Kongenitales embryonales Rhabdomyosarkom am Kopf eines rotbunten Deutsche-Holstein-Kalbes

Tumoren mit Skelettmuskeldifferenzierung sind bei den Haussäugetieren nur sehr selten zu beobachten. Es werden benigne Rhabdomyome von malignen Rhabdomyosarkomen unterschieden. Bei einem weiblichen Kalb der Rasse Deutsche Holstein wurde eine kongenitale, kugelförmige Umfangsvermehrung lateral in der Unterhaut des Kopfes festgestellt. Histologisch bestand die abgekapselte, expansive, zellreiche Umfangsvermehrung aus einem retikulären Maschenwerk kleiner, mäßig pleomorpher, spindelförmiger bis rundlicher Zellen in einem fibrovaskulären bis myxoiden Stroma sowie multifokalen, großen, plumpen, mehrkernigen, Myotuben-ähnlichen Zellen (strap cells). Mittels elektronenmikroskopischer Untersuchung wurden in den strap cells charakteristische zytoplasmatische Bündel von Myofilamenten und Z-Streifen nachgewiesen. Die kleinen spindelförmigen Zellen zeigten eine Immunreaktivität für Vimentin und die strap cells für Desmin. Die vorliegenden Ergebnisse entsprechen dem Befundspektrum eines bovinen kongenitalen embryonalen Rhabdomyosarkoms.

[Congenital embryonal rhabdomyosarcoma of the head in a red and white German Holstein calf]

Tumours with skeletal-muscle differentiation are rare in companion animals. They are differentiated into benign rhabdomyomas and malignant rhabdomyosarcomas. A female German Holstein calf displayed a congenital, spherical, subcutaneous mass at the lateral side of the head. Histology revealed an encapsulated, expansile, highly cellular mass consisting of a reticular meshwork of moderately pleomorphic, small spindle-shaped to round cells within a fibrovascular to myxoid stroma as well as multifocal, large, blunt, multinucleated myotube-like cells (strap cells). Electron microscopy demonstrated characteristic cytoplasmic bundles of myofilaments and Z-stripes within the strap cells. Immunoreactivity for vimentin was observed in the small spindle-shaped cells and for desmin in the strap cells. The results are consistent with the spectrum of findings characteristic for a bovine congenital embryonal rhabdomyosarcoma.

Two-exon skipping within MLPH is associated with coat color dilution in rabbits

Coat color dilution turns black coat color to blue and red color to cream and is a characteristic in many mammalian species. Matings among Netherland Dwarf, Loh, and Lionhead Dwarf rabbits over two generations gave evidence for a monogenic autosomal recessive inheritance of coat colour dilution. Histological analyses showed non-uniformly distributed, large, agglomerating melanin granules in the hair bulbs of coat color diluted rabbits. We sequenced the cDNA of MLPH in two dilute and one black rabbit for polymorphism detection. In both color diluted rabbits, skipping of exons 3 and 4 was present resulting in altered amino acids at p.QGL[37-39]QWA and a premature stop codon at p.K40*. Sequencing of genomic DNA revealed a c.111-5C>A splice acceptor mutation within the polypyrimidine tract of intron 2 within MLPH. This mutation presumably causes skipping of exons 3 and 4. In 14/15 dilute rabbits, the c.111-5C>A mutation was homozygous and in a further dilute rabbit, heterozygous and in combination with a homozygous frame shift mutation within exon 6 (c.585delG). In conclusion, our results demonstrated a colour dilution associated MLPH splice variant causing a strongly truncated protein (p.Q37QfsX4). An involvement of further MLPH-associated mutations needs further investigations.

Congenital sensorineural deafness in dalmatian dogs associated with quantitative trait loci

A genome-wide association study (GWAS) was performed for 235 Dalmatian dogs using the canine Illumina high density bead chip to identify quantitative trait loci (QTL) associated with canine congenital sensorineural deafness (CCSD). Data analysis was performed for all Dalmatian dogs and in addition, separately for brown-eyed and blue-eyed dogs because of the significant influence of eye colour on CCSD in Dalmatian dogs. Mixed linear model analysis (MLM) revealed seven QTL with experiment-wide significant associations (-log10P>5.0) for CCSD in all Dalmatian dogs. Six QTL with experiment-wide significant associations for CCSD were found in brown-eyed Dalmatian dogs and in blue-eyed Dalmatian dogs, four experiment-wide significant QTL were detected. The experiment-wide CCSD-associated SNPs explained 82% of the phenotypic variance of CCSD. Five CCSD-loci on dog chromosomes (CFA) 6, 14, 27, 29 and 31 were in close vicinity of genes shown as causative for hearing loss in human and/or mouse.

