Mary B. Mitchell and Gene Conversion

George W. Beadle in 1949, with an unnamed assistant who could plausibly be Mitchell but might not be.

I was reading up on gene conversion this week, and vaguely recalled that a woman discovered it, so I looked her up for the Zuskateer Party Calendar of women scientists' birthdays. Although I found her name easily enough - Mary B. Mitchell - and the 1955 paper in which she presented her results was available online, I found no birthday, no photo, and no biographical details except that her birth name was Houlahan. There wasn't even a description of her discovery on any blogs. Unto the breach! You can count this as an early entry for Ada Lovelace Day.

It may surprise you how good an understanding of genes scientists managed to achieve before they had any clue what exactly genes were. These days, if you choose your organism right, you can practically treat genes like Lego bricks, and break'em apart and stick'em back together how you please. But in the first half of the twentieth century, scientists worked out a lot about the nature of heredity, genetic variation, and the organisation and transmission of genetic information, largely by Counting Things.


22,747 mutants, ah ah ah. Mitchell counted over 100,000 spores for her gene conversion paper.

Fly-counters like Morgan are probably more famous, but one could argue that foost-counters like Beadle made even greater contributions. Mitchell worked in Beadle's lab, and she noticed something odd.


Photo by N. B. Raju, nicked from here.

This is the bread mould Neurospora, the fungus Mitchell worked on, under the microscope. Those things that look like strings of beads are groups of spores that have all come from one parent cell. Spores are made by meiosis - the same process that makes egg or sperm cells in people - and usefully, they're all held together so you can see which cell made what spores. Mendel's laws state that if the parent cell has two kinds of a gene, they should be doled out evenly to the spores. That's what's happening in the picture above: each set of eight spores is made up of four that are green and four that aren't.

Except it wasn't always true. Very occasionally there were six of one and and two of the other. It seemed Mendel's laws had some kind of loophole.


There were attempts to explain away this observation. Most blamed experimenter error, or insisted that two genes rather than one were involved, which would allow for a six to two split (if you're a biologist and can't see how, you should scribble your Punnett Squares right now and work it out). Mitchell's paper shot these doubts down: her experiments are meticulously controlled and double-checked at every stage to refute possible counterarguments. In her fungi, rarely but surely, a gene would sometimes change to match another one.

"Blimey," I hear you exclaim sarcastically, "how riveting. And how extremely surprising that a monk in 1850 knew a bit less than a professional geneticist in 1950." Sark ye not! Mitchell's results really did matter and they still do.
First, the findings lit the way to a better molecular understanding of the way in which genes are dealt out into sperm or eggs (or spores) and shuffled from generation to generation. Mitchell's discussion says: It might even be supposed that the event which gives rise to crossing-over took place in each case... but that this event results in an actual exchange in, statistically, only half the cases. This was startlingly prescient; explaining why is a whole 'nother post which I might write if there is general clamour for it, i.e. someone asks nicely.

Secondly, gene conversion has evolutionary implications that are still being argued over. It might affect the evolution of whole sets of similar genes, or the repetitive bits of our DNA (which is nearly all of it).

My third reason is more nebulous, and more tenuous, but I think it holds some water. Mitchell and the other founding mothers of non-Mendelian inheritance (Ruth Sager and Barbara McClintock - and maybe we can count Nettie Stevens) started people thinking about why genes are inherited the way they are, and what might happen if genes didn't play by the usual rules. They provided illustrative examples, conceptual frameworks, and probably a bit of inspiration, to the evolutionary biologists of the following few decades who were developing theories that centred on conflicts between selfish genes. So I'm particularly saddened that we don't know her birthday. I'd certainly celebrate it lavishly: I suspect she helped to kick-start my own field.

Amiable Cookies with Mean Choc Chips

Cromagnon made these by accident when he used a bar of intense fuck-off 85% cocoa solids cooking chocolate instead of the normal stuff meant for eating. It was an adaptive mutation and we've been making them this way ever since. The cookie dough should be as mild and all-American as possible to contrast with the dark, bitter chocolate.
They're freezer cookies, so you make a vast batch of dough, freeze it in a cylinder shape, and slice off a few cookies at a time for baking. I defy the Breakfast Police and eat them for weekday breakfasts with orange juice and an espresso. Oh yes.
Makes about 100 cookies but not necessarily all at once.

