Table 2 |
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|
Evaluation of methods for swine transgenesis |
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|
Pronuclear (naked DNA) |
Pronuclear (transposon)a |
SCNT (PFF) |
Lentiviral |
|
|
|
||||
|
Live-born/embryo manipulated |
10% to 15% |
ND |
0.05% to 1.2% |
18% to 27% |
|
Transgenic per live-born |
+ |
++ |
+++ |
++ |
|
Integration preference |
Random |
Random/class specific |
Random or targeted |
Gene coding regions |
|
Null/hypomorph |
RNAi/DN |
RNAi/DN |
Gene targeting/RNAi/DN |
RNAi/DN |
|
Cargo size limitationsb |
ND |
ND |
ND |
About 8 kilobases |
|
Integrations per live-born |
Typically 1 |
1 to 10 |
Typically 1 |
1 to 20 |
|
Mosaicism |
Often |
Often |
Seldom |
often |
|
Ease of vector production |
++ |
++ |
++/(± HR constructs) |
+ |
|
Concatemer instability |
Yes |
No |
Yesc |
No |
|
Precision (to the base pair) |
No |
Yes |
Noc |
Yes |
|
Homologous recombination |
No |
No |
Yes |
No |
|
Genome aberrations |
Yes |
No |
No |
No |
|
Heritable expression |
++ |
+++ |
++d |
++ |
|
Preimplantation screen |
± |
± |
++e |
± |
|
Selection required |
No |
No |
Yes |
No |
|
|
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|
aAs observed previously in mice. bIncreasing size invariably decreases efficiency. cTargeted alleles are stable. dMosaicism observed in clones of clones [200]. eExpression in SCNT donor cells does not ensure expression in animal. DN, dominant negative translocations; HR, homologous recombination; ND, not determined; PFF, porcine fetal fibroblasts; RNAi, RNA interference; SCNT, somatic cell nuclear transfer. |
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|
Clark et al. Genome Biology 2007 8(Suppl 1):S13 doi:10.1186/gb-2007-8-s1-s13 |
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