1,721,084 research outputs found
Geni e molecole, tra evoluzione, similarit� e differenze delle forme viventi: dagli alberi � sceso l'uomo 'ipergenetico'.
No full textIn questo saggio scientifico-letterario vengono descritte e discusse le visioni dell'uomo alla luce delle scoperte in campo della evoluzione della vita, dei geni e genomi e della specie umana. In particolare viene affrontato il problema della definizione di differenza e di similarità tra gruppi etnici, come anche delle potenzialità offerte dalla tecnologia genetica per il controllo del futuro genetico dell'uomo
Final RCM on Development and Evaluation of Improved Strains of Insect Pests for Sterile Insect Technique
No full textSex-specific gene regulation in insects of economical and medical relevance: its origin, evolution and its use in biotechnology.
No full textInsect biotechnolog
The Medfly Sex Determination pathway is partially conserved in the mosquitoes Aedes aegypti: further support to the bottom up evolution model
No full textIn the medfly Ceratitis capitata female sex determination is promoted in XX individuals by an autoregulating master gene, Cctransformer (Cctraep), which controls, dsx and fru sex-specific expression and epigenetically maintains its own activity. In XY individuals a Y-linked M factor, still to be identified, represses the activity of Cctraep. Comparing medfly and Drosophila pathways, only the upstream regulators are apparently different: in Drosophila X-linked elements in XX embryos activate Sxl, which in turn positively autoregulates and activates transformer. In Ceratitis, Cctraep hence has a novel additional autoregulatory epigenetic function. The Ceratitis Cctraep>dsx/fru genetic module is widely conserved also in other insect orders, such as Hymenoptera and Coleoptera, but not in the dipteran mosquito Aedes aegypti, neither in the lepidopteran Bombyx mori. An evolutionary perspective of the sex determining genetic pathways in insects will be presented toward a better understanding of this regulatory mechanism in mosquitoes and other diseases vectors, which can be useful for sexing and SIT
The transformer gene of the agricultural pest Ceratitis capitata: a widely conserved master switch for insects sex determination.
No full textIl gene transformer di Ceratitis capitata: un meccanismo epigenetico per la determinazione del sesso conservato negli insetti (ad eccezione di Drosophila) ed utile per fini biotecnologici.
No full textSex Determination in Insects: Variations on a Common Theme
No full textRecent studies in a representative selection of holometabolous insects suggest that, despite diversity at the instructive level, the signal-relaying part of the sex-determining pathway is remarkably well conserved. In principle, it is composed of the transformer gene (tra), which acts as a common binary switch that transduces the selected sexual fate, female when ON, male when OFF, to the downstream effector doublesex(dsx) that controls overt sexual differentiation. An interesting recurrent feature is that tra is switched ON in the early zygote by maternally provisioned tra activity. Different male-determining signals evolved, which prevent maternal activation of zygotic tra to allow for male development. In some species, where lack of maternal activation leaves tra in the OFF state, novel female-determining signals were deployed to activate zygotic tra. It appears that both the instructive end of the pathway upstream of tra as well as the executive end downstream of dsx are primary targets of evolutionary divergence, while the transduction part seems less prone to changes. We propose that this is a feature shared with many other signaling cascades that regulate developmental fates
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