Publications (29)54.21 Total impact
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Article: Short communication: evaluation of bovine milk residues from routine milk testing programs as DNA source for genotyping.
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ABSTRACT: Genome-wide association studies and genomic evaluation using a dense set of genetic markers both require a large number of genotyped individuals. Collection of the respective samples contributes substantially to the cost of the approach. In dairy cattle research, the use of residues from routine milk recording would be a cost-saving alternative to obtain samples for an appropriate number of individuals with specific phenotypes in a very short time. To assess the suitability of milk recording residues, we concurrently investigated milk residues obtained after standardized milk recording procedures and blood samples from 115 cows originating from 3 farms with different milking systems by genotyping 15 microsatellite markers. We found that 4% of the milk samples were possibly assigned to the wrong animal (i.e., conflicts) and that at least 27% of the milk residues were contaminated, as indicated by an extra allele not present in the blood sample. These additional alleles primarily originated from a sample with a higher somatic cell score that went through the milk sample analyzer in the milk laboratory before the target sample. Furthermore, additional allele carryover was observed across more than one sample, when the difference in somatic cell count between samples exceeded 100,000 cells/mL. Finally, in several samples, the extra allele could not be traced back to previous samples passing through the milk sample analyzer. One source of those contaminations might be sample collection on-farm due to milk traces from the previously milked cow in the hose. No correlation was found between the farm management and conflicts or contaminations. We conclude that residues from routine milk recording are not suitable for genomic evaluation or genome-wide association studies because of the high prevalence of contamination generated at several steps during the collection and processing of milk residual samples.Journal of Dairy Science 09/2012; 95(9):5436-41. · 2.56 Impact Factor -
Article: Revisiting the quantitative trait loci for milk production traits on BTA6.
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ABSTRACT: A parallel association study was performed in two independent cattle populations based on 41 validated, targeted single nucleotide polymorphisms (SNPs) and four microsatellite markers to re-evaluate the multiple quantitative trait loci (QTL) architecture for milk performance on bovine chromosome 6 (BTA6). Two distinct QTL located in the vicinity of the middle region of BTA6, but differing unambiguously regarding their effects on milk composition and yield traits were validated in the German Holstein population. A highly significant association of the protein variant ABCG2 p.Tyr581Ser with milk composition traits reconfirmed the causative molecular relevance of the ABCG2 gene in QTL region 1, whereas in QTL region 2, significant and tentative associations between gene variants RW070 and RW023 (located in the promoter region and exon 9 of the PPARGC1A gene for milk yield traits) were detected. For the German Fleckvieh population, only RW023 showed a tentative association with milk yield traits, whereas those loci with significant effects in German Holsteins (ABCG2 p.Tyr581Ser, RW070) showed fixed alleles. Even though our new data highlight two variants in the PPARGC1A gene (RW023, RW070) in QTL region 2, based on the results of our study, currently no unequivocal conclusion about the causal background of this QTL affecting milk yield traits can be drawn. Notably, the German Holstein and Fleckvieh populations, known for their divergent degree of dairy type, differ substantially in their allele frequencies for the growth-associated NCAPG p.Ile442Met locus.Animal Genetics 06/2012; 43(3):318-23. · 2.40 Impact Factor -
Article: Evaluation of a replacement method for mammary gland biopsies by comparing gene expression in udder tissue and mammary epithelial cells isolated from milk.
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ABSTRACT: Somatic cells isolated from milk offer an attractive non-invasive replacement of invasive udder biopsies for monitoring bovine mammary gland metabolism. However, for metabolic gene expression studies the mammary gland epithelial cells (MEC) isolated from milk have to be purified from the non-epithelial leukocyte fraction in milk samples. In our study, enrichment of MEC by using anti-cytokeratin peptide 18 (KRT18) antibody coated magnetic beads was evaluated. MEC showed a substantially increased expression of the epithelial-cell-specific KRT18 gene compared to udder tissue. The expression levels of genes specific for mammary gland epithelial cells (CSN3 and LALBA) showed a significant positive correlation in MEC and also in udder tissue. However, no significant correlation of the expression of a specific gene was found between udder and MEC samples. Therefore, MEC isolated from total milk samples via KRT18 antibodies probably do not reflect the true metabolic situation of the bovine udder. Thus, quantitative gene expression profiling of MEC isolated via KRT18 antibodies has to be interpreted carefully with respect to the situation in the udder.Research in Veterinary Science 01/2012; 93(2):970-4. · 1.65 Impact Factor -
Article: The SNP c.1326T>G in the non-SMC condensin I complex, subunit G (NCAPG) gene encoding a p.Ile442Met variant is associated with an increase in body frame size at puberty in cattle.
