1,721,044 research outputs found
Molecular and genetic analysis of three autosomal mutations interfering with the crystal-Stellate system in Drosophila melanogaster and a brief description of crystal and Stellate homologous sequences in different Drosophila species
No full textL'abstract corrisponde ad una relazione al III Convegno Internazionale dell'Eterocromatina.
Pur svolgendosi in Italia, si tratta di un importante congresso internazionale con la partecipazione di molti relatori sia americani che europei. Si svolge ogni due anni
Molecular and genetic analysis of three autosomal mutations interfering with the crystal-Stellate system in Drosophila melanogaster and a brief description of crystal and Stellate homologous sequences in different Drosophila species.
No full textL'abstract corrisponde ad una relazione al V Convegno Internazionale dell'Eterocromatina nel 2001.
Pur svolgendosi in Italia, si tratta di un importante congresso internazionale con la partecipazione di molti relatori sia americani che europei. Si svolge ogni due anni
Different aubergine alleles confirm the specificity of different RNAi pathways in Drosophila melanogaster
No full textThe crystal-Stellate system is one of the best-known examples of heterochromatin-euchromatin interaction. The components of this system are homologous repetitive sequences clustered in three regions: 12E1 and h27 on the X and h11 on the Y. The symptom of a disrupted crystal-Stellate interaction is the presence of crystals in the spermatocytes of males lacking the crystal region. Stellate silencing is based on the RNAi process. Many modifiers of this system have been isolated and many of these are involved in RNAi. One of these modifiers is aubergine(sting); this is a "gain of function" allele in somatic tissues. Here we report the different behavior of two aubergine alleles with respect to the RNAi pathway: aub(sting) and a "loss of function" heteroallelic combination aub(HN)/aub(QC42). An increased amount of Aub interferes with the correct functioning of the somatic yellow hairpin RNAi, whereas the Aub reduction does not. We also demonstrate the different behavior of these alleles on the I transposon silencing in ovaries. Intriguingly, neither of these aubergine alleles silence the Stellate locus. We can conclude that the crystal-Stellate system reveals different RNAi pathways even though much still remains to be done to completely explain the molecular bases of the crystal-Stellate interaction
L'associazione genica e la mappatura genetica.Il controllo genetico dello sviluppo embronale
No full textLa regolazione dell'espressione genica.
Il controllo genetico dello sviluppo embrional
Effetti dell'afidicolina in Drosophila melanogaster
No full textSi tratta di un poster presentato al Congresso AGI (Associazione Genetica Italiana) nel 198
Multiple upstream regulatory elements control the expression of the Drosophila white gene
No full textConstructions containing the Drosophila white gene and different amounts and arrangements of its regulatory region were introduced into the germ line of white mutant flies by P-mediated transformation. The results obtained with the different transposon constructions show that different parts of the 1.8-kb region preceding the transcription start are required for the expression of the gene in different tissues and at different developmental stages. Different sequences independently control the expression of the gene in the adult testes, in the larval and adult Malpighian tubules and in the eye. Another sequence located greater than 1080 bp upstream of the transcription start is the target of zeste interaction. The results also suggest that sequences required for dosage compensation are contained between -216 and the transcription start site. We show that at least some of these regulatory elements are equally functional if their distance from the promoter is varied or if their orientation is inverted. Their properties suggest that they act as enhancer-like elements to regulate the activity of the white promoter and, at least in the case of the zeste regulatory site, that they can act also in 'trans' on a white promoter locked in close physical proximity by homologous chromosome pairing
Induction by hydrocortisone 21-sodium succinate of the 70K heat-shock polypeptide in isolated salivary glands of Drosophila melanogaster.
No full textThe vertebrate steroid hormone hydrocortisone-21-sodium succinate induces in isolated salivary glands of
Drosophila melanogaster 3rd instar larvae a protein identified as the 70K heat-shock polypeptide by 1- and 2-dimensional
gel electrophoresis analysis. This response is accompanied by significant induction of the puffs 87A and 87C
Mutations in the glutamine syntetase I (GSI) gene produce embryo-lethal female sterility in Drosophila melanogaster.
No full textA female-sterile mutation (fs(2) PM11-19) was recovered in a screen for P-M hybrid dysgenesis induced mutations uncovered by a deletion of region 21B and was identified as an allele of the gene encoding the Drosophila glutamine synthetase I (GSI) mitochondrial isozyme. Molecular analysis has shown that fs(2)PM11-19 contains a 5 kb insert within 500 bp upstream of the transcriptional start site of the gsI gene. Mutant flies have extremely low levels of gsI transcription and GSI activity. A pre-existing deficiency (Df(2L) netPM1) with a breakpoint near the transcription start site was also found to be a female-sterile allele of gsI. All eggs laid by PM11-19 homozygous females, as well as by females heterozygous for this mutation and a deletion or any of several recessive lethal alleles of the gsI gene, fail to hatch. We conclude that an adequate level of maternally supplied GSI activity is necessary in the early stages of Drosophila embryonic development
Distribuzione degli elementi Ste-like e cry-like nel genere Drosophila
No full textSi tratta di un poster presentato al 5° Congresso FISV nel 200
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