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G Erhardt

Publications and source records attributed to G Erhardt.

At least 55 records · Page 3Linked to original sources
PubMed2001

Genetic polymorphism of goat kappa-casein (CSN3) in different breeds and characterization at DNA level.

Data on genetic differences at CSN3 in goat breeds including a DNA based typing method and the mutations responsible for variation on protein and DNA level are presented here. Isoelectric focusing (IEF) in ultrathin polyacrylamide gels with carrier ampholytes was used to demonstrate CSN3 polymorphism in milk samples of Italian (Orobica n=88; Ionica n=68) and German goat breeds (Bunte Deutsche Edelziege n=244; Weisse Deutsche Edelziege n=134; Toggenburger n=25; Thüringer Waldziege n=70). A further CSN3 band was found presenting a more cathodic migration than CSN A. After chymosin action, the genetic polymorphism was also observed in the para-kappa-casein fraction. The new allele CSN3(B) was spread mainly in Orobica (37%), Bunte Deutsche Edelziege (11%) and Ionica (10%). CSN3(B) occurred in low frequency (<3%) in Thüringer Waldziege and in Weisse Deutsche Edelziege, and could not be demonstrated in milk samples of Toggenburger. The populations were in Hardy-Weinberg equilibrium at CSN3. The codominant genetic control of CSN3(B) was confirmed by genetic studies. Discrimination of CSN3 alleles A and B was also obtained by DNA SSCP analysis. Sequencing of CSN3(B) revealed four transitions at position 247, 309, 471, and 591 compared with CSN3(A). From these transitions, the following amino acid substitutions are deduced: 44 Gln --> Arg, 65 Val --> Ile, 119 Val --> Ile, and 159 Ser --> Pro. Among the four mutations, only the 44 Gln --> Arg can be revealed by milk protein IEF analysis while at DNA level three further genetic variants should exist in addition to CSN3(A) and CSN3(B).

Alleles↗
PubMed2001

Pattern of Eimeria oocyst output and repeatability in naturally infected suckling Rhön lambs.

The faeces of 14 Rhön lambs were examined every second day between 7 and 99 days of age for the presence of Eimeria oocysts. Eimeria absata, E. bakuensis, E. faurei, E. granulosa, E. intricata, E. ovinoidalis, E. pallida, E. parva and E. crandallis/weybridgensis were identified. The predominant species were E. ovinoidalis, E. parva, E. crandallis/weybridgensis and E. bakuensis. Using a statistical model, the oocyst excretion rate was described as a sequence of periods with decreasing levels and varying length ('excretion periods') interrupted by intervals with no or very low oocyst counts. Several variables could be deduced from these two parameters, including the length of an excretion period and the maximum output during an excretion period. Thc estimated repeatability for oocyst counts for the different species ranged from 0.05 to 0.41. This result provides a starting point for possible genetic selection based on faecal oocyst counts of Rhön sheep for resistance to Eimeria infections.

Animals↗
PubMed2001

Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass.

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and are predominantly responsible for serious postoperative psychoneurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles from the arterial blood, was tested in a clinical study. The aim was to evaluate the efficiency of microbubble removal under clinical conditions. As blood passes through the DBT, which is placed in the arterial line between the arterial filter and arterial cannula, it is converted into a rotating stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the microbubbles before and after the DBT, and also the number of high-intensity transient signals (HITS) in the right and left middle cerebral artery during extracorporeal circulation. A significant reduction of microbubbles in the arterial line (3,990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.

Adult↗
PubMed2001

[Breed and sex differences in the temperament of calves in a cow-calf operation].

