TY - JOUR
T1 - Development of rat tetraploid and chimeric embryos aggregated with diploid cells
AU - Shinozawa, T.
AU - Sugawara, A.
AU - Matsumoto, A.
AU - Han, Y. J.
AU - Tomioka, I.
AU - Inai, K.
AU - Sasada, H.
AU - Kobayashi, E.
AU - Matsumoto, H.
AU - Sato, E.
PY - 2006/11/1
Y1 - 2006/11/1
N2 - In the present study, we examined the preimplantation and postimplantation development of rat tetraploid embryos produced by electrofusion of 2-cell-stage embryos. Developmental rate of tetraploid embryos to morula or blastocyst stage was 93% (56/60) and similar to that found in diploid embryos (95%, 55/58). After embryo transfer, rat tetraploid embryos showed implantation and survived until day 8 of pregnancy, however the conceptuses were aberrant on day 9. In mouse, tetraploid embryos have the ability to support the development of blastomeres that cannot develop independently. As shown in the present study, a pair of diploid blastomeres from the rat 8-cell-stage embryo degenerated immediately after implantation. Therefore, we examined whether rat tetraploid embryos have the ability to support the development of 2/8 blastomeres. We produced chimeric rat embryos in which a pair of diploid blastomeres from an 8-cell-stage green fluorescent protein negative (GFP-) embryo was aggregated with three tetraploid blastomeres from 4-cell GFP-positive (GFP+) embryos. The developmental rate of rat 2n(GFP-)↔4n(GFP+) embryos to the morula or blastocyst stages was 93% (109/117) and was similar to that found for 2n(GFP-)↔2n(GFP+) embryos (100%, 51/51). After embryo transfer, 2n(GFP-) ↔ 4n(GFP+) conceptuses were examined on day 14 of pregnancy, the developmental rate to fetus was quite low (4%, 4/109) and they were all aberrant and smaller than 2n(GFP-) ↔ 2n(GFP+) conceptuses, whereas immunohistochemical analysis showed no staining for GFP in fetuses. Our results suggest that rat tetraploid embryos are able to prolong the development of diploid blastomeres that cannot develop independently, although postimplantation development was incomplete.
AB - In the present study, we examined the preimplantation and postimplantation development of rat tetraploid embryos produced by electrofusion of 2-cell-stage embryos. Developmental rate of tetraploid embryos to morula or blastocyst stage was 93% (56/60) and similar to that found in diploid embryos (95%, 55/58). After embryo transfer, rat tetraploid embryos showed implantation and survived until day 8 of pregnancy, however the conceptuses were aberrant on day 9. In mouse, tetraploid embryos have the ability to support the development of blastomeres that cannot develop independently. As shown in the present study, a pair of diploid blastomeres from the rat 8-cell-stage embryo degenerated immediately after implantation. Therefore, we examined whether rat tetraploid embryos have the ability to support the development of 2/8 blastomeres. We produced chimeric rat embryos in which a pair of diploid blastomeres from an 8-cell-stage green fluorescent protein negative (GFP-) embryo was aggregated with three tetraploid blastomeres from 4-cell GFP-positive (GFP+) embryos. The developmental rate of rat 2n(GFP-)↔4n(GFP+) embryos to the morula or blastocyst stages was 93% (109/117) and was similar to that found for 2n(GFP-)↔2n(GFP+) embryos (100%, 51/51). After embryo transfer, 2n(GFP-) ↔ 4n(GFP+) conceptuses were examined on day 14 of pregnancy, the developmental rate to fetus was quite low (4%, 4/109) and they were all aberrant and smaller than 2n(GFP-) ↔ 2n(GFP+) conceptuses, whereas immunohistochemical analysis showed no staining for GFP in fetuses. Our results suggest that rat tetraploid embryos are able to prolong the development of diploid blastomeres that cannot develop independently, although postimplantation development was incomplete.
KW - Embryo
KW - Postimplantation development
KW - Preimplantation development
KW - Rat
KW - Tetraploid
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U2 - 10.1017/S096719940600387X
DO - 10.1017/S096719940600387X
M3 - Article
C2 - 17266787
AN - SCOPUS:33845295496
VL - 14
SP - 287
EP - 297
JO - Zygote
JF - Zygote
SN - 0967-1994
IS - 4
ER -