TY - JOUR
T1 - In vitro and in vivo developmental capabilities and kinetics of in vitro development of in vitro matured oocytes from adult, unstimulated and hormone-stimulated prepubertal ewes
AU - Morton, Katherine M.
AU - Catt, Sally L.
AU - Maxwell, W. M.Chis
AU - Evans, Gareth
PY - 2005/10/1
Y1 - 2005/10/1
N2 - The in vitro and in vivo developmental capabilities and kinetics of in vitro development of embryos derived from adult ewes and from unstimulated (16- to 24-week-old) and hormone-stimulated prepubertal (3- to 5-week-old) ewes were assessed. Cleavage was lower for hormone-stimulated (617/1025; 60.2%) than unstimulated prepubertal (117/169; 69.2%) and adult ewe oocytes (184/267; 68.9%; P < 0.05). Blastocyst formation by Day 7 (from zygotes) was similar for unstimulated (45/117; 38.5%), hormone-stimulated prepubertal (229/617; 37.1%) and adult ewes (101/184; 54.9%). Blastocysts derived from hormone-stimulated prepubertal ewes developed mainly on day 7, compared with Day 6 for adult and unstimulated prepubertal ewes. Pregnancy rates (day 60) and embryonic loss (between Days 20 and 60) did not differ after transfer to adult recipient ewes of adult, unstimulated and hormone-stimulated prepubertal-derived fresh or frozen-thawed embryos. The number of lambs born as a proportion of embryos transferred did not differ for fresh and frozen embryos derived from adult ewes (3/16; 18.8% and 1/12; 8.3%, respectively) and unstimulated prepubertal lambs (2/6; 33.3%, and 1/10; 10.0%, respectively), but was higher for fresh than frozen embryos from hormone-stimulated prepubertal ewes (7/16; 43.8%, and 2/14; 14.3%, respectively; P < 0.05). There were high rates of in vitro and in vivo development of oocytes from 3- to 5-week-old lambs, but in vitro development was lower than with oocytes from adult ewes. However, the speed of embryonic development in vitro and the in vivo development of fresh and frozen embryos were similar to those derived from adult and unstimulated prepubertal ewes. The present results were an improvement in the efficiency of producing embryos and offspring from hormone-stimulated 3- to 5-week-old lambs.
AB - The in vitro and in vivo developmental capabilities and kinetics of in vitro development of embryos derived from adult ewes and from unstimulated (16- to 24-week-old) and hormone-stimulated prepubertal (3- to 5-week-old) ewes were assessed. Cleavage was lower for hormone-stimulated (617/1025; 60.2%) than unstimulated prepubertal (117/169; 69.2%) and adult ewe oocytes (184/267; 68.9%; P < 0.05). Blastocyst formation by Day 7 (from zygotes) was similar for unstimulated (45/117; 38.5%), hormone-stimulated prepubertal (229/617; 37.1%) and adult ewes (101/184; 54.9%). Blastocysts derived from hormone-stimulated prepubertal ewes developed mainly on day 7, compared with Day 6 for adult and unstimulated prepubertal ewes. Pregnancy rates (day 60) and embryonic loss (between Days 20 and 60) did not differ after transfer to adult recipient ewes of adult, unstimulated and hormone-stimulated prepubertal-derived fresh or frozen-thawed embryos. The number of lambs born as a proportion of embryos transferred did not differ for fresh and frozen embryos derived from adult ewes (3/16; 18.8% and 1/12; 8.3%, respectively) and unstimulated prepubertal lambs (2/6; 33.3%, and 1/10; 10.0%, respectively), but was higher for fresh than frozen embryos from hormone-stimulated prepubertal ewes (7/16; 43.8%, and 2/14; 14.3%, respectively; P < 0.05). There were high rates of in vitro and in vivo development of oocytes from 3- to 5-week-old lambs, but in vitro development was lower than with oocytes from adult ewes. However, the speed of embryonic development in vitro and the in vivo development of fresh and frozen embryos were similar to those derived from adult and unstimulated prepubertal ewes. The present results were an improvement in the efficiency of producing embryos and offspring from hormone-stimulated 3- to 5-week-old lambs.
KW - Embryo cryopreservation
KW - Ewe
KW - Lamb
KW - Oocyte
UR - http://www.scopus.com/inward/record.url?scp=27644486635&partnerID=8YFLogxK
U2 - 10.1016/j.theriogenology.2005.03.007
DO - 10.1016/j.theriogenology.2005.03.007
M3 - Article
C2 - 16139608
AN - SCOPUS:27644486635
VL - 64
SP - 1320
EP - 1332
JO - Theriogenology
JF - Theriogenology
SN - 0093-691X
IS - 6
ER -