Convergent evolution of gigantism in damselflies of Africa and South America? Evidence from nuclear and mitochondrial sequence data

Extreme large body size is rare in modern Zygoptera (damselflies). Only the South and Central American damselfly family Pseudostigmatidae and one African species, Coryphagrion grandis, share the morphological trait of gigantism. By means of phylogenetic analyses using two mitochondrial markers (16S rDNA and ND1) and one nuclear marker (EF1) in combination with an existing morphological data set, we trace the evolution of gigantism in damselflies. Individual and combined data sets were analyzed using the maximum parsimony, minimum evolution and maximum likelihood algorithms. Regardless of the algorithm used and the data set analyzed all principal tree topologies support a monophyly of the damselfly taxa displaying giant body size. This supports the view that the evolution of gigantism in damselflies from Africa and South America is not the result of convergent evolution due to strikingly similar habitat preferences, but rather the result of close genealogical relationship. Because modern odonates evolved before the split of Africa from Gondwanaland, the proposed phylogeny suggests that C. grandis represents a Gondwana relict.     

Weight loss is not mandatory for exercise-induced effects on health indices in females with metabolic syndrome

The aim of this study was to investigate the impact of moderate aerobic training on functional, anthropometric, biochemical, and health-related quality of life (HRQOL) parameters on women with metabolic syndrome (MS). Fifteen untrained women with MS performed moderate aerobic training for 15 weeks, without modifications of dietary behaviours. Functional, anthropometric, biochemical, control diet record and HRQOL parameters were assessed before and after the training. Despite body weight maintenance, the patients presented decreases in waist circumference (P = 0.001), number of MS components (P = 0.014), total cholesterol (P = 0.049), HDL cholesterol (P = 0.004), LDL cholesterol (P = 0.027), myeloperoxidase activity (P = 0.002) and thiobarbituric acid-reactive substances levels (P = 0.006). There were no differences in total energy, carbohydrate, protein and lipid intake pre- and post-training. Furthermore, improvements in the HRQOL subscales of physical functioning (P = 0.03), role-physical (P = 0.039), bodily pain (P = 0.048), general health (P = 0.046) and social functioning scoring (P = 0.011) were reported. Despite the absence of weight loss, aerobic training induced beneficial effects on functional, anthropometric, biochemical and HRQOL parameters in women with MS.     

Characterization of isogenic carp (Cyprinus carpio L.) lines with a genetically determined high or low antibody production

Antibody production to dinitrophenyl-keyhole limpet haemocyanin (DNP-KLH) served as the immune parameter to divergently select carp (Cyprinus carpio L.) to produce high- and low-responder F, hybrid lines. Antibody production to trinitrophenyl-lipopolysaccharide [TNP-LPS) and to DNP-KLH were similar in magnitude. By contrast, some high-responder lines were low responders to DNP-human serum albumin, and vice versa. Low-responder carp were relatively susceptible to infection with the parasite Trypanoplasma borreli. This suggested that at least one gene with a major influence on resistance differed between the two homozygous parents (69, 85) used to generate the high- and low-responder homozygous families, respectively. The isogenic lines showed no within-line variation in DNA fingerprints, but differed with respect to their MhcCyca-DAB genes.     

Isolation and functional characterization of the heavy and light chains of human tissue-type plasminogen activator

Two-chain tissue-type plasminogen activator (t-PA), which consists of a heavy chain (Mr congruent to 38,000) and a light chain (Mr congruent to 31,000) connected by a disulfide bridge, was reduced with 2-mercaptoethanol and then air-reoxidized at a low protein concentration and carboxamidomethylated. The two chains were separated by means of zinc chelate-agarose, which was found to bind the light chain selectively. The light chain was fully active on the tripeptide substrate H-D-isoleucyl-L-prolyl-L-arginine p-nitroanilide (S-2288) and partially active on plasminogen. The plasminogen activator activity of the light chain was, in contrast to that of two-chain t-PA, not stimulated by fibrin or fibrinogen fragments. Fibrin-agarose chromatography of radiolabeled chains showed that only the heavy chain bound to fibrin. These results indicate that the active site-containing light chain in t-PA needs the heavy chain for fibrin stimulation of its plasminogen activator activity.     

