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11.
Crosses between two classes of Drosophila melanogaster strains (reactive and inducer) may lead to partially sterile F1 females. This sterility, called S.F. sterility, can be characterized by its physiological features. It appears to be the result of an interaction between two factors: "R" brought into the initial croos by the reactive mother and "I" by chromosomes of the inducer father. Except for chromosome 4, each chromosome of the well known inducer strains may carry the I factor (inducer chromosomes). The present results provide evidence for the presence of an inducer fourth chromosome in the inducer strain Nagasaki.  相似文献   
12.
Comparing cytotoxicity of tubulosine and of six newly synthesized pseudo-tubulosines in the Allium test, we have characterized all the current features of protein inhibition. Nevertheless cytotoxicity of the six pseudotubulosines is much weaker. Furthermore, "floating poles anaphasis", a disturbance characteristic of the action of tubulosine, has been found with a lesser intensity with the other compounds.  相似文献   
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The demography of a population of Yarrow's spiny lizard, Sceloporus jarrovii , was examined from 2004 to 2006 in the canyon Las Piedras Encimadas, located in Gomez Palacio, Durango, México. Lizards were studied using a mark-recapture technique. Reproduction in females occurred between November and May, coinciding with dry conditions. Reproductive activity was highest (percent of females with vitellogenic follicles or embryos) in the middle of the dry season (November and December). Thirteen percent of females reached sexual maturity at an average age of 8.5 months. The population structure was similar in spring and fall, but not in summer. A notable feature of summer, coinciding with the wet season, was the greater number of hatchlings and juveniles. The overall sex ratio did not differ from 1:1. The density of adults varied from 12 to 62 animals ? 0.5 ha –1 . Temperate and arid-adapted populations of S. jarrovii exhibited broad similarity in timing of the reproductive season, whereas factors such as density, growth, age at sexual maturity, and survivorship differed.  相似文献   
15.
Variation in FTO contributes to childhood obesity and severe adult obesity   总被引:18,自引:0,他引:18  
We identified a set of SNPs in the first intron of the FTO (fat mass and obesity associated) gene on chromosome 16q12.2 that is consistently strongly associated with early-onset and severe obesity in both adults and children of European ancestry with an experiment-wise P value of 1.67 x 10(-26) in 2,900 affected individuals and 5,100 controls. The at-risk haplotype yields a proportion of attributable risk of 22% for common obesity. We conclude that FTO contributes to human obesity and hence may be a target for subsequent functional analyses.  相似文献   
16.
The autosomal recessive disorder Shwachman-Diamond syndrome, characterized by bone marrow failure and leukemia predisposition, is caused by deficiency of the highly conserved Shwachman-Bodian-Diamond syndrome (SBDS) protein. Here, we identify the function of the yeast SBDS ortholog Sdo1, showing that it is critical for the release and recycling of the nucleolar shuttling factor Tif6 from pre-60S ribosomes, a key step in 60S maturation and translational activation of ribosomes. Using genome-wide synthetic genetic array mapping, we identified multiple TIF6 gain-of-function alleles that suppressed the pre-60S nuclear export defects and cytoplasmic mislocalization of Tif6 observed in sdo1Delta cells. Sdo1 appears to function within a pathway containing elongation factor-like 1, and together they control translational activation of ribosomes. Thus, our data link defective late 60S ribosomal subunit maturation to an inherited bone marrow failure syndrome associated with leukemia predisposition.  相似文献   
17.
Centronuclear myopathies are characterized by muscle weakness and abnormal centralization of nuclei in muscle fibers not secondary to regeneration. The severe neonatal X-linked form (myotubular myopathy) is due to mutations in the phosphoinositide phosphatase myotubularin (MTM1), whereas mutations in dynamin 2 (DNM2) have been found in some autosomal dominant cases. By direct sequencing of functional candidate genes, we identified homozygous mutations in amphiphysin 2 (BIN1) in three families with autosomal recessive inheritance. Two missense mutations affecting the BAR (Bin1/amphiphysin/RVS167) domain disrupt its membrane tubulation properties in transfected cells, and a partial truncation of the C-terminal SH3 domain abrogates the interaction with DNM2 and its recruitment to the membrane tubules. Our results suggest that mutations in BIN1 cause centronuclear myopathy by interfering with remodeling of T tubules and/or endocytic membranes, and that the functional interaction between BIN1 and DNM2 is necessary for normal muscle function and positioning of nuclei.  相似文献   
18.
Hypertriglyceridemia is a hallmark of many disorders, including metabolic syndrome, diabetes, atherosclerosis and obesity. A well-known cause is the deficiency of lipoprotein lipase (LPL), a key enzyme in plasma triglyceride hydrolysis. Mice carrying the combined lipase deficiency (cld) mutation show severe hypertriglyceridemia owing to a decrease in the activity of LPL and a related enzyme, hepatic lipase (HL), caused by impaired maturation of nascent LPL and hepatic lipase polypeptides in the endoplasmic reticulum (ER). Here we identify the gene containing the cld mutation as Tmem112 and rename it Lmf1 (Lipase maturation factor 1). Lmf1 encodes a transmembrane protein with an evolutionarily conserved domain of unknown function that localizes to the ER. A human subject homozygous for a deleterious mutation in LMF1 also shows combined lipase deficiency with concomitant hypertriglyceridemia and associated disorders. Thus, through its profound effect on lipase activity, LMF1 emerges as an important candidate gene in hypertriglyceridemia.  相似文献   
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The Vision Conference: Facilitating Creative Processes   总被引:1,自引:1,他引:1  
This paper presents the principles behind the design and management of the Vision Conference: a one-day workshop in which a large group of participants meet to create ideas, projects, and visions for the future activities of a local community or an organization. A case study from a local community in Denmark is also presented to illustrate the organization, planning, and management of a Vision Conference. The paper focuses on the three central social processes of the conference: group work, problem solving, and facilitation. The paper ends with a discussion of creativity and creativity techniques suitable for Vision Conferences.  相似文献   
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