zygo-, zyg-, -zygous; zygomatico- +
(Greek: yoke, forming pairs; joined, union; or indicating a relationship to a junction; meaning a yoke or crossbar by which two draft animals; such as, oxen could be hitched to a plow or wagon)
A gene which allows the normal functioning of gametes (reproductive cells in animals and plants), but has deadly effects during embryonic or larval development: A zygotic lethal gene is a changed or an altered version of a healthy gene, which is necessary for viability of a zygote, and causes a deletion or loss of the entire gene.