A genome-wide association study identifies risk loci to equine recurrent uveitis in German warmblood horses

Equine recurrent uveitis (ERU) is a common eye disease affecting up to 3-15% of the horse population. A genome-wide association study (GWAS) using the Illumina equine SNP50 bead chip was performed to identify loci conferring risk to ERU. The sample included a total of 144 German warmblood horses. A GWAS showed a significant single nucleotide polymorphism (SNP) on horse chromosome (ECA) 20 at 49.3 Mb, with IL-17A and IL-17F being the closest genes. This locus explained a fraction of 23% of the phenotypic variance for ERU. A GWAS taking into account the severity of ERU, revealed a SNP on ECA18 nearby to the crystalline gene cluster CRYGA-CRYGF. For both genomic regions on ECA18 and 20, significantly associated haplotypes containing the genome-wide significant SNPs could be demonstrated. In conclusion, our results are indicative for a genetic component regulating the possible critical role of IL-17A and IL-17F in the pathogenesis of ERU. The associated SNP on ECA18 may be indicative for cataract formation in the course of ERU.

Analysis of copy number variants by three detection algorithms and their association with body size in horses

Background

Copy number variants (CNVs) have been shown to play an important role in genetic diversity of mammals and in the development of many complex phenotypic traits. The aim of this study was to perform a standard comparative evaluation of CNVs in horses using three different CNV detection programs and to identify genomic regions associated with body size in horses.

Results

Analysis was performed using the Illumina Equine SNP50 genotyping beadchip for 854 horses. CNVs were detected by three different algorithms, CNVPartition, PennCNV and QuantiSNP. Comparative analysis revealed 50 CNVs that affected 153 different genes mainly involved in sensory perception, signal transduction and cellular components. Genome-wide association analysis for body size showed highly significant deleted regions on ECA1, ECA8 and ECA9. Homologous regions to the detected CNVs on ECA1 and ECA9 have also been shown to be correlated with human height.

Conclusions

Comparative analysis of CNV detection algorithms was useful to increase the specificity of CNV detection but had certain limitations dependent on the detection tool. GWAS revealed genome-wide associated CNVs for body size in horses.

The genetics of equine osteochondrosis

Osteochondrosis (OC) develops in growing horses due to disturbed differentiation and maturation of cartilage, particularly at the predilection sites of the fetlock, hock and stifle joints. Horses with osteochondrotic lesions are at a high risk of developing orthopaedic problems later in life. This article briefly reviews the published heritability estimates for OC and offers perspectives for selection in the horse industry. Heritabilities for OC in Warmblood and Standardbred horses have been estimated at 0.1-0.4 in animal threshold models. Whole genome scans using microsatellites have identified 14 quantitative trait loci (QTL) and the eight most important QTL have been refined using dense marker maps. Genome-wide association studies with single nucleotide polymorphisms revealed further QTL in Thoroughbred, Standardbred and Hanoverian horses. Only a few QTL have corresponding locations among the different breeds. Comparative genomics using positional candidate genes and next-generation-sequencing may lead to new insights into the genetic determination of equine OC and might help in understanding the molecular mechanisms of its pathogenesis. Implementation of selection schemes based on breeding values, or even genomic selection against OC, should be considered as an option for improving equine musculoskeletal health.

