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1.
Helmut Bäumlein Istvan Nagy† Raimundo Villarroel Dirk Inzé Ulrich Wobus 《The Plant journal : for cell and molecular biology》1992,2(2):233-239
A 2.4 kb fragment containing the 5'-flanking region and the 5'-noncoding sequence of the Vicia faba legumin gene LeB4 mediates high level seed-specific expression in transgenic tobacco plants. Deleted derivatives of this legumin upstream sequence were fused to the npt-II reporter gene to determine the tissue-specific activity of the chimeric constructs in stably transformed tobacco plants. The results indicate the presence of positive regulatory, enhancer-like cis elements within 566 bp of the upstream sequence. Most importantly, however, these elements are only fully functional in conjunction with the core motif CATGCATG of the legumin box around position -95, since destruction of the motif by a 6 bp deletion in an otherwise intact 2.4 kb upstream sequence drastically reduces expression in seeds. At the same time, low level expression in leaves is observed. The occurrence of similar CATGCATG consensus cis elements with alternating purine and pyrimidine base pairs in front of several other plant genes suggests a functional role of the motif in a wider range of plant promoters. 相似文献
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In situ hybridization with a 125I-rDNA clone from Vicia faba was performed against Allium cepa and three strains of top onion, which represent hybrids between A. cepa and A. fistulosum. In principle, the labelling patterns correspond to the patterns of the silver-stained nucleolus organizing regions (NORs) in the same species. This strongly supports the inference drawn from the Ag-NOR patterns that NORs can jump between terminal heterochromatin blocks of different Allium chromosomes in the parental species A. cepa as well as in their interspecific hybrids. 相似文献
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Nucleotide sequence information from a partial genomic clone, a cDNA clone, a RACE clone and a PCR fragment was combined to reconstruct the first reported complete gene sequence encoding a large legumin subunit, designated LelB3. The length difference to the well-characterized major legumin subunits is caused by an extended glutamin/glutamic acid-rich region encoded by the C-terminal part of the chain. Amino acid sequence comparisons reveal that gene LelB3 is more closely related to B-type than to A-type legumin genes of Vicia faba. Gene LelB3 is a member of a small gene family as indicated by published (Pich and Schubert, Biol Zbl 112 (1993); 342–350) and limited own data. 相似文献
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The effect of food deprivation on ova transport, hormonal profiles and metabolic changes was studied in 20 crossbred multiparous
sows during their second oestrus after weaning. To determine the time of ovulation, transrectal ultrasonographic examination
was performed. The sows were divided into 2 groups, one control group (C-group), which was fed according to Swedish standards,
and one experimental group (E-group). The E-group sows were deprived of food from the first morning meal after ovulation until
slaughter. Blood samples were collected every second hour from about 12 h before expected ovulation in the second oestrus
after weaning until slaughter and were analysed for progesterone, prostaglandin F2α-metabolite, insulin, glucose, free fatty acids and triglycerides. All sows were slaughtered approximately 48 h after ovulation
and the genital tract was recovered. The isthmic part of the oviduct was divided into 3 equally long segments and flushed
separately with phosphate buffered saline (PBS). Uterine horns were also flushed with PBS. A significantly greater number
of ova were found in the first and second part of the isthmus in the E-group (p = 0.05) while in the C-group most of the ova
were found in the third part of the isthmus or the uterus (p = 0.01). The level of prostaglandin F2α-metabolite was significantly higher in the E-group compared with the C-group. The concentration of progesterone increased
in both groups after ovulation but there were no significant differences between the groups. The other blood parameters showed
that the food-deprived sows were in a catabolic state. The 48 h period of fasting results, directly or indirectly in an delayed
ova transport, which may be due to a delayed relaxation in the smooth circular muscle layer of the isthmus. 相似文献