New markers for linkage analysis of X-linked hypophosphataemic rickets

Three polymorphic markers have been used to improve the genetic map of the region Xp22.1-p22.2, which contains the HYP (hypophosphataemic rickets) locus. DXS365 gave no recombinants with HYP, with a peak Lod score of 5.4 at = 0.0. A microsatellite marker mPA274 was derived for the DXS274 locus; it detects five alleles with a polymorphism information content of 0.55. Combining information from this microsatellite and the original DXS274 marker, probe CRI-L1391, the peak Lod score for DXS274 against HYP was 9.6 at = 0.02. A microsatellite associated with the DXS207 locus (mPA207) gave a peak lod score against HYP of 4.7 at = 0.14. A consideration of key recombinants and multilocus analysis suggests the gene order: Xpter-DXS207-DXS43-DXS197-(DXS365, HYP)-DXS274-DXS41-Xcen.     

Growth activation of the microalga Isochrysis galbana by the aqueous extract of the seaweed Monostroma nitidum

Cell growth of the marine microalga Isochrysis galbana was regulated by the addition of seaweed extracts in the culture medium. Methanol-soluble extracts from 27 species of seaweed showed growth activation only from Enteromorpha linza, and growth inhibition from Ishige foliacea and Sargassum sagamianum. Water-soluble extracts from Grateloupia turuturu and Monostroma nitidum showed growth activation, while none of the seaweed showed growth inhibition. From results of growth activation of extracts on I. galbana, the water extract of M. nitidum was the most effective up to two-fold increase in cell density with the addition of 1 mg mL^-1 of extract to the medium. The cell growth rate was increased from 0.52 to 0.65 d^-1. Cell size, gross biochemical compositions, fatty acid compositions, and digestion efficiency by shellfish differed marginally between cultures of I. galbana grown with and without the M. nitidum aqueous extract. This extract has also enhanced the growth of other feed microalgae tested, including Dunaliella salina. This revised version was published online in August 2006 with corrections to the Cover Date.     

Osteopenia in 37 members of seven families: analysis based on a model of dominant inheritance.

BACKGROUND: The genetic factors involved in determining bone mineral density (BMD) have not been fully elucidated. We have begun genetic linkage analysis of seven families in which many members are osteopenic, in order to identify chromosomal loci that are potentially involved in determining BMD. MATERIALS AND METHODS: Spine BMD was measured in 143 members of seven kindred with familial osteopenia. The absolute BMD values for the spine (L2-L4) were converted to the age-, gender-, and weight-adjusted Z scores, and this corrected value was used as the quantitative trait on which to base subsequent genetic analyses. Simulations of linkage were performed in order to determine the information content of the pedigree set, and actual linkage analysis was conducted using polymorphic markers either within or near three candidate loci: COL1A1, COL1A2, and vitamin D receptor (VDR). RESULTS: The distribution of the corrected Z scores was bimodal (p = 0.001) suggesting a monogenic mode of inheritance of the low BMD trait. Simulation of linkage analysis suggested that the family data set was sufficient to detect linkage under a single major gene model. Actual linkage analysis did not support linkage to the three candidate loci. In addition, the VDR genotype was not statistically associated with low bone density at the spine. CONCLUSIONS: Loci other than COL1A1, COL1A2 and VDR are very likely responsible for the low BMD trait observed in these families. These families are suitable for a genome-wide screen using microsatellite repeats in order to identify the loci that are involved in osteopenia.     

