MSC therapy in livestock models

Mesenchymal stem cells (MSCs) have great value as therapeutic tools in a wide array of applications in regenerative medicine. The wide repertoire of cell functions regarding tissue regeneration, immunomodulation, and antimicrobial activity makes MSC-based therapy a strong candidate for treatment options in a variety of clinical conditions and should be studied to expand the current breadth of knowledge surrounding their physiological properties and therapeutic benefits. Livestock models are an appropriate resource for testing the efficacy of MSC therapies for their use in biomedical research and can be used to improve both human health and animal agriculture. Agricultural animal models such as pigs, cattle, sheep, and goats have grown in popularity for in vivo research relative to small animal models due to their overlapping similarities in structure and function that more closely mimic the human body. Cutaneous wound healing, bone regeneration, osteoarthritis, ischemic reperfusion injury, and mastitis recovery represent a few examples of the types of disease states that may be investigated in livestock using MSC-based therapy. Although the cost of agricultural animals is greater than small animal models, the information gained using livestock as a model holds great value for human applications, and in some cases, outcompetes the weight of information gained from rodent models. With emerging fields such as exosome-based therapy, proper in vivo models will be needed for testing efficacy and translational practice, i.e., livestock models should be strongly considered as candidates. The potential for capitalizing on areas that have crossover benefits for both agricultural economic gain and improved health of the animals while minimizing the gap between translational research and clinical practice are what make livestock great choices for experimental MSC models.

Defining Trends in Global Gene Expression in Arabian Horses with Cerebellar Abiotrophy

Equine cerebellar abiotrophy (CA) is a hereditary neurodegenerative disease that affects the Purkinje neurons of the cerebellum and causes ataxia in Arabian foals. Signs of CA are typically first recognized either at birth to any time up to 6 months of age. CA is inherited as an autosomal recessive trait and is associated with a single nucleotide polymorphism (SNP) on equine chromosome 2 (13074277G>A), located in the fourth exon of TOE1 and in proximity to MUTYH on the antisense strand. We hypothesize that unraveling the functional consequences of the CA SNP using RNA-seq will elucidate the molecular pathways underlying the CA phenotype. RNA-seq (100 bp PE strand-specific) was performed in cerebellar tissue from four CA-affected and five age-matched unaffected horses. Three pipelines for differential gene expression (DE) analysis were used (Tophat2/Cuffdiff2, Kallisto/EdgeR, and Kallisto/Sleuth) with 151 significant DE genes identified by all three pipelines in CA-affected horses. TOE1 (Log2(foldchange) = 0.92, p = 0.66) and MUTYH (Log2(foldchange) = 1.13, p = 0.66) were not differentially expressed. Among the major pathways that were differentially expressed, genes associated with calcium homeostasis and specifically expressed in Purkinje neurons, CALB1 (Log2(foldchange) = -1.7, p < 0.01) and CA8 (Log2(foldchange) = -0.97, p < 0.01), were significantly down-regulated, confirming loss of Purkinje neurons. There was also a significant up-regulation of markers for microglial phagocytosis, TYROBP (Log2(foldchange) = 1.99, p < 0.01) and TREM2 (Log2(foldchange) = 2.02, p < 0.01). These findings reaffirm a loss of Purkinje neurons in CA-affected horses along with a potential secondary loss of granular neurons and activation of microglial cells.

Tissue resolved, gene structure refined equine transcriptome

BACKGROUND

Transcriptome interpretation relies on a good-quality reference transcriptome for accurate quantification of gene expression as well as functional analysis of genetic variants. The current annotation of the horse genome lacks the specificity and sensitivity necessary to assess gene expression especially at the isoform level, and suffers from insufficient annotation of untranslated regions (UTR) usage. We built an annotation pipeline for horse and used it to integrate 1.9 billion reads from multiple RNA-seq data sets into a new refined transcriptome.

RESULTS

This equine transcriptome integrates eight different tissues from 59 individuals and improves gene structure and isoform resolution, while providing considerable tissue-specific information. We utilized four levels of transcript filtration in our pipeline, aimed at producing several transcriptome versions that are suitable for different downstream analyses. Our most refined transcriptome includes 36,876 genes and 76,125 isoforms, with 6474 candidate transcriptional loci novel to the equine transcriptome.

CONCLUSIONS

We have employed a variety of descriptive statistics and figures that demonstrate the quality and content of the transcriptome. The equine transcriptomes that are provided by this pipeline show the best tissue-specific resolution of any equine transcriptome to date and are flexible for several downstream analyses. We encourage the integration of further equine transcriptomes with our annotation pipeline to continue and improve the equine transcriptome.

Validation of International Society of Urological Pathology (ISUP) grading for prostatic adenocarcinoma in thin core biopsies using TROG 03.04 'RADAR' trial clinical data

In 2014 a consensus conference convened by the International Society of Urological Pathology (ISUP) adopted amendments to the criteria for Gleason grading and scoring (GS) for prostatic adenocarcinoma. The meeting defined a modified grading system based on 5 grading categories (grade 1, GS 3+3; grade 2, GS 3+4; grade 3, GS 4+3; grade 4, GS 8; grade 5, GS 9-10). In this study we have evaluated the prognostic significance of ISUP grading in 496 patients enrolled in the TROG 03.04 RADAR Trial. There were 19 grade 1, 118 grade 2, 193 grade 3, 88 grade 4 and 79 grade 5 tumours in the series, with follow-up for a minimum of 6.5 years. On follow-up 76 patients experienced distant progression of disease, 171 prostate specific antigen (PSA) progression and 39 prostate cancer deaths. In contrast to the 2005 modified Gleason system (MGS), the hazards of the distant and PSA progression endpoints, relative to grade 2, were significantly greater for grades 3, 4 and 5 of the 2014 ISUP grading scheme. Comparison of predictive ability utilising Harrell's concordance index, showed 2014 ISUP grading to significantly out-perform 2005 MGS grading for each of the three clinical endpoints.

The transgenic animal platform for biopharmaceutical production

The recombinant production of therapeutic proteins for human diseases is currently the largest source of innovation in the pharmaceutical industry. The market growth has been the driving force on efforts for the development of new therapeutic proteins, in which transgenesis emerges as key component. The use of the transgenic animal platform offers attractive possibilities, residing on the low production costs allied to high productivity and quality of the recombinant proteins. Although many strategies have evolved over the past decades for the generation of transgenic founders, transgenesis in livestock animals generally faces some challenges, mainly due to random transgene integration and control over transgene copy number. But new developments in gene editing with CRISPR/Cas system promises to revolutionize the field for its simplicity and high efficiency. In addition, for the final approval of any given recombinant protein for animal or human use, the production and characterization of bioreactor founders and expression patterns and functionality of the proteins are technical part of the process, which also requires regulatory and administrative decisions, with a large emphasis on biosafety. The approval of two mammary gland-derived recombinant proteins for commercial and clinical use has boosted the interest for more efficient, safer and economic ways to generate transgenic founders to meet the increasing demand for biomedical proteins worldwide.

A quantitative model for differential motility of gliomas in grey and white matter

We have extended a mathematical model of gliomas based on proliferation and diffusion rates to incorporate the effects of augmented cell motility in white matter as compared to grey matter. Using a detailed mapping of the white and grey matter in the brain developed for a MRI simulator, we have been able to simulate model tumours on an anatomically accurate brain domain. Our simulations show good agreement with clinically observed tumour geometries and suggest paths of submicroscopic tumour invasion not detectable on CT or MRI images. We expect this model to give insight into microscopic and submicroscopic invasion of the human brain by glioma cells. This method gives insight in microscopic and submicroscopic invasion of the human brain by glioma cells. Additionally, the model can be useful in defining expected pathways of invasion by glioma cells and thereby identify regions of the brain on which to focus treatments.