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ABSTRACT: Recently, we had located a bovine carcass weight QTL, CW-2, to a 591-kb interval on BTA6 and have identified the SNP c.1326T>G in the NCAPG (non-SMC condensin I complex, subunit G) gene that leads to the amino acid change p.Ile442Met in the NCAPG protein, which is a candidate causative variation. Here, we examined the association of the NCAPG:c.1326T>G locus with linear skeletal measurements of growth-associated traits during adolescence, which is a period of intensive growth, using two historically and geographically distant cattle populations: 792 Japanese Black steers and 161 F(2) bulls of an experimental cross from Charolais and German Holstein. In both populations, the SNP NCAPG:c.1326T>G was associated with each component of body frame size: height, length and width at puberty. The associations of CW-2 with height- and length-associated traits were observed at an earlier growth period compared to the associations with thickness- and width-associated traits, indicating that the primary effect of the CW-2 QTL may possibly be exerted on skeletal growth. The significant associations of the NCAPG:c.1326T>G locus with growth-associated skeletal measurements are similar to the effects of the syntenic region on human chromosome 4 that are associated with adult height in humans, supporting the hypothesis that CW-2 is analogous to the human locus and pointing to a conserved growth-associated locus or chromosomal region present in both species.Animal Genetics 12/2011; 42(6):650-5. · 2.40 Impact Factor -
Article: A genetic predisposition for bovine neonatal pancytopenia is not due to mutations in coagulation factor XI.
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ABSTRACT: Bovine neonatal pancytopenia (BNP) is a newly emerging disease in many European countries that causes haemorrhagic diathesis and mortality in neonatal calves. This study tested the hypothesis that genetic factors might be involved in BNP, since genetic defects resulting in coagulation disorders have been described in many species, including cattle. A familial pattern of occurrence of BNP cases was observed in an experimental population of cattle in Germany and BNP was diagnosed in nine calves on an experimental dairy herd from May 2007 to December 2009. All affected calves were descendents of a single F(1) sire in a specific F(2) resource population generated from Charolais and German Holstein bloodlines. Sequence analysis of the bovine coagulation factor XI (F11) gene as a functional candidate gene for BNP revealed an unusually high number of non-synonymous mutations within the gene compared to a whole genome mutation screen in cattle targetting random sequences. However, none of the mutations in the F11 gene were concordant with BNP status. Although these data and further pedigree analysis excluded a simple mode of inheritance of the BNP phenotype, there was a statistically significant (P=0.0001) accumulation of BNP cases in the specific pedigree examined, suggesting that a genetic component is involved in the development of BNP.The Veterinary Journal 11/2010; 190(2):225-9. · 2.24 Impact Factor -
Article: Differences in milk production, glucose metabolism, and carcass composition of 2 Charolais x Holstein F2 families derived from reciprocal paternal and maternal grandsire crosses.
