Genome wide association study in Swedish Labrador retrievers identifies genetic loci associated with hip dysplasia and body weight.

Genome wide association studies (GWAS) have been utilized to identify genetic risk loci associated with both simple and complex inherited disorders. Here, we performed a GWAS in Labrador retrievers to identify genetic loci associated with hip dysplasia and body weight. Hip dysplasia scores were available for 209 genotyped dogs. We identified a significantly associated locus for hip dysplasia on chromosome 24, with three equally associated SNPs (p = 4.3 × 10-7) in complete linkage disequilibrium located within NDRG3, a gene which in humans has been shown to be differentially expressed in osteoarthritic joint cartilage. Body weight, available for 85 female dogs, was used as phenotype for a second analysis. We identified two significantly associated loci on chromosome 10 (p = 4.5 × 10-7) and chromosome 31 (p = 2.5 × 10-6). The most associated SNPs within these loci were located within the introns of the PRKCE and CADM2 genes, respectively. PRKCE has been shown to play a role in regulation of adipogenesis whilst CADM2 has been associated with body weight in multiple human GWAS. In summary, we identified credible candidate loci explaining part of the genetic inheritance for hip dysplasia and body weight in Labrador retrievers with strong candidate genes in each locus previously implicated in the phenotypes investigated.

Danish dog owners' use and the perceived effect of unlicensed cannabis products in dogs.

The interest in the use of medical cannabis has increased in recent years in both human and veterinary fields. In Denmark, there are no veterinary-licensed medical cannabis or cannabinoid supplements, and it is illegal to prescribe or sell cannabinoids intended for the treatment of veterinary patients. This study aimed to explore the unlicensed cannabinoid use in Danish dogs, by questioning dog owners about usage, indication for use, way of purchase, and their perceived effect of the cannabinoid treatment. An anonymous online survey was distributed via social media. The total number of respondents were 2,002, of which 38% indicated using or having administered cannabinoids to their dog. The majority of the respondents confirming the use of cannabinoids (93%) had used cannabidiol drops/oil and only few (4%) reported using Δ9-tetrahydrocannabinol-based products. Most owners (67%) purchased the products online. The three most common indications for use were pain alleviation, behavioural issues, and allergy. When asked about the respondent-perceived effect the majority reported a good or very good effect. The indication with the highest percentage of owner-perceived positive effect (77%) was pain alleviation. This study shows that, despite no licensed veterinary cannabinoid products being available in Denmark, dog owners do supplement their dogs with cannabinoids and the majority of these perceive that the treatment had a positive effect. This supports the need for more evidence-based knowledge in veterinary cannabinoid therapy.

Evaluation of intensity-modulated electron FLASH radiotherapy in a clinical setting using veterinary cases.

PURPOSE: The increased normal tissue tolerance for FLASH radiotherapy (FLASH-RT), as compared to conventional radiotherapy, was first observed in ultra-high dose rate electron beams. Initial clinical trials in companion animals have revealed a high risk of developing osteoradionecrosis following high-dose single-fraction electron FLASH-RT, which may be related to inhomogeneities in the dose distribution. In the current study, we aim to evaluate the possibilities of intensity-modulated electron FLASH-RT in a clinical setting to ensure a homogeneous dose distribution in future veterinary and human clinical trials. METHODS: Our beam model in the treatment planning system electronRT (.decimal, LLC, Sanford, FL, USA) was based on a 10-MeV electron beam from a clinical linear accelerator used to treat veterinary patients with FLASH-RT in a clinical setting. In electronRT, the beam can be intensity-modulated using tungsten island blocks in the electron block cutout, and range-modulated using a customized bolus with variable thickness. Modulations were first validated in a heterogeneous phantom by comparing measured and calculated dose distributions. To evaluate the impact of intensity modulation in superficial single-fraction FLASH-RT, a treatment planning study was conducted, including eight canine cancer patient cases with simulated tumors in the head-and-neck region. For each case, treatment plans with and without intensity modulation were created for a uniform bolus and a range-modulating bolus. Treatment plans were evaluated using a target dose homogeneity index (HI), a conformity index (CI), the near-maximum dose outside the target ( D 2 % , Body - PTV ${D_{2{\mathrm{\% }},{\mathrm{\ Body}} - {\mathrm{PTV}}}}$ ), and the near-minimum dose to the target ( D 98 % ${D_{98\% }}$ ). RESULTS: By adding intensity modulation to plans with a uniform bolus, the HI could be improved (p = 0.017). The combination of a range-modulating bolus and intensity modulation provided a further significant improvement of the HI as compared to using intensity modulation in combination with a uniform bolus (p = 0.036). The range-modulating bolus also improved the CI compared to using a uniform bolus, both with an open beam (p = 0.046) and with intensity modulation (p = 0.018), as well as increased the D 98 % ${D_{98\% }}$ (p = 0.036 with open beam and p = 0.05 with intensity modulation) and reduced the median D 2 % , Body - PTV ${D_{2\% ,{\mathrm{\ Body}} - {\mathrm{PTV}}}}$ (not significant). CONCLUSIONS: By using intensity-modulated electron FLASH-RT in combination with range-modulating bolus, the target dose homogeneity and conformity in canine patients with simulated tumors in complex areas in the head-and-neck region could be improved. By utilizing this technique, we hope to decrease the dose outside the target volume and avoid hot spots in future clinical electron FLASH-RT studies, thereby reducing the risk of radiation-induced toxicity.