226 HUMAN LACTOFERRIN EXPRESSED IN COW MILK CAN EXTEND THE SHELF LIFE OF MILK

Lactoferrin (LF) is an antimicrobial protein that is produced at high levels in human secretions, including milk, but is present at very low levels in the milk of ruminants. Lactoferrin is an iron-binding protein, and because iron is required by some bacteria to grow, lactoferrin can reduce the growth of certain bacteria. Lactoferrin can inhibit the growth of gram-negative bacteria, gram-positive bacteria, yeast, and some antibiotic-resistant pathogens. Lactoferrin also has bacteriocidal activity, killing the organism by inducing membrane perturbations often in conjunction with other antimicrobial agents such as lysozyme. Due to these properties, lactoferrin has the potential to increase the health of lactating animals as well as extend the shelf life of the milk. A herd of cows were genetically engineered to produce milk containing recombinant human lactoferrin (rhLF-milk) at approximately the same concentration found in human milk. In this study, growth of bacteria in raw milk samples from 2 control cows was compared with that from 2 cows that produce rhLF-milk. The experiment examined the shelf life of milk at room temperature over a 72-h period and the shelf life of milk left at 4°C over 3 weeks by plating aliquots on agar plates and counting the number of bacterial colonies that grew on plates after 24 and 48 h. The milk left at room temperature was plated at 0, 24, 48, and 72 h. The milk left in at 4°C was measured at 0, 4, 7, 11, 14, 18, and 21 days. Statistical evaluations were conducted using SAS statistical software, version 9.3 (SAS Institute Inc., Cary, NC, USA). Bacterial data were compared using the repeated-measures function in SAS and the Greenhouse-Geisser epsilon test to determine differences. For all tests, P-values <0.05 were considered statistically significant. The rhLF-milk showed less bacteria growth than control milk over the 4 time periods when left at room temperature (P = 0.0029), but did not inhibit the growth of bacteria when held for longer periods at 4°C (P = 0.6031). This shows that rhLF-milk may have an extended shelf life at room temperature and thus may be a means to increase food availability in developing countries. The next step in this research will be examining the populations of bacteria in the milk to determine how rhLF alters the populations of bacteria growing in milk over time, the different types of bacteria populations between the rhLF and control milk and what their effects are.

221 SOMATIC CELL GOAT CLONING USING ALLOGENEIC OR SYNGENEIC TRANSGENIC CELL LINES

The aim of this study was to compare the efficiency of goat cloning by using cell lineages from distinct transgenic backgrounds. Primary fibroblast skin cell cultures from 2 females (allogeneic), transgenic for the human lysozyme gene (hLZ), were established following standard procedures. Cells from one hLZ genotype were used for the establishment of 2 double transgenic syngeneic cell lines by cell transfection (Nucleofector®, Lonza, Germany) with transgene cassettes containing either the human glucocerebrosidase gene (hGC) and neomycin resistance gene, or the human lactoferrin gene (hLF) with no selection gene. The hGC-transfected hLZ cells were antibiotic-selected (G418, Sigma-Aldrich, St. Louis, MO, USA) until the isolation of positive cell colonies, whereas hLF-transfected hLZ cells were seeded onto 100-mm culture plates (100 cells/plate) to allow colony outgrowth from individual cells. Isolated colonies were screened by PCR using specific primers for each transgene (hGC or hLF) and for hLZ and GAPDH (controls). Positive cells from one hLZ-hGC and one hLZ-hLF colony were used for cloning at passage 9, whereas hLZ cells from the other genotype were at passage 4. Cells were synchronized by high confluence and 24 h of serum starvation. Goat cloning was performed according to standard procedures (Feltrin et al. 2012 Reprod. Fertil. Dev. 25, 163). Briefly, cumulus-oocyte complexes from abattoir ovaries were in vitro-matured for 20 h. Oocyte enucleation and hLZ, hLZ-hGC, or hLZ-hLF donor cell insertion were done by micromanipulation. Reconstructed structures were fused by two 1.2-KV cm–1 DC pulses for 20 μs. Cloned embryos were cultured for 1 h in cytochalasin B and then activated in ionomycin/6-DMAP. After 12 h of in vitro culture in G-1™ medium (Vitrolife, USA), 1-cell stage embryos were transferred into the oviduct of synchronous females (Keefer et al. 2002 Biol. Reprod. 66, 199-203). Pregnancy diagnosis was performed by ultrasonography on Day 30, with weekly monitoring afterwards. Preliminary data from 6 replicates were analysed by the chi-square test (P < 0.05). Maturation rate and survival after enucleation were 42.8% (610/1425) and 72.9% (291/399), respectively. A total of 271 structures were reconstructed using the 3 donor cell lines. Fusion rates did not differ between hLZ (59.5%), hLZ-hGC (47.5%), and hLZ-hLF (48.5%) groups. A total of 68 hLZ, 92 hLZ-hGC, and 39 hLZ-hLF-derived embryos were transferred to 5, 7, and 3 recipients, respectively. No pregnancies were detected with the use of hLZ and hLZ-hLF cells. However, 3 pregnancies (one nonviable) were detected on Day 30 with hLZ-hGC cells (42.9%), with both viable pregnancies lost on Days 40 and 130 of gestation. Molecular analyses confirmed both concepti as transgenic clones from the hLZ-hGC cell line. In summary, antibiotic selection of positive colonies was effective at maintaining cell viability, with a positive response when used for cloning. Replications are in progress to evaluate the effect of cell colony isolation from individual cells (e.g. hLZ-hLF cells) on cell viability over time and on cloning outcome.

219 EFFECTS OF ADMINISTRATION OF MILK FROM TRANSGENIC COWS CONTAINING RECOMBINANT HUMAN LACTOFERRIN IN A PIG MODEL OF MALNUTRITION

Infant mortality is still a major problem, with the interaction between malnutrition and diarrhoea among the leading causes of death. One option to fight both diarrhoea and malnutrition is breastfeeding. Benefits of breast milk are attributed to the actions of antimicrobial proteins in human milk, such as lactoferrin (LF), which increase intestinal and systemic immune functions. One way to convey the benefits of LF to children is the use of transgenic animals that express human proteins in the mammary gland. In this sense, the availability of animal milk with properties of human milk can be a potential source to increase and prolong the protective benefits of human milk in reducing disease and stimulating growth. Transgenic cows expressing rhLF were produced by pronuclear microinjection with the goal of using the milk to improve human health. To test this hypothesis, we have created a model of malnutrition in pigs by reducing the intake (50%) of calories and protein. The animals (n = 26) were randomly divided as follows: after weaning at 3 weeks of age, 18 animals were fed the protein and calorie-restricted diet (mal) for 3 weeks and 8 animals served as a control group and were fed standard feed (full-fed). After 3 weeks, 4 animals in each group were necropsied and the remaining animals (n = 18) were placed into the following experimental groups: 4 animals remained in the control group (full-fed-no milk), and the 14 malnourished animals were divided as follows: 4 animals were maintained on food restriction but received no milk (mal-no milk) and 10 animals were maintained on food restriction with 5 receiving 500 mL of control milk/day (con milk) and 5 receiving 500 mL of rhLF milk/day (rhLF milk) for a total of 15 days. Intestinal permeability and morphology, mRNA expression of tight junction proteins (ZO1, claudin, occludin), and cytokines (TGF-β, TLR-4, IL-10, TNF-α, IL-6 IL-8, CCL-11) in the intestine, and hematological parameters were assessed. Data were analysed by ANOVA with P-values <0.05 considered statistically significant. The restricted diet was capable of inducing a state of malnutrition after 3 weeks as demonstrated by multiple changes in blood chemistry, a significant decrease in gut surface area, and an increase in electrical conductance indicative of compromised intestinal barrier function. Supplementation of the diet with either control milk or rhLF milk promoted the recovery of the intestine as indicated by significantly improved intestinal morphology and permeability. Levels of TNF-α were increased in the mal-no milk group; however, rhLF-fed animals were capable of regulating the expression of TNF-α, which did not significantly differ from full-fed controls. Tight junction proteins were also significantly up-regulated in the rhLF group. Overall, a model of malnutrition was established and the administration of both control and rhLF milk was beneficial in the recovery of the gastrointestinal tract. Our intention is that such milk from transgenic animals can benefit malnourished children around the world.

