Presse et revues
44 pages
- Aller à la page de la table des matièresI
- CONTENTS 1989 - VOLUME 309 - SECTION III - N° 19
- .......... Page(s) .......... 709
- .......... Page(s) .......... 709
- Examination of the predicted transmembrane topology of eukaryotic integral membrane proteins reveals marked structural differences between proteins from the inner mitochondrial membrane and from thylakoids depending on whether they are synthesized in the organelle or imported from the cytosol. It is suggested that the necessity of unfolding proteins prior to import imposes restrictions to the number of hydrophobic segments an imported protein may contain. This hypothesis would explain why multispanning proteins as a rule are encoded in the organelle, while imported material is comprised of short proteins, often made up of a single transmembrane
-helix, that are "microassembled" into complexes after import.
- Cellular Biochemistry
- (see Tome 309, Series III, 1989, p. 709)
- Evolution
- (see Tome 309, Series III, 1989, p. 735)
- .......... Page(s) .......... 715
- .......... Page(s) .......... 715
- Imitation synkineses had not been described in cerebellar ataxia and were not known in cerebellar experimental neurophysiology. We describe here imitation synkineses when alternate movements of foot or hand were performed, in 2 cases of pure genetic cerebellar ataxia. The phenomenon was observed in other types of cerebellar ataxia (8 cases of anterior lobe cortical atrophy, 2 cases of surgical injury of the vermis). More imitation synkineses occurred on the right side in right-handed subjects, suggesting that the cerebellum physiologically inhibits a contralateral transfer of the copy of the movement. This inhibition would be particularly effective on the dominant side.
- .......... Page(s) .......... 723
- The micrografting technique described makes it possible to graft apical meristems belonging to mature Pinus pinaster onto in vitro young seedlings with an average rate of success of 68%. The grafted meristems produce more or less rapidly leafy shoots some of which exhibit characterized juvenile morphological traits maintained after acclimatization.
- .......... Page(s) .......... 729
- .......... Page(s) .......... 729
- The possibility of producing haploid plants with pollen inactived by irradiation was explored for cabbage. The experiment included the use of three early nuclear genetic markers, pollinations with pollen irradiated with 200 to 1,200 Gy doses, and in vitro culture of embryos. After plant sorting, mostly as early as in vitro plantlet stage, two haploid plants resulting from parthenogenesis in situ induced were obtained for the first time in cabbage.
- .......... Page(s) .......... 735
- The plasma corticosterone response to novelty as an emotional stressor was compared between three populations of house mice (Mus musculus domesticus). One of them lives in the open, whereas the two others are commensal to man. Among the commensal the individuals of one population display chromosomal divergence (2n=24 chromosomes instead of 2n=40). The corticoadrenal responses of "outdoors" mice are higher than the commensal mice responses. Moreover among the commensal, only the 2n=24 individuals present a significant seasonal variations of their corticosterone responses. Results are interpreted in terms of adaptation, and we discuss to what extent this could be correlated to the chromosomal evolution in this species.
- COMPTES RENDUS DE L'ACADEMIE DES SCIENCES SCIENCES DE LA VIE 1989 - Tome 309 - Série III - n° 19
Le taux de reconnaissance estimé pour ce document est de 99.98%.
En savoir plus sur l'OCR
En savoir plus sur l'OCR
Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour ce document est de 99.98%.
Facebook
Twitter
Pinterest