White matter aging drives microglial diversity

1. Download : Download high-res image (221KB)
2. Download : Download full-size image

     

Genetic diversity of Crocus antalyensis B. Mathew (Iridaceae) and a new subspecies from southern Anatolia

Crocus antalyensis B. Mathew is a bulbous plant endemic to Turkey. It is morphologically variable within the western part of Anatolia. Amplified fragment length polymorphism (AFLP) marker system was used to detect genetic variation among the Crocus taxa. Twenty-two primer combinations were used to screen for polymorphism among the samples. Genetic variation ranged from 0.44 to 0.69. We demonstrated the efficiency of the AFLP marker system for discriminating between individual C. antalyensis specimens. A high level of genetic variation was present among C. antalyensis specimens collected from different locations in Turkey. We also observed that C. antalyensis subspp. are genetically distinct from their relative Crocus flavus Haw. subsp. dissectus Baytop & B. Mathew. A new subspecies of C. antalyensis B. Mathew from southern Turkey is described. It is characterized by striped outer perianth segments, waist-shaped flowers, and glabrous throat of the perianth. A composite image of the new subspecies is presented.     

Evaluation of intra-amniotic surfactant administration for lung maturation in preterm sheep

We aimed to evaluate the effects of intra-amniotic surfactant administration on alveolar lecithin/sphingomyelin ratio, density of type II pneumocytes, and fetal lung function in preterm merino sheep. Pregnant ewes at 119 days gestation either received 200 mg intra-amniotic surfactant (n=4) or saline solution (n=4). After 24 h, the lambs were delivered by hysterotomy and mechanically ventilated. Lecithin/sphingomyelin ratios in alveolar fluid, inflating pressure–volume relationships, and type II pneumocyte counts in histological specimens were compared among the groups. All of the lambs completed the protocol. Mean lecithin/sphingomyelin ratio increased significantly in amniotic (p=0.03) and alveolar fluid (p=0.03) samples of surfactant-treated animals. Lung function in terms of pressure–volume curves did not differ between two groups. Type II pneumocyte density tended to be higher (p=0.057) after intra-amniotic surfactant administration. Single-dose treatment with intra-amniotic surfactant seems to improve amniotic and alveolar lecithin/sphingomyelin ratio questionably by increasing alveolar type II cells. Pressure–volume relationships from inflation of the lungs might be unaltered with intra-amniotic surfactant treatment.     

Doubled haploid plant production from unpollinated ovules of sugar beet (Beta vulgaris L.)

 The effects of cold pretreatment, AgNO₃ and activated charcoal on haploid plant production from unpollinated sugar beet ovules were investigated. Both cold pretreatment and the addition of charcoal increased the frequency of embryo formation, whereas AgNO₃ decreased or completely inhibited it. Colchicine (50, 100, 150 or 500 mg l^–1) and trifluralin (1.7, 3.4 or 5.0 mg l^–1) for 12, 24, 36 or 48 h were compared in agar-solidified, agarose-solidified or liquid media. Although colchicine gave a higher doubling rate (25.3%) than trifluralin (18.2%), the difference was not significant. Both agents were more effective when used in liquid (29.1%) than agarose-solidified medium (20.7%) and agar-solidified medium (15.4%). A treatment duration of 48 h was significantly more effective (27.5%) than 12 h (13.6%) but it was not different from 24 h (16.3%) or 36 h (18.6%). Received: 25 October 1999 / Revision received: 18 May 2000 / Accepted: 29 May 2000     

Identification of quantitative trait loci influencing annual height- and diameter-increment growth in loblolly pine (Pinus taeda L.)

 Quantitative trait loci (QTLs) for annual height- and diameter-increment growth were estimated in each of two three-generation loblolly pine pedigrees. Annual height-increment was measured in three consecutive years in the BASE pedigree and in four consecutive years in the QTL pedigree. Annual diameter-increment was measured only in the QTL pedigree for two consecutive years. An interval mapping-approach was used to estimate the number of QTLs, the magnitude of QTL effects, and their position on genetic linkage maps. Thirteen different height-increment and eight different diameter-increment QTLs were detected, suggesting that the these traits are, at least in part, controlled by a few genes of large effect. Little evidence was found for the expression of individual QTLs in multiple years or in multiple genetic backgrounds. These results were discussed in terms of the power of the experiment and their consequences for marker-assisted breeding. Received: 12 July 1998/Accepted: 5 August 1998     

Evaluation of trichothecene and nontrichothecene mycotoxins produced byFusarium in soybeans

Each of 12 cultures ofFusarium, comprising four species, isolated from moldy soybeans suspected of being involved in illness of wild geese, were grown separately in autoclaved moist rice, in autoclaved moist soybeans, and in surface sterilized-disinfected soybeans, assayed for various mycotoxins, and fed to rats. Four additional cultures that produced known toxins on rice were also grown on soybeans as controls. All isolates, except one ofF moniliforme, grown in rice resulted in weight loss of rats, and that one resulted in weight gain; 12 of the isolates caused death. One isolate ofF poae grown in soybeans caused death when consumed by rats, but none of the other 15 resulted in weight loss or overt injury. Much larger amounts of zearalenone, deoxynivalenol (DON), T-2 toxin, neosolaniol, T-2 tetraol, wortmannin, and moniliformin were produced by the cultures on rice than on soybeans, but more HT-2 toxin was produced by one isolate ofF poae grown on soybeans than when grown on rice. Soybeans appear to be a poor substrate for elaboration of most of the toxins produced by the isolates tested.     

2-(7,13-Dihydroxy-2-trans-octadecenoylamino)ethanesulfonic acid (lipotaurine) as an intermediate of taurolipids biosynthesis

A hydroxy fatty-acid-combined taurine (lipotaurine) was found in the taurolipids fraction of Tetrahymena thermophila. Lipotaurine accounted for about 1.4% of the total taurolipids of the cells, and was composed of taurine and 7,13-dihydroxy-2-trans-octadecenoic acid. By nuclear magnetic resonance, mass and infrared spectrometries, the chemical structure of lipotaurine was identified as 2-(7,13-dihydroxy-2-trans-octadecenoylamino)ethanesulfonic acid. When cells of T. thermophila were incubated with the double-labeled lipotaurine which was biosynthesized from [2(n)-3H]taurine and [1-14C]stearic acid, both the radioactivities were detected in taurolipid A, B and C. Furthermore, the ratio of the radioactivities of 3H and 14C in the lysotaurolipids were the same as that of the lipotaurine. From these results, it is suggested that lipotaurine is an intermediate of taurolipid biosynthesis.