31 IN VITRO SURVIVAL AND PREGNANCY OUTCOME OF ZONA-FREE TRANSGENIC GOAT CLONED EMBRYOS AFTER OVIDUCTAL TRANSFER TO FEMALE RECIPIENTS ON DAY 1 OF DEVELOPMENT

Survival to term following embryo transfer is usually low after cloning by somatic cell nuclear transfer (SCNT). The aims of this study were to evaluate the effects of the zona pellucida (presence or absence) and the cell nucleus transfer method (cell fusion or cell injection) on the in vitro survival and pregnancy outcome of Day-1 goat cloned embryos transferred into the oviduct of recipient females. In vitro-matured goat oocytes from slaughterhouse ovaries were polar body selected, with a group of oocytes subjected to enzymatic zona pellucida removal. Zona-free (ZF) and zona-intact (ZI) oocytes were enucleated by micromanipulation procedures (Oback and Wells 2003 Cloning Stem Cells 5, 3–12; Keefer et al. 2000 Biol. Reprod. 66, 199–203). Somatic nucleus donor cells from 3 transgenic females for mammary gland expressing human lysozyme (Maga et al. 2003 Trans. Res. 12, 485–496) were either fused (CF) with enucleated ZI and ZF oocytes or injected (CI) into enucleated ZI oocytes, with the assessment of fusion or injection survival rates performed after 60 min. Two direct-current (DC) pulses were used to induce fusion in the ZI group (2 kV cm–1 each for 10 µs) and in the ZF group (1.0 kV cm–1 for 20 µs). Embryo reconstruction using ZI oocytes was done by micromanipulation. Zona-free (CF) or ZI (CF or CI) reconstructed cloned embryos were chemically activated in ionomycin/DMAP, followed by in vitro culture for 12 h prior to the surgical embryo transfer into the oviducts of synchronous female recipients (Day 1). Pregnancy diagnosis was carried out on Day 30 of gestation by ultrasonography. Survival after cell fusion, cell injection, and embryo transfer were compared by the χ2 test, for P < 0.05. After 16 replications, 1047 in vitro-matured oocytes obtained from 208 does were used for embryo reconstruction (Table 1). In vitro survival was higher in ZI oocytes that were injected with somatic cells than in ZI oocytes or ZF subjected to cell fusion. Pregnancy rates were similar between groups, irrespective of the cell nucleus transfer method or the presence or not of the zona pellucida, but the overall efficiency (fetal survival/recipients) was higher in the ZI-CF group. Currently, 2 ongoing pregnancies carrying 3 cloned concepti from ZI oocytes fused to somatic cells are in late gestation (>110 days). In conclusion, the cell injection method promoted higher survival and, consequently, better efficiency than cell fusion for the reconstruction of goat cloned embryos. However, the zona removal did not affect subsequent in vivo embryo development, as the transfer of zona-free embryos into the oviducts of synchronous recipients resulted in similar pregnancy rates than with zona-intact embryos. Table 1.In vitro survival and pregnancy outcome of goat cloned embryos after embryo reconstruction and transfer to female recipients on Day-1 of development

284 CHARACTERIZATION OF GOAT MESENCHYMAL STEM CELLS DERIVED FROM BONE MARROW AND ADIPOSE TISSUE

Gene modification of cells in vitro followed by somatic cell nuclear transfer (SCNT) currently offers the best route for creating genetically modified livestock species. However, low cloning efficiencies in differentiated somatic cells have been attributed to the possibility of improper nuclear reprogramming. Adult stem cells may have greater developmental potential and better nuclear reprogramming potential following cloning. There is considerable interest in using goats as models for genetically engineering dairy animals and for using stem cells as therapeutics for bone and cartilage repair. Mesenchymal stem cells (MSC) are adult stem cells that that have been isolated and characterised from various species, but are poorly characterised in goats. Three MSC lines were isolated from bone marrow (9004 BM-MSC, 9003 BM-MSC) and adipose tissue (9003 A-MSC) of neonatal goats. In this study, these MSC lines were characterised to verify MSC-specific characteristics and assess their amenability to genetic modification in vitro. Passage 5 cells were evaluated for capacity to differentiate into osteogenic, adipogenic, and chondrogenic lineages, as well as for colony-forming efficiency after 10 days of culture from low-density plating. Expression of MSC-specific positive cell surface markers CD90, CD73, and CD105, as well as pluripotency markers Nanog, Oct-4, and Sox-2, was examined by RT-PCR. Oct-4 protein localization was examined by immunofluorescence. The MSC were also assessed for their potential for gene modification by nucleofection with circular and linearized plasmids expressing green fluorescent protein (GFP) and neomycin resistance. Differences between cell lines were statistically analysed using ANOVA. The 9003 BM-MSC cells were also utilised for SCNT. All 3 MSC lines showed a normal karyotype. The MSC lines were capable of undergoing osteogenic, adipogenic, and chondrogenic differentiation, with observed differences in capacities between the BM-MSC and A-MSC lines, as shown by staining with Alizarin Red S, Oil Red O, and Alcian Blue. Expression of CD90, CD73, CD105, Nanog, Oct-4, and Sox-2 was detected, and Oct-4 was localised in the cytoplasm. There were significant differences in clonability between the cell lines, with 9004 BM-MSC showing the highest colony-forming efficiency (61% ± 5.4; P < 0.05). There were no significant differences in the percentage of GFP-positive cells from transfections done with the circular plasmid, but 9003 BM-MSC yielded a significantly lower number of integrant colonies per 500 000 cells transfected with the linear plasmid and G418 selection (12.75 ± 3.24; P < 0.05). Somatic cell nuclear transfer was able to reprogram 9003 BM-MSC and produce pregnancies. One hundred forty-four embryos were reconstructed, 101 embryos were transferred into 8 recipients, and the resulting pregnancy rate was 73%. Our findings provide characterisation information on goat MSC, and show that significant differences can exist between MSC isolated from different tissues and from within the same tissue.

Short communication: Identification of coagulase-negative staphylococcus species from goat milk with the API Staph identification test and with transfer RNA-intergenic spacer PCR combined with capillary electrophoresis

Coagulase-negative staphylococci (CNS) are the most commonly isolated bacteria from goat milk, but they have often been identified with phenotypic methods, which may have resulted in misclassification. The aims of this paper were to assess the amount of misclassification of a phenotypic test for identifying CNS species from goat milk compared with transfer RNA intergenic spacer PCR (tDNA-PCR) followed by capillary electrophoresis, and to apply the tDNA-PCR technique on different capillary electrophoresis equipment. Milk samples were collected from 416 does in 5 Californian dairy goat herds on 3 occasions during lactation. In total, 219 CNS isolates were identified at the species level with tDNA-PCR and subjected to the API 20 Staph identification test kit (API Staph; bioMérieux, Durham, NC). If the same species was isolated multiple times from the same udder gland, only the first isolate was used for further analyses, resulting in 115 unique CNS isolates. According to the tDNA-PCR test, the most prevalent CNS species were Staphylococcus epidermidis, Staphylococcus caprae, and Staphylococcus simulans. Typeability with API staph was low (72%). Although the API Staph test was capable of identifying the majority of Staph. epidermidis and Staph. caprae isolates, sensitivity for identification of Staph. simulans was low. The true positive fraction was high for the 3 most prevalent species. It was concluded that the overall performance of API Staph in differentiating CNS species from goat milk was moderate to low, mainly because of the low typeability, and that genotypic methods such as tDNA-PCR are preferred.

Vignettes from the field of mathematical biology: the application of mathematics to biology and medicine

The application of mathematical models in biology and medicine has a long history. From the sparse number of papers in the first half of the twentieth century with a few scientists working in the field it has become vast with thousands of active researchers. We give a brief, and far from definitive history, of how some parts of the field have developed and how the type of research has changed. We describe in more detail just two examples of specific models which are directly related to real biological problems, namely animal coat patterns and the growth and image enhancement of glioblastoma brain tumours.