A Single Nucleotide Polymorphism within the Interferon Gamma Receptor 2 Gene Perfectly Coincides with Polledness in Holstein Cattle

Polledness is a high impact trait in modern milk and beef production to meet the demands of animal welfare and work safety. Previous studies have mapped the polled-locus to the proximal region of the bovine chromosome 1 (BTA1) and narrowed it down to approximately 1 Mb. Sequencing of the positional candidate genes within the 1 Mb polled region and whole genome sequencing of Holsteins revealed a single nucleotide polymorphism (SNP) AC000158: g.1390292G>A within intron 3 of the interferon gamma receptor 2 gene (IFNGR2) in perfect co-segregation with polledness in Holsteins. This complete association was validated in 443 animals of the same breed. This SNP allows reliable genotyping of horned, heterozygous and homozygous polled Holsteins, even in animals that could not be resolved using the previously published haplotype for Holstein.

Morphometric magnetic resonance imaging and genetic testing in cerebellar abiotrophy in Arabian horses

Background

Cerebellar abiotrophy (CA) is a rare but significant disease in Arabian horses caused by progressive death of the Purkinje cells resulting in cerebellar ataxia characterized by a typical head tremor, jerky head movements and lack of menace response. The specific role of magnetic resonance imaging (MRI) to support clinical diagnosis has been discussed. However, as yet MR imaging has only been described in one equine CA case. The role of MR morphometry in this regard is currently unknown. Due to the hereditary nature of the disease, genetic testing can support the diagnosis of CA.

Therefore, the objective of this study was to perform MR morphometric analysis and genetic testing in four CA-affected Arabian horses and one German Riding Pony with purebred Arabian bloodlines in the third generation.

Results

CA was diagnosed pathohistologically in the five affected horses (2 months - 3 years) supported by clinical signs, necropsy, and genetic testing which confirmed the TOE1:g.2171G>A SNP genotype A/A in all CA-affected horses.

On MR images morphometric analysis of the relative cerebellar size and relative cerebellar cerebrospinal fluid (CSF) space were compared to control images of 15 unaffected horses. It was demonstrated that in MR morphometric analyses, CA affected horses displayed a relatively smaller cerebellum compared to the entire brain mass than control animals (P = 0.0088). The relative cerebellar CSF space was larger in affected horses (P = 0.0017). Using a cut off value of 11.0% for relative cerebellar CSF space, the parameter differentiated between CA-affected horses and controls with a sensitivity of 100% and a specificity of 93.3%.

Conclusions

In conclusion, morphometric MRI and genetic analysis could be helpful to support the diagnosis of CA in vivo.

[Congenital cardiac anomalies (pentalogy of Fallot) in a two year old ram with brachygnathia inferior]

In a nearly two-year-old ram, descending from a breeding trial to investigate the effects of shortness of the lower jaw (brachygnathia inferior), a congenital cardiac anomaly was observed. At the age often months the affected animal, a cross breed of Cameroon Sheep and East Friesian Milk Sheep, showed exercise-induced respiratory distress for the first time. Auscultation revealed a loud systolic heart murmur (grade 5) on both sides of the thorax, most prominent over the left third intercostal space at shoulder height. Postmortem examination of the ram's heart showed a pentalogy of Fallot, consisting of a pulmonic stenosis, a ventricular septal defect, an overriding aorta, a right ventricular hypertrophy and a patent foramen ovale. A genetic defect has to be considered as a possible reason.

Congenital infection with Anaplasma phagocytophilum in a calf in northern Germany

Anaplasma phagocytophilum is a Gram-negative, obligate intracellular tick-transmitted bacterium that replicates in neutrophils. It causes tick-borne fever (TBF) in sheep and cattle, but also elicits febrile disease in humans as well as in other domestic animals such as dogs, horses, and cats. Although increasingly recognized in Europe, the first laboratory-confirmed case of TBF in cattle from Germany has been published only recently. We here present the unusual case of an intrauterine transmission of A. phagocytophilum in a calf from northern Germany. To our knowledge, this is the first report of such an event occurring under field conditions in cattle.