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ABSTRACT: Two F(2) Charolais x German Holstein families comprising full and half sibs share identical but reciprocal paternal and maternal Charolais grandfathers differ in milk production. We hypothesized that differences in milk production were related to differences in nutritional partitioning revealed by glucose metabolism and carcass composition. In 18F(2) cows originating from mating Charolais bulls to German Holstein cows and a following intercross of the F(1) individuals (n=9 each for family Ab and Ba; capital letters indicate the paternal and lowercase letter the maternal grandsire), glucose tolerance tests were performed at 10 d before calving and 30 and 93 d in milk (DIM) during second lactation. Glucose half-time as well as areas under the concentration curve for plasma glucose and insulin were calculated. At 94 DIM cows were infused intravenously with 18.3 micromol of d-[U-(13)C(6)]glucose/kg(0.75) of BW, and blood samples were taken to measure rate of glucose appearance and glucose oxidation as well as plasma concentrations of metabolites and hormones. Cows were slaughtered at 100 DIM and carcass size and composition was evaluated. Liver samples were taken to measure glycogen and fat content, gene expression levels, and enzyme activities of pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and glucose 6-phosphatase as well as gene expression of glucose transporter 2. Milk yield was higher and milk protein content at 30 DIM was lower in Ba than in Ab cows. Glucose half-life was higher but insulin secretion after glucose challenge was lower in Ba than in Ab cows. Cows of Ab showed higher glucose oxidation, and plasma concentrations at 94 DIM were lower for glucose and insulin, whereas beta-hydroxybutyrate was higher in Ba cows. Hepatic gene expression of pyruvate carboxylase, glucose 6-phosphatase, and glucose transporter 2 were higher whereas phosphoenolpyruvate carboxykinase activities were lower in Ba than in Ab cows. Carcass weight as well as fat content of the carcass were higher in Ab than in Ba cows, whereas mammary gland mass was lower in Ab than in Ba cows. Fat classification indicated leaner carcass composition in Ba than in Ab cows. In conclusion, the 2 families showed remarkable differences in milk production that were accompanied by changes in glucose metabolism and body composition, indicating capacity for milk production as main metabolic driving force. Sex chromosomal effects provide an important regulatory mechanism for milk performance and nutrient partitioning that requires further investigation.Journal of Dairy Science 07/2010; 93(7):3007-18. · 2.56 Impact Factor -
Article: Evolutionary break point analysis between the proximal half of bovine chromosome 27 and conserved segments of the human genome.
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ABSTRACT: The proximal half of Bos taurus chromosome 27 (BTA27prox) delimited by microsatellite markers BM3507 and CSSM043 reveals complex rearrangements compared to its corresponding Homo sapiens chromosome (HSA) fragments. A comparative mapping approach combining somatic and radiation hybrid cell mapping techniques and related cytogenetic data resulted in an improved physical map for BTA27prox, which provides candidate genes for several important economic traits. The generated comprehensive map includes anchor loci for 103 genes and microsatellite markers. Mapping of genes proximal to BM3507 matching a region from 0.60 to 2.78 megabase pairs (Mb) of HSA8 confirmed recent sequence annotations on BTA27. Assignments of loci predicted to be on BTA27 to BTA1, BTA8, and BTA17 narrowed down evolutionary chromosome break points compared with corresponding chromosome segments in human. New physical anchors obtained in this study confirm in more detail the described evolutionary conservation between the proximal half of BTA27 and homologous segments of HSA4 and HSA8 and will contribute to the completion of the cattle DNA genome sequence.Cytogenetic and Genome Research 02/2009; 125(1):33-9. · 1.53 Impact Factor -
Article: An investigation into the genetic background of coat colour dilution in a Charolais x German Holstein F2 resource population.
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ABSTRACT: The molecular background of many loci affecting coat colour inheritance in cattle is still incompletely characterized, although it is known that coat colour results from the joint effects of several loci, e.g. agouti, extension and dilution. Dilution alleles are responsible for a dilution effect on the original coat colour of an individual, which is determined by the agouti and extension loci. Different loci affecting dilution of pigment are suggested in Charolais (Dc) and Simmental (Ds). To enable chromosomal mapping of the Dc mutation, 133 animals from an F2 full-sib resource population generated from a cross of Charolais and German Holstein were scored for the coat colour dilution phenotype. Linkage analysis covering all autosomes revealed a significant linkage of the dilution phenotype with microsatellite markers on bovine chromosome 5. No recombination was observed between marker ETH10 and the Dc locus. Positional and functional information identified the bovine silver homolog (SILV) gene as a candidate for the Dc mutation. Results from comparative sequencing of the SILV gene in individuals with different dilution coat colour phenotypes confirmed the presence of a c.64G>A non-synonymous mutation, which had previously been identified in the Charolais breed. The alleles at this locus were associated with coat colour dilution in this study. However, further investigation of colour inheritance within the F2 resource population indicated that a single diallelic mutation in the SILV gene cannot explain the total observed variation of coat colour dilution.Animal Genetics 04/2007; 38(2):109-13. · 2.40 Impact Factor -
Article: Forward to a detailed sequence map of bovine chromosome 6.
