North Indian Muslims: Enclaves of foreign DNA or Hindu converts?

The mtDNA composition of two Muslim sects from the northern Indian province of Uttar Pradesh, the Sunni and Shia, have been delineated using sequence information from hypervariable regions 1 and 2 (HVI and HVII, respectively) as well as coding region polymorphisms. A comparison of this data to that from Middle Eastern, Central Asian, North East African, and other Indian groups reveals that, at the mtDNA haplogroup level, both of these Indo-Sunni and Indo-Shia populations are more similar to each other and other Indian groups than to those from the other regions. In addition, these two Muslim sects exhibit a conspicuous absence of West Asian mtDNA haplogroups suggesting that their maternal lineages are of Indian origin. Furthermore, it is noteworthy that the maternal lineage data indicates differences between the Sunni and Shia collections of Uttar Pradesh with respect to the relative distributions of Indian-specific M sub-haplogroups (Indo Shia > Indo Sunni) and the R haplogroup (Indo Sunni > Indo Shia), a disparity that does not appear to be related to social status or geographic regions within India. Finally, the mtDNA data integrated with the Y-chromosome results from an earlier study, which indicated a major Indian genetic (Y-chromosomal) contribution as well, suggests a scenario of Hindu to Islamic conversion in these two populations. However, given the substantial level of the African/Middle Eastern YAP lineage in the Indo-Shia versus its absence in the Indo-Sunni, it is likely that this conversion was somewhat gender biased in favor of females in the Indo-Shia.     

Ontogeny of glyoxysomes in maturing and germinated cotton seeds—a morphometric analysis

Morphometric procedures were used with light and electron microscopy to examine glyoxysome number, volume, shape and distribution as well as mesophyll cell volume, in cotyledons of mature (50 d postanthesis), imbibed (5h) and germinated (24 and 37 h) cotton (Gossypium hirsutum L.) seeds. Additionally, activities of five glyoxysomal marker enzymes in cotyledon extracts were assayed at each of the above ages. Cell volume was determined from photomicrographs of Epon-embedded sections by the point-counting procedure. Analysis of variance showed that cell volume was not different among the tissue segments studied. Glyoxysomes were cytochemically stained for catalase (EC 1.11.1.6) activity with the 3,3-diaminobenzidine-tetrahydrochloride procedure. Analyses involving both phase and electron microscopy, and two separate sterologic calculations for determining the number of glyoxysomes per cell, indicate that glyoxysomes are numerous in mature seeds, persist through desiccation and imbibition, then increase dramatically in volume (seven fold) but not number (a maximum of 1.5-fold), when enzyme activities increase two to six times (depending on the enzyme). During the entire period of increase in glyoxysomal enzyme activities, no ultrastructural evidence was found for glyoxysome formation or destruction. Our data, in contrast to some proposals in the literature, indicate that cottonseed glyoxysomes form during seed maturation, then develop following seed imbibition into pleomorphic organelles by posttranslational accumulation of proteins from the cytosol and transfer of membrane components probably from the endoplasmic reticulum.Abbreviations DAB 3,3-diaminobenzidine tetrahydrochloride - DPA days postanthesis - ER endoplasmic reticulum     

