Sustained leukaemic phenotype after inactivation of BCR-ABLp190 in mice.

Pharmacological inactivation of cancer genes or products is being used as a strategy for therapy in oncology. To investigate the potential role of BCR-ABLp190 cessation in leukaemia development, we generated mice carrying a tetracycline-repressible BCR-ABLp190 transgene. These mice were morphologically normal at birth, and developed leukaemias. Disease was characterized by the presence of B-cell blasts co-expressing myeloid markers, reminiscent of the human counterpart. BCR-ABLp190 activation can initiate leukaemia in both young and adult mice. Transitory expression of BCR-ABLp190 is enough to develop leukaemia. Suppression of the BCR-ABLp190 transgene in leukaemic CombitTA-p190 mice did not rescue the malignant phenotype, indicating that BCR-ABLp190 is not required to maintain the disease in mice. Similar results were obtained by inactivation of BCR-ABLp190 with STI571 (Gleevec; Novartis, East Hanover, NJ, USA) in leukaemic CombitTA-p190 mice. However, gradual suppression of BCR-ABLp190 in leukaemic CombitTA-p190 mice identified a minimum level of BCR-ABLp190 expression necessary to revert the specific block in B-cell differentiation in the leukaemic cells. Overall, the findings indicate that BCR-ABLp190 appears to cause epigenetic and/or genetic changes in tumour-maintaining cells that render them insensitive to BCR-ABLp190 inactivation.

Factors from damaged sperm affect its DNA integrity and its ability to promote embryo implantation in mice.

Endogenous nucleases in mouse sperm can be activated by freeze-thawing the spermatozoa in media without cryoprotection and cleaving spermatozoa DNA. The role of sperm chromatin integrity during intracytoplasmic sperm injection (ICSI) is of critical importance. We analyzed in the B6D2 mouse the proportion of DNA-fragmented spermatozoa (DFS) produced by incubation in conditioned medium (CM) generated by freeze-thawing sperm in the absence of cryoprotection. We then examined the subsequent development, implantation, and offspring obtained after ICSI with incubated spermatozoa. When fresh sperm cells were incubated for 90 minutes in this CM, a significant increase in the amount of DFS was detected by the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay (27% vs 4.5% in fresh sperm). After ICSI of fresh and incubated spermatozoa, embryos were cultured in vitro to either the 2-cell or blastocyst stage before they were transferred into pseudopregnant CD1 females. On day 14, recipients were sacrificed, and implantation rates, estimated as the number of live fetuses plus resorptions, were determined. When ICSI was performed with sperm incubated in CM, no effects on fertilization, embryo cleavage, blastocyst rate, or blastocyst morphology were detected; however, the quality of the embryos was affected because the total implantation rate decreased significantly (P < .05) when 2-cell embryos or blastocysts were transferred. Independently of sperm pretreatment, in vitro cultures significantly affected the percentage of live fetuses present on day 14 of pregnancy. These results demonstrated that there are factors released from fragmented spermatozoa capable of inducing DNA fragmentation in intact sperm that may compromise, to some extent, birth rates after ICSI.

Engineering passive immunity in transgenic mice secreting virus-neutralizing antibodies in milk.

Protection against enteric infections can be provided by the oral administration of pathogen-neutralizing antibodies. To provide passive immunity, 18 lines of transgenic mice secreting a recombinant monoclonal antibody (Mab) neutralizing transmissible gastroenteritis coronavirus (TGEV) into the milk were generated. The genes encoding a chimeric Mab with the variable modules of the murine TGEV-specific Mab 6A.C3 and the constant modules of a human IgG, isotype Mab were expressed under the control of regulatory sequences derived from the whey acidic protein, which is an abundant milk protein. The Mab 6A.C3 binds to a highly conserved epitope present in coronaviruses of several species, which does not allow the selection of neutralization escape mutants. Antibody expression titers of 10(6) were obtained in the milk of transgenic mice that reduced TGEV infectivity 10(6)-fold. The antibody was synthesized at high levels throughout lactation. Integration of matrix attachment region sequences with the antibody genes led to a 20- to 10,000-fold increase in the antibody titer in 50% of the transgenic animals. Antibody expression levels were transgene copy number independent and related to the site of integration. The generation of transgenic animals producing virus neutralizing antibodies in milk could provide an approach to protection against neonatal infections of the enteric tract.

