Observations of knock-out mice suggest that breathing at birth requires correct development of a specific hindbrain territory corresponding to rhombomeres (r) 3 and 4. Focusing on this territory, we examined the development of a neuronal rhythm generator in the chick embryo. We show that rhythmic activity in r4 is inducible after developmental stage 10 through interaction with r3. Although the ...

We have previously demonstrated that inactivation of the Krox20 gene led to the disappearance of its segmental expression territories in the hindbrain, the rhombomeres (r) 3 and 5. We now performed a detailed analysis of the fate of prospective r3 and r5 cells in Krox20 mutant embryos. Genetic fate mapping indicates that at least some of these cells persist in the absence of a functional Krox20...

the effects of postharvest application of cobalt chloride were investigated on vase life of rose stood individually in vials and the other ones placing daffodil flowers in a vase with a rose flower.  therefore, roses were treated with: cocl 2 (100, 200, 300 mg l -1 , respectively) or distilled water (control). the results showed that the decreased vase life of rose flowers, after daffodil was p...