Factors influencing the efficiency of generating genetically engineered pigs by nuclear transfer: multi-factorial analysis of a large data set
Podcast
Podcaster
Beschreibung
vor 11 Jahren
Background: Somatic cell nuclear transfer (SCNT) using genetically
engineered donor cells is currently the most widely used strategy
to generate tailored pig models for biomedical research. Although
this approach facilitates a similar spectrum of genetic
modifications as in rodent models, the outcome in terms of live
cloned piglets is quite variable. In this study, we aimed at a
comprehensive analysis of environmental and experimental factors
that are substantially influencing the efficiency of generating
genetically engineered pigs. Based on a considerably large data set
from 274 SCNT experiments (in total 18,649 reconstructed embryos
transferred into 193 recipients), performed over a period of three
years, we assessed the relative contribution of season, type of
genetic modification, donor cell source, number of cloning rounds,
and pre-selection of cloned embryos for early development to the
cloning efficiency. Results: 109 (56%) recipients became pregnant
and 85 (78%) of them gave birth to offspring. Out of 318 cloned
piglets, 243 (76%) were alive, but only 97 (40%) were clinically
healthy and showed normal development. The proportion of stillborn
piglets was 24% (75/318), and another 31% (100/318) of the cloned
piglets died soon after birth. The overall cloning efficiency,
defined as the number of offspring born per SCNT embryos
transferred, including only recipients that delivered, was 3.95%.
SCNT experiments performed during winter using fetal fibroblasts or
kidney cells after additive gene transfer resulted in the highest
number of live and healthy offspring, while two or more rounds of
cloning and nuclear transfer experiments performed during summer
decreased the number of healthy offspring. Conclusion: Although the
effects of individual factors may be different between various
laboratories, our results and analysis strategy will help to
identify and optimize the factors, which are most critical to
cloning success in programs aiming at the generation of genetically
engineered pig models.
engineered donor cells is currently the most widely used strategy
to generate tailored pig models for biomedical research. Although
this approach facilitates a similar spectrum of genetic
modifications as in rodent models, the outcome in terms of live
cloned piglets is quite variable. In this study, we aimed at a
comprehensive analysis of environmental and experimental factors
that are substantially influencing the efficiency of generating
genetically engineered pigs. Based on a considerably large data set
from 274 SCNT experiments (in total 18,649 reconstructed embryos
transferred into 193 recipients), performed over a period of three
years, we assessed the relative contribution of season, type of
genetic modification, donor cell source, number of cloning rounds,
and pre-selection of cloned embryos for early development to the
cloning efficiency. Results: 109 (56%) recipients became pregnant
and 85 (78%) of them gave birth to offspring. Out of 318 cloned
piglets, 243 (76%) were alive, but only 97 (40%) were clinically
healthy and showed normal development. The proportion of stillborn
piglets was 24% (75/318), and another 31% (100/318) of the cloned
piglets died soon after birth. The overall cloning efficiency,
defined as the number of offspring born per SCNT embryos
transferred, including only recipients that delivered, was 3.95%.
SCNT experiments performed during winter using fetal fibroblasts or
kidney cells after additive gene transfer resulted in the highest
number of live and healthy offspring, while two or more rounds of
cloning and nuclear transfer experiments performed during summer
decreased the number of healthy offspring. Conclusion: Although the
effects of individual factors may be different between various
laboratories, our results and analysis strategy will help to
identify and optimize the factors, which are most critical to
cloning success in programs aiming at the generation of genetically
engineered pig models.
Weitere Episoden
Kommentare (0)