Single-cell embryos contain a set of maternal and paternal chromosomes, and as the embryo grows, daughter cells receive a copy of each. In a study published online in Genome Research, researchers have discovered errors during the earliest stages of embryonic development can lead to entire sets of maternal and paternal chromosomes segregating into different cells, resulting in chimeric embryos.
“This is a novel fundamental insight into the origin of chimerism, a very rare condition in humans, which can lead to birth defects,” senior author Joris Vermeesh, from KU Leuven, said.
Previous studies involving in vitro fertilized (IVF) human embryos have demonstrated large fractions of embryos contain at least one cell with either whole or partial gains or losses of chromosomes. This chromosomal instability can lead to reduced fecundity and birth defects. To investigate in more detail, an international team of researchers employed in vitro fertilization in cattle as a flexible system to study chromosomal changes in single embryonic cells.
In vitro fertilized bovine embryos are used for examining abnormal chromosome segregation during development
Image Credit: Maaike Catteeuw, Ghent University