An attempt to estimate the predatory pressure exerted by the lesser weever, Trachinus vipera Cuvier, in the southern North Sea

In order to evaluate the impact of the lesser weever on the ecosystem of the southern North Sea, geographical distribution, density, growth, production and food requirements have been estimated. High densities were found on and around the Brown Ridge, an area with high tidal current velocities, medium grain-size of the sediment and a poor benthic fauna. Growth is restricted to the months of June October. During the winter cessation of growth a considerable loss of weight (about 20%) takes place. Mortality has been estimated by using the average size frequency distribution of all catches made from 1972 to 1984. The resulting convex type of survival curve indicates a high survival rate of the II to IV-group fishes. The production (estimated with Allen's graphical method) of a population of 100 individuals including all age groups (0-VI) amounts to 123.7 g AFDW-year'. In areas with highest densities, consequently, production amounts to 0.018–0.078 g AFDW-m² -year^-1. With an assumed transfer efficiency of 10% through the year, food requirements amounts to 0.18–0.78 g AFDW-m ² -year ^-1. Since the lesser weever feeds mainly on fish (85.6%), almost exclusively on gobies (Pomatoschistus sp.), and with an assumed transfer efficiency of approximately 10%, the indirect predatory pressure exerted by it may amount to 1.6 6.7g AFDW-m ².year ^-1. A possible feeding by gobies on pelagic organisms (calanoids, mysids) is discussed.     

A 60 kd cdc2-associated polypeptide complexes with the E1A proteins in adenovirus-infected cells

p60 is a cellular protein that binds to the adenovirus E1A protein complex in virally infected or transformed human cells. In both infected and uninfected cells, p60 was found in a complex with the cdc2 protein kinase. Immune complexes containing p60 and cdc2 display a cell cycle-dependent histone H1 kinase activity that is most active in interphase. The previously described cdc2-p62/cyclin complex also acts as a histone H1 kinase but is maximally active in mitotic metaphase. The shift in the timing of activation of different cdc2-containing complexes suggests that each might play a distinct role in regulation of the cell cycle.     

Lectin binding by microvillous membranes and coated-pit regions of human syncytial trophoblast

Summary The distribution of saccharides on the microvillous membrane of the human syncytial trophoblast was investigated using ferritin conjugates of four lectins: concanavalin A (specific for -d-manno- and -d-glucopyranosyl residues), wheatgerm agglutinin (specific forN-acetylglucosamine),Limulus polyphemus lectin (specific forN-acetylneuraminic acid), andLotus tetragonolobus lectin (specific for -l-fucose). Concanavalin A and wheatgerm agglutinin (WGA) reacted strongly with the surface membrane and ferritin deposits were also observed in coated pit regions of the membrane. Lectins fromL. polyphemus andL. tetragonolobus, however, reacted only weakly with the microvillous border and neither reacted with coated pits.Enhanced agglutinability of trophoblast cells in comparison with other foetal cells from the same conceptus was seen with WGA. This agglutination was inhibited by addition of acetylglucosamine or by a solubilized membrane fraction which was bound by a column of WGA-Sepharose. The membrane fraction which did not bind to the column did not inhibit agglutination. Electrophoresis of the WGA-bound membrane proteins revealed six subunits, the major band having an apparent mol. wt. of 55 000. A protein of this mol. wt was also seen in coated vesicles isolated from equivalent human placentae.     

The botanical neolithic revolution

It is proposed, on the basis of evidence from geological history and paleoclimatology, that annual grasses and legumes did not appear as significant components of the vegetation of Asia until the Neothermal, some 11,000 years B.P. The new combination of environmental factors which then became operative induced a widespread physiological and genetic change from a perennial to an annual habit in ecoclimatic zones in which annual types of ancestral perennials had not earlier occurred in any number. The annual prototypes of the Asian cereals and grain legumes therefore became rather suddenly and abundantly available to primitive man in his still biological ecosystems. Once this botanical revolution had occurred throughout the isoxerothermic zones around the inner cores of Asia, progress towards what came to be called civilizations, based on increasingly economic agricultural ecosystems involving cultivation and domestication of crops, followed in a gradual step-by-step manner.     

