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1.
Anim. Reprod. (Online) ; 17(4): e20200524, 2020. graf, tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1461535

Resumo

The objective was to evaluate the influence of colony aging in a Swiss Webster (SW) outbred stock used as recipients for embryo transfer. In the first study, a retrospective analysis was performed throughout several generations during a 38-month period in 2,398 embryos transferred to 108 SW recipients. A decrease in the percentage of live pups from transferred embryos was found at the end of the period. Impairment occurred due to the incidence of maternal cannibalism that increased from 0% to 67-100% (P 0.05), while pregnancy rate (pregnant/transferred recipients) and number of pups per delivered female were not affected throughout the period (P=NS). A following study was carried out to compare the reproductive performance of SW stock vs. B6D2F1 hybrid females in a 5-year interval. The study was conducted on a total of 893 embryos transferred to 40 females (20 SW and 20 B6D2F1) in Year /1, and 514 embryos transferred to 30 females (15 SW and 15 B6D2F1) in Year /5. No cases of maternal cannibalism were found on Year /1 in any of the strains (0/10 and 0/10). However, an incidence of 44,4% (4/9) was seen on Year /5 for SW, while for B6D2F1 the incidence was 0% (0/12) (P 0.05). Further examination of the uterus showed endometrial cysts and abnormal implantation sites in SW on Year /5 but not in B6D2F1 females. In conclusion, this study reports an impairment of the reproductive performance of an early aged SW outbred stock colony mainly due to the occurrence of maternal cannibalism. This finding has important implications for embryo transfer programs conducted in mouse facilities.


Assuntos
Feminino , Animais , Camundongos , Camundongos/anatomia & histologia , Camundongos/embriologia , Camundongos/fisiologia , Comportamento Reprodutivo , Transferência Embrionária/veterinária , Canibalismo
2.
Anim. Reprod. ; 17(4): e20200524, 2020. graf, tab, ilus
Artigo em Inglês | VETINDEX | ID: vti-29733

Resumo

The objective was to evaluate the influence of colony aging in a Swiss Webster (SW) outbred stock used as recipients for embryo transfer. In the first study, a retrospective analysis was performed throughout several generations during a 38-month period in 2,398 embryos transferred to 108 SW recipients. A decrease in the percentage of live pups from transferred embryos was found at the end of the period. Impairment occurred due to the incidence of maternal cannibalism that increased from 0% to 67-100% (P 0.05), while pregnancy rate (pregnant/transferred recipients) and number of pups per delivered female were not affected throughout the period (P=NS). A following study was carried out to compare the reproductive performance of SW stock vs. B6D2F1 hybrid females in a 5-year interval. The study was conducted on a total of 893 embryos transferred to 40 females (20 SW and 20 B6D2F1) in Year /1, and 514 embryos transferred to 30 females (15 SW and 15 B6D2F1) in Year /5. No cases of maternal cannibalism were found on Year /1 in any of the strains (0/10 and 0/10). However, an incidence of 44,4% (4/9) was seen on Year /5 for SW, while for B6D2F1 the incidence was 0% (0/12) (P 0.05). Further examination of the uterus showed endometrial cysts and abnormal implantation sites in SW on Year /5 but not in B6D2F1 females. In conclusion, this study reports an impairment of the reproductive performance of an early aged SW outbred stock colony mainly due to the occurrence of maternal cannibalism. This finding has important implications for embryo transfer programs conducted in mouse facilities.(AU)


Assuntos
Animais , Feminino , Camundongos , Camundongos/anatomia & histologia , Camundongos/embriologia , Camundongos/fisiologia , Comportamento Reprodutivo , Transferência Embrionária/veterinária , Canibalismo
3.
Artigo em Espanhol | VETINDEX | ID: biblio-1489685

Resumo

Los animales transgénicos son empleados en investigación biomédica para estudiar la función y regulación de los genes, como modelos de enfermedades humanas y para ensayar estrategias terapéuticas. Asimismo, la transgénesis es aplicada en animales productivos para la generación de proteínas recombinantes y la mejora animal, y para la realización de xenotrasplantes. La Unidad de Animales Transgénicos y de Experimentación del Institut Pasteur de Montevideo produce ratones transgénicos a demanda para investigadores locales y de la región. El objetivo de este trabajo es mostrar la eficiencia durante la puesta a punto de alguna de las técnicas empleadas: (i) microinyección pronuclear de ADN (Tg clásica); (ii) transgénesis mediada por lentivirus (LV); y (iii) microinyección de células madre embrionarias (ESC) en blastocistos. Los parámetros evaluados fueron: sobrevida embrionaria 30 min post-inyección, tasa de preñez, de nacimiento, de transgénesis y tasa global de transgénesis. La sobrevida embrionaria resultó en 54,6%, 78,8% y 87,8% para Tg clásica, ESC y LV, respectivamente. El número de embriones GFP (proteína verde fluorescente) + inyectados con LV resultó 42,6%. La tasa de preñez fue 54,8% y 25,0%; la tasa de nacimiento fue 21,3% y 24,0%; la tasa de transgénesis fue 4,5% y 24,1%; y la tasa de transgénesis global fue 0,2% y 0,8%, para Tg clásica y ESC, respectivamente. En suma, se produjeron 21 animales fundadores por Tg clásica, 7 animales quiméricos por inyección de ESC, y más de un 50% de embriones resultaron GFP+ con la técnica de inyección de LV. Las técnicas empleadas resultaron efectivas para obtener los modelos transgénicos solicitados. CEUA Nº 01-012.