Recipe
To make the dough, beat 175g caster sugar and 110g brown soft sugar with 225g butter (at room temperature), then beat in 2 eggs and 1 tsp vanilla extract.
Next, sift 450g plain flour with 1/2 tsp salt, 1 tsp baking powder and 1/2 tsp bicarbonate of soda, and mix all that in. Finally stir 55ml milk and 100g very dark chocolate chunks through the dough. (Green & Black, Lindt and Cote d'Or all make 100g bars with 85-90% cocoa solids which you can chop up into little bits). Chill the mixture for an hour or so in the fridge if you have time.
Then tip it out onto a floured board and squish it into two sausage shapes about 5cm across and 30cm long. Wrap them in baking parchment and shove them in the freezer until needed. They keep for a good few weeks.

When you want cookies, preheat the oven to 200 deg C. Cut off 5mm slices of dough like slicing a salami, and put them on a baking sheet lined with baking parchment (or just well greased). Leave room between them so they can spread out a bit. Bake them for 7 minutes. Let them cool slightly before trying to remove them from the tray, as they're still very soft when they leave the oven.

Compare and Contrast

Here are some edited highlights of a BBC news story published yesterday, about some medical research that only looked at female subjects:

Women... Women... Women... women... women... The women... the study did not include men, the authors believe the findings may not apply to men. The women... men who drink might not do this... the way men and women break down alcohol in their liver may differ, which help might explain why women... you... people should be wary... women... women.

Here are some edited highlights of a BBC news story published today, about some medical research that only looked at male subjects:

you... you... your body... us... we... we... our mood... we... People... we... volunteers... people... volunteers... volunteers... patients... patients.

Book review: The Immortal Life of Henrietta Lacks

My copy, on campus at the University of Thighmarcester. I couldn't wait for the UK version to come out so I ordered the US one for a princely sum, and the VERY NEXT DAY someone offered me a review copy for free. Gah.

Are you a scientist? If you're not, I recommend that you read Rebecca Skloot’s The Immortal Life of Henrietta Lacks because it's a jolly decent popular science book.

But if you are, I urge you to read it, because it is not really a popular science book at all. It has yer standard pop-sci format – human interest, historical background, there's the eccentric genius, here comes the science bit, concentrate… but at heart it's a human story, albeit one that stirs up questions of politics, race relations, and medical ethics. What's inspired about it is that Skloot has inverted the usual "framing" of pop-sci, where personal narratives are a means to inspire the lay reader's interest, and instead uses scientific content to draw nerds like me into caring about a family history.

The family in question is that of Henrietta Lacks, who had eleventy squillion and six offspring: four sons, two daughters, and an immortal cell line cultured from the cancer that killed her in 1951. HeLa cells, as they were labelled, have thrived in laboratories across the world ever since: they’ve been to space, they’ve caught AIDS and Ebola, they’ve tested innumerable drugs, and they’ve caused an international scientific scandal. They’ve even been classed by Van Valen* as a new species of unicellular mammal, a distinction they share only with two transmissible cancers.

Henrietta's eldest daughter, Deborah Lacks, spent twenty years unaware of her mother's legacy, and when – by coincidence – she did find out, she was haunted for as long again by worries about the pain and distress her mother must be feeling as the subject of such horrific experimentation. If at this point you're tempted to snigger at Deborah’s ignorance, as I was when I heard a garbled version of this story thirteen years ago, you just exposed your own. The medical and scientific establishment made no attempt to inform the Lacks family about the situation - unless you count sending a postdoc who spoke little English to sample their blood and talk over their heads about adrenergic receptor genotypes - and the shadow of the Tuskegee syphilis study alone would have justified almost any level of paranoia. In fact, Deborah’s grace and forgiveness, her eagerness to understand her mother's contribution to science, and the extraordinary manner in which she comes to interpret it, lift the mood of a book that could otherwise have been a relentlessly miserable piece of Improving Literature.

