Inbred Sperm Fertilize Fewer Eggs, Beetle Study Finds

[The Straight Story]

Inbred Sperm Fertilize Fewer Eggs, Beetle Study Finds

ScienceDaily (June 16, 2010) — Inbred male sperm have been found to fertilize fewer eggs when in competition with non-inbred males, according to a new study by the University of East Anglia.

Research into the breeding habits of the red flour beetle, published in Proceedings of the Royal Society B, shows that the reduced fitness of inbred beetles, known as 'inbreeding depression', reveals itself in competitive scenarios.

Inbreeding is a potentially important problem in declining species across the world, and conserving genetic variation is now recognized as a priority by the International Union for Conservation of Nature. The new research is potentially vital for the successful implementation of recovery programs of inbred species.

When populations deplete or fragment, relatives can be forced into reproduction, often leading to inbreeding depression.

Led by Dr. Matt Gage, the new research into the promiscuous red flour beetle (Tribolium castaneum) measured how male reproduction responded to forced inbreeding.

http://www.sciencedaily.com/releases/2010/06/100615191514.htm

[brewens]

1. Being from Idaho, this is welcomed news. I'm not sure it will have

enough effect though.

[frustrated_lefty]

2. The actual fertilization of an egg by sperm is really interesting

We've all experienced high school lectures on how the sperm penetrates the egg and it makes an omelet. Don't ask questions, just ask your hormones, the spermatazoa is like a nuclear missile diving into the inner bunker of the egg!

In higher level biology courses, there are suggestions of protein interactions between the egg and the sperm, protein receptors on the surface which create a lock and key mechanism which link the two cells together. We're basically drilled to think of proteins as the movers and shakers of the molecular world, which is cool in and of itself. Dad's sperm A locks with mom's egg B to unlock a mystery which produces the miracle of a child! Voila!

Then, in late graduate or post-graduate studies, you start hearing about lectins and ligands. Lectins are simple sugar moieties, chains of sugar molecules, which get attached to proteins. Without the proper lectin orientation and ligand binding to lectin, proteins fail to recognize their receptors, sperm fail to recognize eggs, and the species dies.

I'd be curious to see what lectins and ligands are expressed on the surface of inbred vs outbred sperm and egg.

Sorry to go off on a tangent, it's just an amazing process and we understand so little about it.