Mutations in the melanocortin 1 receptor (MC1R) gene are associated with coat colours in the domestic rabbit (Oryctolagus cuniculus)

We sequenced almost the complete coding region of the MC1R gene in several domestic rabbits (Oryctolagus cuniculus) and identified four alleles: two wild-type alleles differing by two synonymous single nucleotide polymorphisms (c.333A>G;c.555T>C), one allele with a 30-nucleotide in-frame deletion (c.304_333del30) and one allele with a 6-nucleotide in-frame deletion (c.280_285del6). A polymerase chain reaction-based protocol was used to distinguish the wild-type alleles from the other two alleles in 263 rabbits belonging to 37 breeds or strains. All red/fawn/yellow rabbits were homozygous for the c.304_333del30 allele. This allele represents the recessive e allele at the extension locus identified through pioneering genetic studies in this species. All Californian, Checkered, Giant White and New Zealand White rabbits were homozygous for allele c.280_285del6, which was also observed in the heterozygous condition in a few other breeds. Black coat colour is part of the standard colour in Californian and Checkered breeds, in contrast to the two albino breeds, Giant White and New Zealand White. Following the nomenclature established for the rabbit extension locus, the c.280_285del6 allele, which is dominant over c.304_333del30, may be allele E(D) or allele E(S).

Genetic diversity within and between European pig breeds using microsatellite markers

An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole continent using microsatellites. Fifty-eight European pig breeds and lines were analysed including local breeds, national varieties of international breeds and commercial lines. A sample of the Chinese Meishan breed was also included. Eleven additional breeds from a previous project were added for some analyses. Approximately 50 individuals per breed were genotyped for a maximum of 50 microsatellite loci. Substantial within-breed variability was observed, with the average expected heterozygosity and observed number of alleles per locus being 0.56 [range 0.43-0.68] and 4.5 respectively. Genotypic frequencies departed from Hardy-Weinberg expectations (P < 0.01) in 15 European populations, with an excess of homozygotes in 12 of them. The European breeds were on average genetically very distinct, with a Wright F(ST) index value of 0.21. The Neighbour-Joining tree drawn from the Reynolds distances among the breeds showed that the national varieties of major breeds and the commercial lines were mostly clustered around their breeds of reference (Duroc, Hampshire, Landrace, Large White and Piétrain). In contrast, local breeds, with the exception of the Iberian breeds, exhibited a star-like topology. The results are discussed in the light of various forces, which may have driven the recent evolution of European pig breeds. This study has consequences for the interpretation of biodiversity results and will be of importance for future conservation programmes.

Genetic diversity in European pigs utilizing amplified fragment length polymorphism markers

The use of DNA markers to evaluate genetic diversity is an important component of the management of animal genetic resources. The Food and Agriculture Organisation of the United Nations (FAO) has published a list of recommended microsatellite markers for such studies; however, other markers are potential alternatives. This paper describes results obtained with a set of amplified fragment length polymorphism (AFLP) markers as part of a genetic diversity study of European pig breeds that also utilized microsatellite markers. Data from 148 AFLP markers genotyped across samples from 58 European and one Chinese breed were analysed. The results were compared with previous analyses of data from 50 microsatellite markers genotyped on the same animals. The AFLP markers had an average within-breed heterozygosity of 0.124 but there was wide variation, with individual markers being monomorphic in 3-98% of the populations. The biallelic and dominant nature of AFLP markers creates a challenge for their use in genetic diversity studies as each individual marker contains limited information and AFLPs only provide indirect estimates of the allelic frequencies that are needed to estimate genetic distances. Nonetheless, AFLP marker-based characterization of genetic distances was consistent with expectations based on breed and regional distributions and produced a similar pattern to that obtained with microsatellites. Thus, data from AFLP markers can be combined with microsatellite data for measuring genetic diversity.