The Immortal Life is thought-provoking, challenging, and downright harrowing at times. I hesitate to say you ought to read it because nobody likes a chore, but thankfully it's well-paced, suspenseful and inherently fascinating, so I only need to say you ought to start reading it and you'll finish it in no time (keep tissues handy if you have a soul - I cried). It's due out in the UK on the 10th of June, so get your pre-order in now so's you can smugly lend it to your friends after it wins a bunch of prizes.

*I will consider myself grown up when I can read the name of this distinguished evolutionary theorist with no accompanying urge to play air guitar.

Got Lurgi? Try Laudanum!

*brushes away cobwebs and comment spam*
Hello! Life got busy and I went away and twittered a lot, and am now debating with myself whether and how to start blogging again. I'm starting to think I'd prefer to write about science under my real name, 'cos then I can claim it as Outreach and Writing For Lay Audiences and all that, but on the other hand I'd rather not attach my real name to too much swearing and pinko-commie-feminazi gubbins because we all know what nasty internet trollbags tend to do when they both disagree with you and know the email address of your employer. I'm sure anyone with ten minutes and a smidge of savvy could work out who I am, but I count on a. internet trollbags having short attention spans and b. my blog never getting very much traffic anyway, which has worked so far. (By Trollbag Logic, of course, writing pseudonymously is paranoid but writing under your real name is asking for trouble.)

Anyway, the lovely DrugMonkey asked for this picture a year ago. I'd only just got round to sending it to him when I also saw this post about historical attitudes to drugs, which reminded me that I had been meaning to blog it.
This is a page from my great-grandmother's cookery notebook. She was a cook in England in the late nineteenth century (yes, we have long generation times in my family). Elsewhere in the notebook she seems to be planning a menu for a visit by Lord Roberts of Kandahar, so her employers were clearly very, very posh. And, whenever they got a cold, very, very high.



Click pic for bigger. Here's a transcript (as best I can read it):
Hethys recipe for cough mixture

1 pennyworth of each
Antimonial Wine
Acetic Acid
Tincture of opium
Oil of aniseed
Essence of peppermint
1/2lb best treacle

Well mix and make up to Pint with water

I'm rather snot-ridden myself at the moment - can anyone sell me a penn'orth of laudanum?

Spot The Difference

Here's a series of recent tweets from excellent pop-sci writer and academic ninja Ben Goldacre, on those infuriating "charity muggers" who stop you in the street and ask you to set up a direct debit to a charity, of which their company gets a cut:

charity muggers mean your experience of walking down the street is defined by having to say "no" all the time. this is really corrosive.

also, when i'm walking down the street, i'm thinking, and it's really important time to me. someone is paid to ruin it, for a margin.

RT @Natt: Realised the other day that I had developed a semi-permanent street-scowl to discourage them. And to put me in a bad mood.

how can this be healthy for a community? not sort of thing you'd make illegal, but massive, collective censure, surely?

okay, i want an idea for collective action, that any individual approached can use, to eradicate charity mugging. t-shirt+glory to best.

RT @WHOMcD: Eckhart saw this coming. Forced facial expressions drive mood. Charities may be materially increasing the crime rate!

OK: you're minding your own business, and someone interrupts your train of thought, impinges on your time, asks you intrusive questions, persists when you say no politely and gets tetchy when you say no directly. Remind you of anything?

The difference between this and the kind of street harassment women put up with all. the. fucking. time. is that chuggers aren't actually frightening and probably won't outright swear or spit at you or try to follow you home. And I'm none-too-foxy, but I still get catcalled more often than I get approached by a chugger.

Ben's started a #chuggerstop tag. It has a few people defending chuggers by saying they raise a lot for charidee. Strangely, however, there's been no "can't you just take three seconds to be polite" and no "they think you look wealthy and generous, so you should be flattered!" and no "just ignore it" and no "well you should expect that to happen if you go to the shopping centre at that time of day" and certainly no "don't get so angry, haven't you anything important to worry about?"
I can't think of a witty closing sentence, so I'll just beat my head against this handy wall.