EXCYSTMENT AND GROWTH OF CHRYSOPHYTES AND DINOFLAGELLATES AT LOW TEMPERATURES AND HIGH SALINITIES IN ANTARCTIC SEA-ICE1

Extreme environmental conditions have been thought to limit algal growth in the upper sea-ice. In McMurdo Sound, Antarctica, chrysophyte statocysts (stomatocysts) and dinoflagellate hypnozygotes (resting cysts) overwinter in first- and second-year land-fast sea-ice exposed to temperatures of -20° C or lower. In early November, when temperatures in the upper ice are < ?8°C and brine salinities are >126 psu, dinoflagellate cysts activate and shortly thereafter excyst. During early November, chrysophyte statocysts also begin to excyst. Net daily primary production occurs in the sea-ice brine at temperatures as low as ?7.1° C, at brine salinities as high as 129 psu, and at average photon flux densities as low as 5 μmol photons.m^?2.s^?1. Dinoflagellate densities were >10⁶ vegetative cells.L^?1 of ice while temperatures in the upper ice were between ?6.8 and ?5.8° C and brine salinities were ～100 psu. Chrysophyte densities reached >10⁶.L^?1 of ice by early December. High densities of physiologically active clyo- and halotolerant algae can occur in the upper land-fast sea-ice under extreme conditions of temperature and salinity.     

The role of temperature,stress, and other factors in the neurotoxicity of the substituted amphetamines 3,4-methylenedioxymethamphetamine and fenfluramine

Amphetamines (AMPs) can cause long-term depletions in striatal dopamine (DA) and serotonin (5-HT), and these decrements are often accepted asprima facie evidence of AMP-induced damage to the dopaminergic and serotonergic projections to striatum. Rarely are indices linked to neural damage used to evaluate the neurotoxicity, of the AMPs. Here, were determined the potential neurotoxic effects of two substituted AMPs,d-methylenedioxymethamphetamine (d-MDMA), andd-fenfluramine (d-FEN) in group-housed female C57BL6/J mice. Astrogliosis, assessed by quantification of glial fibrillary acidic protein (GFAP), was the main indicator of d-MDMA-induced neural damage. Assays of tyrosine hydroxylase (TH), DA, and 5-HT were used to determine effects on DA and 5-HT systems. Since AMPs are noted for both their stimulatory and hyperthermia-inducing properties, activity, as well as core temperature, was monitored in several experiments. To extend the generality of our findings, these same end points were examined in singly housed female C57BL6/J mice in and group-housed male C57BL6/J or female B6C3F1 mice after treatment with d-MDMA. Mice, received either d-MDMA (20 mg/kg) singly housed mice received dosages of 20, 30, or 40 mg/kg) or d-FEN (25 mg/kg) every 2 h for a total of four sc injections. d-MDMA caused hyperthermia, whereas d-FEN induced hypothermia. d-MDMA cause a large (300%) increase in striatal GFAP that resolved by 3 wk and a 50–75% decrease in TH and DA that was still apparent at 3 wk, d-FEN did not affect any parameters in striatum. d-MDMA is a striatal dopaminergic neurotoxicant in both male and female C57BL6/mice, as evidence by astrogliosis and depletions of DA in this area in both sexes. The greater lethality to males suggests they may be more sensitive, at least to the general toxicity of d-MDMA, than females. d-MDMA (20 mg/kg) induced the same degree of damage whether mice were housed singly or in groups. Higher dosages in singly housed mice induced greater lethality, but not greater neurotoxicity. d-MDMA was also effective in inducing striatal damage in mice of the B6C3F1 strain. Significant increases in activity were induced by d-MDMA, and these increases were not blocked by pretreatment with MK-801, despite the profound lowering of body temperature induced by this combination. A lowering of body temperature, whether by a 15°C ambient temperature (approx 2°C drop), pretreatment with MK-801 (1.0 mg/kg prior to the first and third d-MDMA injections; approx 5–6°C drop) or restraint (approx 5–6°C drop), was effective in blocking the neurotoxicity of d-MDMA in both C57BL6/J and B6C3F1. The stimulatory effects of d-MDMA appeared to have little impact on the neurotoxicity induced by d-MDMA or the protection conferred by MK-801. These data suggest that in the mouse, the neurotoxic effects of d-MDMA, and most likely other AMPs, are linked to an effect on body temperature.     