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ABSTRACT: Numerous QTL for a variety of phenotypic traits in dairy and beef cattle have been mapped on bovine chromosome 6 (BTA6). The complete and validated information on the molecular genome organization is an essential prerequisite for the conclusive identification of the causative sequence variation underlying the QTL. In our study we describe efforts to improve the genomic sequence map assembly of BTA6 by filling-in gaps and by suggesting sequence contig rearrangements. This is achieved by the generation and in silico mapping of BAC-end sequences (BESs) from clones containing sequences placed on our high-resolution radiation hybrid (RH) map of BTA6 onto the genome sequence map. Linking high-resolution RH mapping with in silico mapping of BESs on BTA6 enabled the detection of discrepancies in chromosomal assignments of genome sequence contigs and improved the resolution of non-conclusive assignments on the genome sequence assembly. Furthermore, 37% of BESs enabled chromosomal assignment of contigs previously unassigned. Anchoring of 66% of BESs onto HSA4 confirmed the synteny of the respective region of BTA6 including the known evolutionary breakpoints. The BESs will play an important role in the ongoing efforts to complete the sequence of the bovine genome and will also provide a source for the identification of new polymorphic sites in the genome sequence to resolve QTL-containing intervals.Cytogenetic and Genome Research 02/2007; 116(1-2):72-9. · 1.53 Impact Factor -
Article: A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 7 and comparative mapping to the cattle and human genomes.
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ABSTRACT: A preliminary radiation hybrid (RH) map containing 50 loci on chromosome 7 of the domestic river buffalo Bubalus bubalis (BBU; 2n = 50) was constructed based on a comparative mapping approach. The RH map of BBU7 includes thirty-seven gene markers and thirteen microsatellites. All loci have been previously assigned to Bos taurus (BTA) chromosome BTA6, which is known for its association with several economically important milk production traits in cattle. The map consists of two linkage groups spanning a total length of 627.9 cR(5,000). Comparative analysis of the BBU7 RH(5,000) map with BTA6 in cattle gave new evidence for strong similarity between the two chromosomes over their entire length and exposed minor differences in locus order. Comparison of the BBU7 RH(5,000) map with the Homo sapiens (HSA) genome revealed similarity with a large chromosome segment of HSA4. Comparative analysis of loci in both species revealed more variability than previously known in gene order and several chromosome rearrangements including centromere relocation. The data obtained in our study define the evolutionarily conserved segment on BBU7 and HSA4 to be between 3.5 megabases (Mb) and 115.8 Mb in the HSA4 (genome build 36) DNA sequence.Cytogenetic and Genome Research 02/2007; 119(3-4):235-41. · 1.53 Impact Factor -
Article: Assignment of the fibroblast growth factor 10 (FGF10) gene to bovine chromosome 20q16-->q17 by fluorescence in situ hybridization and somatic cell panel analysis.
