Variability in host plant resistance of Sorghum to Striga Hermonthica infestation in West Africa

Fourteen elite sorghum lines were evaluated for their resistance to Striga hermonthica at three locations in Nigeria and Mali. Results showed that many of the lines especially MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64 (Keninkédié) and the check SRN 39 remained resistant to Striga in all locations with low emerged Striga counts, while SAMSORG 14 had the highest Striga infestation in all locations. Considerable variation in reaction to Striga infestation was observed on Séguètana, 97-SB-F5DT-63 (Wasa), 97-SB-F5DT-65, CMDT 38, CMDT 39 and CMDT 45 which were susceptible to Striga at Samaru, Nigeria but were resistant to Striga at both locations in Mali. Based on low Striga resistance and high grain yield, lines MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64, 97-SB-F5DT-65, CMDT 39 and SAMSORT 14 have been nominated for wider evaluation across more West African countries.     

Chromosome C-banding patterns in isolated population of the grasshopper Podisma pedesis (L.) (Orthoptera,Acrididae) from the Altai Mts

The C-banding patterns in the embryo chromosomes of the grasshopper Podisma pedestris (L.) from the Altai Mts are reported. The additional second C-heterochromatic arms in at least five pairs of autosomes and in the X-chromosome were revealed. The paracentromeric, interstitial, and telomeric C-bands were observed. The studied population of P. pedestris shows some differences in the distribution and amount of the heterochromatin in comparison with European populations.     

Two common nonsynonymous paraoxonase 1 (<Emphasis Type="Italic">PON1</Emphasis>) gene polymorphisms and brain astrocytoma and meningioma

Background  

Human serum paraoxonase 1 (PON1) plays a major role in the metabolism of several organophosphorus compounds. The enzyme is encoded by the polymorphic gene PON1, located on chromosome 7q21.3. Aiming to identify genetic variations related to the risk of developing brain tumors, we investigated the putative association between common nonsynonymous PON1 polymorphisms and the risk of developing astrocytoma and meningioma.     

Long-term effects of graduated compression stockings on cardiorespiratory performance

The use of graduated compression stockings (GCS) in sport has been increasing in the last years due to their potential positive effects for athletes. However, there is little evidence to support whether these types of garments actually improve cardiorespiratory performance. The aim of this study was to examine the cardiorespiratory responses of GCS during running after three weeks of regular use. Twenty recreational runners performed three tests on different days: test 1) – a 5-min maximal effort run in order to determine the participants’ maximal aerobic speed; and tests 2) and 3) – a fatigue running test of 30 minutes at 80% of their maximal aerobic speed with either GCS or PLACEBO stockings at random. Cardiorespiratory parameters (minute ventilation, heart rate, relative oxygen consumption, relative carbon dioxide production, ventilatory equivalents for oxygen and carbon dioxide, and oxygen pulse) were measured. Before each test in the laboratory, the participants trained with the randomly assigned stockings (GCS or PLACEBO) for three weeks. No significant differences between GCS and PLACEBO were found in any of the cardiorespiratory parameters. In conclusion, the present study provides evidence that running with GCS for three weeks does not influence cardiorespiratory parameters in recreational runners.     

Molecular phylogeny of Palaearctic genera of Gomphocerinae grasshoppers (Orthoptera, Acrididae)

Abstract.  Molecular phylogenetic methods were used to examine morphologically based hypotheses concerning the taxonomic structure and relationships of the grasshopper subfamily Gomphocerinae. Two mitochondrial gene (cytochrome b and cytochrome oxidase subunit I) sequences were determined for twenty-five species representing eleven Palaearctic genera. The studied Gomphocerinae species constituted a monophyletic group; furthermore, the earlier division of Gomphocerinae into tribes was supported, with each tribe monophyletic. There was no support for various systems uniting Stenobothrini and Gomphocerini into one tribe. Two separate clusters were discerned in Gomphocerini and two tribes were distinguished – Gomphocerini (genera Aeropus , Stauroderus , Chorthippus ) and Stenobothrini (genera Omocestus , Stenobothrus ).     

B chromosomes, translocation between B and autosomes, and C-heterochromatin polymorphism of the grasshopper Podisma sapporensis Shir. (Orthoptera, Acrididae) in Hokkaido, northern Japan.

