TY - JOUR
T1 - In vitro production of horse embryos predisposes to micronucleus formation, whereas time to blastocyst formation affects likelihood of pregnancy
AU - Ducheyne, Kaatje D
AU - Rizzo, Marilena
AU - Cuervo-Arango, Juan
AU - Claes, Anthony
AU - Daels, Peter F
AU - Stout, Tom A E
AU - de Ruijter-Villani, Marta
N1 - Funding Information:
Kaatje Ducheyne was funded by the Agentschap voor Innovatie door Wetenschap en Technologie (IWT; Grant 141492). The authors thank Mabel Beitsma and Claudia Deelen for IVP and assistance during embryo transfer and Karin Hendriks for the collection and immunostaining of the in vivo-derived embryos. Confocal microscopic images were acquired at the Centre for Cellular Imaging at the Faculty of Veterinary Medicine, Utrecht. The authors thank Richard Wubbolts and Esther van't Veld for their help and technical assistance.
Funding Information:
Kaatje Ducheyne was funded by the Agentschap voor Innovatie door Wetenschap en Technologie (IWT; Grant 141492). The authors thank Mabel Beitsma and Claudia Deelen for IVP and assistance during embryo transfer and Karin Hendriks for the collection and immunostaining of the in vivo-derived embryos. Confocal microscopic images were acquired at the Centre for Cellular Imaging at the Faculty of Veterinary Medicine, Utrecht. The authors thank Richard Wubbolts and Esther van‘t Veld for their help and technical assistance.
Publisher Copyright:
© 2019 CSIRO.
PY - 2019/1
Y1 - 2019/1
N2 - Invitro embryo production is an increasingly popular means of breeding horses. However, success is limited by a high incidence of early embryo loss. Although there are various possible causes of pregnancy failure, chromosomal abnormalities, including aneuploidy, are important potential contributors. This study evaluated the frequency of micronucleus formation as a proxy for aneuploidy in invitro-produced (IVP) and invivo-derived horse blastocysts. Associations between IVP embryo morphology, frequency of nuclear abnormalities and the likelihood of pregnancy were investigated. IVP blastocysts exhibited a higher frequency of cells with micronuclei than invivo-derived embryos (10% vs 1% respectively; P=0.05). This indication of chromosomal instability may explain the higher incidence of pregnancy failure after transfer of IVP embryos. However, the frequency of micronuclei was not correlated with brightfield microscopic morphological characteristics. Nevertheless, IVP embryos reaching the blastocyst stage after Day 9 of invitro culture were less likely to yield a pregnancy than embryos that developed to blastocysts before Day 9 (27% vs 69%), and embryos that had expanded before transfer were more likely to undergo embryonic death than those that had not expanded (44% vs 10%). These findings indicate that current embryo culture conditions are suboptimal and that the speed of embryo development is correlated with pregnancy survival.
AB - Invitro embryo production is an increasingly popular means of breeding horses. However, success is limited by a high incidence of early embryo loss. Although there are various possible causes of pregnancy failure, chromosomal abnormalities, including aneuploidy, are important potential contributors. This study evaluated the frequency of micronucleus formation as a proxy for aneuploidy in invitro-produced (IVP) and invivo-derived horse blastocysts. Associations between IVP embryo morphology, frequency of nuclear abnormalities and the likelihood of pregnancy were investigated. IVP blastocysts exhibited a higher frequency of cells with micronuclei than invivo-derived embryos (10% vs 1% respectively; P=0.05). This indication of chromosomal instability may explain the higher incidence of pregnancy failure after transfer of IVP embryos. However, the frequency of micronuclei was not correlated with brightfield microscopic morphological characteristics. Nevertheless, IVP embryos reaching the blastocyst stage after Day 9 of invitro culture were less likely to yield a pregnancy than embryos that developed to blastocysts before Day 9 (27% vs 69%), and embryos that had expanded before transfer were more likely to undergo embryonic death than those that had not expanded (44% vs 10%). These findings indicate that current embryo culture conditions are suboptimal and that the speed of embryo development is correlated with pregnancy survival.
KW - Aneuploidy
KW - Animals
KW - Blastocyst/cytology
KW - Chromosomal Instability/physiology
KW - Chromosome Aberrations/embryology
KW - Embryo Loss/genetics
KW - Embryo Transfer/veterinary
KW - Embryo, Mammalian
KW - Embryonic Development/physiology
KW - Female
KW - Fertilization in Vitro/methods
KW - Horses/embryology
KW - Male
KW - Micronuclei, Chromosome-Defective/embryology
KW - Pregnancy
KW - Pregnancy, Animal/genetics
KW - Time Factors
KW - intracytoplasmic sperm injection
KW - ovum pick-up
KW - chromosomal instability
KW - aneuploidy
UR - http://www.scopus.com/inward/record.url?scp=85075817012&partnerID=8YFLogxK
U2 - 10.1071/RD19227
DO - 10.1071/RD19227
M3 - Article
C2 - 31771747
SN - 1031-3613
VL - 31
SP - 1830
EP - 1839
JO - Reproduction, fertility, and development
JF - Reproduction, fertility, and development
IS - 12
ER -