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Biomedical subjects

M Furia

Publications and source records attributed to M Furia.

At least 19 recordsLinked to original sources
PubMed1995

The role of the BR-C locus on the expression of genes located at the ecdysone-regulated 3C puff of Drosophila melanogaster.

During the third larval instar, the steroid moulting hormone ecdysone activates three temporally distinct puff sets on the D. melanogaster salivary gland polytene chromosome: the so-called intermoult, early and late puffs. Hormonal regulation of intermoult puffs is quite complex and, so far, largely not understood. In order to further investigate this aspect, we have analysed the effects of mutations in a key regulator of the ecdysone response at the onset of metamorphosis, the Broad-Complex (BR-C) locus, on the expression of genes mapping at the 3C intermoult puff. On the basis of an accurate examination of 3C intermoult gene activity in single, carefully staged, third instar larvae of wild-type and BR-C mutant strains, we were able to subdivide these genes into two groups. Each group is characterised by a different temporal expression profile, so that at the beginning of the wandering stage the transcription of the first group declines as group II transcription is induced. Interestingly, the BR-C locus appears to play a regulatory role in establishing this transcriptional switch. By using mutants of each of the three lethal complementation groups, we precisely defined the role of BR-C functions in this developmental transition and we show that this locus also plays an essential role in the early pre-metamorphic hormonal response.

Animals↗
PubMed1993

Opa-like repeats in the genome of the Medfly Ceratitis capitata.

The sequence determination of several genomic clones isolated from the Mediterranean fruitfly Ceratitis capitata identified the existence of opa-like repeats, often more than one being clustered in small chromosomal segments. These repeats have previously been shown to consist of stretches of tandemly reiterated glutamine-encoding residues, and they are found in multiple genes of several organisms. Most of the repeats described here are flanked or interrupted by stop codons in all reading frames and, thus, could not possibly be part of protein-coding sequences. Furthermore, these repeats, of which there are several hundred in the genome of the Medfly, can be used effectively for the determination of sequence polymorphisms, providing a convenient approach to obtain additional landmarks for the construction of genomic maps of this economically important insect.

Amino Acid Sequence↗
PubMed1992

Molecular characterization of a Drosophila melanogaster variant strain defective in the Sgs-4 gene dosage compensation.

The X-linked Sgs-4 gene of Drosophila melanogaster encodes a salivary glue protein. Here we report the molecular characterization of a non-dosage compensated variant strain, named Karsnas, in which males accumulate only about half of the Sgs-4 polypeptide amount as do females. The results obtained show that significant nucleotide sequence alterations are accumulated within the Sgs-4 coding and 3' untranslated region of the variant strain, thus suggesting a possible role of these sequences in the Sgs-4 dosage compensation.

Animals↗
PubMed1992

A cDNA clone representative of a novel splicing pattern of the D. melanogaster dunce gene.

The D. melanogaster dunce gene is involved in both the learning and memory processes of the fly. The gene encodes for a cAMP-specific phosphodiesterase, a function playing a central role in the regulation of the intracellular cAMP level. Molecular cloning of dunce has so far not been completely achieved, although it is known that the gene encodes a large set of RNAs and has a complex organization, extending for more than 140 kilobases and containing several genes within its introns. Here we report the isolation and the characterization of 21/7, a cDNA clone representative of a novel dunce splicing pattern. The nucleotide sequence of this clone led to the identification of a dunce exon included in at least one transcript so far uncharacterized.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1992

Effect of ecd1 mutation on the expression of genes mapped at the Drosophila melanogaster 3C11-12 intermoult puff.

The Drosophila melanogaster ecd1 mutation causes a severe temperature-sensitive deficiency in the titre of the steroid hormone ecdysone. This mutation was used to investigate the role of ecdysone in both the transcription of the genes mapped at the 3C11-12 intermoult puff region and the puff formation. Thoroughly synchronized ecd1 larvae were shifted to the non-permissive temperature at various times of the development; after 24 or 48 h, the levels of the transcripts derived from Sgs-4, Pig-1 and ng-1, the three genes located at the 3C11-12 polytene bands, were determined. The results showed that the levels of the transcripts encoded by Pig-1 and ng-1 are unaffected by the drop in the ecdysone titre occurring in non-permissive conditions whereas the amount of Sgs-4 mRNA is greatly reduced. These data clearly indicate that transcription of the three genes mapped within the puff region is affected differently by the hormone. Furthermore, ecd1 larvae cultured at the non-permissive temperature show a prominent puff at the 3C11-12 polytene bands, indicating that ecdysone is not essential for puff induction and that puff size is not simply correlated with high-level Sgs-4 transcription.

