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.     

Megistospermaticus kenyensis n. comb. pour Microphallus kenyensis Canaris, 1971 (Digenea: Microphallidae)

L'étude anatomique comparée de la voie génitale m^ale de Microphallus kenyensis Canaris, 1971 et de celle du genre Megistospermaticus Deblock & Canaris, 1992 conduit au transfert de l'espèce dans ce dernier genre dont elle possède la m^eme définition.     

Paramaritremopsis solielangi n. sp. et Microphallus kinsellai n. sp. (Digenea: Microphallidae) parasites de Charadrii (Aves) du Bélize (Amérique centrale)

The authors describe and illustrate two trematodes from Belize (Central America): Paramaritremopsis solielangi n. sp. from the small intestine of Arenaria interpres is characterised by a body length of 478 m, two short and pre-acetabular caeca, part of the uterus in close association with the cirrus-sac and left caecum, vitelline glands in the shape of a horseshoe, a short pre-ovarian cirrus-sac containing a long, cylindrical, voluminous and unarmed cirrus (size when evaginated: 150×20–30 m) and Microphallus kinsellai n. sp. from the caeca of Actitis macularia characterised by a body length of 370 m and a phallus which is 30 m in diameter and asymmetrical (basically a pad with a moderately developed accessory lobe) and a straight ejaculatory canal. Levinseniella carteretensis is another microphallid recovered from Arenaria interpres. The term of ``phallus' is proposed to name the male copulatory organ which characterizes the Microphallinae.     

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.     

Contribution à íétude des Microphallidae (Trematoda). XLIX. Espèces d'oiseaux de Tasmanie. Création de Rhyncostophallus n. g.

Les auteurs décrivent et illustrent l'anatomie d'espèces de Microphallidés d'oiseaux Charadriiformes de Tasmanie (Australie). Rhyncostophallus insularegii n. g. n. sp., parasite de Charadrius ruficapillus, mesure 360 m avec une papille mâle sphérique de 39 m de diamètre; le genre est anatomiquement proche du genre Microphallus, à l'exception d'un appareil oral original évoquant un rhyncostome de Probolocoryphe. Microphallus pearsoni n. sp. de C. ruficapillus et Arenaria interpres, mesure 400–500 m avec une papille mâle musculeuse sans lobe accessoire basal, globuleuse, parfois déprimée en cupule, et d'un diamètre de 40 m égal à celui de la ventouse ventrale. Sont aussi mentionnés: (i) Microphallus pseudogonotylus (Chen, 1944) chez C. ruficapillus; (ii) Levinseniella (Levinseniella) howensis (Johnston, 1917) Pearson & Deblock, 1979 chez Arenaria interpres; (iii) L. (Monarrhenos) monodactyla Deblock & Pearson,1970 parasite de C. ruficapillus, dont la singularité morphologique de la ventouse orale est illustrée et comparée aux rhyncostomes de Probolocoryphe et de Rhyncostophallus.     

Tapeworms of the families Progynotaeniidae Fuhrmann, 1936 and Dioecocestidae Southwell, 1930 from shorebirds of South Africa

Among the helminths found in several species of shorebirds, which were collected in South Africa by the second author, were three species of the Progynotaeniidae and one species of the Dioecocestidae. Proterogynotaenia marcusae n. sp. has a single field of testes, a feature by which it differs from nine other species in the genus. Proterogynotaenia paulinae n. sp. differs from closely related species as follows: P. haematopodis (Davies & Rees, 1947) has 34 hooks, compared with 12 in P. paulinae; P. polytestis Belopolskaya, 1973 has 80 testes, compared with 42–60 in P. paulinae; and the large and small hooks of P. rouxi Fuhrmann, 1911 measure 46 and 27 µm long, compared with 34–40 and 6–10 µm respectively in P. paulinae. A key to 10 species of Proterogynotaenia is provided. Paraprogynotaenia charadrii (Yamaguti, 1956) has clusters of eggs surrounded by floats which are described for the first time. Gyrocoelia perversa Fuhrmann, 1899 is reported from three new shorebird hosts, Charadrius marginatus, C. pallidus and C. tricolaris.Revised after Professor Schmidt's death by Hilda Lei Ching, Hydra Enterprises, Vancouver, Canada, V6B 3V7.Requests for reprints should be directed to the second author.Requests for reprints should be directed to the second author.     

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.      

Higher‐order assemblies of oligomeric cargo receptor complexes form the membrane scaffold of the Cvt vesicle

Selective autophagy is the mechanism by which large cargos are specifically sequestered for degradation. The structural details of cargo and receptor assembly giving rise to autophagic vesicles remain to be elucidated. We utilize the yeast cytoplasm‐to‐vacuole targeting (Cvt) pathway, a prototype of selective autophagy, together with a multi‐scale analysis approach to study the molecular structure of Cvt vesicles. We report the oligomeric nature of the major Cvt cargo Ape1 with a combined 2.8 Å X‐ray and negative stain EM structure, as well as the secondary cargo Ams1 with a 6.3 Å cryo‐EM structure. We show that the major dodecameric cargo prApe1 exhibits a tendency to form higher‐order chain structures that are broken upon interaction with the receptor Atg19 in vitro. The stoichiometry of these cargo–receptor complexes is key to maintaining the size of the Cvt aggregate in vivo. Using correlative light and electron microscopy, we further visualize key stages of Cvt vesicle biogenesis. Our findings suggest that Atg19 interaction limits Ape1 aggregate size while serving as a vehicle for vacuolar delivery of tetrameric Ams1.