Y chromosome lineage- and village-specific genes on chromosomes 1p22 and 6q27 control visceral leishmaniasis in Sudan

Familial clustering and ethnic differences suggest that visceral leishmaniasis caused by Leishmania donovani is under genetic control. A recent genome scan provided evidence for a major susceptibility gene on Chromosome 22q12 in the Aringa ethnic group in Sudan. We now report a genome-wide scan using 69 families with 173 affected relatives from two villages occupied by the related Masalit ethnic group. A primary ten-centimorgan scan followed by refined mapping provided evidence for major loci at 1p22 (LOD score 5.65; nominal p = 1.72 × 10⁻⁷; empirical p < 1 × 10⁻⁵; λ_S = 5.1) and 6q27 (LOD score 3.74; nominal p = 1.68 × 10⁻⁵; empirical p < 1 × 10⁻⁴; λ_S = 2.3) that were Y chromosome–lineage and village-specific. Neither village supported a visceral leishmaniasis susceptibility gene on 22q12. The results suggest strong lineage-specific genes due to founder effect and consanguinity in these recently immigrant populations. These chance events in ethnically uniform African populations provide a powerful resource in the search for genes and mechanisms that regulate this complex disease.     

Oxidative stress in the root nodules of Phaseolus vulgaris is induced under conditions of phosphorus deficiency

One of the most adverse effects of phosphorus (P) deficiency on N₂-fixing legumes is the generation of harmful active oxygen species which cause oxidative stress. And although oxidative stress has been widely studied in roots and shoots of various plant species, it has not yet sufficiently been documented in bean nodules so far. In this study, two recombinant inbred lines RIL115 (P-deficiency tolerant) and RIL147 (P-deficiency sensitive) of common bean and Concesa (local variety) were inoculated separately with the reference strain R. tropici CIAT899, RhM₁₁ (R. gallicum) or RhM₁₄ (R. tropici); two local strains of the Marrakesh region of Morocco. Nodulated plants were grown under semi-hydroponic conditions with sufficient or deficient P supply and analyzed for their oxidative responses at the flowering stage. The results indicated that P-deficiency decreased the growth of shoots (48 %) and nodules (32 %), particularly with RhM₁₄ exhibiting the highest decrease (52 %) of nodulation. This constraint increased electrolyte leakage of nodules (40 %) as compared to leaves (20 %), especially for plants inoculated with RhM₁₄ and CIAT899. Moreover, high H₂O₂ and malondialdehyde contents were noticed in P-deficient nodules of RhM₁₄ and RhM₁₁. These variations were associated with peroxidase activity stimulation in P-deficient nodules induced by CIAT899 and RhM₁₄. In symbiosis with RIL115, these last strains exhibited the highest nodule phenol content. Overall, phenol content was mainly enhanced in P-deficient nodules (35 %) as compared to the leaves (16 %). It was concluded that the genotypes inoculated with CIAT899 and RhM₁₁ are relatively P-deficiency tolerant combinations as compared to those inoculated with RhM₁₄. Increase of oxidative stress in nodules rather than in leaves points to the need for further investigations of mechanisms that improve the root-nodule efficiency under adverse conditions.     

Morphological Characteristics and Gene Mapping of Purple Apiculus Formation in Rice

Plant Molecular Biology Reporter - Apiculus color of grain is an important trait which is used as a morphological marker in rice (Oryza sativa. L). In the present study, the purple apiculus mutant...     

Molecular Differentiation of Lactococcus lactis Subspecies lactis and cremoris Strains by Ribotyping and Site Specific-PCR

Twenty-five strains of Lactococcus lactis subspecies lactis and subspecies cremoris obtained from dairy industry and environmental collections were examined by 16S RNA automated ribotyping profiles and site-specific PCR (S-PCR). By automated ribotyping, the majority of strains were classified in accordance with phenotypic characterization, with the exception of one lactis (220) and two cremoris (BO32 and 140) strains. A complete differentiation of subspecies lactis and cremoris in agreement with conventional phenotypic methods was achieved by S-PCR with a set of site-specific primer pairs (PR1, RM4, and F3) designed particularly from a deletion region found in subspecies cremoris, but not in lactis. Therefore, S-PCR with primers (PR1, RM4, and F3) is a rapid and very sensitive method for the distinction of lactis and cremoris subspecies in dairy production. Received: 19 June 2000 / Accepted: 17 July 2000     

Bioavailability to Fish of Sediment PAH as an Indicator of the Success of In Situ Remediation Treatments at an Experimental Oil Spill

A weathered medium crude oil was applied to experimental plots of Scirpus pungens (Three-square Bulrush) in a freshwater wetland to determine the efficacy of strategies for shoreline oil spill bioremediation based on nutrient enrichment (bioremediation) and plant growth (phytoremediation). Plots were unoiled, oiled with no added nutrients, or oiled with repeated applications of phosphate and nitrate fertilizers. Following initial treatments, the experimental plots were raked to simulate the activity of wave action on oil penetration, and plants in one fertilized plot were cut repeatedly. The sediments were sampled at regular intervals for 15 months after oiling, and the loss of oil was assessed by 4-day laboratory tests of polynuclear aromatic hydrocarbon (PAH) bioaccumulation by trout, as demonstrated by increases in activity of liver cytochrome P450 (CYP1A) enzymes. Oil alone, oil mixed with sediments in the lab, and oiled sediments from treated plots all induced CYP1A activity relative to untreated controls, indicating the presence and bioavailability of PAH. Induction did not vary with nutrient treatments, but declined by 80% within 15 months of oiling, and chemical analyses indicated equivalent losses of hydrocarbons in sediment. These results demonstrate that bioavailable PAHs persisted in measurable quantities for at least 1.25 years following oiling, and that stimulation of plant growth did not affect the rate of oil disappearance. The controlling factors were likely weathering and sediment movement.     

