Sentence examples for no life span from inspiring English sources
Consistent with this finding, we saw no life span extension for the uninduced ELAV-Gene Switch>Sir2-3.
Over-expression of p53-259H in adult flies using the ubiquitous Act-GS-255B driver produced increased median life span in females (+8%) but not males (-2.8%), and no life span increase when expressed in larvae (Table 3).
When the Sir2-3 transgene was expressed ubiquitously using the Tubulin-Gene Switch driver in the presence of RU-486, we observed no life span extension compared with genetically identical uninduced (ethanol-fed) flies.
A recent study reported no life span extension when dSir2 was over expressed by using the constitutive, ubiquitously expressing Tubulin-Gal4 driver, either with the dSir2EP2300 line, or with either of two newly constructed lines containing an inducible UAS-dSir2 transgene in addition to the endogenous copy of dSir2 [ 10].
Shortened life spans occurred only in the female mice irradiated at 1.1 mGy per day (there was no life span change in the other groups irradiated at 1.1 and 0.05 mGy per day) compared to controls; this life-shortening was attributed to premature aging as there was no increased incidence of tumors.
Interestingly, the temperature-dependent life span phenotype of hif-1 mutants is the opposite of that of the mutants with thermosensory defects: hif-1 mutants have a long life span when they are cultured at 25°C or shifted from 20°C to 25°C [ 16, 26, 28] and display no life span phenotypes at low temperatures (20°C and 15°C) [ 16, 26, 30].
This is, however, unlikely because there is no life-span extension in ercc-1 and xpf-1 mutants if daf-2 is unaffected.
"There is no fixed life span," says Dr. James Vaupel, no wall of death dictated by basic biology that we are edging toward.
When Guarente's team deleted the sir2 gene from the yeast and then restricted calories, the diet no longer lengthened life span.
Even with no defined life span, compensating controls are not an eternal free pass.
In general, genetically engineered cells using vectors that integrate the genetic material into the host cell genome have no limited life span, express permanently high levels of the transgene.