Cytogenetic and Genome Research 02/2005; 109(4):533. · 1.53 Impact Factor -
Article: Investigations in the character of QTL affecting negatively correlated milk traits
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ABSTRACT: The primary aim of this study was to investigate the quantitative trait loci (QTL) on BTA6 that affect negatively correlated milk traits, using bivariate covariance component analysis of milk yield and fat (or protein) content, protein yield and fat content, and fat yield and protein content. A set of five different genetic models was adapted to differentiate trait-specific QTL in close linkage from pleiotropy. Using a grand-daughter design consisting of five half-sib families from the German Holstein population and 298 sons genotyped for 16 microsatellite markers on BTA6, we found significant trait-specific QTL for fat content and protein yield, 24 cM apart. Markers BM1329 and FBN12 bracketed the QTL for fat content, and the region between TGLA37 and FBN13 most likely harbours a QTL for protein yield. The analysis based on the close linkage model fully confirmed this result. Despite the pure QTL findings confirming results from the literature, distinguishing pleiotropic and closely linked QTL for competitive traits is a new aspect. Our multivariate analysis results did not suggest a pleiotropic QTL for the investigated negatively correlated traits. The QTL-based trait correlations were discussed as an important aspect of modelling that needs to be considered in the future.ZusammenfassungDas Ziel des Beitrages ist es, QTL auf BTA6 bezüglich ihrer Wirkung auf negativ korrelierte Milchleistungsmerkmale näher zu untersuchen. Die Kombinationen Milchmenge und Fett- (oder Protein-)gehalt, Proteinmenge und Fettgehalt sowie Fettmenge und Eiweißgehalt wurden jeweils einer bivariaten Covarianzanalyse unterzogen. Fünf verschiedene genetische Modelle wurden eingesetzt, um festzustellen, ob es sich um zwei eng gekoppelte QTL oder um einen pleiotrop-wirkenden QTL handelt. Das Enkellinnen-Design bestand aus fünf Halbgeschwisterfamilien aus der deutschen Holstein- Population und 298 Söhnen, genotypisiert an 16 Mikrosatellitenmarkern. Merkmalsspezifische (signifikante) QTL im Abstand von 24 cM wurden für den Fettgehalt und für die Proteinmenge gefunden. Der QTL für Fettgehalt befindet sich wahrscheinlich zwischen den Markern BM1329 und FBN12. Die Region zwischen TGLA37 und FBN13 enthält sehr wahrscheinlich einen QTL für Proteinmenge. Die auf dem ’Modell enge Kopplung’ basierende Analyse bestätigte das Ergebnis. Es gab keinen Hinweis auf einen pleiotropen QTL für die untersuchten Kombinationen negativ- korrelierter Merkmale. Obwohl die gefundenen QTL- Positionen bereits publizierte QTL bestätigen stellt die Unterscheidung zwischen pleiotropen und eng gekoppelten QTL für konkurrierende Merkmale’ einen neuen Aspekt dar. Ferner wurden die QTL-basierten Merkmalskorrelationen im Zusammenhang mit künftigen Modellerweiterungen erörtert.Journal of Animal Breeding and Genetics 01/2004; 121(1):40 - 51. · 1.46 Impact Factor -
Article: Search for pleiotropic QTL on chromosome BTA6 affecting yield traits of milk production.
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ABSTRACT: The primary aim of this study was to investigate whether previous findings of similar quantitative trait loci (QTL) positions for correlated yield traits are due to a pleiotropic QTL. We applied a multitrait variance component based QTL mapping method to a dataset involving five granddaughter families from the German Holstein dairy cattle population. The marker map contained 16 microsatellite markers, distributed across chromosome BTA6. A chromosomewise significance threshold was used, because BTA6 is known to harbor QTL for several milk traits. To evaluate the results from the multivariate, across-family analysis, we also conducted single-family analyses using the least squares method of QTL estimation. The results provided two significant QTL findings at 49 and 64 cM for milk yield in different families and putative QTL at 68 cM for fat yield and at 71 cM for protein yield in another family. The results for fat and protein yield were confirmed by a univariate, across-family variance components analysis. The multivariate analysis of three bivariate trait combinations resulted in a significant pleiotropic QTL finding at 68 cM for fat yield and protein yield, bracketed by markers TGLA37 and FBN13. The estimates of variance contribution due to this QTL were 23% and 25%, respectively.Journal of Dairy Science 04/2003; 86(3):999-1008. · 2.56 Impact Factor -
Article: Multiple QTL on chromosome six in dairy cattle affecting yield and content traits
