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Biomedical subjects

B Brenig

Publications and source records attributed to B Brenig.

At least 37 records · Page 2Linked to original sources

Molecular characterization of porcine hyaluronidase genes 1, 2, and 3 clustered on SSC13q21.

Hyaluronidase genes (HYAL) encode hyaluronidase enzymes required for hyaluronan degradation. Both in humans and in mouse, clustered hyaluronidase genes have been identified. Here, the porcine hyaluronidase cluster consisting of genes HYAL1, HYAL2 and HYAL3 was characterized. The porcine cDNA sequences and proteins share homologies to human orthologs of 85 and 81% for HYAL1, 87 and 89% for HYAL2 and 86 and 83% for HYAL3, respectively. The porcine hyaluronidase proteins approximately share a 40% homology with each other. Furthermore, genes FUS1 and FUS2 were found within this cluster, which was assigned to SSC13q21. A total of seven SNPs were detected in the genes (four in HYAL1, two in HYAL2 and one in HYAL3). Three of the four SNPs in HYAL1 led to amino acid exchanges (C622G --> Asp24 to Glu; C633T --> Pro28 to Leu, and G1298T --> Ala250 to Ser). The amino acid replacements induce putative changes in the extended strand at Asp24, in the extended strand and the random coil at Pro28, and finally in the random coil and the alpha helix at Ala250. Frequency estimations for four SNPs located in genes HYAL1 and HYAL3 using animals (n = 295) of nine European and six Chinese pig breeds indicated several significant deviations. For example, there were no significant differences in allele frequencies between pigs representing breeds Hampshire and Jiangquhai at SNP C633T (HYAL1), but between Hampshire respectively Jiangquhai animals and Rongchang pigs. Analysis of the same breeds at SNP C588T (HYAL3) indicates significant differences between Hampshire and Jiangquhai respectively Rongchang, but not between Jiangquhai and Rongchang. The breed Göttingen Minipig displayed significant differences concerning two SNPs with respect to the other European pig breeds tested. For all three hyaluronidase genes, N-glycosylation sites are typical. For HYAL2 the lysosomal character was proven. The catalytic site responsible for HAase activity is conserved in the three enzymes. Expression of hyaluronidases was determined by RT-PCR and quantitative PCR. Broad gene expression was observed in different tissues for the three genes, respectively.

Amino Acid Sequence↗

Characterization and chromosome localization of a processed pseudogene related to the bovine laminin receptor gene family.

A bovine BAC clone containing a processed laminin receptor pseudogene (LAMR1P) has been isolated and characterized. A 2,901-bp sequence was produced from the clone, of which 1,187 bp represented seven identifiable exon-like domains, but no intervening sequences. The pseudogene sequence reveals several transversions and transitions, as well as insertions and deletions. A premature stop codon motif is present at nucleotide position 115 located in the exon-2-like domain. Physical mapping of the gene was performed by FISH and RH panel mapping and assigned LAMR1P to BTA4q24-->q26 with the closest linkage to BM6458 (19 cR, LOD score of 11.6). The functional laminin receptor putatively plays an important role in the transmission of bovine spongiform encephalopathy (BSE). In this process, the receptor supposedly acts as the binding site for prion proteins to enter mammalian cells. Considering the existence of several human laminin receptor pseudogenes forming a complex family, any knowledge of even pseudogene sequences might be helpful to isolate the functional bovine laminin receptor gene.

Animals↗

[Case-report. Malignant nerve sheath tumor in a cow with symptoms of suspected BSE].

We report here on a 3 1/2-year-old mother cow with a malignant perineural tumour near the pontine angle of the cerebellum, but which first drew attention because of clinical signs of BSE. Neurological symptoms that manifested during the course of the disease included disturbances in behaviour, movement and aesthesia, as described by BRAUN et al. (2001) in cases of BSE. Inconsistent with a diagnosis of BSE were focal neurological disturbances (head held aslant to the right, tendency to fall to the right, right-sided facial weakness, left-sided nystagmus and ventral strabismus). Following euthanasia, magnetic resonance imaging (MRI) revealed a tumour in the cerebellopontine angle. Histological findings describe a malignant peripheral nerve tumour of the vagal nerve with rhabdoid differentiation (a so-called Triton tumour) with an intracranial and an extracranial part.

Animals↗

Polymorphisms in MHC-DRA and -DRB alleles of water buffalo (Bubalus bubalis) reveal different features from cattle DR alleles.

Seventy-five individuals of Bubalus bubalis belonging to four different breeds, three of river buffalo and one of swamp buffalo, were studied for polymorphism in MHC DRB (Bubu-DRB) and DRA (Bubu-DRA) loci. Eight alleles of Bubu-DRB were found, and all alleles in the swamp type were shared with the three river breeds. All alleles sampled from the breed of European origin (Mediterranean) were present in breeds sampled in Brazil, thus variability of this locus may have been preserved to a great extent in the more recently founded Brazilian population. Bubu-DRB alleles contained higher proportions of synonymous vs. non-synonymous substitutions in the non-peptide-binding sites (PBS) region, in contrast to the pattern of variation found in BoLA-DRB3, the orthologous locus in cattle. This indicated that either the first domain exon (exon 2) of Bubu-DRB has not undergone as much recombination and/or gene conversion as in cattle alleles, or Bubu-DRB may be more ancient than BoLA-DRB3 alleles. Phylogenetic analysis of DRB alleles from Bubalus, Syncerus c. caffer, the Cape buffalo, and domestic cattle demonstrated transspecies polymorphism. Water buffalo contained two alleles of DRA that differed from each other in two amino acid positions, including one in the PBS (alpha22) that was also shared with Anoa depressicornis, the anoa. Discovery of variation in DRA was surprising as the first domain of DRA is a highly conserved polypeptide in mammals in general and especially in ruminants, where no other substitution in PBS was seen.

