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L Ferretti

Publications and source records attributed to L Ferretti.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cosmid-derived markers anchoring the bovine genetic map to the physical map.

The mapping strategy for the bovine genome described in this paper uses large insert clones as a tool for physical mapping and as a source of highly polymorphic microsatellites for genetic typing, and was one objective of the BovMap Project funded by the European Union (UE). Eight-three cosmid and phage clones were characterized and used to physically anchor the linkage groups defining all the bovine autosomes and the X Chromosome (Chr). By combining physical and genetic mapping, clones described in this paper have led to the identification of the linkage groups corresponding to Chr 9, 12, 16, and 25. In addition, anchored loci from this study were used to orient the linkage groups corresponding to Chr 3, 7, 8, 9, 13, 16, 18, 19, and 28 as identified in previously published maps. Comparison of the estimated size of the physical and linkage maps suggests that the genetic length of the bovine genome may be around 4000 cM.

Animals↗
PubMed1997

Isolation of coding sequences from bovine cosmids by means of exon trapping.

Exon trapping was employed to identify coding sequences from a collection of 46 bovine cosmids, previously characterized for the presence of microsatellite markers and physically mapped to chromosomes by FISH. The sequence analysis of 104 clones revealed 18 putative exons, 10 of which showed near identity to known sequences. Among these were the human (cytosine-5)-methyltransferase (DNMT), ATP-citrate lyase (ACLY), the mouse Lbcl1 oncogene, the bovine mitochondrial aconitase (ACO2) and beta-arrestin 1 (ARR1). The chromosomal localization of the cloned exons was inferred from the localization of the parent cosmids. DNMT and ACLY were not previously known in cattle, but the physical localization of the cloned bovine exons is in agreement with the published comparative human and bovine maps. The trapping of exons for bovine ACO2 and ARR1 confirms the available mapping information based on synteny and provides a physical assignment for the genes.

ATP Citrate (pro-S)-Lyase↗
PubMed1997

Telomeric fusions in cultured human fibroblasts as a source of genomic instability.

In a human fibroblast clone we studied the evolution, during culture propagation, of a dicentric chromosome consisting of the end-to-end association of the short arm of chromosome 5 and the long arm of chromosome 16. Dual-color fluorescence in situ hybridization (FISH) with painting probes allowed us to define the structure of a variety of derivative chromosomes and to identify the mechanisms by which they originated. Asymmetric interchanges involving the intercentromeric region of the dicentric, bridge-breakage-fusion events, or breaks followed by sister chromatid fusion, originate unstable hetero- or homodicentric chromosomes with deletion or duplication; breakages not followed by reunion, or intradicentric recombination, presumably originate stable rearranged monocentric chromosomes. The variety of the derivatives is extremely large because the observed events may involve any site of the intercentromeric region, although the majority of them occurs after a break in 16qh. The results of this investigation document the evolution through successive steps of a telomeric fusion, a chromosome anomaly frequently observed in tumor and senescent cells. They also demonstrate that in cultured cells of normal origin, starting with this anomaly, various chromosomal mechanisms may produce translocations, duplications, and deletions. The karyotype instability produced by a telomeric fusion can be relevant for carcinogenesis because it may generate genetic changes critical in the multistep process of transformation.

Cells, Cultured↗
PubMed1997

Six bovine cosmid-derived microsatellites mapping different syntenic groups are fluorescence in situ hybridization mapped to six river buffalo chromosomes.

Six bovine cosmid-derived microsatellites (IDVGA53, BTA3/U6; IDVGA61, U13; IDVGA41, BTA12/U27; IDVGA32, BTA15/U19; IDVGA59, BTA26/U26 and IDVGA71, U8), previously assigned to cattle chromosomes, were FISH-mapped to river buffalo chromosomes (BBU) 6q15, 8q34, 13q15, 16q25, 23q22 and 24q13 respectively. Sequential FISH/RBA-banding allowed the precise identification of chromosomes and localization of probe-signals on chromosome bands. These localizations allowed us to assign indirectly, for the first time, six bovine syntenic groups to river buffalo chromosomes, thereby extending its physical map. The localization of IDV-GA71 (bovine U8) to the marker BBU24 adds further information to resolve definitively cattle chromosome ambiguities involving cattle chromosomes 25, 27 and 29.

Animals↗
PubMed1997

FISH mapping of bovine U21, U1 and U7 molecular markers to river buffalo chromosomes 3p, 5q and 5p.

Three bovine cosmid-derived microsatellites (IDV-GA49, IDVGA7 and IDVGA47), previously assigned to cattle syntenic groups U1, U7 and U21, respectively, were fluorescence in situ hybridization (FISH) mapped to river buffalo (Bubalus bubalis, L., 2n = 50) chromosomes (BBU) 3p22 (IDVGA47, U21), BBU 5q21 (IDVGA49, U1) and BBU 5p19 (IDVGA7, U7) using sequential FISH and R-banding techniques. These localizations allowed the assignment, for the first time, of the bovine syntenic groups U21, U1 and U7 to specific river buffalo chromosomes. FISH mapping of IDVGA7 (U7) to cattle rob(1;29) p-arms confirms the banding homologies between BTA 29 and BBU 5p and further supports the idea that cattle standard karyotypes need adjustments.