Bovine papillomavirus type-2 (BPV-2) infection and expression of uroplakin IIIb, a novel urothelial cell marker, in urinary bladder tumors of cows

Several immunohistochemical markers have been used to define the differentiation pattern of urothelial cell tumors of the urinary bladder. We investigated the expression of the recently characterized uroplakin (UP) IIIb, an urothelium-specific and differentiation-dependent protein, in 39 urothelial tumors of the urinary bladder in cows that had suffered from chronic enzootic hematuria for several years. Bovine papillomavirus type 2 DNA was amplified and UP IIIb protein was detected in all these tumors. In papillomas and papillary carcinomas, UP IIIb expression was mostly seen as superficial staining; luminal and peripheral patterns were also observed. In nonpapillary carcinomas, UP IIIb appeared to define clearly the cell membrane lining intercellular and intracellular lumina as well as the cell borders in deeper cell layers. In benign and malignant lesions, an intracytoplasmic immunoreactivity was also detected. Coarse intracytoplasmic UP IIIb-positive material close to the nucleus occurred in some malignant cells. Focally strong membraneous immunostaining that marked single cells with complete ringlike peripheral pattern was seen. Although UP IIIb expression does not seem to correlate with the biological behavior of urothelial tumors, it appears to be a highly sensitive marker for bovine urothelial tumors.

Generation of tumour-specific cytotoxic T-cell clones from histocompatibility leucocyte antigen-identical siblings of patients with melanoma

Lymphodepletion and infusion of autologous expanded tumour-infiltrating lymphocytes is effective therapy for patients with malignant melanoma. Antitumour responses are likely to be mediated by HLA class I- and II-restricted immune responses directed at tumour antigens. We assessed whether the peripheral blood of normal HLA-matched siblings of patients with melanoma could be used to generate lymphocytes with antimelanoma activity for adoptive immunotherapy after allogeneic blood or marrow transplantation. Melanoma cell lines were derived from two donors and were used to stimulate the mononuclear cells of three HLA-identical siblings. CD4(+) clones dominated cultures. Of these, approximately half were directly cytotoxic towards recipient melanoma cells and secreted interferon-gamma in response to tumour stimulation. More than half of the noncytotoxic clones also secreted interferon-gamma after melanoma stimulation. No CD4(+) clones responded to stimulation with recipient haemopoietic cells. The majority of CD8(+) clones directly lysed recipient melanoma, but did not persist in long-term culture in vitro. No crossreactivity with recipient haemopoietic cells was observed. The antigenic target of one CD4(+) clone was determined to be an HLA-DR11-restricted MAGE-3 epitope. Antigenic targets of the remaining clones were not elucidated, but appeared to be restricted through a non-HLA-DR class II molecule. We conclude that the blood of allogeneic HLA-matched sibling donors contains melanoma-reactive lymphocyte precursors directed at tumour-associated antigens. Adoptive immunotherapy with unselected or ex vivo-stimulated donor lymphocytes after allogeneic stem cell transplantation has a rational basis for the treatment of malignant melanoma.

The in vivo targeting of tumor antigens to DCs by administration of transduced autologous lymphocytes results in robust and prolonged immunization: Pre-clinical validation and results of a pilot clinical studies of vaccination for metastatic melanoma

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Background: Genetically-modified-lymphocytes (GML) can induce a specific immune response against the transgene product (HSV-TK), when injected into immunocompetent patients (Science 276:1719, 1997). In tumor-bearing mice the infusion of tumor-associated-antigen (TAA)-transduced lymphocytes induced protective immunity and long-term memory. In this experimental setting, the T-cell effectors were generated by a cross-presentation pathway, mediated by host dendritic cells (DCs). Indeed, DCs isolated from lymph nodes of treated mice contained fragments of labeled GML and were able to elicit antigen-specific responses ex vivo. Methods: To validate this novel vaccination strategy in humans, we treated 10 patients affected by stage IIIc/IV MAGE-A3+ melanomas with escalating doses of autologous GML expressing MAGE-A3 and the tracer antigen HSV-TK. HSV-TK allows to monitor the immune status of the patients. Immune responses were monitored by DTH and in vitro T cell assays (semi-quantitative recall assays and ELISPOT). Tumor status was monitored by conventional imaging analyses. Results: No toxicity was reported. From the 10 patients, 9 were clinically evaluable because responding to the tracer antigen HSV-TK. We observed one complete response with vitiligo surrounding the lesions and one long lasting stable disease (50 mo). Moreover, one patient with no evidence of disease remained free of disease at >48 mo. The 3 responding patients experienced both DTH reactivity to MAGE-A3 and sustained increase of circulating CD8+ and CD4+ MAGE-A3-specific effectors. The immune response was long lasting since MAGE-A3-specific effectors were still detectable both in vivo and in vitro 1 year after the last vaccination. Conclusions: We describe a new method for in vivo loading of TAA on DCs that may circumvent the limitations of ex vivo manipulation of DCs. Genetically modified lymphocytes, acting as antigen carriers, efficiently target DCs in vivo in tumor-bearing mice and in melanoma patients, resulting in the generation of TAA-specific effectors that correlate with clinical benefit.