Prevalence of osteochondral fragments, osteochondrosis dissecans and palmar/plantar osteochondral fragments in Hanoverian Warmblood horses

In this study, the prevalences of osteochondral fragments in the distal (DUI) and proximal interphalangeal joints (PIJ) as well as in the fetlock, hock and stifle joints, of palmar/plantar osteochondral fragments in the fetlock joints (POFs) and of osteochondrosis dissecans (OCD) in fetlock, hock and stifle joints were estimated in a large sample of Hanoverian Warmblood horses. For this purpose, radiographic findings of 9478 Hanoverian Warmblood horses collected from 2005 to 2011 were analyzed. Overall 31.9% of the horses showed one or more osteochondral fragments in at least one joint. The fetlocks were predominantly affected with a prevalence of 19.7%, followed by the hocks with 8.2% and the stifles with 2.7%. For OCD, an overall prevalence of 14.3% was determined. In fetlock joints, 5.4% of the horses had OCD, in the hock joints 6.9% and in the stifle joints 2.6%, with bilateral occurrence in 25.8% of the hock, 24.9% of the stifle and 12.6% of the fetlock joints. POFs were observed in 6.8% of the horses. With a prevalence of 6.3%, the hindlimbs were significantly more frequently affected than the forelimbs with 0.6%. Of the horses with POFs, 16.5% were also affected with OCD. The high prevalences for osteochondral fragments determined in this study show their great importance with regard to economics and animal welfare.

Genome-wide association analysis identifies loci for left-sided displacement of the abomasum in German Holstein cattle

Left-sided displacement of the abomasum (LDA) is one of the most common disorders of the digestive system in many dairy breeds and particularly in Holstein dairy cows. We performed a genome-wide association study for 854 German Holstein cows, including 225 cases and 629 controls. All cows were genotyped using the Illumina Bovine SNP50 BeadChip (Illumina Inc., San Diego, CA). After quality control of genotypes, a total of 36,226 informative single nucleotide polymorphisms (SNP) were left for analysis. We used a mixed linear model approach for a genome-wide association study of LDA. In total, 36 SNP located on 17 bovine (Bos taurus) chromosomes (BTA) showed associations with LDA at nominal -log10P-values >3.0. Two of these SNP, located on BTA11 at 46.70 Mb and BTA20 at 16.67 Mb, showed genome-wide significant associations with LDA at -log10P-values >4.6. Pathway analyses indicated genes involved in calcium metabolism and insulin-dependent diabetes mellitus to be factors in the pathogenesis of LDA in German Holstein cows.

Expression levels of LCORL are associated with body size in horses

Body size is an important characteristic for horses of various breeds and essential for the classification of ponies concerning the limit value of 148 cm (58.27 inches) height at the withers. Genome-wide association analyses revealed the highest associated quantitative trait locus for height at the withers on horse chromosome (ECA) 3 upstream of the candidate gene LCORL. Using 214 Hanoverian horses genotyped on the Illumina equine SNP50 BeadChip and 42 different horse breeds across all size ranges, we confirmed the highly associated single nucleotide polymorphism BIEC2-808543 (−log₁₀P = 8.3) and the adjacent gene LCORL as the most promising candidate for body size. We investigated the relative expression levels of LCORL and its two neighbouring genes NCAPG and DCAF16 using quantitative real-time PCR (RT-qPCR). We could demonstrate a significant association of the relative LCORL expression levels with the size of the horses and the BIEC2-808543 genotypes within and across horse breeds. In heterozygous C/T-horses expression levels of LCORL were significantly decreased by 40% and in homozygous C/C-horses by 56% relative to the smaller T/T-horses. Bioinformatic analyses indicated that this SNP T>C mutation is disrupting a putative binding site of the transcription factor TFIID which is important for the transcription process of genes involved in skeletal bone development. Thus, our findings suggest that expression levels of LCORL play a key role for body size within and across horse breeds and regulation of the expression of LCORL is associated with genetic variants of BIEC2-808543. This is the first functional study for a body size regulating polymorphism in horses and a further step to unravel the mechanisms for understanding the genetic regulation of body size in horses.

Genetic diversity in the modern horse illustrated from genome-wide SNP data

Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. F(ST) calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection.

Genome-wide analysis reveals selection for important traits in domestic horse breeds

Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F(ST)-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle biopsies showed a promoter variant and intronic SNP of MSTN were each significantly associated with higher Type 2B and lower Type 1 muscle fiber proportions in the Quarter Horse, demonstrating a functional consequence of selection at this locus. Signatures of selection on ECA23 in all gaited breeds in the sample led to the identification of a shared, 186-kb haplotype including two doublesex related mab transcription factor genes (DMRT2 and 3). The recent identification of a DMRT3 mutation within this haplotype, which appears necessary for the ability to perform alternative gaits, provides further evidence for selection at this locus. Finally, putative loci for the determination of size were identified in the draft breeds and the Miniature horse on ECA11, as well as when signatures of selection surrounding candidate genes at other loci were examined. This work provides further evidence of the importance of MSTN in racing breeds, provides strong evidence for selection upon gait and size, and illustrates the potential for population-based techniques to find genomic regions driving important phenotypes in the modern horse.

