dispersal.     

A new species of Dyrosaurus (Crocodylomorpha, Dyrosauridae) from the early Eocene of Morocco: phylogenetic implications

A new dyrosaurid is described from the Ypresian of the phosphatic deposits of the Oulad Abdoun Basin of Morocco. It is based on numerous cranial and postcranial remains, allowing an almost complete reconstruction. This new Dyrosaurus species, Dyrosaurus maghribensis sp. nov. , is currently only known from Morocco. It differs from D. phosphaticus , present in contemporaneous levels of Algeria and Tunisia, by several autapomorpies, including a smooth dorsal margin of the parietal and widely opened choanae. A phylogenetic analysis, using 47 taxa and 234 morphological characters, shows the dyrosaurids as the sister taxon of pholidosaurids, which include Elosuchus , Sarcosuchus , Terminonaris and Pholidosaurus , and the thalattosuchians. Goniopholididae is a non-monophyletic group; however, if dyrosaurids are not included in the analysis, the result differs and the goniopholidids form a distinct clade. If Thalattosuchia is excluded, both Goniopholididae and Pholidosauridae become paraphyletic assemblages. Thus, phylogenetic problems remain with respect to longirostrine clade, and more attention should be paid to resolving their evolutionary relationships amongst the crocodyliforms.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 603–656.     

Effects of selective logging on the arboreal ants of a Bornean rainforest

We examined the effect of selective logging and corresponding forest canopy loss on arboreal ant diversity in a tropical rainforest. Arboreal ants were collected from an unlogged forest plot and from forest plots selectively logged 14 years and 24 years earlier in Danum Valley, Sabah, Malaysia, using a canopy fogging method. Selective logging was associated with a significant decrease in canopy cover and an increase in understory vegetation density relative to unlogged forest. Our study showed that selective logging in primary forest might not dramatically decrease total species number and overall abundance of arboreal ants; however, it may influence the species composition and dominance structure of the ant community, accompanied by an increase in abundance of shrub‐layer species and trophobiotic species. In view of the results of this study, management techniques that minimize logging impact on understory vegetation structure are likely to help maintain the conservation value of logged forests for arboreal ants. Our results also suggest that accurate assessment of the impacts on biodiversity should not be based only on measurement of species number and overall abundance, but also on analysis of species composition and community structure.     

Genotypic Differences in the Temperature Responses of Tropical Crops: II. SEEDLING EMERGENCE AND LEAF GROWTH OF GROUNDNUT (ARACHIS HYPOGAEA L.) AND PEARL MILLET (PENNISETUM TYPHOIDES S. & H.)

Mohamed, H. A., Clark, J. A. and Ong, C. K. 1988. Genotypicdifferences in the temperature responses of tropical crops.II. Seedling emergence and leaf growth of groundnut (Arachishypogaea L.) and pearl millet (Pennisetum typhoides S. &H.).—J. exp. Bot. 39: 1129-1135. Measurements of seedling emergence and leaf growth of five milletand seven groundnut genotypes were made at soil temperaturesranging from 7 to 27?C. The rate of seedling emergence (R_e)varied greatly between millet genotypes but R_e was remarkablysimilar in groundnut genotypes. In pearl millet there is a strongcorrelation between the rate of germination and the rate ofleaf production, hourly leaf extension and seedling emergence.The results are discussed in terms of the thermal time requirementsof various processes. Key words: Temperature, emergence, groundnut, millet     

Linear and Cyclic α-Melanotropin [4–10]-Fragment Analogues That Exhibit Superpotency and Residual Activity

Two analogues of α-MSH (Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂), Ac-[Nle⁴, Asp⁵, D-Phe⁷, Lys¹⁰]α-MSH_4–10NH₂ and Ac-[Nle⁴, Asp⁵, D-Phe⁷, Lys¹⁰] α-MSH_4–10-NH₂, were synthesized, and the melanotropic activities of the peptides were compared in several bioassays. Potencies were determined in the in vitro frog and lizard skin bioassays and in the S91 melanoma cell tyrosinase assay. Both analogues were equipotent or more potent than α-MSH in all bioassays, and the activities of the analogues were prolonged compared to α-MSH. The two analogues were very resistant to inactivation by purified proteolytic enzymes (α-chymotrypsin, trypsin, and pepsin). The two peptides could be topically applied and transdermally delivered across the skin of mice in vivo, resulting in a shift from pheomelanogenesis to eumelanogenesis within follicular melanocytes. The cyclic analogue exhibited greater potency, prolonged activity, and stability against enzyme inactivation than did the linear peptide. The significance of the findings for the further design of melanotropin analogues is discussed, as in the possible relevance of these melanotropin analogues for use in biomedical studies.     

Amylase and Invertase Activities and Carbohydrate Contents in Relation to Physiological Sink in Carnation

In carnation, Dianthus caryophyllus L. cv. Hanacy, initiation of flower primordia was followed by mobilization of polysaccharides from leaves to developing flower buds and mature flowers. This process functioned by integrative activities of amylase and invertase, ensuring abundant flow of the mobilized carbohydrates from the source to the sink. Successive stages of floral development exhibited different sink strengths as indicated by amylase and invertase activities and carbohydrate contents in stem apices, which increased with progression of floral development.     

In Vitro Penetration of Pig Skin by Heavy Metals in Soil

The potential health risk from exposure to heavy metal contaminated soil is often based on the quantity of metal that can be removed from soil by vigorous extraction procedures. This approach can overestimate risk since it ignores complex interactions between metals and soil that can result in a reduction in the amount of metal that desorbs from soil and is subsequently absorbed by the body. The aim of this research was to determine the relative contribution of the soil matrix and heavy metal sequestration in soil with time (“aging”) on the dermal penetration of arsenic, mercury, and nickel, respectively, as arsenic acid, mercuric chloride, and nickel chloride. In vitro flow-through diffusion cell studies were performed utilizing dermatomed male pig skin and radioactive compounds to measure total penetration (the sum of each metal in receptor fluid and skin). For arsenic and nickel, the soil matrix produced a 78–87% reduction in dermal penetration compared to 12–19% after aging. A greater effect was observed with aged mercury (52–56% decrease in dermal penetration) than in freshly spiked soil (40–43%). The results indicate that the potential health risk from dermal exposure to the metals can be significantly reduced by soil and aging.