pronucleus

The CC support the stage IVM to MII of the oocyte and contribute in the cytoplasmic maturation required for optimal developmental capacities, such as male pronucleus formation and blastocyst stage development.

Oocytes containing two polar bodies and/or double pronucleus were classified as zygotes.

In vitro maturation of bovine cumulus-oocyte complexes in undiluted follicular fluid: Effect on nuclear maturation, pronucleus formation and embryo development.

At this meiotic process, the haploid female pronucleus is formed in the cytoplasm of the fertilized egg.

The inadequate sperm chromatin decondensation and its transformation into the Male Pronucleus (MPN) together with a failure to activate the oocyte seem to be the major causes behind the poor ICSI efficiency in some species (4,5).

Although it seems that CRISPR/Cas9 has higher HDR rates in normal, dual pronucleus compared to tripronuclear zygotes, off-target effects and mosaicism were still observed in both studies.

pX330 plasmid (5 ng/ [micro]L) mixed with 10ng/[micro]L repair template was microinjected into the pronucleus of fertilized eggs.

Without appearance of an additional female pronucleus (PN) caused by non-extrusion of the second polar body (PB), this phenomenon would have escaped detection.

The continuous monitoring of the progress of the embryo development is possible by following the key indicators of this process (both positive and negative) such as formation of the pronucleus, early cleavage, cell cycle intervals, synchronization of cell division and initiation of blastulation, and multinucleation, etc., since all these contribute to the selection of the best embryos for transfer [11].

Structures were classified as non-fertilized (absence of sperm and/or male pronucleus); correctly fertilized (presence of two polar bodies and two (male and female) pronuclei); or improperly fertilized (presence of polyspermy, of more than two pronuclei).