Search results for "Restriction"
showing 10 items of 527 documents
Centromeric heterochromatin and satellite DNA in the Chironomus plumosus species group
1994
Species of the Chironomus plumosus group display significant differences in their amount of centromeric heterochromatin. A tandem-repetitive satellite-like DNA has been isolated from C. plumosus. This DNA accounts for a major part of the centromeric heterochromatin. The DNA element has a Sau3AI restriction site ("Sau elements") and a monomer length of 165 or 166 bp. It is A-T rich (73%) and reveals a moderate DNA curvature, as shown by gel migration and computer analysis. The chromosomal localization and genomic organization of Sau elements were studied in 24 Chironomus species by in situ hybridization and (or) Southern analysis. The DNA is predominantly located in the centromeric regions …
Diagnosis of flavobacteriosis by direct amplification of rRNA genes
2002
A broad-range bacterial PCR method with universal 16S rDNA targeting primers and bacterial cultivation was used to identify the putative pathogen in flavobacterial outbreaks. Restriction fragment length polymorphism (PCR-RFLP) analysis and sequencing of the partial 16S rDNA PCR products of 10 skin samples and 10 representative isolates derived from the same fish specimens revealed differences between direct molecular and cultivation-based analysis. Flavobacterium columnare-like sequences dominated in the direct molecular analysis in most cases, whereas most of the isolates belonged to a phylogenetically heterogeneous group of flavobacteria clustering with F. hibernum. F. columnare was isola…
ABO genotyping by PCR-RFLP and cloning and sequencing
2005
A refined PCR-RFLP based method was established to genotype ABO blood groups. The main objective of this study was to make the techniques also suitable for working with degraded DNA. Specific primer design was carried out to choose fragments shorter than 200 bp as necessary in forensic and archaeological applications. Four fragments of exon 6 and 7 of the ABO gene were amplified and digested by in total 7 restriction endonucleases. Particular attention was paid to the base changes at nucleotide positions 261(delG), 297, 526, 703, 721, 771, 796 and 1060(delC) in order to distinguish the six common alleles A101, A201, B, O01, O02 and O03. Furthermore, this method also enables determination of…
Improved acid tolerance of a recombinant strain of Escherichia coli expressing genes from the acidophilic bacterium Oenococcus oeni.
2001
Aims:Oenococcus oeni is a lactic acid bacterium used in wine fermentation. Two open reading frames (orfB and orfC) were identified in the upstream region of the hsp18 gene, encoding the small heat-shock protein Lo18. Expression of these genes in conditions of acid stress was studied in Escherichia coli. Methods and Results: Sequence analysis showed that orfB encodes a putative transcriptional regulator of the LysR family. The protein encoded by orfC shares homologies with multi-drug resistance systems. Heterologous expression of orfB, orfC and hsp18 genes in Escherichia coli significantly enhanced the viability of the host strain under acidic conditions. Conclusions: It was demonstrated tha…
Sequence analysis of the rDNA spacer of Paracentrotus lividus and observations about pre-rRNA processing. NTS sequence of Paracentrotus lividus rDNA.
1993
We have isolated and sequenced one intergenic region and a small part of the flanking regions (18S and 26S rRNA coding regions) of the rRNA-encoding genes (rDNA) from the sea urchin Paracentrotus lividus. This region is about 3.8 Kb long. Northern blot hybridizations and S1 mapping experiments demonstrated the presence of a partially processed 21S rRNA precursor while has the same 5' terminus as the 32S primary precursor, also in developmental stages characterized by a low rate of rRNA synthesis.
Reinterpreting a community outbreak of Salmonella enterica serotype Enteritidis in the light of molecular typing
2007
Abstract Background In November 2005, a large outbreak due to Salmonella enterica serotype Enteritidis (S. Enteritidis) was observed within children who had eaten their meals at 53 school cafeterias in Florence and the surrounding area. A total of 154 isolates of S. Enteritidis were recovered from human cases between November 2005 and January 2006. All strains were assigned phage type 8 (PT8) and a common XbaI pulsotype. This paper reports the findings of a molecular epidemiological investigation performed on 124 strains of S. Enteritidis isolated in the years 2005 and 2006 in Florence and the surrounding area, including the epidemic isolates. Methods One hundred twenty-four human isolates …
Phage types and ribotypes of Salmonella enteritidis in southern Italy.
1996
Differently from other European countries, Southern Italy was affected by a considerable increase in human infections due to Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) only after 1990. On the present investigation, two groups of S. Enteritidis strains isolated during the low-incidence period 1980-1984 and the epidemic period 1990-1993, respectively, have been submitted to phage-typing and ribotyping in order to ascertain whether the epidemic increase was determined by the spread of a foreign bacterial clone or not. Among the 150 isolates relative to the aforesaid two periods, 12 different phage types (PTs) were observed. PT4 was the most common phage type among…
Genetic population structure of Epinephelus marginatus (Pisces, Serranidae) revealed by two molecular markers
2006
In this paper, data are presented regarding the population structure of dusky grouper (Epinephelus marginatus) which was sampled in the Mediterranean Sea and Atlantic Ocean using two different molecular markers, ND2 RFLP and cytochrome b (cyt b) sequence analysis. The main objective of the study is to analyse the genetic variability of E. marginatus in the Mediterranean Sea to define how the biological characteristics of the species, such as the dispersal capability of pelagic larvae and the benthonic-sedentary life style, can affect the genetic population structure or maintaining the gene flow or determining genetic differences. Furthermore, we considered an Atlantic sample to establish th…
Meat production from dairy breed lambs due to slaughter age and feeding plan based on wheat bran
2019
This experiment aimed to investigate the possibility to increase the carcass weight of dairy breed lambs and produce moderate-fat meat by applying inexpensive feeding strategies based on restriction and through the use of a fibrous byproduct such as the durum wheat bran (DWB). Sixty-five 45-day-old lambs of the Valle del Belice breed, divided into 6 groups, were fed alfalfa hay supplemented with concentrate feeds including DWB at 0% or 20% (DWB0, DWB20), supplied ad libitum (L) or restricted at 75% (R), and slaughtered at 90 or 120 days of age. The groups were as follows: DWB0-90L (n = 14), DWB20-90L (n = 14), DWB0-120R (n = 10), DWB20-120R (n = 9), DWB0-120L (n = 9), DWB20-120L (n = 9). Th…
Metilazione del DNA in artrite reumatoide
2005
Lo stato di metilazione del DNA genomico e del gene PTHrP è stato valutato con tecniche molecolari e citogenetiche in artrite reumatoide (AR), patologia autoimmune caratterizzata anche da alta incidenza di linfomi e da ipercalcemia per overespressione del gene PTHrP. La metilazione del DNA, infatti, ha un ruolo critico nello sviluppo delle malattie neoplastiche; il gene PTHrP avendo tre promotori uno dei quali contiene un’isola CpG è un buon candidato per la deregolazione da alterato pattern di metilazione locale. Le indagini sulla metilazione genomica, condotte su DNA estratto da sangue periferico di pazienti e di donatori e amplificato in reazioni di Methylation-Sensitive Arbitrarily Prim…