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A Dalmasso

Publications and source records attributed to A Dalmasso.

At least 19 recordsLinked to original sources
PubMed2004

A multiplex PCR assay for the identification of animal species in feedstuffs.

A multiplex Polymerase Chain Reaction (PCR) assay was applied to feedstuff analysis for the identification of the most used species in rendering plants (ruminant, poultry, fish and pork materials). Primers were designed in different regions of mitochondrial DNA (12S rRNA, tRNA Val and 16S rRNA) after alignment of the available sequences in the GenBank database. The primers generated specific fragments of 104-106, 183, 220-230 and 290 bp length for ruminants, poultry, fish and pork, respectively. The detection limit was 0.004% for fish primers and 0.002% for ruminants, poultry and pork primers. The multiplex PCR proposed in this study can be considered a valid alternative to the microscopic method for the detection of animal derived materials banned by a European Union Regulation as a preventive measure against the spread of Bovine Spongiform Encephalopathy.

Animal Feed↗
PubMed2004

Development of a multiplex PCR assay for the identification of pathogenic genes of Escherichia coli in milk and milk products.

A multiplex PCR for the simultaneous detection of some pathogenic genes of enteropathogenic, enterotoxigenic and verocytotoxin-producing Escherichia coli was developed. In this study primers found in literature as well as primers to the purpose designed were used. In this way, it was possible to generate specific fragments of 96, 170, 229, 285, 348, 414 and 510 bp for Hlya, St, EaeA, Lt, Vt1, UidA and Vt2 genes, respectively. When applied to bacterial strains experimentally inoculated in milk and milk products, the proposed PCR showed a detection limit of 5 x 10(4)CFU/ml for Hyla, St, Eaea, Vt1 primers, while for Lt and Vt2 primers the limit resulted of 10(6)CFU/ml.

Animals↗
PubMed2000

Virulence and molecular diversity of parthenogenetic root-knot nematodes, Meloidogyne spp.

Root-knot nematodes (RKN) are sedentary endoparasites causing severe damage to a wide variety of crops, including tomato. Among them, the parthenogenetic species Meloidogyne arenaria, M. incognita and M. javanica are of particular economic importance. The genetic diversity and relationships of 17 populations belonging to these three major species, either avirulent or virulent against the tomato Mi resistance gene, were investigated in order to determine whether (a)virulence of the nematodes could be related to their molecular fingerprints. Genomic polymorphisms between populations were assessed by using amplified fragment length polymorphism (AFLP) markers, and data were treated by means of a multiple correspondence analysis. A total of 1550 polymorphic amplified DNA fragments were identified and used to compute the relationships between the populations. As expected, the three RKN species were clearly distributed into distinct groups, but combination of data for virulence phenotypes and DNA markers showed that clustering of populations was not associated with their (a)virulence against the tomato Mi resistance gene. Such a lack of correlation indicates that most of the observed DNA polymorphism is independent of virulence, which is presumably under host selection. This result demonstrates that virulent populations do not share a common origin, and strongly suggests that they might have appeared late after the establishment of these clonal lineages, as the result of independent mutational events.

Animals↗
PubMed1998

RPE, a plant gene involved in early developmental steps of nematode feeding cells.

Sedentary plant-parasitic nematodes are able to induce the redifferentiation of root cells into multinucleate nematode feeding sites (NFSs). We have isolated by promoter trapping an Arabidopsis thaliana gene that is essential for the early steps of NFS formation induced by the root-knot nematode Meloidogyne incognita. Its pattern of expression is similar to that of key regulators of the cell cycle, but it is not observed with the cyst nematode. Later in NFS development, this gene is induced by both root-knot and cyst nematodes. It encodes a protein similar to the D-ribulose-5-phosphate 3-epimerase (RPE) (EC 5.1.3.1), a key enzyme in the reductive Calvin cycle and the oxidative pentose phosphate pathway (OPPP). Quantitative RT-PCR showed the accumulation of RPE transcripts in potato, as in Arabidopsis NFS. Homozygous rpe plants have a germination mutant phenotype that can be rescued in dwarf plants on sucrose-supplemented medium. During root development, this gene is expressed in the meristems and initiation sites of lateral roots. These results suggest that the genetic control of NFSs and the first stages of meristem formation share common steps and confirms the previous cytological observations which indicate that root cells undergo metabolic reprogramming when they turn into NFSs.

Amino Acid Sequence↗
PubMed1998

High-resolution DNA fingerprinting of parthenogenetic root-knot nematodes using AFLP analysis.