The mast cells of the mammalian central nervous system. IX. Development of the mast cells in the brain of the young rat

There are four potentially granular or frankly granular cells within the connective tissue compartment of the mammalian central nervous system, whether this is part of the surface leptomeninges or the leptomeningeal sleeves around parenchymal blood vessels larger than capillaries. These are: Cells that behave like macrophages, part of the mononuclear phagocyte system of the body; they are granular to varying degrees (containing lysosomes). Brown-pigmented granular cells which are mainly located on the surface but are also seen for varying distances along blood vessels as they pass inside the CNS of pigmented animals. Mast cells (MCs) which are granular and located especially prominently in surface leptomeninges of young mammals, and, in adults, are restricted to special parts of the CNS. Granular cells, referred to by me as neurolipomastocytoid cells (NLMs), are numerous, ubiquitously distributed, and seem to have morphological features in common with those of both MCs and macrophages. The exact identity of these NLMs still needs to established. One approach was to study the development of all three non-pigmented cells in the immature brain of the albino rat, especially at the ultrastructural level. This communication represents the findings regarding the MCs. The MCs appear to arise from a small mononuclear cell and to go through maturation stages identical to those described by others for MCs outside the CNS. The greatly flattened adjacent leptomeningeal cells are an easily identifiable entity especially due to their peculiar glycogen content in the young.     

m-Octopamine: Normal Occurrence with p-Octopamine in Mammalian Sympathetic Nerves

The development of a radiochemical enzyme assay for p-octopamine in 1969 led to its identification in a large number of invertebrate nerve systems and in mammalian sympathetic nerves. The original method by which p-octopamine was measured has now been found to be nonspecific; however, modifications of this procedure can determine both m- and p-octopamine. We recently developed a new specific method for the unequivocal identification and quantitative determination in tissue of the six octopamine and synephrine isomers. With this method--negative chemical ionization gas chromatography-mass spectrometry--the more physiologically active m-octopamine has been found in association with p-octopamine in 10 organs of the rat. m-Octopamine is present in concentrations equal to those of p-octopamine in heart, spleen, and liver and in concentrations from 30 to 60% of p-octopamine in adrenals, vas deferens, brain, kidney, large intestine, bladder, and lungs. In vivo inhibition of monoamine oxidase markedly increased the concentrations of both m- and p-octopamine in all organs examined. Both amines were virtually absent from all organs except the adrenals following chemical sympathectomy with 6-hydroxydopamine, thereby establishing that m- and p-octopamine are localized within sympathetic nerve endings.     

Economic activity in the South-Asian population in Britain: the impact of ethnicity,religion, and class

This paper expands the existing literature on ethnicity and economic activity in Britain by studying the impact of religion and class. It argues that while the class location of the different South-Asian groups is important in determining their labour market outcomes, it does not operate independently from ethnicity; rather it is highly influenced by ethnicity in the process of determining the labour market participation of these groups. We use data obtained from the 2001 UK Census on Indian, Pakistani, and Bangladeshi men and women aged between twenty and twenty nine. Our findings confirm that class structure of the South-Asian groups is highly ethnicized, in that the ethno-religious background and class are interwoven to the extent that the separation between them is not easy, if not impossible.     

Taxonomic review of the “Bulimes”, terrestrial gastropods from the continental Eocene of the Hamada de Méridja (northwestern Sahara,Algeria) (Mollusca: Stylommatophora: Strophocheilidae?), with a discussion of the genera of the family Vidaliellidae

Terrestrial gastropods occur in many North African localities in Eocene continental deposits. Here we analyse the faunal assemblage from the Hamada de Méridja Formation in southwestern Algeria, dated as Early to Middle Eocene on the basis of charophytes. The assemblage consists of three closely related species that to date have been classified either in the extant Madagascan genus Leucotaenius v. Martens, 1860, or in the SW European Eocene genera Romanella Jodot, 1957 and Vicentinia Jodot, 1957. This is rejected for shell morphological and phylogeographical reasons, and a new classification as Maghrebiola gen. nov. is proposed. Maghrebiola is tentatively placed in the South American family Strophocheilidae, as species from the Early Eocene Itaboraí Basin of Brazil, currently placed in the genus Eoborus Klappenbach and Olazarri, 1970 in the family Strophocheilidae, superfamily Acavoidea, have a very similar shell habitus. This record possibly extends the known geographical range of the Strophocheilidae into the African continent during the Eocene. Immigration of this stock into North Africa during the Cretaceous via a still existing plate connection is assumed. An attribution of Maghrebiola to the African family Achatinidae is unlikely for shell morphological reasons despite certain habitus similarities, although the Priabonian genera Arabicolaria and Pacaudiella from Oman most likely belong into this family, and not to the Vidaliellidae as originally proposed. Possible causes for the very low diversity of the assemblage are mainly unfavourable living conditions, i.e. a relatively dry climate resulting in sparse vegetation and only occasional presence of water bodies, which may have had increased salinities, accounting for the lack of freshwater mollusks. The absence of any competing large gastropods may possibly have facilitated high intraspecific variability leading to sympatric occurrence of three closely related species, due to the animals occupying a wide range of available ecological niches. As the species discussed here have also been attributed to the genera Romanella and Vicentinia in the Vidaliellidae, we provide an appendix with annotated characterisations of most genera of the Vidaliellidae and list the nominal species assigned to them. This family is tentatively placed in the South American superfamily Orthalicoidea; its stock would have similarly immigrated from South America, but have successfully colonized mainly SW Europe, with only one Eocene species [Romanella kantarensis (Jodot, 1936)] recognized in Algeria.