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1.
L Vicari G De Dominicis M Vito C Placida E De Marinis 《Bollettino della Società italiana di biologia sperimentale》1985,61(2):271-278
The teratogenic and goitrogenic effects of Propineb, dithiocarbamate pesticide and Propylenthiourea (PLTU), its metabolite and degradation product have been studied. The aim of this study was to show the possible correlation between the two activities. Female Sprague-Dawley rats were treated with Propineb and PLTU starting from 6th to 16th day of pregnancy. The functional state of maternal and foetal thyroid, the toxicity of products versus dams and embryotoxic and teratogenic effects were examined. The observed goitrogenic effect may be compared to that reported in the previous studies of the authors, if considering time of sacrifice. In fact, the lesion quickly rises and as rapidly regresses when treatment is stopped. The foetal thyroid has not been affected by the product administered to the dams. PLTU showed a clear teratogenic activity at doses that did not show any maternal toxicity (45 and 90 mg/k). 相似文献
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The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from
nucleotide sequence variation across a 765-bp region in the cytochrome
oxidase I and II genes of the mitochondrial genome. Most parsimonious
relationships of 25 haplotypes from 16 Greya species and two outgroup
genera (Tetragma and Prodoxus) showed substantial congruence with the
species relationships indicated by morphological variation. Differences
between mitochondrial and morphological trees were found primarily in the
positions of two species, G. variabilis and G. pectinifera, and in the
branching order of the three major species groups in the genus. Conflicts
between the data sets were examined by comparing levels of homoplasy in
characters supporting alternative hypotheses. The phylogeny of Greya
species suggests that host-plant association at the family level and larval
feeding mode are conservative characters. Transition/transversion ratios
estimated by reconstruction of nucleotide substitutions on the phylogeny
had a range of 2.0-9.3, when different subsets of the phylogeny were used.
The decline of this ratio with the increase in maximum sequence divergence
among taxa indicates that transitions are masked by transversions along
deeper internodes or long branches of the phylogeny. Among transitions,
substitutions of A-->G and T-->C outnumbered their reciprocal
substitutions by 2-6 times, presumably because of the approximately 4:1
(77%) A+T-bias in nucleotide base composition. Of all transversions,
73%-80% were A<-->T substitutions, 85% of which occurred at third
positions of codons; these estimates did not decrease with an increase in
maximum sequence divergence of taxa included in the analysis. The high
frequency of A<-->T substitutions is either a reflection or an
explanation of the 92% A+T bias at third codon positions.
相似文献
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A. Barbarino A. Serra E. Menini G. Pizzolato E. Moneta E. Pasargiklian L. de Marinis R. Bova 《Human genetics》1978,42(2):119-127
Summary In two patients with testicular feminization syndrome, one Yq12-positive and the other Yq12-negative, we compared phenotype, gonadal histology and ultrastructure, in vivo steroid response of the testes to the administration of exogenous gonadotropin during adrenal suppression, and of the adrenal gland to ACTH. The assumption that the constitutive Y heterochromatin could function as a regulator of steroid biosynthesis and metabolism, with or without effect at other levels, was not firmly supported by the observations reported here. However, further studies along this line may help elucidate the biologic role of this portion of the Y chromosome in humans. 相似文献
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Field and greenhouse experiments showed that yield losses of sugarbeet, Beta vulgaris, did not occur in soil infested with fewer than eight Heterodera schachtii eggs/g soil. However, larger population densities greatly reduced sugarbeet yield. In the field experiment, the yield in microplots inoculated with more than 64 eggs/g soil was less than 20% of yields in uninoculated microplots. Nevertheless, tolerance limits of 4 and 1.8 eggs/g soil, in greenhouse and field microplots, respectively, were derived by fitting the data with the equation y =m + (l - m)zP-T. Maximum rates of multiplication of 55 and more than 300, and equilibrium densities of 340 and 130 eggs/g soil, were estimated in greenhouse and field microplot tests, respectively. 相似文献