Dr. ALBERTINI’s PHOTO GALLERY
Egging our way forward, one small step at a time
Building off the Center for Human Reproduction’s theme of “fighting for every egg,” this month’s image gallery is all about the starting point for IVF treatment - the Egg. The development of a human egg cell involves a long journey within the cozy confines of the ovarian follicle, with most estimates being around 100 days in duration to move from the earliest stages (Figure 1) to a fully activated state (Figure 4).
Figure 1
This shows one of the secrets of the egg cell in its early of development, the green stain shows a special molecule that allows the egg to talk to the cells of the follicle residing outside. Its technical name is GDF9, and we consider it to be the conductor of the symphony that will lead the follicle all the way up to the time of ovulation.
Figure 2
This gives us a glimpse into the growing egg, biding its time by building up the stockpiles of materials needed to support embryo development, here the chromosomes of the egg are shown in blue with the outer blue nuclei representing those of the follicle granulosa cells.
Figure 3
This shows what happens during the time of ovulation when the egg positions its chromosomes (seen in white) on the meiotic spindle (blue, center) and in the moment captured by this image, one can appreciate the forces pulling the chromosomes apart from one another as the egg goes through maturation
Figure 4
This shows the finished product of ovulation-the mature egg with its polar body at twelve noon (blue bubble) and the eggs chromosomes remaining in the cytoplasm awaiting the opportunity to undergo fertilization, should a willing and capable sperm be introduced after IVF or ICSI. So ends the journey of an egg from its beginnings through to ovulation!
David F. Albertini, PhD, is Editor-in-Chief of the Journal of Assisted Reproduction and Genetics (JARG), Professor and Chair of Developmental Biology at the Bedford Research Foundation in Massachusetts and a Visiting Senior Scientist at The Center for Human Reproduction (CHR) in NYC, and a Visiting Researcher at Rockefeller University.