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Unusual rapid evolution of type B aortic dissection in a marfan patient following heart transplantation: successful endovascular treatment

A patient with Marfan syndrome with previous Bentall operation for mitral and tricuspid valve repair, required orthotopic cardiac transplantation for end stage cardiomyopathy. Postoperatively he suffered type-B aortic dissection, despite normal aortic diameters. Following sudden increase of aortic diameters, two years later, he underwent successful stent graft implantation. In patients with Marfan syndrome, post transplantation morbidity is high, with a 40% incidence of thoracic aortic dissection. This case highlights the potential of endovascular approach for treating post-transplantation aortic dissection.

Genetic diversity analysis using lowly polymorphic dominant markers: the example of AFLP in pigs

DNA markers are commonly used for large-scale evaluation of genetic diversity in farm animals, as a component of the management of animal genetic resources. AFLP markers are useful for such studies as they can be generated relatively simply; however, challenges in analysis arise from their dominant scoring and the low level of polymorphism of some markers. This paper describes the results obtained with a set of AFLP markers in a study of 59 pig breeds. AFLP fingerprints were generated using four primer combinations (PC), yielding a total of 148 marker loci, and average harmonic mean of breed sample size was 37.3. The average proportion of monomorphic populations was 63% (range across loci: 3%-98%). The moment-based method of Hill and Weir (2004, Mol Ecol 13:895-908) was applied to estimate gene frequencies, gene diversity (F(ST)), and Reynolds genetic distances. A highly significant average F(ST) of 0.11 was estimated, together with highly significant PC effects on gene diversity. The variance of F(ST) across loci also significantly exceeded the variance expected under the hypothesis of AFLP neutrality, strongly suggesting the sensitivity of AFLP to selection or other forces. Moment estimates were compared to estimates derived from the square root estimation of gene frequency, as currently applied for dominant markers, and the biases incurred in the latter method were evaluated. The paper discusses the hypotheses underlying the moment estimations and various issues relating to the biallelic, dominant, and lowly polymorphic nature of this set of AFLP markers and to their use as compared to microsatellites for measuring genetic diversity.

Interventional techniques in the treatment of aortic dissection

Acute aortic dissection continues to be one of the most catastrophic cardiovascular events. While there is a general consensus on immediate surgical repair when the ascending aorta is involved, the optimal treatment strategy for type B aortic dissection (B-AD) remains controversial. Recently, endovascular treatment with percutaneous stent-graft implantation, originally used for aortic aneurysm exclusion, has acquired an important role in the treatment of B-AD. Imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and angiography have a fundamental role in the search for the anatomic details necessary to tailor the stent graft and in evaluating the most suitable anatomy for stent graft. Transesophageal echocardiography is fundamental during the procedure to monitor the correct release of the stent graft and evaluate the result of the procedure expressed by immediate thrombosis out of the stent-graft. Again, imaging techniques, more notably CT, have a fundamental role in the postoperative followup after stent-graft placement. The risk of endoleaks may compromise the result of endovascular repair and increase the risk of aortic rupture. Several reports and a few trials attesting to technical feasibility and safety of stent-graft implantation procedures for B-AD have been reported so far. Also, a randomised trial comparing type B aortic stent-graft placement with medical therapy is currently underway. According to the investigators, new therapeutic indications are likely to emerge also in uncomplicated B-AD.