THUNK.
THONK.
THOP.

Just Ask A Brit! and then delete her answer

I happened across this post attempting to scare fat Americans with bogeystories about fat people being denied medical treatment under "socialised healthcare". (I gather similar scare stories are being told to old Americans, along the lines of "The gubmint will come round on your 65th birthday and SHOOT YOU".)

Anyway, said post contained the line If you think it can’t happen, ask someone who lives in the United Kingdom or elsewhere. They’ll set you straight on that, and quickly.

So I commented saying yes, please do ask someone who lives in the UK! I'm one! And what d'you know, it seems they deleted my comment. It's possible it's some kind of auto-mod, although the comment showed up earlier and had no links or swearies in. Their blog, their rules an'all that, so I thought I might as well put what I can remember of my answer here, with extra ranting:


Contrary to popular American belief, NHS hospitals do not look like this.

I can tell you dozens of stories of fat friendsandrelations (and myself - I think I'm currently "overweight" by BMI) getting excellent, prompt treatment on the NHS. I've never known anyone be denied treatment on the basis of weight, although I've heard about it on the news occasionally regarding knee replacements. (Of course, US insurance companies often deny treatment to fat people too. And I'm sure there's as much prejudice here as anywhere.)

I've lived in the US (with good insurance), so I know both systems a bit. I've never known anyone who's lived under both systems who prefers the US one - an impression borne out by the comments here.
And to those of us who grew up outside the US, your system with its 22000 preventable deaths a year and its bankruptcies and its get-cancer-lose-your-house and its I've-spilt-a-chip-pan-down-myself-but-I-can't-afford-to-go-to-the-hospital and its "you're a biologist, do you think my kidney pain might be something serious?" looks utterly, criminally insane.

Well, you did ask.

Change at Baker Street

Has it been ten weeks? Urk. I blame Twitter for letting off too much blogsteam.



Youse should all go and see Robin's play Broken Holmes on the Edinburgh Fringe.
It's got witty metafictional gubbins, knob jokes, angst, murder and poisonous snakes. And the cast are brilliant. I went to a preview in a pub in that there London, and had to leave my beer undrunk during the performance for fear of laughing it up my nose. You can, and should, buy tickets here.

The Singh thing: law being an ass

Disclaimery bobbins: I kno o about law. This post is my opinion based on a bit of cursory reading and if you want 100% reliable truefacts the legal bloggers are a much better place to look.

The blogs are all over this story, but it's not in the papers yet. Physicist Simon Singh followed up his successful pop-sci book Fermat's Last Theorem with a new one called Trick or Treatment? on alternative medicine. In it, he called out* the British Chiropractic Association for promoting bogus treatments. The BCA, as is usual for a pore ole downtrodden group of penniless but well-meaning practitioners who just want a chance to debate the evidence, sent in the legal team.

The libel court's preliminary ruling, which lawblogger Jack of Kent describes as astonishing, was that to defend himself, Singh will have to prove that the BCA are deliberately and knowingly lying to patients. This is going to be almost impossible, because they are probably not doing so, which is why Singh never said they were in the first place. He was saying the treatments don't work, which they don't, and that the BCA promotes them, which it does.

I wish Simon all the best with the case and will for deffo buy his book now.

*In the present-day American meaning of "publicly challenged them", not the Regency "slapped them in the face with a glove, dashed a glass of Burgundy over their small-clothes and demanded single combat." Although that would be much cooler.

I fear change

but I signed up for one of them there twitter accounts anyway. I used my real name, so if you know it, you can find out what I had for lunch without all that tedious mucking about with blogs. Interweb friends who don't know my real name are welcome to email me and ask!

Also, sorry I didn't join in Blog Against Disablism Day like I said I would. Blogger wouldn't let me post because some lagging mongrel of a 'bot thought it was spam. It's true: my blog ate my homework.