FELASA guidelines for the production and nomenclature of transgenic rodents.

The standardized nomenclature of rodent strains, genes and mutations has long been the focus of careful attention. Its aim is to provide proper designation of laboratory animals used in research projects and to convey as much information on each strain as possible. Since the development of different techniques to mutate the genome of laboratory rodents on a large scale, the correct application of current nomenclature systems is of increased significance. It facilitates not only the accurate communication of scientific results but is indispensable in controlling the dramatically increased number of transgenic animal models in experimental units, archives and databases. It is regrettable that many publications, especially on transgenic rodents, use vague and inappropriate strain designation. This situation should definitely be improved, particularly considering the increasingly emphasized importance of genetic background on the phenotype of mutations. The aim of these guidelines is to raise awareness about specific features of production and of the current nomenclature system used for transgenic rodents.

SLUG (SNAI2) overexpression in embryonic development.

The Snail-related zinc-finger transcription factor, SLUG (SNAI2), is critical for the normal development of neural crest-derived cells and loss-of-function SLUG mutations have been proven to cause piebaldism and Waardenburg syndrome type 2 in a dose-dependent fashion. However, little is known about the consequences of SLUG overexpression in embryonic development. We report SLUG duplication in a child with a unique de novo 8q11.2-->q13.3 duplication associated with tetralogy of Fallot, submucous cleft palate, renal anomalies, hypotonia and developmental delay. To investigate the effects of Slug overexpression on development, we analyzed mice carrying a Slug transgene. These mice were morphologically normal at birth, inferring that Slug overexpression is not sufficient to cause overt morphogenetic defects. In the adult mice, there was a 20% incidence of sudden death, cardiomegaly and cardiac failure associated with incipient mesenchymal tumorigenesis. These findings, while not directly implicating Slug in congenital and acquired heart disease, raise the possibility that Slug overexpression may contribute to specific cardiac phenotypes and cancer development.

Developmental consequences of sexual dimorphism during pre-implantation embryonic development.

Abnormalities of development potential arising from pre-implantation environment are not limited to in vitro culture (IVC) (for, i.e. in ruminants the large offspring syndrome produced by IVC), they may also be consequence of specific stress conditions experienced in vivo, like maternal diet, toxins, etc. A complex group of mechanisms (gene expression, epigenetic, metabolic, etc.) may operate to link early embryo environment with future health. Furthermore, during the pre-implantation period, in vitro produced male embryos have a higher metabolic rate, they grow faster than females, and they also have differential gene transcription of genes located in the Y-, X-, or in autosomal-chromosomes. As a consequence of these differences embryos may be affected differentially by natural or artificial environmental conditions, depending on their gender. It has been suggested that under some stress conditions male embryos are more vulnerable than females; however the biological fragility of male embryos is poorly understood. Evidences suggest that epigenetic differences produced by the presence of one or two X-chromosomes are the principal cause of the male and female pre-implantation differences, and we put forward the possible role of these early sex differences to control sex ratio of the offspring under different environmental conditions in Nature. By following the differences between male and female early embryos not only may be possible to manipulate sex ratio in farm animals, we can also gain further insight into aspects of early embryo development, X inactivation, and epigenetic and genetic processes related with early development that may have a long-term effect on the offspring.

Liposarcoma initiated by FUS/TLS-CHOP: the FUS/TLS domain plays a critical role in the pathogenesis of liposarcoma.

