| 3 matches found in 2 documents. Search time: 0.263 seconds. |
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| Title: Nuclear gene sequences and DNA variation of Cryptomeria japonica samples from the postglacial period .
| | Author: Tani N Tsumura Y Sato H | | Journal: Mol . Ecol . Citation: V : 12 ( 4 ) P : 859-68 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12753207 Accession (PMID): 12753207 | | Abstract: Genomic DNA was extracted from heartwood blocks of six Cryptomeria japonica individuals that had been buried ( in an area now covered by rice fields ) for about 3600 years .
Attempts were made to determine the sequences of five nuclear genes following polymerase chain reaction amplification , using previously obtained C japonica expressed sequence tag ( EST ) information .
We detected 15 nucleotide substitutions and four insertion/deletions ( indels ) in a partial GapC gene sequence among 13 individuals of the buried and an extant population , which allowed us to estimate the extent of DNA variation within the buried populations , and the level of genetic differentiation between the buried population and the extant population growing in a neighbouring area .
For the entire haplotypes of the GapC region , pi and theta nucleotide diversity estimates were 0 . 0063 and 0 . 0010 , respectively , when both populations were included , while corresponding figures for the buried population alone were 0 . 0009 and 0 . 0017 .
Estimates of DNA divergence statistics ( dXY = 0 . 0062 , dA = 0 . 0005 , FST = 0 . 0832 and KST = 0 . 0935 ) suggest that differentiation between the two populations was not great .
However , permutation tests gave FST and KST values rejecting the null hypothesis ( that populations were not differentiated ) at the 5% and 1% probability levels , respectively .
The significant genetic differentiation between the two populations was mainly caused by differences in haplotype diversity .
The significant level of haplotype diversity in the extant population compared to the buried population might be the result of gene flow from neighbouring artificial forests .
Alternatively , it is possible that we failed to detect all the DNA variation in the buried population because of clonal growth in the buried population .
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[ Sen. 3, subscore: 1.00 ]: We detected 15 nucleotide substitutions and four insertion/deletions ( indels ) in a partial GapC gene sequence among 13 individuals of the buried and an extant population , which allowed us to estimate the extent of DNA variation within the buried populations , and the level of genetic differentiation between the buried population and the extant population growing in a neighbouring area .
[ Sen. 4, subscore: 1.00 ]: For the entire haplotypes of the GapC region , pi and theta nucleotide diversity estimates were 0 . 0063 and 0 . 0010 , respectively , when both populations were included , while corresponding figures for the buried population alone were 0 . 0009 and 0 . 0017 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
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| Title: Replacing Escherichia coli NAD-dependent glyceraldehyde 3-phosphate dehydrogenase ( GAPDH ) with a NADP-dependent enzyme from Clostridium acetobutylicum facilitates NADPH dependent pathways .
| | Author: Martinez I Zhu J Lin H Bennett GN San KY | | Journal: Metab Eng Citation: V : 10 P : 352-9 Year: 2008 Type: In-Process | | Literature: oryza Field: abstract Doc ID: pub18852061 Accession (PMID): 18852061 | | Abstract: Reactions requiring reducing equivalents , NAD ( P ) H , are of enormous importance for the synthesis of industrially valuable compounds such as carotenoids , polymers , antibiotics and chiral alcohols among others .
The use of whole-cell biocatalysis can reduce process cost by acting as catalyst and cofactor regenerator at the same time ; however , product yields might be limited by cofactor availability within the cell .
Thus , our study focussed on the genetic manipulation of a whole-cell system by modifying metabolic pathways and enzymes to improve the overall production process .
In the present work , we genetically engineered an Escherichia coli strain to increase NADPH availability to improve the productivity of products that require NADPH in its biosynthesis .
The approach involved an alteration of the glycolysis step where glyceraldehyde-3-phosphate ( GAP ) is oxidized to 1 , 3 bisphophoglycerate ( 1 , 3-BPG ) .
This reaction is catalyzed by NAD-dependent endogenous glyceraldehyde-3-phosphate dehydrogenase ( GAPDH ) encoded by the gapA gene .
We constructed a recombinant E coli strain by replacing the native NAD-dependent gapA gene with a NADP-dependent GAPDH from Clostridium acetobutylicum , encoded by the gene gapC .
The beauty of this approach is that the recombinant E coli strain produces 2 mol of NADPH , instead of NADH , per mole of glucose consumed .
Metabolic flux analysis showed that the flux through the pentose phosphate ( PP ) pathway , one of the main pathways that produce NADPH , was reduced significantly in the recombinant strain when compared to that of the parent strain .
The effectiveness of the NADPH enhancing system was tested using the production of lycopene and epsilon-caprolactone as model systems using two different background strains .
The recombinant strains , with increased NADPH availability , consistently showed significant higher productivity than the parent strains .
| Matching Sentences:
[ Sen. 7, subscore: 1.00 ]: We constructed a recombinant E coli strain by replacing the native NAD-dependent gapA gene with a NADP-dependent GAPDH from Clostridium acetobutylicum , encoded by the gene gapC .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