Molecular detection of bovine leukosis virus in naturally infected dairy and dual-purpose cattle in Mexico.

The objective of this study was to determine the prevalence of bovine leukosis virus (BLV) in specialized and dual-purpose dairy cows located in the central zone of Veracruz state in Mexico, using endpoint polymerase chain reaction (PCR). The study population consisted of 307 specialized dairy cows and 95 dual-purpose cows from 13 municipalities located in the study area. All cows were apparently healthy and ≥ 3 years old. Cows were stratified by age (3 - 5, 6 - 8 and ≥ 9 years). The overall prevalence of infection was 6.96%; the calculated prevalence in dairy cows was 7.82% and in dual-purpose cows it was 4.21%. The municipality with the highest proportion was Acajete (14.28%), followed by Huatusco and Tomatlán (11.53%). The association analysis confirms the infection's independence to the cows' productive purpose. The results by age strata were 3 - 5 (4.60%), 6 - 8 (8.00%) and ≥ 9 (18.40%) with X2 = 9.96, with an odds ratio of 4.68 for the stratum ≥ 9 years with a significant difference. The present study determined the prevalence of proviral DNA of BLV in dairy and dual-purpose cows in six municipalities in the central zone of Veracruz state, Mexico, using endpoint PCR.

Quality of Life After Partial Mandibulectomy or Maxillectomy in 45 Dogs With Oral Tumors.

Treatment for oral tumors in dogs may involve aggressive surgery, radiation therapy, and/or chemotherapy. It is of utmost importance that veterinarians can document the good quality of life (QoL) for patients during and after cancer treatment. In this retrospective study, medical records from 2 private practices during a 10-year period (2011-2020) were searched to identify dogs with confirmed histopathological diagnosis of an oral tumor. Owners of dogs who underwent surgery received a questionnaire to assess their perception of QoL before and after surgery, clinical signs from the oral tumor, pain before and after surgery, physical appearance, and drinking and eating ability after surgery. Forty-two of 45 (93%) owners answered the questionnaire. Thirty-eight owners (90%) perceived that their dog had not changed its appearance after surgery after the hair had regrown. Thirty owners (71%) reported that their dog prehended food and water normally within 4 weeks after surgery. Forty owners (95%) perceived that their dog had more "good'' than ''bad'' days after surgery. Thirty-eight owners (90%) would choose the same treatment again. Our results strongly support that dog owners perceived that their dogs had good QoL after partial mandibulectomy or maxillectomy.

PIK3CA is recurrently mutated in canine mammary tumors, similarly to in human mammary neoplasia.

Biological features of neoplastic disease affecting mammary gland tissue are shared between canines and humans. Research performed in either species has translational value and early phase clinical trials performed in canines with spontaneous disease could be informative for human trials. The purpose of this study was to investigate the somatic genetic aberrations occurring in canine mammary neoplasia by exome capture and next generation sequencing. Based on 55 tumor-normal pairs we identified the PIK3CA gene as the most commonly mutated gene in canine mammary tumors, with 25% of samples carrying mutations in this gene. A recurrent missense mutation was identified, p.H1047R, which is homologous to the human PIK3CA hotspot mutation found in different types of breast neoplasia. Mutations homologous to other known human mutation hotspots such as the PIK3CA p.E545K and the KRAS p.G12V/D were also identified. We identified copy number aberrations affecting important tumor suppressor and oncogenic pathways including deletions affecting the PTEN tumor suppressor gene. We suggest that activation of the KRAS or PIK3CA oncogenes or loss of the PTEN suppressor gene may be important for mammary tumor development in dogs. This data endorses the conservation of cancer across species and the validity of studying cancer in non-human species.

Ixovex-1, a novel oncolytic E1B-mutated adenovirus.

There is a great demand for improved oncolytic viruses that selectively replicate within cancer cells while sparing normal cells. Here, we describe a novel oncolytic adenovirus, Ixovex-1, that obtains a cancer-selective replication phenotype by modulating the level of expression of the different, alternatively spliced E1B mRNA isoforms. Ixovex-1 is a recombinant adenovirus that carries a single point mutation in the E1B-93R 3' splice acceptor site that results in overexpression of the E1B-156R splice isoform. In this paper, we studied the characteristics of this novel oncolytic adenovirus by validating its in vitro behaviour in a panel of normal cells and cancer cells. We additionally studied its anti-tumour efficacy in vivo. Ixovex-1 significantly inhibited tumour growth and prolonged survival of mice in an immune-deficient lung carcinoma tumour implantation model. In complementation experiments, overexpression of E1B-156R was shown to increase the oncolytic index of both Ad5wt and ONYX-015. In contrast to prior viruses of similar type, Ixovex-1 includes a functional E3B region for better in vivo efficacy. Throughout this study, the Ixovex-1 virus has been proven to be superior in competency compared to a virus with multiple deletions.