The most common chromosomal translocation in liposarcomas, t(12;16)(q13;p11), creates the FUS/TLS-CHOP fusion gene. We previously developed a mouse model of liposarcoma by expressing FUS-CHOP in murine mesenchymal stem cells. In order to understand how FUS-CHOP can initiate liposarcoma, we have now generated transgenic mice expressing altered forms of the FUS-CHOP protein. Transgenic mice expressing high levels of CHOP, which lacks the FUS domain, do not develop any tumor despite its tumorigenicity in vitro and widespread activity of the EF1alpha promoter. These animals consistently show the accumulation of a glycoprotein material within the terminally differentiated adipocytes, a characteristic figure of liposarcomas associated with FUS-CHOP. On the contrary, transgenic mice expressing the altered form of FUS-CHOP created by the in frame fusion of the FUS domain to the carboxy end of CHOP (CHOP-FUS) developed liposarcomas. No tumors of other tissues were found in these transgenic mice despite widespread activity of the EF1alpha promoter. The characteristics of the liposarcomas arising in the CHOP-FUS mice were very similar to those previously observed in our FUS-CHOP transgenic mice indicating that the FUS domain is required not only for transformation but also influences the phenotype of the tumor cells. These results provide evidence that the FUS domain of FUS-CHOP plays a specific and critical role in the pathogenesis of liposarcoma.

The chimeric FUS/TLS-CHOP fusion protein specifically induces liposarcomas in transgenic mice.

The characteristic t(12;16)(q13;p11) chromosomal translocation, which leads to gene fusion that encodes the FUS-CHOP chimeric protein, is associated with human liposarcomas. The altered expression of FUS-CHOP has been implicated in a characteristic subgroup of human liposarcomas. We have introduced the FUS-CHOP transgene into the mouse genome in which the expression of the transgene is successfully driven by the elongation factor 1alpha (EF1alpha) promoter to all tissues. The consequent overexpression of FUS-CHOP results in most of the symptoms of human liposarcomas, including the presence of lipoblasts with round nuclei, accumulation of intracellular lipid, induction of adipocyte-specific genes and a concordant block in the differentiation program. We have demonstrated that liposarcomas in the FUS-CHOP transgenic mice express high levels of the adipocyte regulatory protein PPARgamma, whereas it is not expressed in embryonic fibroblasts from these animals following induction to differentiation toward the adipocyte lineage, indicating that the in vitro system does not really reflect the in vivo situation and the developmental defect is downstream of PPARgamma expression. No tumors of other tissues were found in these transgenic mice despite widespread activity of the EF1alpha promoter. This establishes FUS-CHOP overexpression as a key determinant of human liposarcomas and provide the first in vivo evidence for a link between a fusion gene created by a chromosomal translocation and a solid tumor.

Different behavior toward bovine spongiform encephalopathy infection of bovine prion protein transgenic mice with one extra repeat octapeptide insert mutation.

In humans, insert mutations within the repetitive octapeptide region of the prion protein gene (Prnp) are often associated with familial spongiform encephalopathies. In this study, transgenic mice expressing bovine PrP (boTg mice) bearing an additional octapeptide insertion to the wild type (seven octapeptide repeats instead of six) showed an altered course of bovine spongiform encephalopathy (BSE) infection, reflected as reduced incubation times when compared with boTg mice expressing similar levels of the wild-type six-octapeptide protein. In both boTg mouse lines (bo6ORTg and bo7ORTg), incubation times were affected drastically depending on transgene expression levels and the inoculum used. In accordance with the lack of an interspecies barrier to BSE infection, we detected the typical signs of CNS spongiform degeneration by histopathological analysis and the presence of the bovine prion PrP(res) by Western blot or immunohistochemical analyses. When 7OR-PrP(res) was propagated in bo7ORTg mice, a similar earlier onset of clinical signs was observed compared with bo6ORTg mice. Proteins PrP(C) and PrP(res) containing seven octapeptides (7OR-PrP(C) and 7OR-PrP(res)) showed similar protease sensitivity and insolubility in nondenaturing detergents to homologous 6OR-PrP(C) and 6OR-PrP(res). In addition, bo7ORTg mice showed a higher sensitivity than bo6ORTg mice for detecting prion infection in specimens previously diagnosed as negative by conventional biochemical techniques. In the absence of clinical signs of disease, 7OR-PrP(res) could be detected as early as 120 d after inoculation by immunohistochemical and Western blot analyses. These findings may help us improve the current mouse bioassays and understand the role of the octapeptide repeat region in susceptibility to disease.

Transgenic mice expressing bovine PrP with a four extra repeat octapeptide insert mutation show a spontaneous, non-transmissible, neurodegenerative disease and an expedited course of BSE infection.

Transgenic (Tg) mice carrying four extra octapeptide repeats (OR) in the bovine PrP gene (10OR instead of 6) have been generated. In these mice, neuropathological changes were observed depending upon the level of transgene expression. These changes primarily involved a slowly advancing neurological disorder, characterized clinically by ataxia, and neuropathologically, by vacuolization in different brain areas, gliosis, and loss of cerebellar granule cells. Accumulation of insoluble bovine 10OR-PrP (bo10OR-PrP) was observed depending on the level of expression but no infectivity was found associated with this insoluble form. We also compared the behavior of bo6OR-PrP and bo10OR-PrP Tg mouse lines in response to BSE infection. BSE-inoculated bo10ORTg mice showed an altered course of BSE infection, reflected by reduced incubation times when compared to bo6ORTg mice expressing similar levels of the wild type 6OR-PrP. In BSE-inoculated mice, it was possible to detect PrP(res) in 100% of the animals. While insoluble bo10OR-PrP from non-inoculated bo10ORTg mice was non-infectious, brain homogenates from BSE-inoculated bo10ORTg mice were highly infectious in all the Tg mouse lines tested. This Tg mouse model constitutes a new way of understanding the pathobiology of bovine transmissible spongiform encephalopathy. Its potential applications include the assessment of new therapies against prion diseases.

Transient inhibition of foot-and-mouth disease virus infection of BHK-21 cells by antisense oligonucleotides directed against the second functional initiator AUG.

The antiviral activity of antisense oligonucleotides corresponding to different regions of foot-and-mouth disease virus (FMDV) genome has been assessed in BHK-21 cells. The locations of the oligonucleotides used were: (i) two regions within the internal ribosome entry site (IRES), involved in the regulation of the translation initiation of the viral polyprotein; (ii) each of the two functional initiator AUGs; (iii) an internal sequence of P2A gene; and (iv) a region at the 3' end non-coding region. Cytoplasmic microinjection of oligodeoxyribonucleotides and oligoribonucleotides complementary to the second AUG resulted in a transient inhibition of viral VP1 expression in infected cells. Significant inhibitions, ranging from 35 to 52%, were obtained at 5 h post-infection using oligonucleotide concentrations of 125 microM and higher. The extent and duration of this inhibition seemed to be mediated by both a rapid transport to the nucleus and the short half-life of the oligonucleotide. This inhibition of FMDV protein synthesis was correlated with a reduction of virus yield of about 50%, as observed after the addition to the cell culture of an oligodeoxyribonucleotide phosphorothioate complementary to the second AUG.

Transgenic animal technology.

There are numerous tools available to modify the genetic makeup of animals. They are being used to good advantage for studying basic biological phenomena. Within the decade, biomedical products derived from transgenic animals will be available, but the use of this technology for enhancing the quality and efficiency of livestock production will await further refinements in the technology.

Influence of glucose on the sex ratio of bovine IVM/IVF embryos cultured in vitro.

The effect of glucose in the medium used during in vitro culture on the sex ratio of bovine blastocysts derived from in-vitro-matured and in-vitro-fertilized oocytes was evaluated. Oocytes were matured and inseminated with mixed sperm from three bulls and were cultured in vitro in modified synthetic oviducal fluid medium with 10% fetal calf serum, with or without glucose supplementation. The overall rate of cleaved embryos that developed to expanded blastocyst in the medium without glucose (27.0%) was significantly greater (P < 0.05) than the percentage observed when embryos were cultured in medium with glucose (17.5%). Analysis of variance was performed to analyse the effect of glucose on the proportion of male embryos reaching the blastocyst stage (or arrested at the morula stage) during Days 7 to 10. Regardless of the presence or absence of glucose in the medium, significantly (P < 0.05) more male than female embryos were harvested as expanded blastocysts on Day 7 and on Day 8 of culture. On Days 9 plus 10 of culture, a sex ratio imbalance only occurred in the absence of glucose in the culture medium (P < 0.05). Glucose did not produce any significant effect on the sex ratio of the overall number of expanded blastocysts harvested by Day 10 of in vitro culture. However a significantly greater proportion of females (P < 0.01) were found among those embryos that developed only to the morulae stage after 10 days in vitro. These results show that glucose supplementation of culture media produces a preferential loss of female embryos during culture to the blastocyst stage.

Lactogenic immunity in transgenic mice producing recombinant antibodies neutralizing coronavirus.

Protection against coronavirus infections can be provided by the oral administration of virus neutralizing antibodies. To provide lactogenic immunity, eighteen lines of transgenic mice secreting a recombinant IgG1 monoclonal antibody (rIgG1) and ten lines of transgenic mice secreting recombinant IgA monoclonal antibodies (rIgA) neutralizing transmissible gastroenteritis coronavirus (TGEV) into the milk were generated. Genes encoding the light and heavy chains of monoclonal antibody (MAb) 6A.C3 were expressed under the control of regulatory sequences derived from the mouse genomic DNA encoding the whey acidic protein (WAP) and beta-lactoglobulin (BLG), which are highly abundant milk proteins. The MAb 6A.C3 binds to a highly conserved epitope present in coronaviruses of several species. This MAb does not allow the selection of neutralization escaping virus mutants. The antibody was expressed in the milk of transgenic mice with titers of one million as determined by RIA, and neutralized TGEV infectivity by one million fold corresponding to immunoglobulin concentrations of 5 to 6 mg per ml. Matrix attachment regions (MAR) sequences were not essential for rIgG1 transgene expression, but co-microinjection of MAR and antibody genes led to a twenty to ten thousand-fold increase in the antibody titer in 50% of the rIgG1 transgenic animals generated. Co-microinjection of the genomic BLG gene with rIgA light and heavy chain genes led to the generation of transgenic mice carrying the three transgenes. The highest antibody titers were produced by transgenic mice that had integrated the antibody and BLG genes, although the number of transgenic animals generated does not allow a definitive conclusion on the enhancing effect of BLG co-integration. Antibody expression levels were transgene copy number independent and integration site dependent. The generation of transgenic animals producing virus neutralizing antibodies in the milk could be a general approach to provide protection against neonatal infections of the enteric tract.

Superovulatory response of Murciana goats to treatments based on PMSG/Anti-PMSG or combined FSH/PMSG administration.

Superovulation in goats is frequently restricted by the cost of gonadotropin or the handling requirements. In this situation PMSG has the advantage of a lower cost and single dose protocol, but the variability of response obtained restricts its use. Thus, 2 alternative treatments with the advantages of PMSG were tested. In Experiment 1, we compared the ovulatory response of does treated with PMSG in combination or not with anti-PMSG antibodies at the onset of estrus, during season and out of season. In Experiment 2, we explored the effect of a partial substitution of FSH by PMSG at the end of treatment, comparing this treatment with a standard FSH protocol. Our results showed a significant (P < 0.01) seasonal effect on the incidence of corpora lutea (CL) regression in both experiments. The mean of viable embryos collected from does treated with anti-PMSG antibodies (mean = 5.75) was significantly higher than in the control PMSG-treated group (mean = 2.74) during spring (P < 0.05). Response during the fall was significantly lower regardless of treatment, and administration of antibody did not provide any significant improvement in superovulatory response (2.14 vs 1.77). In Experiment 2, the partial substitution of 3 doses of FSH by a single administration of PMSG did not reduce the number of CL or viable embryos, and no seasonal differences were observed, confirming that FSH provides a less variable response. From our results, it can be concluded that the use of PMSG antibodies for super-ovulating goats is an efficacious treatment which increases the number of viable embryos collected. However, partial replacement of FSH with PMSG at the end of treatment also did not compromise the number of embryos collected. Both approaches can be considered a valid alternative to treatments based on FSH.

In vitro survival of murine morulae after quick freezing in the presence of chemically defined macromolecules and different cryoprotectants.

We studied the ability of frozen-thawed mouse morulae to develop in vitro when the cryoprotectant proteins were substituted with one of the following nonorganic macromolecules: polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), and ficoll. We also determined how these agents interacted with 3 different cryoprotectants: glycerol (GLY), propylene glycol (PG), and ethylene glycol (EG). The influence of both of the above factors was measured on the basis of post-thaw morphological appearance, the percentage of development to the expanded blastocyst stage and the total cell count. Morulae (n=950) were collected from superovulated mice. Those classified as good or excellent were distributed among the 12 different freezing solutions, obtained by combining the 3 cryoprotectants with the 4 macromolecules (the 3 mentioned above, plus a control of 5% fetal calf serum) in phosphate buffered saline (PBS). Embryos frozen in PVA, PVP and ficoll tended to be a little difficult to recover from the straws. Development to the expanded blastocyst stage was significantly lower (P<0.05) in propylene glycol (43.6%) than in ethylene glycol (79.5%) or in glycerol (76.1%). Polyvinyl alcohol provided a higher survival rate when combined with glycerol (90.3) or ethylene glycol (95.0), but when it was combined with propylene glycol, only 56.5% of embryos survived after thawing. A positive interaction was observed between glycerol and PVA and between ethylene glycol and PVA or ficoll. The results indicate that fetal serum could be successfully substituted for any of the 3 chemically defined macromolecules. However, our findings also suggest that the use of PG as a cryoprotectant should be avoided when mouse morulae are frozen using the quick freezing method.

Comparison of superovulatory response of mature outbred mice treated with FSH or PMSG and developmental potential of embryos produced.

A superovulatory treatment for mice based on FSH administration was compared with a standard one based on PMSG. Our aim was to determine if a mean number of embryos recovered per donor could be increased and if in vitro or in vivo viability was affected by the hormonal treatment used. Thus, female Swiss mice were subjected to 2 superovulatory treatments, and the 1-cell and 2-cell stage embryos were cultured in 2 different media to the blastocyst stage or were transferred to pseudopregnant recipients. The data show that despite a lower mating percentage (52% with FSH vs 66% with PMSG), the FSH-treated mice provided twice the number of total embryos (53.4 vs 24.5) with a similar percentage of morphologically normal embryos (74% for FSH vs 69% for PMSG). We also found that in vitro culture results can be influenced by the source of gonadotropins depending on the culture medium used. A culture medium such as CZB which prevents the 2-cell block, provided the same developmental rates regardless of hormonal treatment used. However, with M-16 medium, which does not prevent this blockage, only 39% of the 2-cell FSH-derived embryos and 49% of the PMSG-derived 2-cell embryos developed into blastocysts (P<0.05). FSH-derived embryos resulted in a higher percentage of pregnant recipients (73 vs 56%) than PMSG-derived embryos, but the number of alive fetuses and the number of implantations per pregnant recipient was affected only by the kind of culture system used before transfer. The results show that FSH can provide very good superovulatory response in mice, thus reducing the number of donors needed for a given experiment and providing embryos of at least the same quality as those derived from the standard PMSG treatment.

Effect of the in vitro culture system on the kinetics of blastocyst development and sex ratio of bovine embryos.