Behavioural traits related to temperament were studied in German Angus (Aberdeen Angus x German dual purpose breeds) and German Simmental cattle. Temperament was defined as the animal's behavioural response to handling. 498 calves (279 German Angus, 219 German Simmental) were tested with two different restrain tests. The animals were tested three times individually during a fixation procedure (days of live: 5, 19, 33) or weighting (days of live: 62, 138, 193). LSQ-means were calculated with a model including breed, year and sex as fixed effects and the sire as a random. Furthermore a regression on the age of the calf was included. Behaviour of the animals were recorded. Significant differences in the recorded parameters were found between the breeds on day 19 and 33 for one test and day 62 for another test. German Angus and male calves were less difficult to handle regarding the different parameters. Both tests could be used to show differences between the breeds.

Age Factors↗
PubMed2000

Consensus and comprehensive linkage maps of bovine chromosome 7.

The objective of this project was to integrate the currently available linkage maps for bovine chromosome 7 (BTA7) by combining data sets from eight research groups. A total of 54 unique markers were typed in eight pedigrees. Multilocus linkage analysis with CRI-MAP produced a bovine chromosome 7 consensus framework map of 27 loci ordered with odds greater than 1000:1. Furthermore, we present a bovine chromosome 7 comprehensive map integrating 54 loci. The locus order is in general agreement with the recently published linkage maps except for one discrepancy. The order of loci BM9289, BMS713, and ILSTS001 was reversed in the consensus framework map relative to the published USDA-MARC bovine chromosome 7 linkage map.

Animals↗
PubMed2000

A dynamic bubble trap reduces microbubbles during cardiopulmonary bypass: a case study.

Microemboli passing to the cerebral circulation during cardiopulmonary bypass can contribute to postoperative neurologic dysfunction. Many studies conclude that air microbubbles predominantly are responsible for this problem. A dynamic bubble trap (DBT) was developed to diminish the number of microbubbles in the arterial line of extracorporeal circulation. The DBT is able to substantially reduce the number of air microbubbles, as shown in two patients undergoing coronary artery bypass grafting, where a high number of microbubbles was assessed. Although a 40-micron arterial filter was used, many bubbles larger than 40 microns occurred in the arterial line. The DBT reduced the number of large microbubbles from 2,267 to 67 in patient 1 and from 897 to 61 in patient 2.

Aged↗
PubMed1999

Transmitochondrial differences and varying levels of heteroplasmy in nuclear transfer cloned cattle.

To assess the extent of cytoplasmic genetic variability in cloned cattle produced by nuclear transplantation procedures, we investigated 29 individuals of seven male cattle clones (sizes 2-6) from two different commercial sources. Restriction enzyme and direct sequence analysis of mitochondrial DNA (mtDNA) detected a total of 12 different haplotypes. Transmitochondrial individuals (i.e., animals which share identical nuclei but have different mitochondrial DNA) were detected in all but one of the clones, demonstrating that mtDNA variation among cloned cattle is a very common phenomenon which prevents true genetic identity. The analyses also showed that the cytoplasmic genetic status of some investigated individuals and clones is further complicated by heteroplasmy (more than one mtDNA type in an individual). The relative proportions of different mtDNA-types in two animals with mild heteroplasmy were estimated at 2:98% and 4:96% in DNA samples derived from blood. This is in agreement with values expected from karyoplast-cytoplast volume ratios. In contrast, the mtDNA haplotype proportions observed in six other heteroplasmic animals of two different clones ranged from 21:79% to 57:43%, reflecting a marked increase in donor blastomere mtDNA contributions. These results suggest that mtDNA type of donor embryos and recipient oocytes used in nuclear transfer cattle cloning should be controlled to obtain true clones with identical nuclear and cytoplasmic genomes.

Animals↗
PubMed1999

Detection of casein fragments in an invertebrate and in a vertebrate using in situ hybridization.

Using a non-radioactive in situ hybridization procedure it has been demonstrated that both invertebrates such as the mollusc Mytilus galloprovincialis and lower vertebrates such as the fish Cyprinus carpio express bovine alphaS1- and kappa-casein homologous mRNAs. In particular, positive results were found in molluscan immunocytes, and in cells located in different fish tissues: intestine, endocrine pancreas and kidney. These findings suggest that the casein genes are highly conserved throughout evolution.