Ganglioside inhibition of neurite outgrowth requires Nogo receptor function: identification of interaction sites and development of novel antagonists

Gangliosides are key players in neuronal inhibition, with antibody-mediated clustering of gangliosides blocking neurite outgrowth in cultures and axonal regeneration post injury. In this study we show that the ganglioside GT1b can form a complex with the Nogo-66 receptor NgR1. The interaction is shown by analytical ultracentrifugation sedimentation and is mediated by the sialic acid moiety on GT1b, with mutations in FRG motifs on NgR1 attenuating the interaction. One FRG motif was developed into a cyclic peptide (N-AcCLQKFRGSSC-NH(2)) antagonist of GT1b, reversing the GT1b antibody inhibition of cerebellar granule cell neurite outgrowth. Interestingly, the peptide also antagonizes neurite outgrowth inhibition mediated by soluble forms of the myelin-associated glycoprotein (MAG). Structure function analysis of the peptide point to the conserved FRG triplet being the minimal functional motif, and mutations within this motif inhibit NgR1 binding to both GT1b and MAG. Finally, using gene ablation, we show that the cerebellar neuron response to GT1b antibodies and soluble MAG is indeed dependent on NgR1 function. The results suggest that gangliosides inhibit neurite outgrowth by interacting with FRG motifs in the NgR1 and that this interaction can also facilitate the binding of MAG to the NgR1. Furthermore, the results point to a rational strategy for developing novel ganglioside antagonists.     

Development of a strain-specific molecular method for quantitating individual campylobacter strains in mixed populations

The identification of sites resulting in cross-contamination of poultry flocks in the abattoir and determination of the survival and persistence of campylobacters at these sites are essential for the development of intervention strategies aimed at reducing the microbial burden on poultry at retail. A novel molecule-based method, using strain- and genus-specific oligonucleotide probes, was developed to detect and enumerate specific campylobacter strains in mixed populations. Strain-specific oligonucleotide probes were designed for the short variable regions (SVR) of the flaA gene in individual Campylobacter jejuni strains. A 16S rRNA Campylobacter genus-specific probe was also used. Both types of probes were used to investigate populations of campylobacters by colony lift hybridization. The specificity and proof of principle of the method were tested using strains with closely related SVR sequences and mixtures of these strains. Colony lifts of campylobacters were hybridized sequentially with up to two labeled strain-specific probes, followed by the generic 16S rRNA probe. SVR probes were highly specific, differentiating down to 1 nucleotide in the target sequence, and were sufficiently sensitive to detect colonies of a single strain in a mixed population. The 16S rRNA probe detected all Campylobacter spp. tested but not closely related species, such as Arcobacter skirrowi and Helicobacter pullorum. Preliminary field studies demonstrated the application of this technique to target strains isolated from poultry transport crate wash tank water. This method is quantitative, sensitive, and highly specific and allows the identification and enumeration of selected strains among all of the campylobacters in environmental samples.     

Polyamine biogenesis in the rat mammary gland during pregnancy and lactation

Polyamines and RNA accumulate in the rat mammary gland during pregnancy, but the major increases occur after parturition. Therefore the major increases occur after the gland has obtained its maximal complement of epithelial cells. During lactation, the spermidine concentration rises above 5mm and RNA content in the lactating mammary gland reaches a value 16 times that of the unstimulated mammary gland. The ratio of spermidine/spermine, an increase of which initially signals an elevation in biosynthetic activity, is near 1 in the normal mammary gland and is greater than 10 in the lactating mammary gland. Putrescine concentration is very low during the entire course of mammary-gland development, with the exception of early pregnancy. The low putrescine concentration probably reflects the very rapid conversion of putrescine into spermidine. Both ornithine decarboxylase, the enzyme that synthesizes putrescine, and putrescine-stimulated S-adenosyl-l-methionine decarboxylase, the enzyme that synthesizes spermidine, increase in activity during middle and late pregnancy; during lactation, both enzyme activities are elevated until the 21st day of lactation, and then decline. These declines are concomitant with involution. Also, it was found that the amount of ribonuclease activity in the mammary gland was very high during lactation, almost double that in the gland during pregnancy.