Nuclear morphometry in canine acanthomatous ameloblastomas and squamous cell carcinomas

The aim of this study was to evaluate whether morphometrical analysis can be of diagnostic value for canine acanthomatous ameloblastoma. We calculated, by means of an automated image analyser, some morphometric nuclear parameters, in particular: mean nuclear area (MNA), mean nuclear perimeter (MNP), maximum and minimum diameters (MDx and MDm) coefficient of variation of the nuclear area (NACV), largest to smallest dimension ratio (LS ratio), and form factor (FF), in 8 canine acanthomatous ameloblastomas, and we compared these morphometric data to those of 13 squamous cell carcinomas of canine gingiva. The results indicated a progressive increase of the MNA, NACV, MNP and MDm proceeding from acanthomatous ameloblastomas (MNA: 42.11+/-8.74; NACV: 28,36+/-7,23; MNP: 24.18+/- 2.68; MDm: 5.69+/-0.49) to squamous cell carcinomas (MNA:49,69+/-9,10; NACV: 30,89+/-7,75; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73). On the contrary, the LS ratio and the FF resulted greater in acanthomatous ameloblastomas (LS ratio: 1,63+/-0,12; FF: 1,13+/-0,002) than in SCCs (LS ratio: 1,40+/-0,12; FF:0.91+/-0.38). Moreover, the MNA, MNP,MDx and MDm resulted similar (MNA: p=0.89; MNP: p=0,65; MDm: p=0,16; MDx: p=0,13) in a subset of four acanthomatous ameloblastomas with cellular atypia (MNA:49,01+/-6,88; MNP: 26,28+/-1,99; MDm: 6.08+/-0.41; MDx: 10.18+/-0.88) and in squamous cell carcinomas (MNA:49.69+/-9,10; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73; MDx: 9.26+/-1.05). While the NACV values resulted higher in typical acanthomatous ameloblastoma (29,99+/-6,06) than in atypical acanthomatous ameloblastoma (26,74+/-8,84) and similar to those of the SCCs (30,89+/-7,75). These results seem to confirm that acanthomatous ameloblastoma is a malignant or potentially malignant lesion and emphasizes that nuclear morphometry analysis can be an useful diagnostic and prognostic method in canine oral pathology.

Bovine papillomavirus E5 oncoprotein binds to the activated form of the platelet-derived growth factor beta receptor in naturally occurring bovine urinary bladder tumours

Studies regarding the functions of the bovine papillomavirus (BPV) E5 oncoprotein in vivo are lacking and no E5-mediated mechanism underlying epithelial carcinogenesis is known. We have shown that BPV-2 DNA is present in the majority of naturally occurring urinary bladder tumours of cattle and that E5 is expressed in the cancer cells. Here we show that the interaction between the platelet-derived growth factor (PDGF) beta receptor and BPV E5, described in vitro in cultured cells, takes place in vivo in bovine urinary bladder cancers. In these cancers, E5 and PDGF beta receptor colocalize, as shown by confocal microscopy, and physically interact, as shown by coimmunoprecipitation. Furthermore, the PDGF beta receptor associated with E5 is highly phosphorylated, suggesting the functional activation of the receptor upon E5 interaction. Our results demonstrate, for the first time, that E5-PDGF beta receptor interaction occurs during the natural history of bovine urinary bladder tumours, suggesting an important role for E5 in carcinogenesis. Finally, the system provides a suitable animal model of papillomavirus-associated cancer to test therapeutic vaccination against E5. Successful bladder tumour regression would provide a valuable model for therapeutic vaccination against papillomavirus-associated tumours.

Transient transfection of porcine granulosa cells after 3D culture in barium alginate capsules

Three-dimensional culture systems in barium alginate capsules can be employed to maintain primary granulosa cells in an undifferentiated state for almost 6 days. This is due to a self-organization of cells in a pseudofollicular structure. The transfection of primary granulosa cells is a necessary condition when employing these culture systems for several purposes, for example as an in vitro toxicity test or the development of oocytes or zygotes. In this work, the feasibility of two transient transfection techniques (liposome-mediated and electroporation) was assessed in primary porcine granulosa cells after a 6-day culture in an artificial extracellular matrix (barium alginate membrane). Human recombinant green fluorescent protein was chosen as a molecular readout, and protein expression was assessed after 48 hours from transfection. Liposome-mediated transfection gave low transfection levels, with increasing yields from 2 to 12 microgDNA/ml of medium; the maximum percentage (85.7%) was reached at 12 microgDNA/ml of medium. Electroporation-mediated transfection yields were higher: the best results (81.7% of transfected cells) were achieved with two 50V pulses and 12 microg/ml DNA. The application of a single or double pulse (50V) at 4 mgDNA/ml gave negligible results. These results indicate that primary granulosa cell cultured in barium alginate capsules can be transfected by electroporation with high transfection yields.