A novel canine reference genome resolves genomic architecture and uncovers transcript complexity.

We present GSD_1.0, a high-quality domestic dog reference genome with chromosome length scaffolds and contiguity increased 55-fold over CanFam3.1. Annotation with generated and existing long and short read RNA-seq, miRNA-seq and ATAC-seq, revealed that 32.1% of lifted over CanFam3.1 gaps harboured previously hidden functional elements, including promoters, genes and miRNAs in GSD_1.0. A catalogue of canine "dark" regions was made to facilitate mapping rescue. Alignment in these regions is difficult, but we demonstrate that they harbour trait-associated variation. Key genomic regions were completed, including the Dog Leucocyte Antigen (DLA), T Cell Receptor (TCR) and 366 COSMIC cancer genes. 10x linked-read sequencing of 27 dogs (19 breeds) uncovered 22.1 million SNPs, indels and larger structural variants. Subsequent intersection with protein coding genes showed that 1.4% of these could directly influence gene products, and so provide a source of normal or aberrant phenotypic modifications.

Targeted sequencing reveals the somatic mutation landscape in a Swedish breast cancer cohort.

Breast cancer (BC) is a genetically heterogeneous disease with high prevalence in Northern Europe. However, there has been no detailed investigation into the Scandinavian somatic landscape. Here, in a homogeneous Swedish cohort, we describe the somatic events underlying BC, leveraging a targeted next-generation sequencing approach. We designed a 20.5 Mb array targeting coding and regulatory regions of genes with a known role in BC (n = 765). The selected genes were either from human BC studies (n = 294) or from within canine mammary tumor associated regions (n = 471). A set of predominantly estrogen receptor positive tumors (ER + 85%) and their normal tissue counterparts (n = 61) were sequenced to ~ 140 × and 85 × mean target coverage, respectively. MuTect2 and VarScan2 were employed to detect single nucleotide variants (SNVs) and copy number aberrations (CNAs), while MutSigCV (SNVs) and GISTIC (CNAs) algorithms estimated the significance of recurrent somatic events. The significantly mutated genes (q ≤ 0.01) were PIK3CA (28% of patients), TP53 (21%) and CDH1 (11%). However, histone modifying genes contained the largest number of variants (KMT2C and ARID1A, together 28%). Mutations in KMT2C were mutually exclusive with PI3KCA mutations (p ≤ 0. 001) and half of these affect the formation of a functional PHD domain. The tumor suppressor CDK10 was deleted in 80% of the cohort while the oncogene MDM4 was amplified. Mutational signature analyses pointed towards APOBEC deaminase activity (COSMIC signature 2) and DNA mismatch repair (COSMIC signature 6). We noticed two significantly distinct patterns related to patient age; TP53 being more mutated in the younger group (29% vs 9% of patients) and CDH23 mutations were absent from the older group. The increased somatic mutation prevalence in the histone modifying genes KMT2C and ARID1A distinguishes the Swedish cohort from previous studies. KMT2C regulates enhancer activation and assists tumor proliferation in a hormone-rich environment, possibly pointing to a role in ER + BC, especially in older cases. Finally, age of onset appears to affect the mutational landscape suggesting that a larger age-diverse population incorporating more molecular subtypes should be studied to elucidate the underlying mechanisms.

Amy2B copy number variation reveals starch diet adaptations in ancient European dogs.

Extant dog and wolf DNA indicates that dog domestication was accompanied by the selection of a series of duplications on the Amy2B gene coding for pancreatic amylase. In this study, we used a palaeogenetic approach to investigate the timing and expansion of the Amy2B gene in the ancient dog populations of Western and Eastern Europe and Southwest Asia. Quantitative polymerase chain reaction was used to estimate the copy numbers of this gene for 13 ancient dog samples, dated to between 15 000 and 4000 years before present (cal. BP). This evidenced an increase of Amy2B copies in ancient dogs from as early as the 7th millennium cal. BP in Southeastern Europe. We found that the gene expansion was not fixed across all dogs within this early farming context, with ancient dogs bearing between 2 and 20 diploid copies of the gene. The results also suggested that selection for the increased Amy2B copy number started 7000 years cal. BP, at the latest. This expansion reflects a local adaptation that allowed dogs to thrive on a starch rich diet, especially within early farming societies, and suggests a biocultural coevolution of dog genes and human culture.

The genomic signature of dog domestication reveals adaptation to a starch-rich diet.

The domestication of dogs was an important episode in the development of human civilization. The precise timing and location of this event is debated and little is known about the genetic changes that accompanied the transformation of ancient wolves into domestic dogs. Here we conduct whole-genome resequencing of dogs and wolves to identify 3.8 million genetic variants used to identify 36 genomic regions that probably represent targets for selection during dog domestication. Nineteen of these regions contain genes important in brain function, eight of which belong to nervous system development pathways and potentially underlie behavioural changes central to dog domestication. Ten genes with key roles in starch digestion and fat metabolism also show signals of selection. We identify candidate mutations in key genes and provide functional support for an increased starch digestion in dogs relative to wolves. Our results indicate that novel adaptations allowing the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in the early domestication of dogs.