Glioblastoma brain tumours: estimating the time from brain tumour initiation and resolution of a patient survival anomaly after similar treatment protocols

A practical mathematical model for glioblastomas (brain tumours), which incorporates the two key parameters of tumour growth, namely the cancer cell diffusion and the cell proliferation rate, has been shown to be clinically useful and predictive. Previous studies explain why multifocal recurrence is inevitable and show how various treatment scenarios have been incorporated in the model. In most tumours, it is not known when the cancer started. Based on patient in vivo parameters, obtained from two brain scans, it is shown how to estimate the time, after initial detection, when the tumour started. This is an input of potential importance in any future controlled clinical study of any connection between cell phone radiation and brain tumour incidence. It is also used to estimate more accurately survival times from detection. Finally, based on patient parameters, the solution of the model equation of the tumour growth helps to explain why certain patients live longer than others after similar treatment protocols specifically surgical resection (removal) and irradiation.

30 EFFECT OF THE CYTOPLAST SOURCE AND KARYOPLAST TYPE ON THE DEVELOPMENT OF HANDMADE CLONED EMBRYOS IN GOATS

The aim of this study was to compare the effect of 2 donor cell types (bone marrow-derived mesenchymal stem cells, BM-MSC and skin fibroblast cells, SFC) and the source of oocytes (in vivo- and in vitro-matured goat oocytes) on the developmental capacity of handmade cloned goat embryos, following our procedures adapted from cattle (Ribeiro et al., 2009, Cloning Stem Cells 11, 377–386). In vivo- and in vitro-matured oocytes obtained postmortem from 36 superovulated and 90 nonstimulated goats were used as cytoplasts for cloning, after 26 h from the induction of ovulation or 20 h from the onset of IVM, respectively. Subsequent to cumulus cell removal and polar body selection, a total of 242 in vivo- and 580 in vitro-matured oocytes were subjected to zona removal, bisection in cytochalasin B and screening under ultraviolet light. Enucleated hemi-cytoplasts were exposed to phytohemoagglutinin and adhered to a single somatic cell (BM-MSC or SF) and electrofused by two 1.2 kV cm–1 DC pulses for 20 μs. Cell primary cultures were established from lysozyme transgenic goats. Prior to cloning, cells between the 3rd and 8th passage and at 50 to 60% (BM-MSC) or >95% (SFC) confluence were evaluated for size and viability using the CountessTM Automated Cell Counter (Invitrogen, Carlsbad, CA, USA). Fused structures were activated in ionomycin/6-DMAP and in vitro-cultured in the well of the well system in SOFaa + 5% FCS + 0.2% BSA, at 38.5°C, in 5% CO2, 5% O2 and 90% N2, for 6 days. After 8 replications, fusion, cleavage (Day 2) and embryo developmental (Day 6) rates were compared by the χ2 test. Data obtained on cell size and viability were analysed by ANOVA (P < 0.05). Cell viability was similar between SFC (86.7 ± 2.2%) and BM-MSC (89.0 ± 2.2%). However, mean cell size was significantly smaller in SFC (14.4 ± 0.4 μm) than in BM-MSC (20.1 ± 0.4 μm). Cell size appeared to be associated with fusion efficiency because fusion rates were also significantly lower with SFC than with BM-MSC (Table 1). However, cell type or oocyte source did not affect any other parameter for embryo production by cloning between groups. A total of 63 compact morulas and blastocysts from both cell and oocyte types were transferred, in groups of 4 to 5 embryos, to 15 synchronous recipients. Pregnancy diagnosis is performed by ultrasonography on Days 28 to 32. Thus far, one pregnancy derived from an embryo reconstructed with in vivo-matured oocytes and BM-MSC was obtained out of 9 recipients that received 37 embryos from all treatment groups. Six recipients with 26 embryos transferred are still pending diagnosis. In conclusion, the handmade cloning procedure using in vivo- and in vitro-matured oocytes and BM-MSC and SFC appears to be an effective alternative for the production of transgenic goats. Table 1.In vitro development of goat embryos produced by handmade cloning using human lysozyme (hLZ) transgenic cell lines Funded by the RECODISA Project, FINEP/MCT/Brazil.

Growth hormone enhances arachidonic acid metabolites in a growth hormone transgenic mouse

In a transgenic growth hormone (GH) mouse model, highly elevated GH increases overall growth and decreases adipose depots while low or moderate circulating GH enhances adipose deposition with differential effects on body growth. Using this model, the effects of low, moderate, and high chronic GH on fatty acid composition were determined for adipose and hepatic tissue and the metabolites of 20:4n-6 (arachidonic acid) were characterized to identify metabolic targets of action of elevated GH. The products of Δ-9 desaturase in hepatic, but not adipose, tissue were reduced in response to elevated GH. Proportional to the level of circulating GH, the products of Δ-5 and Δ-6 were increased in both adipose and hepatic tissue for the omega-6 lipids (e.g., 20:4n-6), while only the hepatic tissues showed an increase for omega-3 lipids (e.g., 22:6n-3). The eicosanoids, PGE₂ and 12-HETE, were elevated with high GH but circulating thromboxane was not. Hepatic PTGS1 and 2 (COX1 and COX 2), SOD1, and FADS2 (Δ-6 desaturase) mRNAs were increased with elevated GH while FAS mRNA was reduced; SCD1 (stearoyl-coenzyme A desaturase) and SCD2 mRNA did not significantly differ. The present study showed that GH influences the net flux through various aspects of lipid metabolism and especially the desaturase metabolic processes. The combination of altered metabolism and tissue specificity suggest that the regulation of membrane composition and its effects on signaling pathways, including the production and actions of eicosanoids, can be mediated by the GH regulatory axis.

Precision genetics for complex objectives in animal agriculture

Indirect modification of animal genomes by interspecific hybridization, cross-breeding, and selection has produced an enormous spectrum of phenotypic diversity over more than 10,000 yr of animal domestication. Using these established technologies, the farming community has successfully increased the yield and efficiency of production in most agricultural species while utilizing land resources that are often unsuitable for other agricultural purposes. Moving forward, animal well-being and agricultural sustainability are moral and economic priorities of consumers and producers alike. Therefore, these considerations will be included in any strategy designed to meet the challenges produced by global climate change and an expanding world population. Improvements in the efficiency and precision of genetic technologies will enable a timely response to meet the multifaceted food requirements of a rapidly increasing world population.

Welfare applications of genetically engineered animals for use in agriculture

The application of genetic engineering to food animals is often viewed as a means to further increase animal productivity without regard for the welfare of the resulting animals. We offer the perspective that, on the contrary, genetic engineering can, and is, being used to improve animal welfare in modern production systems. Several examples are cited from the current work in the field of animal genetic engineering that should be included in the debate over whether genetically engineered animals should be used in production agriculture. The current debate has slowed the advancement of this technology, which could play a key role in improving animal welfare and sustainability, without considering the potential benefits.

