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71.
72.
Desmond R. Jimenez Jeffrey P. Shapiro Raymond K. Yokomi 《Entomologia Experimentalis et Applicata》1994,70(2):143-152
This study was conducted to evaluate the effect of two different biotypes of the sweetpotato whitefly,Bemisia tabaci (Gennadius), on the induction of squash silverleaf (SSL), and to determine if double-stranded RNA (dsRNA) occurs in geographically
remote populations of the two biotypes. Recently collected B-biotype whiteflies from Florida, Arizona, Mississippi, and Texas
(SPW-B) all contained a 7.0 kb dsRNA molecule. Kb dsRNA molecule. Laboratory colonies of A-biotype whiteflies that were originally
collected in 1981 from cotton in Arizona and California did not contain the 7.0 Kb dsRNA. When the two biotypes were compared
only the SPW-B induced rapid onset, grade 5, SSL. DsRNA similar to that found in adult SPW-B was concentrated in whitefly
nymphs, but host plant leaf tissue did not contain any consistent dsRNA molecules. SPW-A only induced low-grade SSL and progeny
of SPW-A that were fed on pumpkin plants displaying SSL did not acquire the ability to express dsRNA or induce SSL. Our data
suggest that dsRNA is not directly involved in the induction of SSL and that SSL is a host-specific response, to a feeding
injury induced by B-biotype whiteflies. The origin and source of the 7.0 Kb dsRNA molecule remains enigmatic but its expression
is constant in the whitefly biotype that is responsible for the induction of SSL and several other plant disorders in the
U.S. 相似文献
73.
The release of alanine and glutamine from perfused muscle of trained and control animals was investigated. Release rates did not differ between trained and control muscle at rest. During contractions in trained muscle, alanine release was higher than at rest, while glutamine release was transiently increased. Phenylalanine release did not differ between trained and control muscle, implying that protein degradation was not increased in trained muscle. The muscle cellular adaptations to training include a selective modification of amino acid output, which could potentially influence gluconeogenic flux and alter muscle ammonia levels during contractions. 相似文献
74.
Several products of metabolism and aromatic ring cleavage of 3-methoxy and 3,4-dimethoxycinnamic acid from ligninolytic cultures of Lentinus edodes were isolated and identified. 相似文献
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76.
Abstract: Derivatives of the lac promoter (tac, pac, rac) belong to the strongest bacterial promoters which are frequently used for the induced overexpression of foreign genes in Escherichia coli . However, their use in fermentation processes is strongly restricted because of the high cost of the inducer iso-propyl-β-D-thiogalactopyranoside (IPTG). The aim of this work was to investigate the possibility of using lac-derived promoters in high cell density processes resulting in a high yield of the induced recombinant protein if glucose is the main carbon and energy source. Lactose is tested as inducer of the main antigenic coat protein (VP1) of the foot and mouth disease (FMD) virus in a T7-RNA polymerase expression system. It was shown that lactose is able to induce the expression of the recombinant gene to an amount of the VP1 protein corresponding to 20% of the total cell protein. 相似文献
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78.
We describe a screen to isolate cDNAs encoding Drosophila mitosis inhibitors capable of suppressing the mitotic catastrophe phenotype resulting in Schizosaccharomyces pombe from the combination of the weel-50 mutation with either a deletion allele of mil1, or with overexpression of cdc25
+. One plasmid was isolated which could suppress the temperature sensitive lethality of both these strains. The cDNA in this plasmid encodes a protein highly homologous to the DEAD-box family of ATP-dependent RNA helicases, rather than to protein kinases as might be expected. It is possible that the RNA helicase described here may regulate entry into mitosis by down regulating the expression of other genes whose activity may be rate-limiting for entry into mitosis. 相似文献
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