Population screening for the mutation associated with osteogenesis imperfecta in dachshunds

Osteogenesis imperfecta (OI) is a genetic disorder causing defects in the development of collagen type I. Clinical signs of affected dachshunds include multiple fractures of bones, joint hyperlaxity and dentinogenesis imperfecta. Recently, a recessive mutation in the SERPINH1 gene was detected in dachshunds and enabled the development of a DNA test to identify dachshunds carrying the mutation. The purpose of the present study was to analyse the dachshund breeding population for the frequency of the SERPINH1 mutation among the nine different breed varieties in dachshunds, birth years and countries of origin. We genotyped the OI-associated SERPINH1 mutation in 1352 dachshunds from 12 different European countries including all nine varieties. Genotyping was done using a restriction fragment length polymorphism validated by DNA sequence analysis. The overall frequency of OI carriers was 12.9 per cent. Across all different size varieties, the SERPINH1 mutation was over-represented in wire-haired dachshunds with 17.3 per cent OI carriers. Among the different countries, the proportion of OI carriers was highest in Germany with 20.4 per cent. The test is useful for dachshund breeders to prevent the occurrence of OI-affected dogs and as a diagnostic tool for veterinarians.

[Renal function tests in milk fed calves--reference values and influence of bovine neonatal pancytopenia (BNP)]

OBJECTIVES

Renal function tests were performed on 38 clinically healthy Holstein calves aged 1435 days, of which seven had survived bovine neonatal pancytopenia (BNP). The main objective was the establishment of reference values for renal fractional excretions (FE) of sodium (Na), potassium (K), calcium (Ca) and phosphate (P) in calves fed milk replacer. Additionally, it should be clarified whether calves suffer from permanent renal disorders as a result of BNP.

MATERIAL AND METHODS

The fractional excretions were determined using wet chemical analyses of simultaneously taken urine and blood samples. Their calculation was based on the endogenous excretion of creatinine.

RESULTS

There were no significant differences in the FE between calves with and without a history of BNP. Based on the values of all 38 calves, reference values were calculated for the FE indicated above, and also for the urinary γ-glutamyltransferase-creatinine ratio as a parameter for the damage of tubular cells.

CONCLUSION

It has been demonstrated that age- and feeding-specific reference values for renal function parameters in cattle are necessary. For renal function analyses in calves, the nutritional supply with electrolytes has to be considered to differentiate the variability of electrolyte excretions due to different feeding regimes from renal disorders. Based on the calculated reference values for calves fed milk replacer, renal function disorders can be determined sensitively and further differentiation is possible.

[Factors affecting pregnancy rates in the German Thoroughbred Breed]

OBJECTIVE

The aim of this study was to evaluate factors affecting pregnancy rates in the German Thoroughbred Breed with particular emphasis on optimisation of fertility rates for breeding stallions of older ages.

MATERIAL AND METHODS

Data from the studbooks of the German Thoroughbred Breeding Association from 1996 to 2009 analysed. This analysis included the records of 319 stallions and 6622 brood mares, resulting in 21,372 pregnancies at the end of the season.

RESULTS

Pregnancy rates were significantly affected by the age of the stallion and mare as well as the season (month in the breeding season in which covering occurred). Furthermore, significant interactions were found between stallion age and book (number of mares covered per stallion), and between stallion age and season. Pregnancy rates decreased with increasing age of the stallion and brood mare as well as with the progression of the breeding season. However, stallions older than 16 years did show higher pregnancy rates when booked for more than 12 brood mares per season. Pregnancy rates for the older stallions were in particular decreased for later months in the breeding season.

CONCLUSION AND CLINICAL RELEVANCE

For breeding with older stallions mares should be bred as early as possible in the breeding season and a sufficiently large number of mares should be covered.