Seven categories of B chromosomes found in the brachypterus grasshopper Podisma sapporensis from Hokkaido populations differ in structure, size, and C-band content. The interchange between B and one autosome from M3 and sporadically M7 was observed in most of the populations examined. Such an interaction between standard and non-standard chromosomal set provides an insight into the integration of supernumerary chromosome. In addition, C-heterochromatin polymorphism was also identified in male karyotypes in some populations. These facts indicate P. sapporensis is a highly polymorphic species from the cytogenetic point of view.     

Differences in ribosomal DNA distribution on A and B chromosomes between eastern and western populations of the grasshopper Eyprepocnemis plorans plorans

Distribution of ribosomal DNA (rDNA) on standard (A) and supernumerary (B) chromosomes of the grasshopper Eyprepocnemis plorans was analysed in specimens collected in Turkey and Armenia, belonging to the E. p. plorans subspecies, and in South Africa, belonging to the E. p. meridionalis subspecies. The latter individuals showed rDNA loci in chromosomes 9 and 11 only, whereas those from Armenia carried it in chromosomes 9 and 11 or else in chromosomes 9-11, depending on the population. The specimens from Turkey carried it in chromosomes 1, 9-11 and X. A comparison of this pattern with those previously observed in populations from Spain, Morocco, and Greece (belonging to E. p. plorans) suggests the existence of two evolutionary patterns in rDNA chromosome location in A chromosomes of this subspecies: eastern populations showing rDNA restricted to the small (9-11) chromosomes (as in E. p. meridionalis and other closely related taxa within the Eyprepocneminae subfamily) and western populations carrying rDNA in most A chromosomes (Spain) or all of them (Morocco). The intermediate pattern discerned in geographically intermediate populations (in Greece and Turkey), with rDNA also being located on the X chromosome, suggests a possible east-west cline. Additional support for east-west differentiation in the rDNA location pattern comes from the analysis of B chromosomes. In eastern populations, including Daghestan, Armenia, Turkey, and Greece, B chromosomes are composed mostly of rDNA, whereas in western populations (Spain and Morocco) they contain roughly similar amounts of rDNA and a 180-bp tandem repeat (satDNA), the latter being scarce in eastern Bs.     

Intragenic duplication and divergence in the spectrin superfamily of proteins

Many structural, signaling, and adhesion molecules contain tandemly repeated amino acid motifs. The alpha-actinin/spectrin/dystrophin superfamily of F-actin-crosslinking proteins contains an array of triple alpha-helical motifs (spectrin repeats). We present here the complete sequence of the novel beta-spectrin isoform beta(Heavy)- spectrin (beta H). The sequence of beta H supports the origin of alpha- and beta-spectrins from a common ancestor, and we present a novel model for the origin of the spectrins from a homodimeric actin-crosslinking precursor. The pattern of similarity between the spectrin repeat units indicates that they have evolved by a series of nested, nonuniform duplications. Furthermore, the spectrins and dystrophins clearly have common ancestry, yet the repeat unit is of a different length in each family. Together, these observations suggest a dynamic period of increase in repeat number accompanied by homogenization within each array by concerted evolution. However, today, there is greater similarity of homologous repeats between species than there is across repeats within species, suggesting that concerted evolution ceased some time before the arthropod/vertebrate split. We propose a two-phase model for the evolution of the spectrin repeat arrays in which an initial phase of concerted evolution is subsequently retarded as each new protein becomes constrained to a specific length and the repeats diverge at the DNA level. This evolutionary model has general applicability to the origins of the many other proteins that have tandemly repeated motifs.      

First evidence of Wolbachia infection in populations of grasshopper Podisma sapporensis (Orthoptera: Acrididae)

The brachypterous grasshopper Podisma sapporensis (Orthoptera: Acrididae) is distributed throughout the Sakhalin, Kunashir and Hokkaido Islands. Karyotypes of this species consist of two major chromosomal races with different sex chromosome systems, XO/XX and XY/XX. Molecular phylogeographic analysis of the chromosome races and subraces confirms the genetic divergence of the races and subraces in P. sapporensis. Here we first report that P. sapporensis is infected with Wolbachia consisting of three variants on wsp locus, while gatB locus was monomorphic. Furthermore, observation of cell tissue of P. sapporensis using electron microscopy confirmed the infection of Wolbachia that was inferred from polymerase chain reaction and revealed the distribution of the bacteria in the head, thorax and abdomen of P. sapporensis embryos. Our finding may shed new light on Wolbachia as a possible agent causing hybrid dysfunction resulting from experimental crosses between chromosome races or subraces of P. sapporensis.