Mosquito love songs

It’s July in Minnesota, and you know what that means: bugs. Clouds of bugs. Some people complain, but I generally rationalize a large population of fecund invertebrates as simply a sign of a healthy ecosystem, so yeah, we’ve got bugs, but it’s good for us.

Except for those mosquitoes. It’s hard to think charitably of some invertebrates when you’re lying in bed at night and you hear…that…high-pitched whine rising as the nearly invisible little blood-sucker buzzes by your exposed flesh. Now, in a discovery calculated to increase my irritation, I learn that the little bastards are singing a love song as they hover about, looking for an opportunity to stab me and suck my blood. “Come to me, come to me, mon chéri,” they sing, “after I gorge myself on ze fat, torpid hu-man (and daintily spit up a little backwash into his capillaries), we shall make sweet, sweet love in the moonlight and zen I shall lay a thousand eggs, and our progeny shall feast on his children!” (Sorry, but now whenever I hear them they’ve also got a silly Pepe LePew French accent.)

[Read more…]

Lighting a fire under the president

George W Bush hasn’t vetoed a single bill in all these long, long years of his presidency. Guess what issue might finally convince him to move?

He’s willing to veto any expansion of stem cell research.

That’s our George. Science isn’t part of his base, so he’ll willingly throw that away to make the church-based ignoramuses happy. Zygotes must be spared! It’s the ones that have been born that can be used as cannon fodder.

Folk genetics

Carel Brest van Kempen has extracted a few fascinating quotes from an old book he has. It’s titled Creative and Sexual Science, by a phrenologist and physiologist from 1870, and it contains some wonderful old examples of folk genetics.

President Bush would be pleased:

“Human and animal hybrids are denounced most terribly in the Bible; obviously because the mixing up of man with beast, or one beast species with another, deteriorates. Universal amalgamation would be disastrous.”

Although, unfortunately, he then goes on to use this as an argument against miscegenation.

Another lesson is that you shouldn’t deny pregnant women anything, or their longing will mark their child.

“A woman, some months before the birth of her child, longed for strawberries, which she could not obtain. Fearing that this might mark her child, and having heard that it would be marked where she then touched herself, she touched her hip. Before the child was born she predicted that it would have a mark resembling a strawberry, and be found on its hip, all of which proved to be true.”

Don’t let them see horrible things, either.

“Mrs. Lee, of London, Ont., saw Burly executed from her window; who, in swinging off, broke the rope, and fell with his face all black and blue from being choked. This horrid sight caused her to feel awfully; and her son, born three months afterwards, whenever anything occurs to excite his fears, becomes black and blue in the face, an instance of which the Author witnessed.”

And…uh-oh. Maybe George W. Bush won’t be so thrilled with this part.

“A child in Boston bears so striking a resemblance to a monkey, as to be observed by all. Its mother visited a menagerie while pregnant with it, when a monkey jumped on her shoulders.”

I think Carel needs to get busy and transcribe the whole thing onto the web. I know I’ll find these examples useful when I teach genetics this spring.

Preach it, brother

Billmon reviews An Inconvenient Truth, and its more of a lament for the fact that science and reason seem to have little compelling power to a nation raised on ranting idiots and authoritarian dogma.

In my darker moments, it sometimes seems as if the entire world is in the middle of a fierce backlash against the Age of Enlightenment, the Scientific Revolution and the ideological challenges they posed to the old belief systems. The forces of fundamentalism and obscurantism appear to be on the march everywhere—even as the moral and technological challenges posed by a global industrial civilization grow steadily more complex.

I think a lot of us have that feeling nowadays.

Bicoid evolution

i-ccbc028bf567ec6e49f3b515a2c4c149-old_pharyngula.gif

I’ve written about this fascinating Drosophila gene, bicoid, several times before. It’s a maternal effect gene, a gene that is produced by the mother and packaged into her eggs to drive important early events in development, in this case, establishing polarity, or which end of the egg is anterior (bicoid specifies which end of the egg will form the fly’s head). Bicoid is also a transcription factor, or gene that regulates the activity of other genes. We also see evidence that it is a relatively new gene, one that is taking over a morphogenetic function that may have been carried out by several other more primitive genes in the ancestral insect.

[Read more…]

Bicoid, nanos, and bricolage

i-ccbc028bf567ec6e49f3b515a2c4c149-old_pharyngula.gif

i-f1b8f142a858f7b3bd35981ba25ebd2a-flagellum_cartoon.jpg

Intelligent Design creationists are extremely fond of diagrams like those on the left. Textbook illustrators like them because they simplify and make the general organization of the components clear—reducing proteins to smooth ovoids removes distractions from the main points—but creationists like them for the wrong reasons. “Look at that—it’s engineered! It’s as if God uses a CAD program to design complex biological systems!” They like the implication that everything is done with laser-guided precision, and most importantly, that every piece was designed with intent, to fill a specific role in an apparatus that looks like it came out of a high-tech machine shop at a Boeing aerospace lab.

This is, of course, misleading. Real organelles in biology don’t look glossy and slick and mechanical; they look, well, organic, with fuzziness and variability and, most importantly, mistakes and slop. What these biological machines look like is not the precisely engineered output of a modern machine shop, but like bricolage. Bricolage is a term François Jacob used to contrast real biology with the false impression of nature as an engineer. It’s an art term, referring to constructions made with whatever is at hand, a pastiche of whatever is just good enough or close enough to the desired result to make do. It covers everything from the sculptures of Alexander Calder to those ticky-tacky souvenirs made from odd bits of driftwood and shells glued together that you can find at seashore gift shops.

[Read more…]

Zygotic genes

i-ccbc028bf567ec6e49f3b515a2c4c149-old_pharyngula.gif

Last week, I wrote a bit about maternal genes, specifically bicoid, and described how this gene was expressed in a gradient in the egg. Bicoid is both a transcription factor and a morphogen. The gene product regulates the activity of other genes, controlling their pattern of expression in the embryo. Today I thought I’d get more specific about the downstream targets of bicoid, the gap genes.

[Read more…]

Transcription factors and morphogens

i-ccbc028bf567ec6e49f3b515a2c4c149-old_pharyngula.gif

In my previous comments about maternal effect genes, I was talking specifically about one Drosophila gene, bicoid, which we happen to understand fairly well. We know its sequence, we know how it is controlled, and we know what it does; we know where it falls in the upstream and downstream flow of developmental information in the cell. So today I’m going to babble a bit more about what bicoid is and does, and how it works.

[Read more…]