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The Ceratitis capitata homologue of the Drosophila sex-determining gene Sex-lethal is structurally conserved, but not sex-specifically regulated.
No full textIn Drosophila, Sxl functions as a binary switch in sex determination. Under the control of the primary sex-determining signal, it produces functional protein only in XX animals to implement female development. Here we report that, in contrast to Drosophila, the Sxl homologue in the Medfly, Ceratitis capitata, expresses the same mRNAs and protein isoforms in both XX and XY animals irrespective of the primary sex-determining signal. Also, experiments with two inducible transgenes demonstrate that the corresponding Ceratitis SXL product has no significant sex-transforming effects when expressed in Drosophila. Similar results have been obtained for the Sxl homologue of Musca domestica (Meise, M., Hilfiker-Kleiner, D., Brunner, C., DŁbendorfer, A., N¿thiger, R. and Bopp, D. (1998) Development 125, 1487-1494). Our findings suggest that Sxl acquired its master regulatory role in sex determination during evolution of the Acalyptratae group, most probably after phylogenetic divergence of the genus Drosophila from other genera of this group
The Ceratitis capitata homologue of the Drosophila sex-determining gene Sex-lethal is structurally conserved, but not sex-specifically regulated.
No full textIn Drosophila, Sxl functions as a binary switch in sex determination. Under the control of the primary sex-determining signal, it produces functional protein only in XX animals to implement female development. Here we report that, in contrast to Drosophila, the Sxl homologue in the Medfly, Ceratitis capitata, expresses the same mRNAs and protein isoforms in both XX and XY animals irrespective of the primary sex-determining signal. Also, experiments with two inducible transgenes demonstrate that the corresponding Ceratitis SXL product has no significant sex-transforming effects when expressed in Drosophila. Similar results have been obtained for the Sxl homologue of Musca domestica (Meise, M., Hilfiker-Kleiner, D., Brunner, C., DŁbendorfer, A., N¿thiger, R. and Bopp, D. (1998) Development 125, 1487-1494). Our findings suggest that Sxl acquired its master regulatory role in sex determination during evolution of the Acalyptratae group, most probably after phylogenetic divergence of the genus Drosophila from other genera of this group
Search of sex-specific genes in the medfly Ceratitis capitata: preliminary data on Sxl.
No full textVienn
A dense cluster of genes is located at the ecdysone-regulated 3C puff of D. melanogaster
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Non-invasive evaluation of autonomic tone changes during isometric exercise innormal subjects and in patients with coronary artery disease
No full textIn order to evaluate the clinical implications of QT/QS2 ratio during manoeuvres
of sympathetic stimulation we studied the effects of handgrip (75% of maximal
voluntary contraction) in 18 middle-aged normal subjects and in 16 patients with
previous myocardial infarction. We also evaluated the effects of propranolol (0.1
mg/kg i.v.) in all normal subjects and in 10 of the 16 patients with coronary
artery disease. At rest the two groups had similar heart rate, blood pressure,
QT, QS2 and QT/QS2 ratio values. A significant increase in heart rate and
systolic blood pressure was recorded during handgrip both in normal subjects and
in patients with coronary artery disease; QT/QS2 significantly increased in
normal subjects but did not show significant variations in patients with coronary
artery disease, with significant differences between the two groups at peak
exercise. Handgrip-induced QT/QS2 changes showed a marked variability both in
normal and diseased subjects. After propranolol, QT/QS2 showed no significant
difference at peak exercise in the two groups. The variability of ratio changes
was nullified by the administration of the drug. These findings suggest that
handgrip-induced QT/QS2 changes might be an expression of beta-adrenergic
discharge. The clinical value of handgrip-induced QT/QS2 changes in detecting
patients with coronary artery disease is limited by the variability of the
response of the ratio observed in the two groups
Effect of the ecd-1 mutation on the transcription of the 3C11-12 polytenic region of Drosophila melanogaster
No full textA dense cluster of genes genes is located at the ecdysone regulated 3C puff di D. melanogaster.
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