Animals↗
PubMed1996

T-banding pattern of bovine chromosomes and karyotype reconstitution with physically mapped cosmids.

Bovine T-banded chromosomes were identified by fluorescence in situ hybridization (FISH) using 27 cosmid probes as chromosome landmarks. Pairwise combinations of probes from chromosomes of markedly different size were cohybridized to metaphase spreads of T-banded chromosomes. This confirmed the association of banding patterns to individual chromosomes. The T-banding pattern appears to be related to R-bands: 80% of T-bands were in corresponding position to R-bands, but not always conserved in size. Band assignments placed 20 probes on similar bands in both patterns. The identification of T-banded chromosomes represents a first step toward the construction of a compositional map of the bovine genome and an additional tool for its study on a comparative basis.

Animals↗
PubMed1996

Six antimicrobial peptide genes of the cathelicidin family map to bovine chromosome 22q24 by fluorescence in situ hybridization.

Six phage clones containing gene members of the family of antimicrobial peptides named cathelicidins, were mapped to bovine chromosome 22q24, by means of fluorescence in situ hybridization. The mapping data suggest the clustering of cathelicidins into a CATHL@ locus, in a similar manner as for beta-defensins, another family of antimicrobial peptides, defining the locus DEFB@ mapped to 27q13-->q14.

Animals↗
PubMed1995

Chromosomal localization and molecular characterization of 53 cosmid-derived bovine microsatellites.

Gene mapping in cattle has progressed rapidly in recent years largely owing to the introduction of powerful genetic markers, such as the microsatellites, and through advances in physical mapping techniques such as synteny mapping and fluorescence in situ hybridization (FISH). Microsatellite markers are often not physically mapped because they are generally isolated from small insert plasmid libraries, which makes their chromosomal localization inefficient. In this report we describe the FISH mapping of a large group of cosmid-derived bovine microsatellite markers, as our contribution to the European mapping initiative, BovMap. One objective of BovMap is to develop a set of anchored loci for the cattle genome map. Two cosmid libraries were screened with probes corresponding to the (AC)n microsatellite motif. Positive clones were mapped by FISH, and then a subset was further analyzed by sequencing the region flanking the microsatellite repeat. In total, 58 clones were hybridized with chromosomes and identified loci on 22 of the 31 different bovine chromosomes. Three clones contained satellite DNA. Two or more markers were placed on 12 chromosomes. Sequencing of the microsatellites and flanking regions was performed directly from 43 cosmids, as previously reported (Ferretti et al. Anim. Genet. 25, 209-214, 1994). Primers were developed for 39 markers and used to describe the polymorphism associated with the corresponding loci.

Animals↗
PubMed1995

Combined Q-banding and fluorescence in situ hybridization for the identification of bovine chromosomes 1 to 7.

Eleven probes were assigned to bovine chromosomes 1 to 7 by fluorescence in situ hybridization (FISH). The identification of chromosomes was based on QFQ-banding prior to in situ hybridization and comparison with the Reading Conference (1976) and ISCNDA (1989) standards. The probes used for FISH can now be utilized as identification and discrimination features for bovine chromosomes 1 to 7 and particularly for chromosomes 4 and 6, which are difficult to distinguish. Comparison of our mapping data with previous assignments and of the standard chromosome banding patterns prompt us to propose a change in the ISCNDA nomenclature: ISCNDA chromosome 4 should be named chromosome 6 and vice versa. Chromosome 4 is marked by the ribosomal RNA cluster RNR3, and chromosome 6 is characterized by the casein gene cluster and an anonymous satellite (D6Z1).

Animals↗
PubMed1995

Presence of a chloroplast DNA sequence in an autonomous circular DNA molecule in cultured rice cells (Oryza sativa L).

Sequence analysis of twelve DNA fragments, which had previously been found to be extensively amplified in suspension-cultured rice cells, revealed that two of them, isolated on plasmids designated pE10 and pE11, have sequences identical to distinct regions of chloroplast DNA (ct-DNA). Both sequences are part of an extrachromosomal circular DNA molecule (ECD). The molecular structure of the ECD was investigated by a combination of restriction analysis, standard and pulsed-field gel electrophoresis, hybridization with ct-DNA probes and amplification by the polymerase chain reaction in the presence of oligonucleotide primers homologous to selected regions of rice ct-DNA. The results showed that a continuous and unrearranged stretch of ct-DNA from the long single-copy region, of at least 28 kbp in length, is present in the ECD. It was estimated that the number of copies of the ECD in cultured cells was almost equivalent to that of ct-DNA molecules in rice leaves, while the ratio of ECD to ct-DNA molecules in the cultured cells was approximately 200:1.

Cells, Cultured↗