131 GENE SILENCING IN BOVINE ZYGOTES: SIRNA TRANSFECTION v. MICROINJECTION

Ribonucleic acid interference (RNAi) has become an effective tool for studying gene function in a variety of cells. The objective of this study was to compare the efficiency of gene silencing when siRNA were introduced into bovine zygotes by microinjection (as done previously; Tesfaye D et al. 2007 Mol. Reprod. Dev. 74, 978-988) v. a novel method of transfection in terms of gene knockdown and embryo development. For microin-jection, in vitro-produced bovine zygotes (16 h post insemination) were randomly assigned to 1 of 3 groups over 2 experiments. In Experiment 1, E-cadherin siRNA was injected at 100 μM (n = 168) and compared with PBS-injected (n = 180) and noninjected controls (n = 152). In Experiment 2, E-cadherin siRNA was injected at 375 μM (n = 154) and compared with PBS-injected (n = 136) and noninjected controls (n = 151). Embryos were subsequently cultured in vitro until Day 7 (day of IVF = Day 0). For transfection, the zona pellucida was removed from in vitro-produced zygotes. Zona-free zygotes were randomly assigned to 1 of 4 groups (i) GAPDH (n = 67), (ii) scrambled (n = 66), (iii) E-cadherin (n = 69) siRNA treatments at 100 nM or (iv) nontransfected controls (n = 66). Zygotes were incubated in transfection medium with siRNA for 1 h at 39°C, cultured individually in the well-of-the-well system to Day 7. The proportion of zygotes undergoing cleavage and developing to the blastocyst stage was recorded, and Day 7 embryos were frozen individually for mRNA analysis. Data for mRNA expression were fitted to a general linear model, and developmental stages were tested using ANOVA. Microinjection of 100 μM E-cadherin siRNA had no effect on phenotype (P > 0.05). Injection of PBS or 375 μM E-cadherin siRNA resulted in a decrease in the number of embryos reaching the 8-cell stage (51.5%, 45.5%, and 62.9%, respectively) and blastocyst stage (39.0%, 32.5%, and 45%, respectively) compared with noninjected controls (P < 0.05). The mRNA abundance of the target gene was suppressed by 36 and 46% when siRNA targeting E-cadherin was injected at 100 μM and 375 μM compared with control and PBS-injected groups (P < 0.05). Transfection with E-cadherin siRNA decreased development of 8-cell embryos (20.3 v. 53.0%, respectively) and blastocysts (7.2 v. 18.2%, respectively) compared with controls (P < 0.05). The mRNA relative abundance was not different between controls (nontransfected, or transfected with GAPDH or scrambled siRNA). However, transfection of zygotes with 100nM E-cadherin siRNA led to a 70% reduction in E-cadherin mRNA relative abundance in Day 7 blastocysts compared with controls (P < 0.05). Zona removal and transfection resulted in decreased embryo development compared with microinjection (P < 0.05). However, transfection yielded more efficient gene silencing of E-cadherin mRNA with reduced embryo development compared with microinjection. This technique of gene silencing could improve the efficiency of gene function studies in early bovine embryogenesis. Supported by Science Foundation Ireland.

Birth of large calves that developed from in vitro-derived bovine embryos

High birth weights were observed in calves that developed from bovine embryos produced by in vitro maturation (IVM) and in vitro fertilization (IVF) procedures. After IVM and IVF, embryos were either co-cultured in vitro with oviductal epithelial cells or transferred into the sheep oviduct for development to the blastocyst stage. Blastocysts were transferred to the reproductive tracts of recipient heifers and cows for development to term. Birth weights and gestation periods were compared between calves that developed from in vitro-derived embryos and calves born after artificial insemination (AI) of cows in the herd from which recipient females were selected. Gestation periods were not different among the groups (P > 0.05), but calves that developed from IVM/IVF-derived embryos co-cultured in vitro were larger at birth than calves born from IVM/IVF-derived embryos that developed into blastocysts in the sheep oviduct and calves born from AI (P < 0.001). Dystocia and calf mortality were associated with large calf size at birth. These data were collected from an experiment designed for other purposes, and confounding variables and small sample size could have influenced the observed differences in birth weights. Nevertheless, the extreme birth weights of some calves suggest that abnormal prenatal growth occurs in some IVM/IVF-derived bovine embryos and that conditions for co-culture to the blastocyst stage may exacerbate the problem.

Production and Processing of Milk from Transgenic Goats Expressing Human Lysozyme in the Mammary Gland

The potential for applying biotechnology to benefit animal agriculture and food production has long been speculated. The addition of human milk components with intrinsic antimicrobial activity and positive charge to livestock milk by genetic engineering has the potential to benefit animal health, as well as food safety and production. We generated one line of transgenic goats as a model for the dairy cow designed to express human lysozyme in the mammary gland. Here we report the characterization of the milk from 5 transgenic females of this line expressing human lysozyme in their milk at 270 microg/mL or 68% of the level found in human milk. Milk from transgenic animals had a lower somatic cell count, but the overall component composition of the milk and milk production were not different from controls. Milk from transgenic animals had a shorter rennet clotting time and increased curd strength. Milk of such nature may be of benefit to the producer by influencing udder health and milk processing.

120 EMBRYO SURVIVAL FOLLOWING LIPID-BASED TRANSFECTION OF 1-CELL STAGE BOVINE EMBRYOS WITH SMALL INTERFERING RNA (siRNA) FRAGMENTS AND/OR DNA

The RNA interference (RNAi) technology is a powerful tool for studies in functional genomics. The aim of this study was to evaluate the effects of a cationic lipid-based small interfering RNA (siRNA) and/or DNA delivery to 1-cell-stage bovine embryos on survival to the blastocyst stage. In vitro-produced (IVP) embryos were generated according to Bertolini et al. 2002 (Theriogenology 58, 973), and cloned embryos were produced by the handmade cloning technique (Vajta et al. 2003 Biol. Reprod. 68, 571) using green fluorescent protein (GFP)-expressing fibroblast cells as nuclear donors. Lipofections were performed on zona-free 1-cell-stage IVP embryos at 24–28 h post-fertilization by exposure to 1% (v/v) Lipofectamine 2000 (Invitrogen Co., CA, USA), 0.002% (w/v) GFP plasmid (pEFGP-N1, Clontech Laboratories, CA, USA) and/or various doses of siRNA GFP-specific siRNA oligonucleotide (Invitrogen) or DNA methyltransferase 1 (Dnmt1)-specific siRNA fragments for 60 min at 39°C, according to 5 treatment groups: (1) zona-intact IVP embryos (controls), (2) zona-free control embryos (controls for embryo development after zona removal), (3) embryos treated with GFP + GFP-siRNA at 0, 50, 100, 200, 400, or 800 nm, (4) embryos treated with Dnmt1-siRNA at 0, 50, 100, 250, or 500 nm, and (5) cloned embryos (positive controls for GFP expression). After treatment, embryos were in vitro-cultured in a WOW culture system (Vajta et al. 2000 Mol. Reprod. Dev. 55, 256) for 7 days. Cleavage and developmental rates to at least 8-cell and to blastocyst stages were assessed at 48, 96, and 168 h post-fertilization (hpf), respectively. Data were analyzed by the chi-square test. Cleavage rates in embryos treated with higher doses of siRNA were lower than in all other groups (Table 1). Embryo survival to at least 8-cell stage at 48 h, based on cleavage, was similar among all treatments (data not shown), but survival to blastocyst stage was affected by higher doses of GFP- or Dnmt1-siRNA (Table 1). After a qualitative assessment by fluorescence microscopy at 168 hpf, 40 to 63% of GFP-transfected blastocysts showed various levels of fluorescence, irrespective of the siRNA treatments. Fragments of siRNA are known to be short-lived in cultured cells, although we are still uncertain of their behavior and effects in early bovine embryos. We are currently analyzing the effectiveness of the siRNA transfection in the early IVP and clone embryo. In conclusion, liposome transfection of 1-cell-stage embryos did not affect survival and development to the blastocyst stage. However, survival followed an siRNA dose-response effect, with doses higher than 400 nm appearing to be detrimental to embryo development, with a developmental arrest at or close to the embryonic genome activation period. Table 1. Developmental rate of bovine embryos following lipid-based transfection at the 1-cell-stage

Transgene transmission to progeny by oMt1a-oGH transgenic mice

Most studies utilizing transgenic technology focus on the impact to traits of interest, rather than propagation of the transgene to offspring. In animals containing growth hormone constructs, transgene transmission to progeny follows a Mendelian pattern of inheritance in the first few generations following generation of a founder animal, but decreases in subsequent generations. In the present study, the ovine metallothionein 1a-ovine growth hormone (oMt1a-oGH) transgenic mouse was used to determine whether transgene transmission rate to progeny was affected by overexpression of ovine growth hormone in the transgenic parent. The oMt1a-oGH mouse is a useful model for assessing transgene transmission, as the construct is easily regulatable and transgene inactivation results in a return of plasma GH to basal levels. Male and female hemizygous oMt1a-oGH mice were assigned to 1 of 3 treatment groups: (1) mice never actively expressing the transgene, (2) mice actively expressing the transgene from 3 weeks of age, and (3) mice actively expressing the transgene from 3 to 11 (males) or 3 to 8 (females) weeks of age. Transgenic mice were mated to wild type animals and the resulting progeny were genotyped. Males never actively expressing the transgene passed on the transgene to progeny in a Mendelian fashion, while males actively expressing the transgene transmitted the transgene to a smaller than expected number of progeny. However, following inactivation of the oMt1a-oGH construct in transgenic males, subsequent offspring demonstrated Mendelian inheritance of the transgene. In contrast, females expressing the transgene from 3 to 8 weeks of age were able to pass on the oMt1a-oGH construct in a Mendelian fashion, but females from other treatment groups were not. In oMt1a-oGH males, reduced transgene transmission appears to be due to selection against transgenic gametes. In females, however, selection against the transgenic genotype likely occurs at the embryonic level.

