The big. ass. egg.

15 Nov

Womanhood is powerful. If ever you seek a concrete image to illustrate this, look at a human egg flanked by sperm.

The first thing you will notice is that the egg is huge. Sperm cells swarm like tiny rockets around a super planet.

We often think DNA drives everything, but it’s only a small part of the human biological society. Genes are necessary, but not sufficient, to creating life. Put DNA in a Petri dish, and you will not grow a person. Genes are instructions for making the building blocks, the molecular machines, and the molecular messengers that create miraculous masses of hard-working cells.  In short, they provide information about how a person gets built. But they aren’t the person who gets built.
Inside of the egg are the actual starting blocks, or materials, for human construction. Its contents allow the fertilized egg to divide eight times (to become 128 cells big) during the journey from the fallopian tube to the uterus. It also contains all the nutrients this ball of cells will need for about five days, before the mother takes over.

Cells are remarkably “aware.”  They interact with their neighbors and sometimes borrow tools from one another. They play a role in a sort of cellular society. In the same, purely chemical sense, an egg is an incredibly conscious system. The egg has receptors along its surface that protect it and call out, chemically, to sperm.

At the moment of fertilization, the sperm burns through the egg’s “atmosphere.” As soon as it does this, molecules around the egg link up as a solid barrier and a “fence” emerges as a barrier to all competing sperm. The tidal-wave like flow that you see below around the circumference of the egg is the formation of this barrier.

Microtubules inside of the egg then come in like rescue ships to shuttle the nucleus of the sperm to the nucleus of the egg. Along the way these chaperone molecules strip the sperm of proteins. The mitochondria in the sperm never make it into the egg cell, which is why only moms, never dads, pass “mitochondrial DNA” along to their children.

Mitochondrial DNA contains 37 genes that live outside of the cell nucleus. They provide instructions that mitochondria (the cell’s “power plant”) uses to make enzymes, energy, and RNA, the molecules that help build proteins.

The male/ female balance in human genesis is not one of equality. Everything is born of the feminine, sparked by the masculine. The duality of the active sperm and the receptive egg, each with a touch of the opposite attribute, calls to mind the yin yang symbol of Taoist philosophy that describes polar forces acting in concert.

This yin-yang, receptive-active principle operates frequently in biology.  Every receptor protein on a cell surface, for example, has that balance– it is mostly receptive, still and quiet, waiting to receive a signal before it catalyzes an active event.  The brain, too, receives information from both within the body and from the external world that is translated through the body, before the gray goo takes action.  Genes, too, are set up to receive signals, then respond.

Carl Sagan, the astronomer who taught the world about the universe, said that “the beauty of a living thing is not the atoms that go into it but the way those atoms are put together.”

The same can be said of cells; in our bodies are worlds within worlds with parts that interact in astonishing ways.

2 Responses to “The big. ass. egg.”

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  1. The Science of Pregnancy Timeline: Week 0 « - June 15, 2012

    […] egg itself is a universe. What other thing in the entire world is so small and gives rise to something as large, beautiful, […]

  2. The Science of Pregnancy Timeline: Week One — Having sex to become pregnant: Why it is necessary? « - August 15, 2012

    […] posts: The Big. Ass. Egg. Share this:TumblrEmailPrintFacebookRedditStumbleUponLinkedInTwitterDiggPinterestLike this:LikeOne […]

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