Amplified fragment length polymorphism (AFLP) analysis has been used to characterize 15 root-knot nematode populations belonging to the three parthenogenetic species Meloidogyne arenaria, M. incognita and M. javanica. Sixteen primer combinations were used to generate AFLP patterns, with a total number of amplified fragments ranging from 872 to 1087, depending on the population tested. Two kinds of polymorphic DNA fragments could be distinguished: bands amplified in a single genotype, and bands polymorphic between genotypes (i.e. amplified in not all but at least two genotypes). Based on presence/absence of amplified bands and pairwise similarity values, all the populations tested were clustered according to their specific status. Significant intraspecific variation was revealed by AFLP, with DNA fragments polymorphic among populations within each of the three species tested. M. arenaria appeared as the most variable species, while M. javanica was the least polymorphic. Within each specific cluster, no general correlation could be found between genomic similarity and geographical origin of the populations. The results reported here showed the ability of the AFLP procedure to generate markers useful for genetic analysis in root-knot nematodes.

Animals↗
PubMed1994

Cloning and characterization of two satellite DNAs in the low-C-value genome of the nematode Meloidogyne spp.

Two highly reiterated StyI satellite DNAs have been cloned from two nematode species: one from Meloidogyne hapla and another from M. incognita. The monomeric units of these two satellites have a repeat length of 169 and 295 bp, respectively. These StyI repeated element families constitute 5% of the M. hapla and 2.5% of the M. incognita haploid genomes. The A + T content is elevated in both families (i.e., 68% and 77%, respectively). Nucleotide methylation and transcriptional activity are negative. No similarity was found between the two satellites, nor to other known highly repetitive elements. These StyI satellite DNAs are quite homogenous in sequence, showing on average 3% and 3.5% divergence from their respective calculated consensus sequence. An internal subrepeating unit of about 11 bp is observed in the StyI satellite monomer sequences of M. hapla, suggesting that it could have evolved from a shorter sequence. Because of the small size of the Meloidogyne genome (51 Mb) and the abundance of repeated sequences, this genus approaches a limit in terms of coding fraction.

Animals↗
PubMed1993

Expression and biochemical characterization of the DNA binding activity of TcA, the putative transposase of Caenorhabditis elegans transposable element Tc1.

The TcA protein is one of the proteins essential for Tc1 transposition. In order to study the biochemical parameters of Tc1 transposition mechanism, we used TcA protein overproduced in baculovirus system for DNA binding experiments. We show that, despite its relatively strong non specific affinity for DNA, TcA exhibits a better affinity for its Tc1 specific binding sites. The K0.5 is 3.8 nM for the Tc1 whereas in the same type of experiment the K0.5 is 24 nM for calf thymus DNA. The ratio value between specific and non specific DNA binding activity of the TcA protein was also exhibited by other transposases such as those of the bacteriophage Mu, Tn 10 and the Drosophila P element. This nonspecific DNA binding activity may be involved in determining sites of transposable element insertion.

Animals↗
PubMed1991

Sequences homologous to Tc(s) transposable elements of Caenorhabditis elegans are widely distributed in the phylum nematoda.

To have a better understanding of the evolutionary history of mobile elements within the nematodes, we examined the distribution and the conservation of homologues to transposable elements from Caenorhabditis elegans (Tc1, Tc2, Tc3, Tc4, Tc5, and FB1) in 19 nematode species belonging to the class Secernentea. Our results show that Tc1 elements display a distribution restricted to the family Rhabditidae with poor conservation. The Tc2 and FB1 homologous elements have the same patchy distribution within the Rhabditidae. They were only found in Caenorhabditis and in Teratorhabditis. The Tc3 element is widely distributed among nematode species. Tc3 homologous elements are present in the majority of the Rhabditidae but also in two genera within the family Panagrolaimidae, and in Bursaphelenchus, which belongs to the order Aphelenchida. Tc4 and Tc5 homologues show the most limited distribution of all tested elements, being strictly limited to C. elegans. These data indicate that in some cases, the distribution of transposable elements in the nematode cannot be explained by strict vertical transmission. The distribution of Tc3, Tc4, and Tc5 suggests that horizontal transmission may have occurred between reproductively isolated species during their evolutionary history.

Animals↗
PubMed1990

Enterococcal sepsis and lung microvascular injury in sheep.

In a common bile duct contamination model, we studied the effect of Streptococcus faecalis compared with Escherichia coli in sheep with chronic lymph fistulas to investigate the role of enterococcus in acute lung injury and acute sepsis. Early pulmonary hypertension in the E coli group was not expressed in the S faecalis group, probably due to a failure of S faecalis to illicit a thromboxane A2 response. In the late period, E coli was associated with significantly greater lung microvascular damage compared with S faecalis. The lack of difference between groups with respect to complement activation suggests the action of chemotactic factors, in addition to complement, mediating granulocyte aggregation, and neutropenia. In this model, S faecalis demonstrated limited pathogenicity as expressed in lung microvascular injury compared with E coli.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Allo-anti-Chido in a Ch-positive patient.

Allo-anti-Chido (Ch) was detected in a patient whose red cells typed as Ch+. The C4 allotype of the patient was A4,B2 which associates strongly with the Ch phenotype Ch:1,-2,3,4,-5,6. Anti-Ch2 + Ch5 were the Ch specificities identified. Absence of only Ch2 and Ch5 determinants on the C4B protein allowed this unique immune response to blood transfusion.

Aged↗