Alleles↗

Analysis of the 5' region of the canine PAX3 gene and exclusion as a candidate for Dalmatian deafness.

The causative mutation in a gene related to hearing loss in Dalmatians has been elusive. Because of its role in melanocyte migration and differentiation as integral component of the inner ear, we hypothesized that the canine PAX3 (paired box homeotic gene 3) gene could be a candidate for Dalmatian deafness. Therefore, we isolated the canine PAX3 gene and searched for causative mutations within the coding region of important regulatory domains of PAX3. However, no mutations were identified when comparing the DNA sequences of healthy and affected dogs. These results were confirmed by a two-point linkage analysis in 203 Dalmatians transmitting deafness. Our data clearly show that the canine PAX3 gene can be excluded as candidate for Dalmatian deafness.

Animals↗

Generation of a 5.5-Mb BAC/PAC contig of pig chromosome 6q1.2 and its integration with existing RH, genetic and comparative maps.

We generated a sequence-ready BAC/PAC contig spanning approximately 5.5 Mb on porcine chromosome 6q1.2, which represents a very gene-rich genome region. STS content mapping was used as the main strategy for the assembly of the contig and a total of 6 microsatellite markers, 53 gene-related STS and 116 STS corresponding to BAC and PAC end sequences were analyzed. The contig comprises 316 BAC and PAC clones covering the region between the genes GPI and LIPE. The correct contig assembly was verified by RH-mapping of STS markers and comparative mapping of BAC/PAC end sequences using BLAST searches. The use of microsatellite primer pairs allowed the integration of the physical maps with the genetic map of this region. Comparative mapping of the porcine BAC/PAC contig with respect to the gene-rich region on the human chromosome 19q13.1 map revealed a completely conserved gene order of this segment, however, physical distances differ somewhat between HSA19q13.1 and SSC6q1.2. Three major differences in DNA content between human and pig are found in two large intergenic regions and in one region of a clustered gene family, respectively. While there is a complete conservation of gene order between pig and human, the comparative analysis with respect to the rodent species mouse and rat shows one breakpoint where a genome segment is inverted.

Animals↗

Quantitative trait loci mapping of functional traits in the German Holstein cattle population.

A whole-genome scan to detect quantitative trait loci (QTL) for functional traits was performed in the German Holstein cattle population. For this purpose, 263 genetic markers across all autosomes and the pseudoautosomal region of the sex chromosomes were genotyped in 16 granddaughter-design families with 872 sons. The traits investigated were deregressed breedingvalues for maternal and direct effects on dystocia (DYSm, DYSd) and stillbirth (STIm, STId) as well as maternal and paternal effects on nonreturn rates of 90 d (NR90m, NR90p). Furthermore, deregressed breeding values for functional herd life (FHL) and daughter yield deviation for somatic cell count (SCC) were investigated. Weighted multimarker regression analyses across families and permutation tests were applied for the detection of QTL and the calculation of statistical significance. A ten percent genomewise significant QTL was localized for DYSm on chromosome 8 and for SCC on chromosome 18. A further 24 putative QTL exceeding the 5% chromosomewise threshold were detected. On chromosomes 7, 8, 10, 18, and X/Yps, coincidence of QTL for several traits was observed. Our results suggest that loci with influence on udder health may also contribute to genetic variance of longevity. Prior to implementation of these QTL in marker assisted selection programs for functional traits, information about direct and correlated effects of these QTL as well as fine mapping of their chromosomal positions is required.

Animals↗

Mapping of the bovine blood group systems J, N', R', and Z show evidence for oligo-genetic inheritance.

Genes determining the bovine erythrocyte antigens were mapped by linkage analysis. In total 9591 genotypes of 20 grandsire families with 1074 sires from a grand-daughter design were elucidated for the genes determining the erythrocyte antigens EAA, EAB, EAC, EAF, EAJ, EAL, EAM, EAN', EAR', EAS, EAT', and EAZ according to standard paternity testing procedures in the blood typing laboratories. Linkage analyses were performed with 248 microsatellite markers, eight SSCP markers and four polymorphic proteins and enzymes covering the 29 autosomes and the pseudoautosomal region of the sex chromosomes. The number of informative meioses for the blood group systems ranged from 76 to 947. Blood group systems EAM and EAT' were non-informative. Most of the erythrocyte antigen loci showed significant linkage to a single chromosome and were mapped unequivocally. The genes determining erythrocyte antigen EAA, EAB, EAC, EAL, and EAS were mapped to chromosomes 15, 12, 18, 3, and 21, respectively. Lod-score values ranged from 11.43 to 107.83. Moreover, the EAF system could be mapped to chromosome 17. However, the EAN' system previously known as part of the EAF system could be mapped to chromosome 5. In addition, the blood group systems EAJ, the new EAN', EAR', and EAZ, showed significant linkage to microsatellite markers on various chromosomes and also to other blood groups. The appearance of a single blood group system might be therefore either dependent on the existence of other blood group systems or because of an interaction between different loci on various chromosomes as is known in humans and in pigs.

Animals↗