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L Peelman

Publications and source records attributed to L Peelman.

12 recordsLinked to original sources

Technical note: validation of internal control genes for gene expression analysis in bovine polymorphonuclear leukocytes.

Analysis of gene expression is becoming more important in all areas of biological research to evaluate gene expression during physiological and pathological conditions (e.g., mastitis), not the least in the field of animal research. Presently, real-time gene expression analysis is considered to be the method of choice for accurate and sensitive quantification of mRNA transcripts. Because comparison of gene expression levels is frequently the aim of these experiments, there is a critical need to validate internal control genes. When studying gene expression in bovine polymorphonuclear leukocytes, special attention should be paid to this validation, because polymorphonuclear leukocytes are subjected to numerous physiological influences, depending on the stage of lactation. In this study, 8 commonly used reference genes (ACT, GAPD, H2A, TBP, HPRT1, SDHA, YWHAZ, and 18S rRNA) were evaluated in bovine polymorphonuclear leukocytes. The transcription levels of 6 reference genes were determined using real-time PCR. By geometrically averaging the expression levels of these genes, SDHA, YWHAZ, and 18S rRNA were selected as being the most stable genes for accurate normalization of real-time results of bovine polymorphonuclear leukocytes.

Animals↗

Detection of bacterial DNA in synovial fluid from horses with infectious synovitis.

Standard culturing techniques are often unrewarding in confirming diagnosis of synovial infection in the equine patient. Several human studies report the use of sensitive polymerase chain reaction (PCR) techniques for the detection of bacterial involvement in acute synovitis. However, successful extraction of bacterial DNA directly from clinical samples from horses without prior culture has not been reported yet. The goal of this study was to develop a sensitive and reliable method for molecular detection and identification of bacterial species in synovial fluid from horses with infectious synovitis. Synovial fluid samples from 6 horses with culture confirmed synovial infection were used for broad range 16S rRNA gene PCR. Synovial aspirates of 2 healthy horses were used as negative controls. Following extraction and purification of synovial fluid DNA, all samples were processed by touchdown PCR. Amplicons were detected by reverse line blot hybridisation and visualised with chemiluminescence. Pathogen-specific detection of 16S rRNA gene sequences was successful in all 6 synovial fluid samples. No bacterial DNA was detected in the aspirates from the negative control horses using touchdown PCR followed by 25 additional cycles of amplification. The identity of the pathogens was confirmed by DNA sequencing of the amplicons. It can be concluded that broad range 16S rRNA gene PCR followed by reverse line blot hybridisation is a promising technique for detection of bacterial DNA in synovial fluid samples. Further research should aim at the detection of bacterial DNA in synovial fluid samples suspected of infection but having negative culture results. When the 16S PCR proves to be reliable and more sensitive than standard culturing techniques, it may become a powerful tool in the diagnosis of synovial infection.

Animals↗

Detection of polymorphisms in the prion protein gene in the Belgian sheep population: some preliminary data.

The development of clinical signs of TSE/scrapie in sheep has been linked to polymorphisms in the prion protein (PRNP) gene. The most important polymorphisms appear to be at codons 136, 154, and 171. The objective of this study was to investigate the polymorphisms at these codons in the Belgian sheep population, including clinical healthy animals, healthy animals at the slaughterhouse and animals in TSE/scrapie positive farms (including a Nor98 farm).

Animals↗

Bovine melanocortin receptor 4: cDNA sequence, polymorphisms and mapping.

A cDNA encoding the bovine melanocortin receptor 4 (MC4R) was cloned and sequenced. Comparing human, pig and rat homologues showed a 87, 85 and 89% identity on the DNA level, respectively, and over 90% on the protein level. The bovine MC4R gene was mapped to BTU 24 by radiation hybrid mapping. Two nucleotide changes were identified by single stranded conformation polymorphism (SSCP) and sequencing. The substitutions proved to be a T to C and G (allele B) to A (allele A) resulting, respectively, in a conservative valine to alanine substitution (Val 145 Ala) and an alanine to threonine (Ala 172 Thr). Using PCR-RFLP, 13 different cattle breeds were screened for the presence of the Ala 172 Thr substitution. With the exception of one Red Pied animal, allele A could only be detected in Red Holstein animals.

Amino Acid Sequence↗

Pig plasma alpha-protease inhibitors PI2, PI3 and PI4 are members of the antichymotrypsin family.