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ABSTRACT: A granddaughter design containing five half-sib families from German Holstein–Friesian cattle was subjected to QTL analysis starting from the hypothesis of the existence of more than one QTL on chromosome BTA 6 affecting milk yield, fat yield, protein yield and content of fat and protein. The marker map consisted of 16 microsatellite markers with marker heterozygosity varying from 0.44 to 0.94. Two statistical methods were used: least squares (LS) and residual maximum likelihood (REML) allowing for two QTL simultaneously. The test statistics were calculated in steps of one cM along the chromosome. Significant QTL at the chromosome-wise 5% level according to the permutation test critical value were detected mainly in single families. The results were in conformance with the findings of several previous studies with approximate positions of putative QTL at 49 cM for milk yield, at 70 cM for fat and protein yield, and at 46 cM for protein content. Further QTL positions were suggested mostly for yield traits and protein content in the area of the casein gene cluster at 90…95 cM. The results of the two-QTL model analyses when using LS led to family specific inferences of a second QTL for fat yield and content of protein and fat, partly supported by the epistasis model.Multiple QTL auf dem Chromosom BTA 6 des Milchrindes mit Einfluss auf Ertrags- und GehaltsmerkmaleAusgehend von der Hypothese über die Existenz mehrerer QTL auf dem Chromosom 6 des Rindes mit Einfluss auf Milchmengen- sowie Gehaltsmerkmale wurde eine QTL-Studie, basierend auf dem Enkelinnendesign, durchgeführt. Die verwendete Markerkarte enthlt 16 Mikrosatellitenmarker, deren Heterozygotiegrad zwischen 0,44 und 0,94 variiert. Zwei unterschiedliche statistische Methoden wurden verwendet: Least Squares (LS) und Residual Maximum Likelihood (REML). Gleichzeitig können 2 QTL in der Analyse berücksichtigt werden. Die Teststatistik wird in Schritten von 1 cM über das gesamte Chromosom berechnet. Hauptschlich in Familienanalysen wurden QTL geschtzt, die gemss dem chromosomenbezogenen kritischen Wert aus dem Permutationstest (5%- Niveau) signifikant sind. Mit geschtzten QTL- Positionen von 49 cM für Milchmenge, 70 cM für Fett- und Eiweissmenge, und 46 cM für Eiweissgehalt besttigen diese Ergebnisse zum Teil frühere Berichte. Die vorgestellten Ergebnisse sprechen weiterhin für mögliche QTL, insbesondere für Mengenmerkmale und Eiweissgehalt, in Verbindung mit dem Caseingen-cluster entsprechend einer Position von 90…95 cM. Die Ergebnisse aus Analysen mit Modellen, die 2 QTL berücksichtigen, lassen, zum Teil unterstützt durch die Modellierung von Epistasie, familienspezifisch auf einen zweiten gekoppelten QTL für die Fettmenge sowie den Eiweiss- und Fettgehalt schliessen.Journal of Animal Breeding and Genetics 04/2002; 119(2):69 - 82. · 1.46 Impact Factor -
Article: Sex determination in cattle based on simultaneous amplification of a new male-specific DNA sequence and an autosomal locus using the same primers.
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ABSTRACT: A PCR-based method for sex determination of bovine DNA samples and embryo biopsies is presented. Using only one primer pair both the male-specific sequence FBNY (127 bp) and a sex-independent control PCR-fragment, the microsatellite marker FBN17 (136-140 bp) are generated in the same PCR reaction. Synteny mapping assigned the male-specific sequence to bovine chromosome Y (BTA Y), whereas FBN17 was mapped to bovine chromosome 2. Localisation of FBNY on BTA Y was confirmed by fluorescence in hybridisation of two BAC clones containing the male-specific sequence. There was no amplification of the male-specific target sequence FBNY in sheep, pig, goat, mice, man, and several wild species of the tribe Bovini. The bovine male-specific fragment was detected in dilutions containing as little as 10 pg genomic DNA and in blastomeres from embryo biopsies. The PCR assay presented here does require neither restriction endonuclease digestion of the PCR product nor additional nested PCR steps. Owing to the advantage of parallel amplification of the autosomal locus FBN17 no additional control fragment is necessary to detect PCR failure. The results of sex determination in embryo biopsies using FBNY were in agreement with the outcome from a reference assay used in commercial breeding programs.Molecular Reproduction and Development 10/2001; 60(1):13-9. · 2.53 Impact Factor -
Article: Detection of QTL for milk production traits in cattle by application of a specifically developed marker map of BTA6.