Transgenic animals are used in biomedical research to study gene function and regulation, as human disease models, and to test therapeutic strategies. Moreover, transgenic farm animals are used for recombinant protein production, sanitary improvement, and xenotransplantation. The Transgenic and Experimental Animal Unit of Institut Pasteur Montevideo produces transgenic mice for local and regional researchers. The objective of this work is to show the efficiency of transgenesis techniques during their set up at the unit: (i) DNA pronuclear microinjection (classical Tg); (ii) lentiviral-mediated transgenesis (LV); and (iii) embryonic stem cell (ESC) microinjection in blastocysts. The parameters evaluated were: embryo survival 30 min post-injection, pregnancy rate, birth rate, transgenesis rate, and global transgenesis rate. Embryo survival was 54.6%, 78.8% and 87.8% for classical Tg, ESC and LV, respectively. The number of GFP+ embryos injected with LV was 42.6%. Pregnancy rate was 54.8% and 25.0%; birth rate was 21.3% and 24.0%; transgenesis rate was 4.5% and 24.1%; and global transgenesis rate was 0.2% and 0.8%, for classical Tg and ESC, respectively. In total, 21 founder animals were produced by classical Tg, 7 chimeric animals by ESC injection, and more than 50% GFP+ embryos were obtained using LV injection. The techniques used at the unit were effective to obtain the required transgenic models.


Assuntos
Animais , Animais Geneticamente Modificados/genética , Terapias Complementares/tendências , Genes , Lentivirus/genética
4.
R. Soc. bras. Ci. Anim. Lab. ; 1(4): 310-316, 2012.
Artigo em Espanhol | VETINDEX | ID: vti-2657

Resumo

Los animales transgénicos son empleados en investigación biomédica para estudiar la función y regulación de los genes, como modelos de enfermedades humanas y para ensayar estrategias terapéuticas. Asimismo, la transgénesis es aplicada en animales productivos para la generación de proteínas recombinantes y la mejora animal, y para la realización de xenotrasplantes. La Unidad de Animales Transgénicos y de Experimentación del Institut Pasteur de Montevideo produce ratones transgénicos a demanda para investigadores locales y de la región. El objetivo de este trabajo es mostrar la eficiencia durante la puesta a punto de alguna de las técnicas empleadas: (i) microinyección pronuclear de ADN (Tg clásica); (ii) transgénesis mediada por lentivirus (LV); y (iii) microinyección de células madre embrionarias (ESC) en blastocistos. Los parámetros evaluados fueron: sobrevida embrionaria 30 min post-inyección, tasa de preñez, de nacimiento, de transgénesis y tasa global de transgénesis. La sobrevida embrionaria resultó en 54,6%, 78,8% y 87,8% para Tg clásica, ESC y LV, respectivamente. El número de embriones GFP (proteína verde fluorescente) + inyectados con LV resultó 42,6%. La tasa de preñez fue 54,8% y 25,0%; la tasa de nacimiento fue 21,3% y 24,0%; la tasa de transgénesis fue 4,5% y 24,1%; y la tasa de transgénesis global fue 0,2% y 0,8%, para Tg clásica y ESC, respectivamente. En suma, se produjeron 21 animales fundadores por Tg clásica, 7 animales quiméricos por inyección de ESC, y más de un 50% de embriones resultaron GFP+ con la técnica de inyección de LV. Las técnicas empleadas resultaron efectivas para obtener los modelos transgénicos solicitados. CEUA Nº 01-012.(AU)


Transgenic animals are used in biomedical research to study gene function and regulation, as human disease models, and to test therapeutic strategies. Moreover, transgenic farm animals are used for recombinant protein production, sanitary improvement, and xenotransplantation. The Transgenic and Experimental Animal Unit of Institut Pasteur Montevideo produces transgenic mice for local and regional researchers. The objective of this work is to show the efficiency of transgenesis techniques during their set up at the unit: (i) DNA pronuclear microinjection (classical Tg); (ii) lentiviral-mediated transgenesis (LV); and (iii) embryonic stem cell (ESC) microinjection in blastocysts. The parameters evaluated were: embryo survival 30 min post-injection, pregnancy rate, birth rate, transgenesis rate, and global transgenesis rate. Embryo survival was 54.6%, 78.8% and 87.8% for classical Tg, ESC and LV, respectively. The number of GFP+ embryos injected with LV was 42.6%. Pregnancy rate was 54.8% and 25.0%; birth rate was 21.3% and 24.0%; transgenesis rate was 4.5% and 24.1%; and global transgenesis rate was 0.2% and 0.8%, for classical Tg and ESC, respectively. In total, 21 founder animals were produced by classical Tg, 7 chimeric animals by ESC injection, and more than 50% GFP+ embryos were obtained using LV injection. The techniques used at the unit were effective to obtain the required transgenic models.(AU)


Assuntos
Animais , Animais Geneticamente Modificados/genética , Terapias Complementares/tendências , Lentivirus/genética , Genes
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