Hot Topic: Using a Stearoyl-CoA Desaturase Transgene to Alter Milk Fatty Acid Composition

Stearoyl-CoA desaturase enzyme converts specific medium- and long-chain saturated fatty acids to their monounsaturated form. Transgenic goats expressing a bovine beta-lactoglobulin promoter-rat stearoyl-CoA desaturase cDNA construct in mammary gland epithelial cells were produced by pronuclear microinjection. The fatty acid composition of milk from 4 female transgenic founders was analyzed on d 7, 14, and 30 of their first lactation. In 2 animals, the expression of the transgene changed the overall fatty acid composition of the resulting milk fat to a less saturated and more monounsaturated fatty acid profile at d 7 of lactation; however, this effect diminished by d 30. In addition, one animal had an increased proportion of the rumen-derived monounsaturated fatty acid C18:1 trans11 converted by stearoyl-CoA desaturase to the conjugated linoleic acid isomer C18:2 cis9 trans11. Milk that has higher proportions of monounsaturated fatty acids and conjugated linoleic acid may have benefits for human cardiovascular health.

Leptin modulates fertility under the influence of elevated growth hormone as modeled in oMt1a-oGH transgenic mice

Elevated growth hormone (GH) concentrations suppress reproductive function in a variety of species, although it is unclear whether GH directly suppresses reproductive performance, or whether GH activates other pathways to achieve these effects. The ovine metallothionein 1a-ovine GH (oMt1a-oGH) transgenic mouse has been used to model the effects of GH on both body composition and reproductive function. A recent report has documented increased leptin levels in obese oMt1a-oGH mice. Given the importance of leptin in modulation of the reproductive endocrine axis, as well as the reports documenting reduced leptin signal transduction in animals with elevated leptin levels, we hypothesized that high leptin concentrations in response to elevated GH would reduce fertility. To determine the effects of high circulating leptin levels on the reproductive endocrine axis, we assessed hypothalamic neuropeptide Y (NPY) and GnRH expression. At weaning, oMt1a-oGH transgenic (TG) and wild-type (WT) female mice were allocated to one of four treatment groups: oMt1a-oGH females chronically expressing the transgene (TG ON); oMt1a-oGH females expressing the transgene from 3 to 8 weeks of age (TG ON/OFF); WT females receiving the transgene stimulus from 3 to 8 weeks of age (WT ON/OFF); and WT females never receiving the transgene stimulus (WT OFF). Eight-week-old females were housed with males for a 2-week period, after which females were isolated from males and allowed to carry pregnancies to term. Body and gonadal fat pad (GFP) weights, along with plasma leptin concentrations, estrous cyclicity, pregnancy rate and litter characteristics, were recorded for each female. Chronic expression of the oMt1a-oGH transgene resulted in larger leaner mice, and inactivation of the transgene produced obese females. Pregnancy rate was reduced in TG ON females when compared with all other groups, and infertility was associated with elevated leptin levels. In addition, high leptin levels were associated with increased NPY expression, suggesting reduced leptin-signaling capacity, which may contribute to suppression of the reproductive axis in oGH animals.

Dissociation of body growth and adipose deposition effects of growth hormone in oMt1a-oGH transgenic mice

Chronic highly elevated expression of a growth hormone (GH) transgene enhances overall body growth with minimal adipose accretion, while moderate levels of circulating GH fail to enhance body growth yet promote adipose deposition. These findings suggest that the growth response to GH can be dissociated from adipose effects. This hypothesis was tested in the oMtla-oGH transgenic mouse model by titrating circulating GH levels through variable induction of transgene expression. Circulating GH levels in female transgenics were approximately 49, 132, and 750 ng/ml in response to the transgene stimulus at 0, 15, and 25 mM zinc sulfate, respectively. The highest level of circulating GH generated the largest body weight with the smallest fat accrual while the intermediate GH level generated a body weight equivalent to that for the highest GH but the heaviest gonadal fat pads. The lowest GH levels did not increase body size but did enlarge fat depots. Animals exposed to the highest level of GH had an extended growth phase relative to lower GH levels and the nontransgenic controls. In contrast, the duration of the growth phase for the 0 and 15 mM zinc stimulated transgenics was abbreviated relative to the growth phase of the control animals. The two highest levels of circulating GH increased all forms of the GH receptor, IGF-I, and hepatic lipoprotein lipase mRNA. The growth differential observed for the 0 vs. the 15 mM zinc stimulated transgenics may reflect the preferential increase in the full length GH receptor mRNA and the induction of the smaller IGF-I transcripts with the higher circulating GH while the lipid accrual paralleled the disproportionate induction of the truncated GH receptor mRNA form. Liver and bone content of zinc, manganese, copper, and iron primarily reflected dietary zinc supplementation and did not appear to play a role in the differential growth response. The dissociation of GH effects on growth and adipogenesis as a function of circulating GH levels suggests that the level of GHR and IGF-I expression acts through a threshold mechanism and low expression results in adipogenesis while high expression generates body growth.

Virtual and real brain tumors: using mathematical modeling to quantify glioma growth and invasion

Over the last 10 years increasingly complex mathematical models of cancerous growths have been developed, especially on solid tumors, in which growth primarily comes from cellular proliferation. The invasiveness of gliomas, however, requires a change in the concept to include cellular motility in addition to proliferative growth. In this article we review some of the recent developments in mathematical modeling of gliomas. We begin with a model of untreated gliomas and continue with models of polyclonal gliomas following chemotherapy or surgical resection. From relatively simple assumptions involving homogeneous brain tissue bounded by a few gross anatomical landmarks (ventricles and skull) the models have recently been expanded to include heterogeneous brain tissue with different motilities of glioma cells in grey and white matter on a geometrically complex brain domain, including sulcal boundaries, with a resolution of 1 mm(3) voxels. We conclude that the velocity of expansion is linear with time and varies about 10-fold, from about 4 mm/year for low-grade gliomas to about 3 mm/month for high-grade ones.

Ciliary neurotrophic factor improves diabetic parameters and hepatic steatosis and increases basal metabolic rate in db/db mice

Obesity plays a central role in the development of insulin resistance and type 2 diabetes. We therefore examined the effects of a modified form of ciliary neurotrophic factor [Axokine, which is hereafter referred to as ciliary neurotrophic factor (CNTF)Ax15], which uses a leptin-like mechanism to reduce body weight, in the db/db murine model of type 2 diabetes. In previous studies, weight loss produced by CNTF treatment could largely be attributed to its effects on food intake. In contrast, CNTFAx15 treatment of db/db mice caused significantly greater weight loss and marked improvements in diabetic parameters (e.g., levels of glucose, insulin, triglyceride, cholesterol, and nonesterified free fatty acids) than could be accounted for by reduced caloric intake alone. These beneficial effects, above and beyond those seen in animals controlled for either food restriction or body weight, correlated with the ability of CNTFAx15 to increase metabolic rate and energy expenditure and reduce hepatic steatosis while enhancing hepatic responsiveness to insulin. The hepatic effects were linked to rapid alterations in hepatic gene expression, most notably reduced expression of stearoyl-CoA desaturase 1, a rate-limiting enzyme in the synthesis of complex lipids that is also markedly suppressed by leptin in ob/ob mice. These observations further link the mechanisms of CNTF and leptin action, and they suggest important, beneficial effects for CNTF in diabetes that may be distinct from its ability to decrease food intake; instead, these effects may be more related to its influence on energy expenditure and hepatic gene expression.