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ABSTRACT: Interval mapping was carried out to identify quantitative trait loci (QTL) for milk production traits in five granddaughter design families of the German Holstein population. Fourteen randomly generated markers spanning the whole of BTA6 and six targeted microsatellite markers from BTA6q21-31 were included in the analysis. In one family a QTL with effects on milk fat yield and milk protein yield was mapped to the interval TGLA37-FBN13 (3 CM proximal to FBN13, lodscore 3.22) in the middle part of the chromosome. Although there are several reports about QTL with effects on milk production traits on BTA6 in the literature, a QTL with effects on milk fat and milk protein yield has not been previously described.Animal Genetics 11/1999; 30(5):333-40. · 2.40 Impact Factor -
Article: Five bovine polymorphic dinucleotide microsatellite markers: FBN5, FBN16, FBN17, FBN18, and FBN19.
Animal Genetics 11/1998; 29(5):412-3. · 2.40 Impact Factor -
Article: Effect of clenbuterol on growth, carcase and skeletal muscle characteristics in broiler chickens.
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ABSTRACT: 1. Male and female broiler chickens (144 in total) were given diets supplemented with clenbuterol (CB) at 0 (control) and at 1 mg/kg between 28 and 49 d of age to study the effect of CB on growth, carcase and skeletal muscle. 2. CB improved growth in males by increasing daily weight gain and final live weight and by lowering food conversion ratio. In females it changed the carcase composition by reducing abdominal fat pad and by increasing the proportion of protein. Consequently, carcase protein gain was increased in both sexes (11% and 16%, respectively). 3. Skeletal muscle weights were enhanced by between 6% and 22%. Muscle fibre diameters were increased in extensor hallucis longus (EHL) but not in gastrocnemius (GAS) muscle. This increase was more pronounced in females. EHL total muscle fibre number remained unchanged. The proportion of fast-twitch glycolytic fibres was increased at the expense of fast-twitch oxidative fibres in males only. Nuclear/cytoplasm and DNA/protein ratios tended to be decreased by CB. 4. From the elevated EHL muscle RNA/DNA, unchanged protein/RNA and translation activity it is suggested that CB stimulated protein synthesis at the pretranslational level. Reduced protein degradation is deduced from decreased neutral calcium-dependent proteolytic activity. 5. It is concluded that broiler chickens respond to long-term CB treatment as has been shown in various mammals. However, the sex-specific response in growth, carcase composition and skeletal muscle cellularity is more clearly apparent in broiler chickens.British Poultry Science 10/1997; 38(4):366-73. · 1.00 Impact Factor -
Article: Targeted development of microsatellite markers from the defined region of bovine chromosome 6q21-31.
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ABSTRACT: A methodical strategy for the isolation of microsatellite markers specific for targeted regions of bovine chromosomes is presented. The procedure involves directed microdissection of one defined subchromosomal area, its DOP-PCR-amplification and cloning. With this approach, a library specific to the BTA 6q21-31 chromosomal region was constructed. Eleven unique microsatellite-containing sequences were isolated, converted into sequence-tagged microsatellite sites, and characterized concerning their species-specific origin. Seven primer pairs generated bovine-specific PCR products and provided a set of microsatellite markers that generally revealed high informativity in the HF breed. Linkage analysis assigned six of them to their predefined subchromosomal origin on BTA 6 corresponding to the specific rehybridization signal of the DOP-PCR product generated from the microdissected chromosome area 6q21-31. The results underline the usefulness of the BTA 6q21-31 library for targeted isolation of unique sequences that are specific for the dissected chromosomal region as demonstrated here by the isolation of microsatellite markers.Mammalian Genome 02/1997; 8(11):836-40. · 2.89 Impact Factor -
Article: A polymorphic microsatellite within the immunorelevant bovine lysozyme-encoding gene.
Animal Genetics 05/1996; 27(2):125. · 2.40 Impact Factor
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Institutions
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1998–2012
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Leibniz-Institut für Nutztierbiologie
- Forschungsbereich Molekularbiologie
Dummerstorf, Mecklenburg-Vorpommern, Germany
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