Spatio-temporal analysis of vascular endothelial growth factor expression and blood vessel remodelling in pig ovarian follicles during the periovulatory period

Vascular endothelial growth factor (VEGF) expression pattern and blood vessel remodelling were evaluated during the transition from the preovulatory follicle to the corpus luteum (CL). To this end, prepubertal gilts were treated with equine chorionic gonadotrophin (eCG) to collect preovulatory follicles (60 h after eCG) and with human chorionic gonadotrophin (hCG) to obtain periovulatory follicles 18 h and 36 h later. The VEGF mRNA content was analysed by in situ hybridization, while protein localization in follicular fluid (FF) and in granulosa and theca compartments was evaluated by ELISA, immunohistochemistry or western blot. Blood vessel architecture and vascular area (VA) were investigated using immunohistochemistry for von Willenbrand Factor, a specific endothelial marker. Vascular remodelling was finally tested using Ki-67 immunocytochemistry as a proliferation marker, or alpha-smooth muscle actin (alpha-SMA) as a specific mural cell marker. eCG-treated follicles showed high VEGF levels and two concentric blood vessel networks composed of proliferating endothelial cells without any association with mural components. hCG injection inhibited VEGF synthesis in the granulosa compartment and, as a consequence, the protein fell within the FF. In parallel, endothelial cell proliferation stopped and the VA decreased. Close to ovulation, VEGF production restarted in both follicular compartments and VEGF mRNA content significantly increased in the theca layer. Changes in follicular VEGF secretion were observed; the protein disappeared from FF and was observed in the extracellular matrix. An active angiogenesis characterized the follicle; endothelial cell proliferation was associated with a recruitment of alpha-SMA-positive mural cells. The data presented in this work showed that, in the phases preceding ovulation, a complete vascular remodelling occurs, characterized by both an evident neovascularization and the appearance of blood vessels presenting smooth musculature which could be involved in CL formation after ovulation.

Comparison of prenatal muscle tissue expression profiles of two pig breeds differing in muscle characteristics1

The objective of this study was to compare purebred Duroc and Pietrain prenatal muscle tissue transcriptome expression levels at different stages of prenatal development to gain insight into the differences in muscle tissue development in these pig breeds. Commercial western pig breeds have been selected for muscle growth for the past 2 decades. Pig breeds differ for their muscle phenotypes (i.e., myofiber numbers and myofiber types). Duroc and Pietrain pig breeds are extremes; Duroc pigs have redder muscle fiber types with more intramuscular fat, and Pietrain pigs have faster-growing and whiter muscle fiber types. Pietrain pigs are more muscular than Duroc pigs, whereas Duroc pigs are fatter than Pietrain pigs. The genomic background underlying these breed-specific differences is poorly known. Myogenesis is a complex exclusive prenatal process involving proliferation and differentiation (i.e., fusion) of precursor cells called myoblasts. We investigated the difference in the prenatal muscle-specific transcriptome profiles of Duroc and Pietrain pigs using microarray technology. The microarray contained more than 500 genes affecting myogenesis, energy metabolism, muscle structural genes, and other genes from a porcine muscle cDNA library. The results indicated that the expression of the myogenesis-related genes was greater in early Duroc embryos than in early Pietrain embryos (14 to 49 d of gestation), whereas the opposite was found in late embryos (63 to 91 d of gestation). These findings suggest that the myogenesis process is more intense in early Duroc embryos than in Pietrain embryos but that myogenesis is more intense in late Pietrain fetuses than in Duroc fetuses. Transcriptomes of muscle structural genes followed that pattern. The energy metabolism genes were expressed at a higher level in prenatal Pietrain pigs than in prenatal Duroc pigs, except for d 35, when the opposite situation was found. Fatty acid metabolism genes were expressed at a higher level in early (14 to 49 d of gestation) Duroc embryos than in Pietrain embryos. Better understanding of the genomic regulation of tissue formation leads to improved knowledge of the genome under selection and may lead to directed breed-specific changes in the future.