Quantifying efficacy of chemotherapy of brain tumors with homogeneous and heterogeneous drug delivery

Gliomas are diffuse and invasive brain tumors with the nefarious ability to evade even seemingly draconian treatment measures. Here we introduce a simple mathematical model for drug delivery of chemotherapeutic agents to treat such a tumor. The model predicts that heterogeneity in drug delivery related to variability in vascular density throughout the brain results in an apparent tumor reduction based on imaging studies despite continual spread beyond the resolution of the imaging modality. We discuss a clinical example for which the model-predicted scenario is relevant. The analysis and results suggest an explanation for the clinical problem of the long-standing confounding observation of shrinkage of the lesion in certain areas of the brain with continued growth in other areas.

Activation of the hypothalamic arcuate nucleus predicts the anorectic actions of ciliary neurotrophic factor and leptin in intact and gold thioglucose-lesioned mice

Similar to leptin, ciliary neurotrophic factor (CNTF) suppresses appetite and selectively reduces body fat in leptin-deficient ob/ob mice. To assess the relative importance of specific regions of the hypothalamus in mediating these effects, we administered a CNTF analogue (CNTFAx15) or leptin to mice made obese by administration of gold thioglucose (GTG), which destroys a well-defined portion of the medial basal hypothalamus. CNTFAx15 treatment reduced appetite and body weight in obese GTG-lesioned C57BL/6 mice, whereas leptin failed to effect similar changes regardless of whether treatment was initiated before or after the lesioned mice had become obese. Because leptin does not reduce food intake or body weight in most forms of obesity (a condition termed 'leptin resistance'), we also investigated the actions of leptin in GTG-lesioned leptin-deficient (ob/ob) mice. By contrast to C57BL/6 mice, leptin treatment reduced food intake and body weight in GTG-lesioned ob/ob mice, although the effect was attenuated. To further compare the neural substrates mediating the anorectic actions of leptin and CNTF, we determined the patterns of neurone activation induced by these proteins in the hypothalamus of intact and GTG-lesioned mice by staining for phosphorylated signal transducer and activator of transcription 3 (pSTAT3). CNTFAx15 stimulated robust pSTAT3 signalling in neurones of the medial arcuate nucleus in both intact and lesioned C57BL/6 and ob/ob mice. Leptin administration stimulated pSTAT3 signalling in only a few neurones of the medial arcuate nucleus in intact or lesioned C57BL/6 mice, but elicited a robust response in intact or lesioned ob/ob mice. By contrast to CNTFAx15, leptin treatment also resulted in prominent activation of STAT3 in several areas of the hypothalamus outside the medial arcuate nucleus. This leptin-induced pSTAT3 signal was at least as prominent in intact and GTG-lesioned C57BL/6 mice as it was in ob/ob mice, and thus was not correlated with appetite suppression or weight loss. These results indicate that the medial arcuate nucleus is a key mediator of appetite suppression and weight loss produced by CNTF and leptin, whereas GTG-vulnerable regions play a role only in leptin-induced weight loss. Other regions of hypothalamus in which pSTAT3 signal is induced by leptin may regulate energy metabolism through mechanisms other than appetite reduction.

Linkage of the grey coat colour locus to microsatellites on horse chromosome 25

The progressive loss of colour in the hair of grey horses is controlled by a dominantly inherited allele at the Grey locus (GG). In this study, two paternal Quarter Horse (QH) families segregating for the GG allele were genotyped with a set of 101 microsatellite markers spanning the 31 autosomes and the X chromosome. This genome scan demonstrated linkage of Grey to COR018 (RF=0.02, LOD=12.04) on horse chromosome 25 (ECA25). Further chromosome-specific analysis of seven total QH families confirmed the linkage of Grey to a group of ECA25 markers and the map order of NVHEQ43-(0.24)-UCDEQ405-(0.09)-COR080-(0.05)-GREY-(0.14)-UCDEQ464 was produced. Although G was found to be linked to TXN and COR018 in the chromosome-specific analysis, the data were not sufficiently informative to place either marker on our ECA25 map with significant LODs. Our results excluded the equine tyrosinase related protein 1 (TYRP1) and melanocyte protein 17 (Pmel17) genes as possible candidates for the grey phenotype in horses.

A rural mental health research agenda: defining context and setting priorities

This article provides a brief overview of research perspectives on rural mental health services and suggests the importance of building an agenda to bring coherence to studies in this area. The need for sound theory and methodology to guide research is emphasized. The importance of better conceptualization of the rural context as a focus of research is addressed, and 14 propositions concerning issues the authors think will advance rural research are presented. This article is intended to stimulate discussion about a research agenda that will lead to better understanding of rural needs for mental health services as well as more responsive service models.

Effects of pre and antenatal elevated and chronic oMt1a-oGH transgene expression on adipose deposition and linear bone growth in mice

Exposing growing oMtla-oGH transgenic mice with the regulatable metallothionein promotor to elevated growth hormone (GH) for three weeks after weaning enhances bone length and adipocyte differentiation. The objective of the present study was to investigate the consequences of highly elevated GH exposure during fetal and early postnatal growth periods on the mature phenotype. Transgene expression, hence elevated GH, was achieved in fetuses and neonates by providing 25 mM ZnSO4 to the drinking water of the dams. Wildtype and oMtla-oGH male and female mice were a) never exposed to the transgene stimulus, b) exposed from birth to 21 d of age, c) exposed through gestation until 21 d of age, d) exposed only through gestation, or e) exposed only during the first 7 d postpartum. At 84 d of age when mature body size was reached, ulna and humerus lengths, and body, liver gonadal fat pad, mesenteric fat pad, and cleaned gastrointestinal (GI) tract weights were recorded. Bone lengths were also determined in a subset of mice at 22 d of age. While early exposure to the elevated GH increased ulna and humerus length at 22 d of age, the early GH levels failed to produce significant changes in adipose content or bone lengths at maturity. However, chronic exposure to slightly elevated GH, as seen in the transgenics never induced to express the transgenic GH, depressed liver and GI weights and increased adipose depot weights and humerus lengths across both sexes. These results suggest that certain tissues in the body, while capable of responding to GH during early developmental periods, are not fully entrained to sustain that growth response once the GH stimulus is withdrawn. Further, the preadipocyte pool appears unable to respond to GH early in development. Finally, the tissues examined exhibited a differential response to the GH suggesting that different tissues possess distinct response thresholds.

Virtual brain tumours (gliomas) enhance the reality of medical imaging and highlight inadequacies of current therapy

Gliomas are brain tumours that differ from most other cancers by their diffuse invasion of the surrounding normal tissue and their notorious recurrence following all forms of therapy. We have developed a mathematical model to quantify the spatio-temporal growth and invasion of gliomas in three dimensions throughout a virtual human brain. The model quantifies the extent of tumorous invasion of individual gliomas in three-dimensions to a degree beyond the limits of present medical imaging, including even microscopy, and makes clear why current therapies based on existing imaging techniques are inadequate and cannot be otherwise without other methods for detecting tumour cells in the brain. The model's estimate of the extent of tumourous invasion beyond that defined by standard medical imaging can be useful in more accurately planning therapy regimes as well as predicting sites of potential recurrence without waiting for reemergence on follow-up imaging.

