Five new microsatellite polymorphisms at the q21 region of human chromosome 21

Five clones, containing polymorphic CA-repeat sequences, have been isolated from a specific human chromosome 21 phage library and have been localised to band q21 of chromosome 21 using a somatic cell hybrid panel. These highly repetitive sequences (D21S1263, D21S1264, D21S1415, D21S1417 and D21S1420) have been characterised in the CEPH reference parents and have heterozygosities ranging from 0.30 to 0.81 and an average polymorphism information content (PIC) of 0.62. The relative order of these markers, based on the somatic cell hybrid panel, is cen-D21S1417, D21S1420-D21S1263, D21S1415-D21S1264-tel. The most polymorphic marker (D21S1264) has been included in the chromosome 21 genetic map. They have also been localised in the CEPH/ Généthon YAC panel, providing a refined localisation of these polymorphic sequences. These five CA-repeat markers should provide a better characterisation of the q21 region of chromosome 21.     

De novo missense mutation Y174S in exon 1 of the adrenoleukodystrophy (ALD) gene

Adrenoleukodystrophy (ALD) is an X-linked disease, characterised by an alteration of the peroxisomal -oxidation of the very long chain fatty acids. The ALD gene has been identified and mutations have been detected in ALD patients. We report here a new missense mutation in the ALD gene of a male patient, predicting a tyrosine to serine substitution at codon 174 (mutation Y174S). The mother of the ALD patient does not have the Y174S mutation in her leukocyte DNA, indicating that Y174S arose de novo in the patient. Y174S is the first reported de novo mutation in the ALD gene.     

Solubility of plasma proteins in the presence of polyethylene glycol

The solubility of plasma proteins was studied at various pH as a function of polyethylene glycol concentration. Computer analysis of precipitation curves permitted equations to be derived. The equations describe the relationship between protein solubility and polyethylene glycol concentration. The analysis of the equations furnished further data for the validity of the displacement theory.     

Urinary prostaglandin and kallikrein excretion are not flow dependent in the rat

To study the relationship between urine flow, urinary prostaglandin (PG) and kallikrein excretion in the rat high urine flow was induced in hydropenic Long-Evans rats by either hypotonic volume expansion or with manniitol or with furosemide. PGE, excretion remained unchanged during hypotonic volume expansion (134.5 ± 29.7 before and 153.0 ± 48.9 pg/min after) while it decreased significantly with mannitol (from 166.3 ± 32.4 to 45.2 ± 8.2 pg/min, p<0.01) and with furosemide (from 170.0 ± 20.4 to 29.5 ± 5.3 pg/min, p<0.001). PGF_2α excretion rates were slightly reduced following all three interventions. Urinary kallikrein excretion remained unchanged in all three groups of animals. It is concluded that, in contrast to human and dogs in the rat urine flow and urinary PG excretion are not interlinked.     

The chemistry and crustacean zooplankton of the Seewinkel pans: a review of recent conditions

A number of shallow pans was investigated between May 1982 and May 1985 in the Seewinkel region between Neusiedlersee and the Hungarian border. Chemical and zooplankton samples were obtained at three monthly intervals. Analyses indicated some changes during the past decades. Human activity has resulted in some changes to water chemistry and zooplankton composition in a few pans, and many smaller pans have now disappeared.     

Differential manifestation of seed mortality induced by seed-specific expression of the gene for diphtheria toxin A chain in Arabidopsis and tobacco

Summary A pea vicilin promoter-diphtheria toxin A (DTx-A) chain gene fusion was introduced into Arabidopsis and tobacco. The chimeric Dtx-A gene behaves as a dominant, seed-lethal, Mendelian factor, and the segregation ratios are consistent with the numbers of integrated copies as revealed by Southern blotting. Germination deficiency results from distinct developmental abnormalities, thus allowing genetic dissection of seed development. The endosperm is affected first in both species. In Arabidopsis, full cellularization of the initially syncytial endosperm does not take place, which results in shrinkage and a shriveled appearance of the mature dry seed. The embryo, which appears structurally normal and lacks visible lesions, ceases to develop at the partially recurved cotyledon stage and does not use the remaining endosperm. In tobacco, peripheral degeneration and premature termination of cellular endosperm development occurs at the cotyledon initiation stage. Lesions appear in the cotyledons at the advanced cotyledon stage, but the embryo continues to grow and attains nearly the same size and level of differentiation as mature wild-type embryos before degeneration and intracellular disintegration take place throughout. Accumulation of protein bodies and other cytoplasmic inclusions is very limited and occurs only in few cells. The timing and distribution of lesions follow a pattern typical for accumulation of protein bodies in wild-type seeds. These observations are consistent with expression of the vicilin promoter in the enlargement phase of cell differentiation. A novel tissue interaction arises, when the embryo uses up all the arrested endosperm: the embryo proves to be capable of absorbing the parenchyma layers of the integument, which are normally obliterated by, and incorporated into, the endosperm. The mature seed thus consists of a seed coat of one rigid cell layer, and a degenerated embryo. The genetic ablation technique has thus contributed to the establishment of the sequence of events and elucidation of the role of different cell lineages and tissues in seed development.     

Plant regeneration of NaCl-pretreated cells from long-term suspension culture of rice (Oryza sativa L.) in high saline conditions

Cells of a 2-year-old suspension culture of rice (Oryza sativa L.), grown under 1.5% NaCl stress for 3 months, gave rise to plants through embryogenesis in different saline conditions. The high regeneration potential (59.6%) on salt-free medium decreased rapidly with increasing concentration of salt in the regeneration medium. At 1.25% NaCl, healthy shoots were developed in 14.9% of the cultures. Under 1.5% salt stress, embryo formation and embryo germination (6.1%) was observed but further development into plants was inhibited. Cells not pretreated with salt produced plants at a low frequency (2.6–4.2%) both in salt-free and low saline condition (0.75–1% NaCl). Cells pretreated for 3 months with 0.75% salt did not give rise to plants on all tested media. Plants regenerated from the salt-stressed cultures were transferred to soil and grew to maturity in a greenhouse.Abbreviations BA 6-benzyladenine - CH casein hydrolysate - 2,4-D 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid