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The housing conditions of laboratory mice must be strictly controlled in order to reduce the impact of pathophysiological changes that affect animal health and welfare, possibly resulting in increased variability within experimental results. One way to improve the activity and survival of laboratory mice is to provide nesting material. The objective of this study was to determine if nest-building quality could be used to detect changes in murine mating behaviour in a rodent facility under controlled conditions. Nesting scores of 847 cages with monogamous pairs from three different genetic backgrounds (129, B6 and BALB/c) of both sexes were correlated with 18 predefined variables. The effects on nest quality were evaluated using descriptive data analysis, correspondence analysis and ordinal logistic model fitting. The results showed a strong relationship between nest quality and nest position. Humidity, genetic background, cage change and the number and age of pups in the cage affected the nest-building scores. The most important indicators were cage change and relative humidity, both of which exerted significant negative effects on nest-building quality. Even though the criteria were well defined, the observer could still influence nest score appraisal. However, in a long-term observational study, observers could improve their assessment by training and acquiring greater experience in score assignment. Nest-building scores are easy to assess in the cage, with little discomfort to the animal. Moreover, the nest score is a valid indicator of the health and well-being of laboratory mice and can provide valuable support in the management of animal facilities.

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The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.

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Neuroinflammation plays a protective role in the brain; however, in neurological diseases such as epilepsy, overactivated neuroinflammation, along with overexpression of inflammatory mediators, can cause neuronal tissue damage, which can trigger seizures due to loss of ionic or neurotransmitter homeostasis. Therefore, we aimed to evaluate mRNA expression levels of proinflammatory cytokines, early growth response factor 3 (Egr3), and GABA A receptors in the hippocampus of naive audiogenic mutant tremor mice, and stimulated tremor mice after a seizure. Gene expression of Il-1ß, Il-6, Tnf-α, Ccl2, Ccl3, Egr3, Gabra1, and Gabra4 from hippocampal samples of naive and stimulated tremor mice were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Relative to resistant mice, Ccl3 gene expression was increased and Il6 was decreased in the hippocampus of naïve tremor mice. Thirty minutes after a seizure, Ccl3 and Il-1ß mRNA expression were decreased (p < 0.0001; p = 0.0034, respectively) while Il6 was increased (p = 0.0052) in stimulated tremor mice, relative to naïve animals. In addition, Egr3, Gabra1, and Gabra4 mRNA expression was decreased in the hippocampus of naive tremor mice, relative to resistant mice, which increased 30 minutes after a seizure (p = 0.0496; p = 0.0447, and p = 0.0011, respectively), relative to naïve animals. In conclusion, overexpression of Ccl3 in the hippocampus of naive tremor mice, followed by downregulation soon after seizure in stimulated tremor mice, could be involved in changes in the blood-brain barrier (BBB) permeability in epilepsy. Il-1ß may be involved in hippocampal downregulation of GABA A receptors of naive tremor mice, characterizing an important mechanism in audiogenic seizures triggering. Hippocampal alterations of proinflammatory cytokines, Egr3, and GABA A receptors in tremor mice reinforce them as an alternative tool to modeling temporal lobe epilepsy.

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COVID-19 causes more than million deaths worldwide. Although much is understood about the immunopathogenesis of the lung disease, a lot remains to be known on the neurological impact of COVID-19. Here, we evaluated immunometabolic changes using astrocytes in vitro and dissected brain areas of SARS-CoV-2 infected Syrian hamsters. We show that SARS-CoV-2 alters proteins of carbon metabolism, glycolysis, and synaptic transmission, many of which are altered in neurological diseases. Real-time respirometry evidenced hyperactivation of glycolysis, further confirmed by metabolomics, with intense consumption of glucose, pyruvate, glutamine, and alpha ketoglutarate. Consistent with glutamine reduction, the blockade of glutaminolysis impaired viral replication and inflammatory response in vitro. SARS-CoV-2 was detected in vivo in hippocampus, cortex, and olfactory bulb of intranasally infected animals. Our data evidence an imbalance in important metabolic molecules and neurotransmitters in infected astrocytes. We suggest this may correlate with the neurological impairment observed during COVID-19, as memory loss, confusion, and cognitive impairment.

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Although laboratory animals experience pain as a necessary component of the objectives of experimental protocols, the level of pain should be minimized through use of an adequate analgesic regimen. The non-steroidal anti-inflammatory drug meloxicam may be beneficial in alleviating post-operative pain in mice, although no regimen has been demonstrated as universally efficacious owing to differences in experimental protocols, strain, sex, and incomplete descriptions of methodology in the literature. The aim of this systematic literature review was to identify potential applications of meloxicam for pain management in experimental mice and to evaluate the general quality of study design. Searches of MEDLINE, Scopus and CAB Direct databases elicited 94 articles published between January 2000 and April 2020 that focused on the analgesic efficacy of meloxicam in the management of momentary or persistent pain in mice. The extracted data showed that most articles were deficient in descriptions of housing, husbandry, group size calculation and humane endpoint criteria, while few described adverse effects of the drug. A wide range of dosages of meloxicam was identified with analgesic efficiencies that varied considerably according to the different models or procedures studied. It was impossible to correlate the extracted data into a single meta-analysis because of the differences in experimental protocols and strains employed, the low representation of female mice in the studies, and incomplete descriptions of the methodology applied. We conclude that meloxicam has potential application for pain management in mice but that the dosage must be adjusted carefully according to the experimental procedures. Moreover, authors must take more care in designing their studies and in describing the methodology employed.

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Well-controlled anesthesia is critical to reducing potential surgical complications and ensuring safe and successful procedures. Respiratory depression, inducing hypoxia, and hypercapnia are adverse effects of injectable anesthesia in laboratory rats. This study aimed to determine the effect of oxygen supply in laboratory rats anesthetized with the combination of ketamine (K) and xylazine (X) plus acepromazine (A) or methadone (Me). The results showed that oxygenation allowed adequate levels of SO2 and paO2, avoiding hypoxemia. However, all anesthetized rats showed respiratory acidosis with low pH and high paCO2 levels, which was not reversed after oxygen administration. The acidosis could be related to hypoventilation due to respiratory depression induced by the XKMe association, as well as absorption atelectasis with the CO2 accumulation during anesthesia. Despite respiratory acidosis, oxygen administration was beneficial for anesthetized rats preventing hypoxemia. This makes it possible to prevent all the metabolic alterations that cause cell death by hypoxia, improving the well-being of anesthetized rats, as well as the quality of the results obtained.

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After analgesic administration, we evaluated general activity in the Open-Field and anxiety-like behavior in the Elevated Plus Maze of vasectomized mice. We divided C57BL/6J male mice into eight groups: saline, three non-operated control groups treated with 10 mg/kg meloxicam, 20 mg/kg tramadol, or both intraperitoneally, and four vasectomized mice groups treated with the same analgesic protocol as the control groups. One group of vasectomized mice received both treatments and an additional 10 mg/kg lidocaine at the incision site. We conducted the vasectomy via scrotal approach under isoflurane inhalation anesthesia and performed behavioral tests after full anesthesia recovery. Mice treated with meloxicam demonstrated low ambulation, spontaneous activity, and rearing frequency. Mice treated with tramadol showed spontaneous behavior compared with the saline control. Due to behavior changes demonstrated by meloxicam controls, we were unable to identify whether meloxicam provided adequate analgesia. Vasectomized mice treated with tramadol showed general activity behavior similar to their control but displayed significantly less rearing, suggesting that they were under potential signs of pain or discomfort. In conclusion, the Open Field test and the Elevated Plus Maze can usefully pre-evaluate analgesic protocols to identify possible interference caused by adverse drug effects. For future directions, an appropriate regimen of meloxicam and tramadol for enhancing mice welfare post vasectomy should be better investigated.

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Mouse inoculation test (MIT) is a technique widely used for rabies diagnosis and must be liable to refinement due to animal welfare. The present study aims to compare five different anesthetic associations to stablish a protocol to improve the MIT procedure suitable for animal welfare and safe for a routine of viral isolation in newly weaned mice (3 weeks of age). 80 Swiss-Webster mice (Mus musculus) - 40 females and 40 males, 3-week-old, weight ranging from 11 to 14 grams ­ were used to conduct all procedures. Five anesthetic associations were tested: KX (Ketamine 100 mg/kg and Xylazine 10 mg/kg), KXA (Ketamine 80 mg/kg, Xylazine 5 mg/kg, and Acepromazine 1 mg/kg), KXT (Ketamine 80 mg/kg, Xylazine 5 mg/kg, and Tramadol 5 mg/kg), KXAT (Ketamine 100 mg/kg, Xylazine 10 mg/kg, Acepromazine 2 mg/kg and Tramadol 5 mg/kg) and ATI (Acepromazine 1 mg/kg + Tramadol 5 mg/kg + Isoflurane 5% - 0.5 L/min for induction and 2.5% - 0.5L/min for maintenance). Injectable anesthesia was administered intraperitoneally. We monitored the respiratory rate and body temperature. Response to anesthesia was evaluated according to the induction, surgical anesthesia, and recovery periods. The KXAT and ATI protocols induced surgical anesthesia, with the ATI protocol being the most appropriate and safe to perform the MIT procedure with 100% efficiency, absence of mortality, and rapid recovery of respiratory rate and temperature in the period after the procedure.

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The tremor mutant phenotype results from an autosomal recessive spontaneous mutation arisen in a Swiss–Webster mouse colony. The mutant mice displayed normal development until three weeks of age when they began to present motor impairment comprised by whole body tremor, ataxia, and decreased exploratory behavior. These features increased in severity with aging suggesting a neurodegenerative profile. In parallel, they showed audiogenic generalized clonic seizures. Results from genetic mapping identified the mutation tremor on chromosome 14, in an interval of 5 cM between D14Mit37 (33.21cM) and D14Mit115 (38.21cM), making Early Growth Response 3 (Egr3) the main candidate gene. Comparing with wild type (WT) mice, the tremor mice showed higher hippocampal gene expression of Egr3 and Gabra1 and increased concentrations of noradrenalin (NOR; p=.0012), serotonin (5HT; p=.0083), 5-hydroxyindoleacetic acid (5-HIAA; p=.0032), gama-amino butyric acid (GABA; p=.0123), glutamate (p=.0217) and aspartate (p=.0124). In opposition, the content of glycine (p=.0168) and the vanillylmandelic acid (VMA)/NOR ratio (p=.032) were decreased. Regarding to dopaminergic system, neither dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) contents nor the turnover rate of DA showed statistically significant differences between WT and mutant mice. Data demonstrated that audiogenic seizures of tremor mice are associated with progressive motor impairment as well as to hippocampal alterations of the Egr3 and Gabra1 gene expression and amino acid and monoamine content. In addition, the tremor mice could be useful for study of neurotransmission pathways as modulators of epilepsy and the pathogenesis of epilepsies occurring with generalized clonic seizures.

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Euphorbia tirucalli (E. tirucalli) is a tropical and subtropical plant that produces a latex which is used for several purposes. The components of E. tirucalli latex include triterpenes, diterpenes and steroids. The aim of the present study was to evaluate the effects of diluted E. tirucalli latex on murine B16/F10 melanoma cells and lung metastasis. For this purpose, an in vitro study was first performed, in which B16/F10 cells were treated with diluted (1/2 to 1/11,192) E. tirucalli latex. In a second study, B16/F10 melanoma cells were inoculated into the tail vein of mice to generate lung metastases; the mice then received 0.467 µg of latex diluted in 200 ml saline by gavage for 14 days. A significant decrease in B16/F10 cell viability was observed using the MTT assay at 24 and 48 h after treatment with E. tirucalli latex. In addition, a significant decrease in the volume fraction occupied by B16/F10 metastatic colonies in the lungs was observed in mice treated with E. tirucalli latex. These results confirm the antineoplastic effects of diluted E. tirucalli latex.

RESUMO

Otoconia are crucial for the correct processing of positional information and orientation. Mice lacking otoconia cannot sense the direction of the gravity vector and cannot swim properly. This study aims to characterize the behavior of mergulhador (mlh), otoconia-deficient mutant mice. Additionally, the central catecholamine levels were evaluated to investigate possible correlations between behaviors and central neurotransmitters. A sequence of behavioral tests was used to evaluate the parameters related to the general activity, sensory nervous system, psychomotor system, and autonomous nervous system, in addition to measuring the acquisition of spatial and declarative memory, anxiety-like behavior, motor coordination, and swimming behavior of the mlh mutant mice. As well, the neurotransmitter levels in the cerebellum, striatum, frontal cortex, and hippocampus were measured. Relative to BALB/c mice, the mutant mlh mice showed 1) reduced locomotor and rearing behavior, increased auricular and touch reflexes, decreased motor coordination and increased micturition; 2) decreased responses in the T-maze and aversive wooden beam tests; 3) increased time of immobility in the tail suspension test; 4) no effects in the elevated plus maze or object recognition test; 5) an inability to swim; and 6) reduced turnover of dopaminergic system in the cerebellum, striatum, and frontal cortex. Thus, in our mlh mutant mice, otoconia deficiency reduced the motor, sensory and spatial learning behaviors likely by impairing balance. We did not rule out the role of the dopaminergic system in all behavioral deficits of the mlh mutant mice.

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The introduction of new strains of mice in specific pathogen-free (SPF) animal facilities should be performed carefully to avoid breaking sanitary barriers. To meet this need, animals should be rederived to reduce infection risk and thus avoid research interference caused by loss of animal health status and welfare. The objective of this study was to implement mice embryo transfer in the laboratory mouse facility of the Department of Immunology at the Institute of Biomedical Sciences/University of São Paulo, Brazil. Embryo transfers were performed to rederive genetically modified mouse strains with undefined sanitary status, received from different research and educational institutions. Fertilized eggs at two-cell stage were obtained by natural means and transferred into the oviducts of SPF pseudo-pregnant female mice. All surgical procedures were performed under aseptic conditions. A total of 625 embryos were transferred into therecipients. 148 pups were born, of which 140 were reared. Viruses, bacteria and intestinal protozoa were eliminated using this technique. The improvement in the microbiological status of mice allowed their expansion in our SPF facility. With these results, we can stimulate the use of embryo transfer technique between rodent facilities in Brazil and thus encourage the distribution of better models to our scientific community.

A introdução de novas linhagens de camundongos em biotérios livres de patógenos específicos (SPF) deve ser realizada com critérios para evitar a quebra das barreiras sanitárias. Dessa forma, os animais devem ser rederivados para reduzir os riscos de infecção e evitar as interferências provocadas pela perda do status sanitário e do bem-estar dos animais. O objetivo deste estudo foi implementar a transferência de embriões murinos no Biotério do Departamento de Imunologia do Instituto de Ciências Biomédicas da Universidade de São Paulo, Brasil. As transferências embrionárias foram realizadas para rederivar linhagens de camundongos geneticamente modificadas com status sanitário não conhecido, recebidas de diferentes instituições de pesquisa e de ensino. Os embriões em duas células foram obtidos pelos métodos naturais e transferidos para os ovidutos de fêmeas de camundongos SPF pseudoprenhas. Todos os procedimentos cirúrgicos foramrealizados sob condições assépticas. Um total de 625 embriões foram transferidos para as receptoras. Foram obtidos 148 filhotes nascidos vivos, destes 140 foram desmamados. Por meio desta técnica, foram eliminados vírus, bactérias e protozoários intestinais. A melhora no status microbiológico dos camundongos permitiu a expansão destes em nossa colônia SPF. Com esses resultados, podemos promover o uso da técnica de transferência de embriões entre os biotéri

RESUMO

The introduction of new strains of mice in specific pathogen-free (SPF) animal facilities should be performed carefully to avoid breaking sanitary barriers. To meet this need, animals should be rederived to reduce infection risk and thus avoid research interference caused by loss of animal health status and welfare. The objective of this study was to implement mice embryo transfer in the laboratory mouse facility of the Department of Immunology at the Institute of Biomedical Sciences/University of São Paulo, Brazil. Embryo transfers were performed to rederive genetically modified mouse strains with undefined sanitary status, received from different research and educational institutions. Fertilized eggs at two-cell stage were obtained by natural means and transferred into the oviducts of SPF pseudo-pregnant female mice. All surgical procedures were performed under aseptic conditions. A total of 625 embryos were transferred into the recipients. 148 pups were born, of which 140 were reared. Viruses, bacteria and intestinal protozoa were eliminated using this technique. The improvement in the microbiological status of mice allowed their expansion in our SPF facility. With these results, we can stimulate the use of embryo transfer technique between rodent facilities in Brazil and thus encourage the distribution of better models to our scientific community.(AU)

A introdução de novas linhagens de camundongos em biotérios livres de patógenos específicos (SPF) deve ser realizada com critérios para evitar a quebra das barreiras sanitárias. Dessa forma, os animais devem ser rederivados para reduzir os riscos de infecção e evitar as interferências provocadas pela perda do status sanitário e do bem-estar dos animais. O objetivo deste estudo foi implementar a transferência de embriões murinos no Biotério do Departamento de Imunologia do Instituto de Ciências Biomédicas da Universidade de São Paulo, Brasil. As transferências embrionárias foram realizadas para rederivar linhagens de camundongos geneticamente modificadas com status sanitário não conhecido, recebidas de diferentes instituições de pesquisa e de ensino. Os embriões em duas células foram obtidos pelos métodos naturais e transferidos para os ovidutos de fêmeas de camundongos SPF pseudoprenhas. Todos os procedimentos cirúrgicos foram realizados sob condições assépticas. Um total de 625 embriões foram transferidos para as receptoras. Foram obtidos 148 filhotes nascidos vivos, destes 140 foram desmamados. Por meio desta técnica, foram eliminados vírus, bactérias e protozoários intestinais. A melhora no status microbiológico dos camundongos permitiu a expansão destes em nossa colônia SPF. Com esses resultados, podemos promover o uso da técnica de transferência de embriões entre os biotérios brasileiros e assim incentivar a distribuição de modelos mais adequados para a nossa comunidade científica.(AU)

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A Ciência de Animais de Laboratório envolve uma abordagem multi-disciplinar com conhecimento do modelo animal e suas necessidades etológicas espécie-específicas, refinamento de experimentos que melhoram o bem-estar animal com reconhecimento e tratamento da dor, anestesia e eutanásia, bem como delineamento experimental e análise estatística dos resultados experimentais. Para atender à essas necessidades, pessoas que realizam, participam, supervisionam procedimentos experimentais em animais, ou cuidam de animais de laboratório, devem receber treinamento, com programas voltados à implementação dos 3Rs e promoção do bem-estar dos animais de laboratório, garantindo assim a qualidade e reprodutibilidade de experimentos com benefícios éticos, científicos e econômicos. Nos países da Europa e nos Estados Unidos, e requerido mais recen-temente pelo Conselho Nacional de Controle de Experimentação Animal (CONCEA) no Brasil, um veterinário com experiência em medicina de animais de laboratório precisa fazer parte da equipe do Biotério. Este veterinário tem um papel fundamental na orientação de profissionais e pesquisadores em questões relacionadas ao bem--estar e cuidado com animais. Diante desta recomendação, fica clara a importância da formação de graduação e de médicos-veterinários para atuar na área de Animais de Laboratório, e poder desempenhar seu papel nos biotérios visando melhorar o cuidado e apoiar estudos experimentais que envolvem esses animais.(AU)

Laboratory Animal Science requires a multidisciplinary approach. Professionals working with laboratory animals should have the knowledge on how to choose the right animal model and its species-specific ethological needs, how to choose the best anesthesia, analgesia and euthanasia protocol, how to refine the care procedures including recognition and treatment of pain in order to improve the animals welfare , as well as how to design an experimental and to conduct statistical analysis of the experimental data. To meet these needs, professionals who perform, take part, supervise experimental procedures on animals, or take care of laboratory animals, should receive training, with programs aimed to implement the 3Rs and to promote the welfare of laboratory animals, and therefore guarantee the quality and reproducibility of experiments with ethical, scientific and economic benefits. Veterinarians with experience in laboratory animal medicine are required to be part of the Animal Facility staff in Europe and in the United States, and most recently, in Brazil, established by the National Council for the Control of Animal Experimentation (Concea). Veterinarians working with laboratory animals have a key role in guiding other professionals and researchers regarding issues related to animal welfare and care. Since it is necessary to follow the Concea recommendation, it is visible the importance to have the veterinary undergraduate students and veterinarians properly trained in order to provide the best quality of life for the animals used in research and consequently having relevant, translatable scientific data and the most beneficial use of these animals.(AU)

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A Ciência de Animais de Laboratório envolve uma abordagem multi-disciplinar com conhecimento do modelo animal e suas necessidades etológicas espécie-específicas, refinamento de experimentos que melhoram o bem-estar animal com reconhecimento e tratamento da dor, anestesia e eutanásia, bem como delineamento experimental e análise estatística dos resultados experimentais. Para atender à essas necessidades, pessoas que realizam, participam, supervisionam procedimentos experimentais em animais, ou cuidam de animais de laboratório, devem receber treinamento, com programas voltados à implementação dos 3Rs e promoção do bem-estar dos animais de laboratório, garantindo assim a qualidade e reprodutibilidade de experimentos com benefícios éticos, científicos e econômicos. Nos países da Europa e nos Estados Unidos, e requerido mais recen-temente pelo Conselho Nacional de Controle de Experimentação Animal (CONCEA) no Brasil, um veterinário com experiência em medicina de animais de laboratório precisa fazer parte da equipe do Biotério. Este veterinário tem um papel fundamental na orientação de profissionais e pesquisadores em questões relacionadas ao bem--estar e cuidado com animais. Diante desta recomendação, fica clara a importância da formação de graduação e de médicos-veterinários para atuar na área de Animais de Laboratório, e poder desempenhar seu papel nos biotérios visando melhorar o cuidado e apoiar estudos experimentais que envolvem esses animais.

Laboratory Animal Science requires a multidisciplinary approach. Professionals working with laboratory animals should have the knowledge on how to choose the right animal model and its species-specific ethological needs, how to choose the best anesthesia, analgesia and euthanasia protocol, how to refine the care procedures including recognition and treatment of pain in order to improve the animals welfare , as well as how to design an experimental and to conduct statistical analysis of the experimental data. To meet these needs, professionals who perform, take part, supervise experimental procedures on animals, or take care of laboratory animals, should receive training, with programs aimed to implement the 3Rs and to promote the welfare of laboratory animals, and therefore guarantee the quality and reproducibility of experiments with ethical, scientific and economic benefits. Veterinarians with experience in laboratory animal medicine are required to be part of the Animal Facility staff in Europe and in the United States, and most recently, in Brazil, established by the National Council for the Control of Animal Experimentation (Concea). Veterinarians working with laboratory animals have a key role in guiding other professionals and researchers regarding issues related to animal welfare and care. Since it is necessary to follow the Concea recommendation, it is visible the importance to have the veterinary undergraduate students and veterinarians properly trained in order to provide the best quality of life for the animals used in research and consequently having relevant, translatable scientific data and the most beneficial use of these animals.

Assuntos

RESUMO

The introduction of new strains of mice in specific pathogen-free (SPF) animal facilities should be performed carefully to avoid breaking sanitary barriers. To meet this need, animals should be rederived to reduce infection risk and thus avoid research interference caused by loss of animal health status and welfare. The objective of this study was to implement mice embryo transfer in the laboratory mouse facility of the Department of Immunology at the Institute of Biomedical Sciences/University of São Paulo, Brazil. Embryo transfers were performed to rederive genetically modified mouse strains with undefined sanitary status, received from different research and educational institutions. Fertilized eggs at two-cell stage were obtained by natural means and transferred into the oviducts of SPF pseudo-pregnant female mice. All surgical procedures were performed under aseptic conditions. A total of 625 embryos were transferred into the recipients. 148 pups were born, of which 140 were reared. Viruses, bacteria and intestinal protozoa were eliminated using this technique. The improvement in the microbiological status of mice allowed their expansion in our SPF facility. With these results, we can stimulate the use of embryo transfer technique between rodent facilities in Brazil and thus encourage the distribution of better models to our scientific community.(AU)

A introdução de novas linhagens de camundongos em biotérios livres de patógenos específicos (SPF) deve ser realizada com critérios para evitar a quebra das barreiras sanitárias. Dessa forma, os animais devem ser rederivados para reduzir os riscos de infecção e evitar as interferências provocadas pela perda do status sanitário e do bem-estar dos animais. O objetivo deste estudo foi implementar a transferência de embriões murinos no Biotério do Departamento de Imunologia do Instituto de Ciências Biomédicas da Universidade de São Paulo, Brasil. As transferências embrionárias foram realizadas para rederivar linhagens de camundongos geneticamente modificadas com status sanitário não conhecido, recebidas de diferentes instituições de pesquisa e de ensino. Os embriões em duas células foram obtidos pelos métodos naturais e transferidos para os ovidutos de fêmeas de camundongos SPF pseudoprenhas. Todos os procedimentos cirúrgicos foram realizados sob condições assépticas. Um total de 625 embriões foram transferidos para as receptoras. Foram obtidos 148 filhotes nascidos vivos, destes 140 foram desmamados. Por meio desta técnica, foram eliminados vírus, bactérias e protozoários intestinais. A melhora no status microbiológico dos camundongos permitiu a expansão destes em nossa colônia SPF. Com esses resultados, podemos promover o uso da técnica de transferência de embriões entre os biotérios brasileiros e assim incentivar a distribuição de modelos mais adequados para a nossa comunidade científica.(AU)

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Recentemente, os programas de enriquecimento ambiental em biotérios têm sido amplamente discutidos. Muitos estudos, ao longo dos anos, procuraram esclarecer se as diferentes estratégias de enriquecimento ambiental (EA) podem afetar o comportamento e a fisiologia de roedores de laboratório, sendo que a maioria dos autores reconheceu o efeito positivo do EA para a melhora da qualidade de vida dos animais utilizados na experimentação. Neste trabalho foram realizados dois experimentos com o objetivo de avaliar o impacto do EA e do tipo de cama no desempenho reprodutivo e no comportamento maternal de ratas Wistar, bem como no desenvolvimento físico de sua prole. Para isto as ratas foram distribuídas em três grupos: EA-S (enriquecido com cama de sabugo de milho), EA-M (enriquecido com cama de maravalha) e NE-M (não enriquecido com cama de maravalha). Os resultados demonstraram que não houve diferença no intervalo entre partos, número de filhotes nascidos e desmamados nos três grupos avaliados, sendo que esses dados foram semelhantes aos descritos na literatura para ratos Wistar. Também não foi observada diferença estatística no comportamento maternal; no entanto no desenvolvimento físico observou-se antecipação no desdobramento das orelhas, erupção dos dentes incisivos e descida dos testículos dos filhotes do grupo EA-S; além do que as ratas dos grupos expostos ao EA confeccionaram ninhos mais íntegros e de melhor qualidade. Esses resultados reforçam a importância de se fornecer EA, como material de ninho, para que as mães criem seu próprio microambiente, e assim, possam oferecer melhor conforto e bem-estar aos seus filhotes.(AU)

Recently, environmental enrichment (EA) programs in laboratory animal facilities have been widely discussed. Many studies over the years have sought to clarify whether different environmental enrichment strategies may affect the behavior and physiology of laboratory rodents, in which most authors recognized the positive effect of EA for the life of animals used in research. In the present work two experiments were carried out to evaluate the impact of EA and bedding material on the reproductive performance and maternal behavior of Wistar rats, as well as the physical development of their offspring. For this, the rats were divided into three groups: EA-S (enriched with corn cobs bedding), EA-M (enriched with wood shavings bedding) and NE-M (not enriched with wood shavings bedding). The results showed that there was no difference in the interval between births, and number of pups born and weaned of the three groups evaluated, being these data similar to those described in the literature for Wistar rats. There was also no statistical difference in the maternal behavior; however in the physical development we observed anticipation of pinnae detachment, incisor teeth eruption and testicles descent of the EA-S group pups; in addition the female rats of the groups exposed to EA made more intact nests with better quality. These results reinforce the importance of providing EA, such as nest material, for mothers to create their own microenvironment, thus providing better comfort and well-being for their offspring.(AU)

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Recentemente, os programas de enriquecimento ambiental em biotérios têm sido amplamente discutidos. Muitos estudos, ao longo dos anos, procuraram esclarecer se as diferentes estratégias de enriquecimento ambiental (EA) podem afetar o comportamento e a fisiologia de roedores de laboratório, sendo que a maioria dos autores reconheceu o efeito positivo do EA para a melhora da qualidade de vida dos animais utilizados na experimentação. Neste trabalho foram realizados dois experimentos com o objetivo de avaliar o impacto do EA e do tipo de cama no desempenho reprodutivo e no comportamento maternal de ratas Wistar, bem como no desenvolvimento físico de sua prole. Para isto as ratas foram distribuídas em três grupos: EA-S (enriquecido com cama de sabugo de milho), EA-M (enriquecido com cama de maravalha) e NE-M (não enriquecido com cama de maravalha). Os resultados demonstraram que não houve diferença no intervalo entre partos, número de filhotes nascidos e desmamados nos três grupos avaliados, sendo que esses dados foram semelhantes aos descritos na literatura para ratos Wistar. Também não foi observada diferença estatística no comportamento maternal; no entanto no desenvolvimento físico observou-se antecipação no desdobramento das orelhas, erupção dos dentes incisivos e descida dos testículos dos filhotes do grupo EA-S; além do que as ratas dos grupos expostos ao EA confeccionaram ninhos mais íntegros e de melhor qualidade. Esses resultados reforçam a importância de se fornecer EA, como material de ninho, para que as mães criem seu próprio microambiente, e assim, possam oferecer melhor conforto e bem-estar aos seus filhotes.

Recently, environmental enrichment (EA) programs in laboratory animal facilities have been widely discussed. Many studies over the years have sought to clarify whether different environmental enrichment strategies may affect the behavior and physiology of laboratory rodents, in which most authors recognized the positive effect of EA for the life of animals used in research. In the present work two experiments were carried out to evaluate the impact of EA and bedding material on the reproductive performance and maternal behavior of Wistar rats, as well as the physical development of their offspring. For this, the rats were divided into three groups: EA-S (enriched with corn cobs bedding), EA-M (enriched with wood shavings bedding) and NE-M (not enriched with wood shavings bedding). The results showed that there was no difference in the interval between births, and number of pups born and weaned of the three groups evaluated, being these data similar to those described in the literature for Wistar rats. There was also no statistical difference in the maternal behavior; however in the physical development we observed anticipation of pinnae detachment, incisor teeth eruption and testicles descent of the EA-S group pups; in addition the female rats of the groups exposed to EA made more intact nests with better quality. These results reinforce the importance of providing EA, such as nest material, for mothers to create their own microenvironment, thus providing better comfort and well-being for their offspring.

Assuntos

RESUMO

O camundongo mutante recessivo bate-palmas (bapa) originou-se de mutagênese química induzida por ENU (N-ethyl-N-nitrosourea) e apresenta alterações posturais com movimentos anormais dos membros posteriores quando levantado pela cauda. No sequenciamento do exoma identificou-se uma mutação no gene Kmt2d, localizado no cromossomo 15, que foi confirmada pelo sequenciamento do DNA pelo método de Sanger. A perda da função do gene KMT2D localizada no cromossomo 12 em humanos foi descrita como responsável pela síndrome de Kabuki, que é uma anomalia congênita rara, autossômica dominante. O fenótipo clínico da doença é variável, mas algumas características mais comuns são face dismórfica, anormalidades esqueléticas, alterações nas impressões digitais, leve a moderado retardo mental e retardo do crescimento pós-natal. O presente trabalho teve como objetivo a análise do comportamento e da morfologia craniofacial dos camundongos bapa comparando com modelos de mutação do gene Kmt2d descritos na literatura.(AU)

The recessive mutant mouse named bate-palmas (bapa) claps in Portuguese, originates from an ENU (N-ethyl-N-nitrosourea) mutagenesis program, presenting balance impairment and motor incoordination. Exome sequencing identified a mutation in the KMT2D gene, located on chromosome 15, which was confirmed by DNA sequence by the Sanger method. The loss of function of the gene KMT2D, located on chromosome 12 in humans, was described as being responsible for Kabuki syndrome, also known as Niikawa-Koruki syndrome, which is a rare congenital anomaly, autosomal dominant. The clinical phenotype of the disease is variable, but some common characteristics are dysmorphic facial features, skeletal abnormalities, fingerprint alterations, mild to moderate cognitive problems and postnatal growth retardation. The objective os this study was to analyze the behavior and craniofacial morphology of bapa mice comparing to KMT2D gene mutation models described on literature.(AU)

Assuntos

RESUMO

O camundongo mutante recessivo bate-palmas (bapa) originou-se de mutagênese química induzida por ENU (N-ethyl-N-nitrosourea) e apresenta alterações posturais com movimentos anormais dos membros posteriores quando levantado pela cauda. No sequenciamento do exoma identificou-se uma mutação no gene Kmt2d, localizado no cromossomo 15, que foi confirmada pelo sequenciamento do DNA pelo método de Sanger. A perda da função do gene KMT2D localizada no cromossomo 12 em humanos foi descrita como responsável pela síndrome de Kabuki, que é uma anomalia congênita rara, autossômica dominante. O fenótipo clínico da doença é variável, mas algumas características mais comuns são face dismórfica, anormalidades esqueléticas, alterações nas impressões digitais, leve a moderado retardo mental e retardo do crescimento pós-natal. O presente trabalho teve como objetivo a análise do comportamento e da morfologia craniofacial dos camundongos bapa comparando com modelos de mutação do gene Kmt2d descritos na literatura.

The recessive mutant mouse named bate-palmas (bapa) – claps in Portuguese, originates from an ENU (N-ethyl-N-nitrosourea) mutagenesis program, presenting balance impairment and motor incoordination. Exome sequencing identified a mutation in the KMT2D gene, located on chromosome 15, which was confirmed by DNA sequence by the Sanger method. The loss of function of the gene KMT2D, located on chromosome 12 in humans, was described as being responsible for Kabuki syndrome, also known as Niikawa-Koruki syndrome, which is a rare congenital anomaly, autosomal dominant. The clinical phenotype of the disease is variable, but some common characteristics are dysmorphic facial features, skeletal abnormalities, fingerprint alterations, mild to moderate cognitive problems and postnatal growth retardation. The objective os this study was to analyze the behavior and craniofacial morphology of bapa mice comparing to KMT2D gene mutation models described on literature.

Assuntos