Animals↗
PubMed1999

Bovine chromosome 4 workshop: consensus and comprehensive linkage maps.

The report of the bovine chromosome 4 (BTA4) workshop is presented. Six laboratories contributed a total of 30,168 informative meioses from 62 loci. Twenty-two loci were typed by at least two independent laboratories and were used to construct a consensus linkage map of BTA4. The remaining 40 loci were subsequently incorporated into a comprehensive map. The sex-averaged consensus map covered 131.4 cM. The female map was 124.3 cM in length, while the male map was 134.3 cM. The comprehensive sex-averaged map spanned 141.6 cM. The length of the female and male comprehensive maps were 123.1 cM and 156.4 cM, respectively. Average genetic distance between loci was 6 and 2.3 cM for the consensus and comprehensive linkage maps, respectively.

Animals↗
PubMed1999

SSCP analysis at the bovine CSN3 locus discriminates six alleles corresponding to known protein variants (A, B, C, E, F, G) and three new DNA polymorphisms (H, I, A1).

A high resolution SSCP protocol was developed for simultaneous discrimination of the known CSN3 alleles A, B, C, E, F and G. Furthermore, three new DNA polymorphisms were identified in different Bos taurus and Bos indicus breeds or crosses. Mendelian segregation was shown for two of these polymorphisms (named CSN3*H and 1), and the third (named CSN3*A1) was found in unrelated animals, thus indicating the presence of three additional alleles at the bovine CSN3 locus. DNA sequencing revealed single mutations that led to a Thr/Ile substitution in amino acid position 135 for CSN3*H and to a Ser/Ala substitution in position 104 of the deduced amino acid sequence of CSN3*1 (GenBank accession numbers AF105260 and AF121023) compared to CSN3*A. In CSN3*A1, a silent mutation in the third codon position of Pro150 was found (GenBank accession number AF092513).

Alleles↗
PubMed1998

Biochemical characterization of bovine alpha s1-casein F and genotyping with sequence-specific primers.

Bovine alpha s1-casein F (alpha s1-CN F) was found in a genetic resource of Deutsches Schwarzbuntes Niederungsrind cows at a frequency of 0.009. Biochemical characterization of this new variant was obtained by automated sequencing of reversed-phase HPLC-separated tryptic peptides of alpha s1-CN F and alpha s1-CN B. alpha s1-CN F was found to be a subtype of alpha s1-CN B with a single amino acid substitution (SerP/Leu) in position 66. DNA sequencing revealed a C/T transition in position 8418 of the gene. Sequence-specific primers were designed to perform an allele-specific polymerase chain reaction for detection of alpha s1 CnF. Typing of artificial insemination sperm samples included in the genetic resource sperm pool identified one sire heterozygous for alpha s1 CnF.

Alleles↗
PubMed1997

A medium-density genetic linkage map of the bovine genome.

A cattle genetic linkage map was constructed which covers more than 95 percent of the bovine genome at medium density. Seven hundred and forty six DNA polymorphisms were genotyped in cattle families which comprise 347 individuals in full sibling pedigrees. Seven hundred and three of the loci are linked to at least one other locus. All linkage groups are assigned to chromosomes, and all are orientated with regards to the centromere. There is little overall difference in the lengths of the bull and cow linkage maps although there are individual differences between maps of chromosomes. One hundred and sixty polymorphisms are in or near genes, and the resultant genome-wide comparative analyses indicate that while there is greater conservation of synteny between cattle and humans compared with mice, the conservation of gene order between cattle and humans is much less than would be expected from the conservation of synteny. This map provides a basis for high-resolution mapping of the bovine genome with physical resources such as Yeast and Bacterial Artificial Chromosomes as well as providing the underpinning for the interpolation of information from the Human Genome Project.

Animals↗
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↗