Distinct but overlapping functions of Hsp70, Hsp90, and an Hsp70 nucleotide exchange factor during protein biogenesis in yeast

Hsp70 and Hsp90 molecular chaperones play essential roles in protein expression and maturation, and while catalyzing protein folding they can "decide" to target mis-folded substrates for degradation. In this report, we show for the first time distinct but partially overlapping requirements for Hsp90, Hsp70, and an Hsp70 nucleotide exchange factor (NEF) at different steps during the biogenesis of a model substrate, firefly luciferase (FFLux), in yeast. By examining the inducible expression of FFLux in wild type cells and in specific yeast mutants, we find that the Fes1p NEF is required for efficient FFLux folding, whereas the Hsp70, Ssa1p, is required for both protein folding and stability, and to maintain maximal FFLux mRNA levels. In contrast, Hsp90 function was primarily necessary to express the FFLux-encoding gene from an inducible promoter. Together, these data indicate previously unknown roles for these proteins and point to the complexity with which chaperones and cochaperones function in the cell.     

Mapping autosomal dominant progressive limb-girdle myopathy with bone fragility to chromosome 9p21-p22: a novel locus for a musculoskeletal syndrome

Progressive myopathy of a limb-girdle distribution and bone fragility is a rare autosomal dominant disorder of unknown etiology. Affected individuals, within this family, present with various combinations of progressive muscle weakness, easy fracturing, and poor healing of long bones. Additional features include premature graying with thin hair, thin skin, hernias, and clotting disorders. Electromyograms show myopathic changes and biopsies reveal non-specific myopathic changes. Skeletal radiographs demonstrate coarse trabeculation, patchy sclerosis, cortical thickening, and narrowing of medullary cavities. We report genetic mapping of this disorder to chromosome 9p21-p22 in a multigenerational family. A genome-wide scan for the disease locus obtained a maximal LOD score of 3.74 for marker GATA87E02 N (D9S1121). Haplotype analysis localized the disease gene within a 15 Mb interval flanked by markers AGAT142P and GATA5E06P. This region also localizes diaphyseal medullary stenosis with malignant fibrous histiocytoma (DMS-MFH). Identification of the disease gene will be necessary to understand the pathogenesis of this complex disorder.Funding for this study is from the National Institutes of Health NIAMS RO1 AR050236-01A1, R03 AR AR46869-03, NINDS K02 NS02157 award, the Muscular Dystrophy Association, Paget Foundation, Children’s Hospital Boston and Shriners Hospitals for Children.     

Lesions of the anteroventral third ventricle region (AV3V) disrupt cardiovascular responses to an elevation in core temperature

Blood flow is redistributed from the viscera to the periphery during periods of heat stress to maximize heat loss. The heat-induced redistribution of blood flow is strongly influenced by nonthermal inputs such as hydration status. At present, little is known about where thermal and nonthermal information is integrated to generate an appropriate effector response. Recently, the periventricular tissue that surrounds the anteroventral third ventricle (AV3V) has been implicated in the integration of thermal and osmotic information. The purpose of the present study was to determine the effects of electrolytic lesions of the AV3V on the cardiovascular response to a passive heat stress in unanesthetized, free-moving male Sprague-Dawley rats. Core temperature was elevated at a constant rate of approximately 0.03 degrees C/min in sham- and AV3V-lesion rats using an infrared heat lamp. Changes in mesenteric and hindquarter vascular resistance were determined using Doppler flow probes, and heat-induced salivation was estimated using the spit-print technique. The rise in mean arterial pressure (MAP), heart rate (HR), and mesenteric resistance in response to elevations in core temperature were all attenuated in AV3V-lesion rats; however, hindquarter resistance was unaffected. Heat-induced salivation was also diminished. In addition, AV3V-lesion rats were more affected by the novelty of the experimental environment, resulting in a higher basal core temperature, HR, and MAP. These results indicate that AV3V lesions disrupt the cardiovascular and salivatory response to a passive heat stress in rats and produce an exaggerated stress-induced fever triggered by a novel environment.