The cloning and identification of full-length cDNA fragments coding for the Brassica napus phosphatidylinositol-specific phospholipase C2 (BnPLC2), phosphatidylinositol 3-kinase (BnVPS34) and phosphatidylinositol synthase (BnPtdIns S1) is described. In addition, two complementary fragments (120 nucleotides long) corresponding to Arabidopsis PtdIns 4-kinase (PtdIns 4-K) and PtdIns-4-phosphate 5-kinase (PtdIns4P 5-K) sequences were chemically synthesized. These, as well as the cDNA clones, were used as probes to study the corresponding steady state mRNA levels in different tissues and developmental stages of B. napus, as well as in response to different environmental conditions. Transcripts corresponding to BnPLC2, BnPtdIns S1, BnVPS34 and PtdIns 4-K were found constitutively expressed at different levels in most tissues, with young leaves, siliques, and developing seeds showing the lowest levels. No detectable PtdIns4P 5-K transcripts were found in buds or flowers. Up-regulation of BnPLC2 was seen in response to low temperature stress, which was notably accompanied by a parallel down-regulation of BnPtdIns S1, while BnVPS34 and PtdIns 4-K remained at control levels. A moderate increase in PtdIns4P 5-K levels was noted. In high salinity conditions BnPtdIns S1, BnVPS34 and BnPLC2 transcripts had similar responses but at different levels, with no major changes detected for PtdIns 4-K or PtdIns4P 5-K. Significantly, all five transcripts increased under drought stress conditions and all stressed plants clearly showed relatively higher levels of total inositol trisphosphate.
Broad host-range plasmid RK2 is able to replicate in a controlled manner in most Gram negative bacterial species. To analyze the elements of its control mechanism, we have measured the copy number in Escherichia coli of mini-RK2 replicons isogenic except for defined deletions in regions adjacent to the vegetative replication origin, ortVRK2, which have previously been implicated in copy number control because of their expression of plasmid incompatibility. The results indicate that while the previously defined 700-bp HaeII oriVRK2 fragment carries one copy control element (copA), a second (copB) lies at least partly outside this fragment towards the tetracycline resistance genes of RK2. Deletions affecting both these regions give a mini replicon with a copy number of 35-40 compared with 4-7 for parental RK2. Further incompatibility experiments indicate that targets for both incA (copA) and incB (copB) lie within the 700-bp HaeII oriVRK2 fragment.
The nucleotide sequence for a glutamine synthetase (GS) mRNA from gene-amplified Chinese hamster (CHO) cells was determined from recombinant cDNA clones obtained from both pBR322 and lambda gt10 libraries and by primer extension. The sequence obtained contains about 1400 bp corresponding to a minor species of mRNA terminated by a poly A sequence. The mRNA contains 146 nucleotides of 5'-noncoding region, 1119 bp of coding sequence, and 108 bp of 3'-noncoding sequence with a 32 bp poly(A) tail. The polyadenylation site used shows little homology with efficient polyadenylation sites, but has considerable complementarity with U4 RNA. The predicted amino acid sequence, starting from an initiation codon with the preferred sequence surrounding it, indicates that Chinese hamster GS has high homology with published bovine brain GS peptides and enabled an ordering of these peptides. There is homology between the mammalian GS enzymes and glutamine synthetases obtained from plants and cyanobacteria but no obvious homology between the CHO cell GS sequence and that of other ATP hydrolysing enzymes.
For replication, plasmid RK2 encodes a vegetative replication origin, oriV RK2, and a gene, trfA, whose polypeptide product(s) is essential for oriV RK2 activity. The trfA gene is transcribed as part of a polycistronic operon which also includes kilD. Transcription of this operon is negatively regulated by the products of the trfB/korD/korA and korB loci. Mini replicons previously studied in detail lack the korB locus and have copy numbers significantly higher than RK2 itself. Here we report that korB in trans expresses incompatibility towards RK2 replicons either when the korB gene dosage is high or when it is expressed from a strong foreign promoter. This incompatibility can be largely overcome if a trfA gene which is expressed from a foreign promoter, and is therefore not regulated by korB, is supplied in trans. When korB is introduced in cis to mini RK2 replicons the copy number is reduced to within the range estimated for parental RK2. Deletions in the oriV RK2 region which otherwise cause quite large increases in plasmid copy number have only a small effect when korB is present in cis. These results suggest that korB in combination with trfB may be the overriding copy number control element in RK2 reducing trfA expression to levels limiting for replication.
In Organizations productivity is a very important issue. There are several factors that determine productivity of an organization. Nowadays Employee turnover is one of those who are considered to be one of the difficult issues in business. The effect of intension to leave has received huge attention from top management(senior executives), human resource professionals and other industrial psychologists has proven it to be one of the most costly and apparently difficult human resource challenges faced globally by different organizations in the whole world. The main purpose of this research is to discover the real causes behind the turnover and its harmful effects on the productivity of many industries. We (the authors) of this document have studied and visited numerous local organizations in both government and private sectors in Bahawalpur, Punjab, Pakistan, and observed the causes of turnover. The real aim of this research paper was to discover the existing reasons of turnover, adverse affects, and possible results that could be useful for their productivity and market shares for local industries.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.