In-vivo effects of lipopolysaccharide on lymphoid and non-lymphoid cells in the mouse spleen

In mice marginal metallophils are located at the periphery of the white pulp along the inner border of the marginal sinus. These cells have a weak phagocytic capacity but their function is still unclear. In the present study evidence is given that marginal metallophils migrate from the periphery of the follicle towards the follicle centres after administration of at least 7 micrograms lipopolysaccharide (LPS). This migration is most significant after 24 and 48 h and appears to be a specific effect of LPS. In the follicle centre marginal metallophils take up cell debris and may become tingible body macrophages. The similarity between these two cell types is discussed. The possible effects of several other polyclonal B-cell mitogens on marginal metallophils have also been studied. Dextran sulphate also induces migration of marginal metallophils but this compound triggers a migration and accumulation of these cells at the periphery of the follicles.     

Static intraspecific maxillofacial allometry in the chacma baboon

Adult static intraspecific allometry of jaw size and tooth area was evaluated in a sample of 104 Papio ursinus crania (52 male, 52 female). Tooth areas were calculated from mesiodistal and buccolingual measurements of all the teeth in both arcades and were scaled to four viscerocranial measurements: bimaxillary width, maxillo-alveolar length, mandibular length and bigonial width. Craniodental allometric analyses indicate that larger animals will tend to have proportionately shorter and narrower lower jaws. From the log-transformed interspecific analyses between P. ursinus and C. aethiops we conclude that males and females within each species share a common exponential value for jaw length. Hence increased sexual dimorphism for muzzle length in P. ursinus is attributable to increased divergence between the male and female slopes. Post-canine area was found to be significantly correlated to maxillary length and to canine size only in females, with exponential values similar to those reported for the same bivariate regressions in C. aethiops. A hypothesis of nutritional equivalence is advanced to account for these observations. Canine base area and the area of P3 were the only tooth areas that scaled in a positively allometric fashion to jaw size--but only in males. Hence the existence of a canine complex is confirmed in the male Chacma baboon, the size of which is related to jaw length.     

Lipid synthesis in the laticifers of Euphorbia lathyris L. seedlings

Various solutions of labeled precursors were absorbed by the cotyledons of etiolated Euphorbia lathyris L. seedlings. Incorporation of ¹⁴C into triterpenes from [2-¹⁴C]mevalonic acid, [1-¹⁴C]acetate, [3-¹⁴C]pyruvate, [U-¹⁴C]glyoxylate, [U-¹⁴C]glycerol, [U-¹⁴C]serine, [U-¹⁴C]xylose, [U-¹⁴C]glucose, and [U-¹⁴C]sucrose was obtained. The [¹⁴] triterpenes synthesized from [¹⁴C] sugars were mainly of latex origin. [¹⁴C]mevalonic acid was only involved in terpenoid synthesis outside the laticifers. Exogenously supplied glyoxylate, serine, and glycerol were hardly involved in lipid synthesis at all. The ¹⁴C-distribution over the various triterpenols was consistent with the mass distribution of these constituents in gas liquid chromatography when [¹⁴C]sugars, [¹⁴C]acetate, and [¹⁴C]pyruvate were used. These precursors were supplied to the seedlings in the presence of increasing amounts of unlabeled substrates. The amount of substrate directly involved in lipid synthesis as well as the absolute triterpenol yield was calculated from the obtained [¹⁴C]triterpenols. The highest yield was obtained in the sucrose incorporated seedlings, being 25% of the daily increase of latex triterpenes in growing seedlings.     

The effects of tin (Sn) additions on the growth of spinach plants

An increase in bioavailable tin in the environment could result in bioaccumulation thereof in agricultural crops, and therefore, have adverse health consequences on humans that eat these crops. The aims of the current study were thus to assess the uptake of Sn by spinach plants, and the subsequent effects this will have on the uptake of Na, Zn, K, Ca, and Mg as well as the growth of spinach plants. Spinach plants were grown in sand culture and received tin at concentrations of 0.02, 0.2, 2 and 20 mg/L along with a nutrient solution. The uptake of tin at detectible concentrations only occurred at the highest concentrations (2 and 20 mg/L), and it was mostly retained in the roots of the plants. Tin additions also resulted in no visual toxicity symptoms, and might be beneficial to biomass production. Further field trials are needed to ensure that these experimental results remain true under field conditions.