Animals↗
PubMed1991

Molecular organization of the Drosophila melanogaster Pig-1 gene.

The Pre-intermoult gene-1 (Pig-1) of Drosophila melanogaster maps on the X chromosome, at polytene bands 3C11-12, and is nested within the 79 kb intron of the dunce gene. Pig-1 has so far been characterized only preliminarily and its function is still unknown. We analysed the molecular organization of the gene by cDNA clone isolation and sequencing as well as S1 mapping and primer extension analyses. The results obtained reveal that the gene is colinear with its genomic sequence and define the usage of both 5' and 3' alternative sites for Pig-1 transcription; two continuous open reading frames (ORFs) are fully contained within the Pig-1 transcribed region, although several lines of evidence suggest that only the longer ORF is likely to be translated. We also report that the level of Pig-1 transcript is nearly fourfold reduced in a variant strain carrying a deletion within the Pig-1 upstream sequence, thus identifying a regulatory element required for high level gene expression.

Amino Acid Sequence↗
PubMed1990

A new gene nested within the dunce genetic unit of Drosophila melanogaster.

The molecular organization of the dunce gene of Drosophila melanogaster has proved to be particularly complex, with two divergently transcribed genes, Sgs-4 and Pig-1, nested within its 79 kb intron (1). Here we report the identification and the molecular characterization of a third gene nested within the transcription unit of dunce. This newly identified gene is located nearly 6 kb downstream Pig-1, within a more upstream dunce intron. The gene is developmentally regulated and transcribed with the same polarity of dunce; several lines of evidence indicate that it might encode for a salivary gland secreted (Sgs) protein.

Amino Acid Sequence↗
PubMed1988

[Involvement of the posterior eye segment in HLA B27(+) iridocyclitis. Incidence. Value of surgical treatment].

46 patients with the association of acute anterior uveitis and the presence of HLA B27 antigen were studied. Ankylosing spondylitis was found in 19 patients (41.3%). Ophthalmoscopy showed a diffuse vitreous haze in 63%, a macular disease in 21.7%, a papillitis in 17.4%. We performed pars plana vitrectomy on 8 patients (10 eyes) with severe posterior uveitis and/or cystoid macular edema. The postoperative follow-up period averaged 14 months with visual acuity improvement in 5 eyes. The surgical indications are described.

Acute Disease↗
PubMed1988

[Histiocytofibroma of the sclerocorneal limbus].

A case of epibulbar benign fibrous histiocytoma is presented, with an optical microscopic study. A greyish vascularised nodule developed at the corneoscleral limbus in a 65 year-old male. The clinical diagnosis was confirmed by histopathologic evaluation. Complete surgical excision had a curative effect.

Aged↗
PubMed1987

[Surgical treatment of eye wounds with retinochoroidal metal foreign bodies. Apropos of 6 cases].

Six cases of intra-ocular metallic foreign bodies located into the retino-choroidal wall are presented. A surgical treatment was performed, and included a vitrectomy, a foreign body extraction with intraocular forceps, a primary or a secondary scleral buckling for the peripheral wound, and a retino-choroidectomy for one of the posteriorly located foreign bodies. In all the cases, we observed a cicatricial retraction of the retino-choroidal wound. When the wound was peripheral, the retina detached in the cases without buckling and it was necessary to do a secondary scleral buckling procedure. When the wound was located at the posterior pole, the retina remained flat in one case, with a 6 mm metallic body, probably because of the relaxing retinotomy performed to extract the foreign body. We think that it is better to perform a primary scleral buckle of the peripheral wounds. The various aspects of the treatment are discussed.

Adult↗