Three related alpha-protease inhibitors, PI2 I, PI3 C and PI4 C2, of blood serum of the pig (Sus scrofa) were isolated. PI2 I inhibited both trypsin and chymotrypsin; PI3 C and PI4 C2 strongly inhibited chymotrypsin, but did not significantly inhibit trypsin. By using SDS-PAGE, the three proteins were found to be composed of single polypeptide chains, and molecular weights were 63,000 for PI2 I, 58,000 for PI3 C and 64,000 for PI4 C2. All three proteins were shown to be glycoproteins. In PI3 C, eight sialic acid residues were found, and in PI4 C2 (similarly as in PI2 F) 10-11 residues were found. Amino acid composition as well as N-terminal sequences of the three proteins were very similar, indicating close homology. Comparison of these partial amino acid sequences with the cDNA-deduced amino acid sequence of pig alpha-antichymotrypsin (AACT; Buchman, 1989, GenBank, Accession No. M29508) revealed great similarities, the sequence of PI2 I being virtually identical with the pig AACT. On the basis of all available results, PI2 is proposed to be pig AACT, an orthologue of human AACT.

Amino Acid Sequence↗

Polymorphic CAC/T repetitive sequences in the pig genome 1.

Three genomic clones were isolated from a size-selected pig DNA library by hybridization with a DNA-fingerprint probe. Analysis at the sequence level revealed that all three clones contain interrupted stretches of triplet repeats mainly composed of CAC and CAT triplets. Evaluation of the corresponding loci for polymorphism by Southern blot hybridization showed considerable length variation. For two loci the polymorphism was also demonstrated by polymerase chain reaction (PCR) amplification. The PiGMaP reference pedigree was typed for all three loci.

Animals↗

Characterization of six new loci within the swine major histocompatibility complex class III region.

A search for new potential coding sequences was conducted within two overlapping cosmid genomic DNA clusters of about 170 and 45 kb from the swine major histocompatibility complex class III region. The sequences were detected with various probes, including pools of swine cDNA, homologous and heterologous genomic sequences, and synthetic oligonucleotides. The 170 kb cluster was centered on the tumor necrosis factor genes (TNF), and the 45 kb cluster contained the heat-shock protein 70 genes (HSP70). The TNF cluster revealed the presence of five new genes: lymphotoxin beta, BAT1, BAT2, BAT3, and a sequence related to DNA-binding factors. No sequence homologous to B144 was found in the TNF cluster, although other unidentified coding sequences may be present in this cluster. The HSP70 cluster contained a gene identified as BAT6, that is, tRNA-valyl synthetase. These results provide new evidence that the genomic maps of these various genes in the TNF and HSP70 sub-regions are similar in swine and human.

Animals↗

Characterization of porcine polymorphic microsatellite loci.

Twenty-seven (CA)n and two (GA)n microsatellite clones were isolated out of a size-selected genomic pig library. These were sequenced and the number of uninterrupted dinucleotides was found to range from 12 to 26. Flanking primers were chosen for 11 dinucleotide repeats and optimal conditions for polymerase chain reaction (PCR) amplifications were established. Different microsatellite loci were amplified simultaneously by combining primer sets. Related and unrelated pigs were screened for length polymorphisms of the different microsatellite loci. The polymorphic information content (PIC) of these loci ranged between 0.62 and 0.83. Segregation studies in pig reference families established Mendelian inheritance. Locus S0022 was found to be X-linked.

Alleles↗

Polymerase chain reaction analysis of the surgical margins of equine sarcoids for bovine papilloma virus DNA.

OBJECTIVE: To examine apparently normal skin around equine sarcoids for evidence of bovine papilloma virus (BPV) DNA, and to relate this finding to the observed recurrence after surgery. STUDY DESIGN: Prospective study. ANIMALS OR SAMPLE POPULATION: Forty-one equine sarcoids from 19 horses. MATERIALS AND METHODS: The tumors were surgically excised at a measured distance of 8, 12, or 16 mm. Samples from the tumor and of the entire surrounding skin were taken at 4, 8, 12, and 16 mm from the tumor border and analyzed for the presence of BPV DNA using polymerase chain reaction (PCR) amplification. The samples were grouped per examined sarcoid, and a tumor was considered positive at a certain distance as soon as at least one of the samples at that distance was positive. The clinical outcome was recorded for each sarcoid after a minimal follow-up of 6 months. RESULTS: All sarcoids were positive for BPV(1) or BPV(2). The tumor margin was positive at 4, 8, 12, and 16 mm in, respectively, 95%, 73%, 39%, and 33% of the examined sarcoids. Local recurrence was observed in 3 sarcoids on 3 different horses. From survival analysis, there was a greater likelihood for local recurrence when sarcoids had a surgical margin that was positive for BPV DNA. CONCLUSIONS AND CLINICAL RELEVANCE: BPV DNA is often detected in visibly normal skin around sarcoids, and there is a significantly greater probability for local recurrence when the surgical margins are positive for the presence of BPV DNA.

Animals↗