Bovine blastocysts were produced using 6 different systems: 5 commonly used in vitro culture systems (synthetic oviduct fluid medium - SOF- without fetal calf serum, SOF supplemented with 10% serum for the entire culture period, SOF supplemented with 10% serum from Day 4 of culture, M199 coculture with bovine oviduct epithelial cells, M199 coculture with granulosa cell monolayer) and 1 in vivo culture system involving collection of blastocysts from superovulated bovine donors at Day 7. Zygotes obtained from IVM/IVF were assigned randomly to 1 of the 5 systems tested and were cultured for 9 d (Day 0= day of insemination). Cleavage, development to the blastocyst stage and blastocyst sex ratio were assessed in all treatments. In addition, the effect of the IVC system on the kinetics of blastocyst development and sex ratio was assessed on Days 6, 7, 8, and 9. The presence of fetal calf serum in SOF not only resulted in faster development (19.1% of blastocysts in SOF supplemented with serum vs 7.1% in absence of serum at Day 6; P < 0.05) and increased blastocyst production (47.5% of blastocysts in SOF supplemented with serum vs 34.4% in absence of serum; P < 0.05) but it also enhanced overall male survival. The coculture systems produced fewer blastocysts than culture in SOF (27.6 to 28.3% in coculture vs 47.5% in SOF supplemented with serum; P < 0.05), but similar to SOF without fetal calf serum, they had no effect on blastocyst sex ratio.

Behavioral, neurochemical and morphological changes induced by the overexpression of munc18-1a in brain of mice: relevance to schizophrenia.

Overexpression of the mammalian homolog of the unc-18 gene (munc18-1) has been described in the brain of subjects with schizophrenia. Munc18-1 protein is involved in membrane fusion processes, exocytosis and neurotransmitter release. A transgenic mouse strain that overexpresses the protein isoform munc18-1a in the brain was characterized. This animal displays several schizophrenia-related behaviors, supersensitivity to hallucinogenic drugs and deficits in prepulse inhibition that reverse after antipsychotic treatment. Relevant brain areas (that is, cortex and striatum) exhibit reduced expression of dopamine D(1) receptors and dopamine transporters together with enhanced amphetamine-induced in vivo dopamine release. Magnetic resonance imaging demonstrates decreased gray matter volume in the transgenic animal. In conclusion, the mouse overexpressing brain munc18-1a represents a new valid animal model that resembles functional and structural abnormalities in patients with schizophrenia. The animal could provide valuable insights into phenotypic aspects of this psychiatric disorder.

The effect of transport by road and sea on physiology, immunity and behaviour of beef cattle.

The objective of the study was to investigate the physiological, haematological and immunological responses of weanling heifers transported from Ireland to a feedlot in Spain, and of weanling bulls transported from Ireland to a feedlot in Italy. Physiological variables (including interferon-γ production, cortisol, protein, urea, white blood cell numbers and differentials, and acute phase proteins (haptoglobin and fibrinogen) were used to evaluate the welfare status of animals, before, during and after the respective transport journeys. Age-matched control animals were blood sampled for the same measurements at times corresponding to the transported animals that were retained in Ireland. Heifers transported to Spain lost 7.6% of their initial live weight during the sea crossing to France. However, by the time of their arrival in Spain they had regained 3.3% of their initial live weight and had fully recovered to their pre-transport live weight values within 6 days of arriving in Spain. Weanling bulls lost 7.0% of their live weight during the sea crossing from Ireland to France. The live weight loss in control animals ranged from 1% to 2% during the same period. The percentage of time that bulls spent lying was 63.5% for the sea journey and 35.4% for the journey from the French lairage to the Italian feedlot. The average daily gain (kg) of transported animals was greater (P ≤ 0.05) than control animals from day 11 to 38 (Spain) and day 11 to 40 (Italy), respectively. While transient changes in physiological, haematological and immunological variables were found in the transported and control animals relative to baseline levels, the values were within the normal physiological range for the age and weight of animals involved. Physiological measurements made after the road and sea journeys indicated that the 24h rest in the lairage, with hay and water freely available, allowed animals to recover substantially.