Parental role division predicts avian preen wax cycles

Previous studies have shown that preen wax composition in some sandpipers shifts from the usual monoesters to diesters during the breeding season, possibly to reduce the ability of mammalian predators to find nests using olfactory cues. To investigate further the relationship between incubation and wax secretion, we examined seven sandpiper species with different incubation patterns (species in which both sexes incubate, in which only males incubate and in which only females incubate). During the breeding period, diester preen wax was secreted almost exclusively by the incubating sex in species with uniparental incubation, and by both sexes in species with biparental incubation. These findings suggest that diester preen waxes have a function that is directly related to incubation. Unexpectedly, in female-incubating Curlew Sandpiper Calidris ferruginea and Buff-breasted Sandpiper Tryngites subruficollis , some males also secreted diester preen waxes during the breeding period. This suggests that some males may in fact incubate, that these waxes may be a remnant from their evolutionary past when both sexes incubated, or that males need to be olfactorally cryptic because they are involved in the making of nest scrapes. The seasonal pattern of preen wax composition was also studied in captive male, female and female-mimicking male ('faeder') Ruff Philomachus pugnax . Captive female Ruff changed preen wax composition from monoesters to diesters in the spring despite the fact that no incubation took place. This suggests that circannual rhythms rather than actual incubation behaviour may trigger the shift to diester waxes. All captive male Ruff, including the faeders, continued to secrete monoesters, supporting the hypothesis that only the incubating sex secretes diesters.     

Ecological and genetic correlates of range expansion in Coenonympha tullia

Range expansion by the North American butterfly species Coenonympha tullia is associated with dramatic changes in life history and in genetic and morphological variation. Eight of ten independent, variable loci exhibit step-clines in allele frequency; step-clines also occur in four wing pattern characters. Populations from the old part of the range are univoltine, and have significantly less genetic and morphological variation than populations from the recently colonized ranger, which arc bivoltine. The concordance of life history with genetic and morphological variation suggests that differences between univoltine and bivoltine populations are maintained by selection. Increased electrophoretic variation in the recently colonized range may have arisen by selection on rare variants within the old part of the range.     

Ornithine Decarboxylase in Trypanosoma brucei brucei: Evidence for Selective Toxicity of Difluoromethylornithine1

ABSTRACT. Activity of ornithine decarboxylase, the major rate limiting enzyme of polyamine biosynthesis, was determined in bloodstream trypomastigotes of Trypanosoma brucei brucei. The enzyme required pyridoxal-5′-phosphate, dithiothreitol and EDTA for optimal activity. Several properties of the enzyme were investigated and compared to the mammalian enzyme. Most notably, the parasite enzyme was >60-fold more sensitive to the inhibitor DL-α-difluoromethylornithine than its mammalian counterpart, thus making it an attractive target for chemotherapy.     

Postendocytic Provitellin Processing in the Growing Oocyte of the Short Horned Grasshopper, Oxyajaponicajaponica (Orthoptera: Acrididae)

Polyclonal antibodies made against 86 kDa (86 k), 80 kDa (80 k) and 54 kDa (54 k) vitellins of Oxya japonica japonica are used for Western blotting. Anti‐80k vitellin antibody is cross‐reacted with a 95 kDa (95 k) vitellin. While 95 k vitellin is present both in the female hemolymph and in the oocyte, 80 k vitellin is detected only in the oocyte and the laid egg. In the growing oocytes, as 95 k vitellin is faded out gradually, 80 k vitellin is accumulated increasingly, indicating postendocytic processing of 95 k vitellin brings 80 k vitellin. Further conforming the hypothesis, partial digestion of 95 k vitellin with pepsin and α‐chymotrypsin makes several protein bands of molecular weight around 80 kDa. Thus, the 95k vitellin may have a cleavage site (s) to produce 80 k vitellin which forms fairly stable tertiary structure. In the reduced condition (20 mM glutathion), both 95 k and 80 k vitellins were digested throughly by endogenous proteinase at pH 4. Both 86 k and 54 k vitellins, respectively, show no apparent molecular weight changes in the growing oocyte and in the hemolymph.     