Transient dynamics and pattern formation: reactivity is necessary for Turing instabilities

The theory of spatial pattern formation via Turing bifurcations - wherein an equilibrium of a nonlinear system is asymptotically stable in the absence of dispersal but unstable in the presence of dispersal - plays an important role in biology, chemistry and physics. It is an asymptotic theory, concerned with the long-term behavior of perturbations. In contrast, the concept of reactivity describes the short-term transient behavior of perturbations to an asymptotically stable equilibrium. In this article we show that there is a connection between these two seemingly disparate concepts. In particular, we show that reactivity is necessary for Turing instability in multispecies systems of reaction-diffusion equations, integrodifference equations, coupled map lattices, and systems of ordinary differential equations.

The cream dilution gene, responsible for the palomino and buckskin coat colours, maps to horse chromosome 21

The colour locus historically referred to as C in the horse is linked to microsatellites markers on horse chromosome 21. Preliminary results demonstrated linkage of Ccr, thought to be the cream dilution variant of the C locus, to HTG10. An analysis of horse chromosome 21 using additional families confirmed and established a group of markers linked to Ccr. This work also improved the resolution of previously reported linkage maps for this chromosome. Linkage analysis unambiguously produced the map order: SGCV16-(19.1 cM)-HTG10-(3.8 cM)-LEX60/COR73-(1.3 cM)-COR68-(4.5 cM)- Ccr-(11.9 cM)-LEX31. Comparative and synteny data suggested that the horse C locus is not tyrosinase (TYR).

Growth hormone and fertility in oMt1a-oGH transgenic mice

Female mice carrying a regulatable growth hormone transgene (oMt1a-oGH) are subfertile when the transgene is actively expressed. This study was designed to characterize subfertility caused by increased concentrations of growth hormone. In particular, this study aimed to: (i) determine the effects of transgene activation and inactivation on mating, conception, maintenance of pregnancy, ovulation rate, litter characteristics and embryonic survival at day 17 of pregnancy, (ii) characterize oestrous cyclicity in transgenic versus wild-type female mice, and (iii) correlate corticosterone concentrations with transgene expression and reproductive performance. Transgenic and wild-type female mice were allocated randomly to one of four treatment groups at weaning: (i) transgenic female mice that always express the transgene, (ii) transgenic female mice that never express the transgene, (iii) transgenic female mice that express the transgene for up to 8 weeks of age and (iv) non-transgenic wild-type female mice receiving the transgene stimulus until 8 weeks of age. Activation followed by inactivation of the transgene resulted in an increased incidence of remating, resulting in an extended interval to establish pregnancy in comparison with all other treatment groups. Transgenic mice that always expressed the transgene and those that expressed the transgene for up to 8 weeks of age had lower pregnancy rates and higher ovulation rates compared with mice from other treatment groups. Both embryonic survival and the duration of the oestrous cycle did not differ among treatment groups. Active expression of the transgene resulted in an increase in the plasma concentration of corticosterone, which was associated with reduced fertility. These data indicate that the presence of a high growth hormone concentration impedes the establishment and maintenance of pregnancy. Increased plasma corticosterone concentrations may interfere with implantation as well as potentiate leptin resistance, which has been reported previously in studies with these mice.

Segregation ratios and growth rate in inactive ovine metallothionein 1a-ovine growth hormone transgenic mice

Objectives were to determine whether the oMt1a-oGH transgene shows normal Mendelian segregation and whether oMt1a-oGH mice exhibit normal growth without the zinc supplementation required to increase plasma oGH levels and stimulate growth. Transgenic mice were reciprocally backcrossed for four generations to high growth and control lines to form lines GM and GR, respectively. In the fifth generation, hemizygous transgenic mice (T/-) were crossed within each line. Pooled across backcross generations, there was a deficit (P < 0.001) of T/- progeny in lines GM (31.6%) and GR (22.2%) compared with expected (50%). In the T/- x T/- cross, the combined percentage of homozygous (T/T) and hemizygous transgenic mice was less (P < 0.001) than expected (75%) in both GM (44.2%) and GR (38.5%). Backcross T/- mice had lower (P < 0.05) 3-wk BW and lower (P < 0.001) 6-wk BW and 3- to 6-wk postweaning gains than nontransgenic mice. Similar genotypic differences were found in the T/- x T/- cross. No significant growth differences were found between T/T and T/- progeny. Using segregation ratios from the T/- x T/- mating, the relative fitness estimates of T/T, T/-, and -/- (nontransgenic) mice were 0.345, 0.223, and 1.0, respectively, in line GM and 0.218, 0.205, and 1.0 in line GR. Fitness estimates in the back-cross for T/- and -/- were 0.463 and 1.0 in line GM and 0.285 and 1.0 in line GR. Abnormal segregation ratios may be due to germline mosaicism or reduced fitness due to differential embryo survival. Reduced growth of oMt1a-oGH transgenic mice when the transgene is switched off suggests a subtle developmental abnormality, which may contribute to a reduction in fitness.

Calciphylaxis, a poorly understood clinical syndrome: three case reports and a review of the literature

Systemic calcification syndromes are a recognized complication occurring in some patients with end-stage renal disease (ESRD) and secondary hyperparathyroidism. These patients develop severe livedo reticularis and subcutaneous tissue lesions progressing to frank necrosis and ultimately large areas of eschar. Clinically this syndrome is known as calciphylaxis; these lesions are usually resistant to aggressive debridement, systemic antibiotics, and revascularization procedures. We report three patients with somewhat different clinical presentations but all sharing a common link of exquisitely painful leg ulcers initially being treated as ischemic lesions or venous stasis-type ulcerations. These three patients were diagnosed with calciphylaxis on the basis of clinical, biochemical, and histopathological criteria. Two patients underwent parathyroidectomy late in the progression of their disease, with some resolution of their ulcerative lesions.

A quantitative model for the dynamics of serum prostate-specific antigen as a marker for cancerous growth: an explanation for a medical anomaly

Prostate-specific antigen (PSA) is an enzyme produced by both normal and cancerous prostate epithelial cells. Although PSA is the most widely used serum marker to detect and follow patients with prostatic adenocarcinoma, there are certain anomalies in the values of serum levels of PSA that are not understood. We developed a mathematical model for the dynamics of serum levels of PSA as a function of the tumor volume. Our model results show good agreement with experimental observations and provide an explanation for the existence of significant prostatic tumor mass despite a low-serum PSA. This result can be very useful in enhancing the use of serum PSA levels as a marker for cancer growth.

Ciliary neurotrophic factor activates leptin-like pathways and reduces body fat, without cachexia or rebound weight gain, even in leptin-resistant obesity

Ciliary Neurotrophic Factor (CNTF) was first characterized as a trophic factor for motor neurons in the ciliary ganglion and spinal cord, leading to its evaluation in humans suffering from motor neuron disease. In these trials, CNTF caused unexpected and substantial weight loss, raising concerns that it might produce cachectic-like effects. Countering this possibility was the suggestion that CNTF was working via a leptin-like mechanism to cause weight loss, based on the findings that CNTF acts via receptors that are not only related to leptin receptors, but also similarly distributed within hypothalamic nuclei involved in feeding. However, although CNTF mimics the ability of leptin to cause fat loss in mice that are obese because of genetic deficiency of leptin (ob/ob mice), CNTF is also effective in diet-induced obesity models that are more representative of human obesity, and which are resistant to leptin. This discordance again raised the possibility that CNTF might be acting via nonleptin pathways, perhaps more analogous to those activated by cachectic cytokines. Arguing strongly against this possibility, we now show that CNTF can activate hypothalamic leptin-like pathways in diet-induced obesity models unresponsive to leptin, that CNTF improves prediabetic parameters in these models, and that CNTF acts very differently than the prototypical cachectic cytokine, IL-1. Further analyses of hypothalamic signaling reveals that CNTF can suppress food intake without triggering hunger signals or associated stress responses that are otherwise associated with food deprivation; thus, unlike forced dieting, cessation of CNTF treatment does not result in binge overeating and immediate rebound weight gain.