Expression of a New Complement-fixing Antigen reactive with Murine Sarcoma Virus Rat Antiserum in Rat Cells transformed by Polyoma Virus

WE reported accelerated transformation by DNA viruses (SV40 and polyoma) in rat embryo (RE) cells chronically infected with a C-type RNA virus^1,2. Recently we found in RE cells transformed by polyoma virus a new complement-fixing (CF) antigen detectable by rat antisera having broad reactivity with the various intraspecies and interspecies antigens of the RNA tumour viruses^3–8; this antigen, however, was distinct from the murine intraspecies and interspecies group-specific (gs) antigens both immunologically and by virtue of other properties. It is also distinct from the polyoma virion (capsid) and tumour (“T”) antigens.     

Interaction of Acronicta rumicis (Lepidoptera: Noctuidae) and its larval parasitoid, Glyptapanteles liparidis (Hymenoptera: Ichneumonidae)

As a result of parasitism by Glyptapanteles liparidis in the first, second, third and fourth instar larvae of Acronicta rumicis, the mortality of each larval stage was found to be 46.67, 90, 71 and 16.67%, respectively. The mortality was highest when G. liparidis parasitized the second and third instar larvae. The difference in mortality between the parasitized group and the control group was 72.14% in the second instar larvae. With regards to the food consumption of the parasitized larvae, the first and second instar larvae consumed 6495.58 ± 646.52 mm² (leaf surface) and 7951.12 ± 4167.36 mm², respectively, while the third and fourth larvae consumed 13 826.77 ± 3396.66 mm² and 18 599.85 mm², respectively, showing that food consumption increased with instar stages of the host larvae. The clutch size of G. liparidis increased in relation to the instar stages of the host: it was 25.25 ± 7.89, 48.65 ± 53.75, 91.09 ± 44.52 and 114 individuals when they were fed with the first, second, third and the fourth instar larvae of the host, respectively.     

A phylogenetic review of the genus Hexabathynella Schminke, 1972 (Crustacea, Malacostraca, Bathynellacea): with a description of four new species

The genus Hexabathynella (Crustacea, Malacostraca, Bathynellacea) is revised in the sense of the phylogenetic systematics and four new species are described from South Africa ( H. monoaethetasca sp. nov. and H. africana sp. nov. ) and America ( H. schrieveri sp. nov. and H. virginiae sp. nov. ). A comparative analysis of all observable outer structures distributed in 18 known and four new species resulted in a re-evaluation of 18 characters and character states. The phylogenetic analysis using the program PAUP yielded one most-parsimonious tree, which suggests the grouping of ( H. decora (( H. halophila  +  H. aotearoae ) + ( H. pauliani ( H. monoaethetasca  + H. africana )))) + ( H. knoepffleri ( H. nicoleiana ( H. hebrica , H. tenera , H. longiappendiculata , H. breviappendiculata , H. nestica ) +  H. virginiae (( H. minuta ( H. valdecasasi + H. otayana )) + ( H. hessleri + H. muliebris ))) +  H. paranaensis ( H. szidati + H. schrieveri )). The tree is 57 steps long and has a consistency index of 0.6140, a retention index of 0.7982 and a rescaled consistency index of 0.4901. The result does not agree with the previous analyses on the genus. In terms of sampling and coding, the characters used in the previous study are critically assessed.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 71–96.     

Extracellular Amastigote-Like Forms of Leishmania panamensis and L. braziliensis. II. Stage- and Species-Specific Monoclonal Antibodies

Immunochemical evidence, employing monoclonal antibodies, shows that the forms of L. braziliensis complex axenically grown at elevated temperature are amastigote-like. The monoclonal antibodies were raised against membrane proteins of amastigote-like forms, strains of both L. panamensis (WR442) and L. braziliensis (M5052), which were grown axenically. The specificities of these antibodies were examined by indirect radioimmune binding assay, indirect immunofluorescent assay and Western blot analyses. Two distinct groups of monoclonal antibodies were obtained and their specificities were consistent with the 3 methods used. Four antibodies are specific for the species L. panamensis and react with both developmental stages. Six antibodies specifically recognize amastigote-like forms grown at elevated temperature and intracellular amastigotes of both L. panamensis (WR442) and L. braziliensis (M5052). These monoclonal antibodies do not bind to promastigotes of these species, nor to promastigotes of any other species of Leishmania . Therefore these antibodies are specific for amastigotes of L. panamensis (WR442) and L. braziliensis (M5052), and suggest that immunochemically both amastigote forms (culture and macrophage) are developmentally very close, if not identical. The molecules associated with the amastigote-specific antigenic determinants consist of a Mr 12-kD component and a heterogeneous component (Mr from 50 kD to >200 kD); these molecules appear to be identical for both amastigote-like forms and amastigotes isolated from macrophages.