Just dial ‘N’ to order an offspring with ‘niceness’

Originally published 1 February 1993

Are you ready for this? Sperm sorting.

I’m not kid­ding. Sci­en­tists at a British com­pa­ny called Mas­ter­calf, in col­lab­o­ra­tion with the Unit­ed States Depart­ment of Agri­cul­ture, have devised a tech­nique that enables them to sep­a­rate sperm accord­ing to the gene which deter­mines sex. These peo­ple are basi­cal­ly in the cat­tle busi­ness: Dairy farm­ers pre­fer female calves, and meat farm­ers pre­fer male calves. Arti­fi­cial insem­i­na­tion with sort­ed sperm answers both needs.

In cat­tle, as in all mam­mals, X and Y chro­mo­somes deter­mine sex. All nor­mal cells of a cow con­tain two X chro­mo­somes, and an egg bears a sin­gle X. The cells of a bull con­tain both an X and a Y chro­mo­some, and a sperm har­bors one or the oth­er. The sex of an embryo — XX or XY — depends upon which chro­mo­some was car­ried by the sperm to the wait­ing egg.

So how to sort? Well, X chro­mo­somes are larg­er than Y chro­mo­somes; they con­tain 4 per­cent more DNA. The folks at Mas­ter­calf treat the sperm with a flu­o­res­cent dye that sticks to DNA, then illu­mi­nate the sperm with a laser beam. An X‑bearing sperm glows more bright­ly than a Y‑bearing sperm. The lumi­nous lit­tle wig­glers are caused to stream sin­gle-file past a detec­tor that gives them a pos­i­tive or neg­a­tive elec­tric charge depend­ing on their bright­ness. The sperm are then shot out of a device very much like the print­ing head of an ink-jet print­er, and deflect­ed one way or anoth­er accord­ing to their charge.

So far, the Mas­ter­calf researchers are sort­ing sperm at a rate of about 100 per sec­ond. This is peanuts when you con­sid­er than a nor­mal bull ejac­u­late con­tains upwards of 7 bil­lion sperm, but ade­quate for in vit­ro fer­til­iza­tion. Farm­ers will soon be able to order up calves of pre­de­ter­mined sex.

What works for bulls and cows can in prin­ci­ple work for humans too. Sure­ly, it won’t be long before a Japan­ese com­pa­ny pack­ages the process in con­dom-like devices with built-in sort­ing mech­a­nisms — blue devices for boy babies, pink for girls.

The Sony Sperm-jet.

All of which brings to mind the famous scene in Woody Allen’s Every­thing You Always Want­ed To Know About Sex* (*But Were Afraid To Ask) in which actors dressed as sperm are lined up pri­or to ejac­u­la­tion like para­troop­ers wait­ing to bail out of an air­plane, includ­ing Woody ner­vous­ly play­ing “Red Riv­er Val­ley” on a har­mon­i­ca. Except this time add the Sperm-jet appa­ra­tus. Woody is doused with a buck­et of dye, blast­ed with a laser, trot­ted past a pho­tode­tec­tor, zapped with elec­tric charge, and shot wide-eyed into the blue.

Only Allen in his com­ic prime could do jus­tice to the work of the peo­ple from Mastercalf.

And why stop with the genes for sex? Sci­en­tists are rapid­ly map­ping all parts of human DNA. In the not-too-dis­tance future we’ll know where among the chro­mo­somes to find the gene for eye-col­or, skin-pig­ment, innate intel­li­gence, and God-knows-what-else. Flu­o­res­cent dyes will be devel­oped that stick to spe­cif­ic seg­ments of DNA, and sperm sort­ing can begin on a mas­sive scale.

Would-be par­ents will avail them­selves of com­mer­cial sperm-sort­ing ser­vices with access to large banks of donat­ed sperm. These ser­vices would use the Sony Mas­tersperm-jet appa­ra­tus to cus­tomize off­spring — at least inso­far as the male con­tri­bu­tion is con­cerned. Set a knob for blond, anoth­er for curly hair, anoth­er for 5 feet 9 inch­es. Slosh, flash, zap, zip — you get just the kid you want.

I can see it now. Fads in off­spring will no longer be lim­it­ed to names. One year we’ll have noth­ing but blond, blue-eyed, female cheer­leader-types named Jen­nifer. The next year, it’ll be all male Michael Jack­son look-alikes named Jason. Teach­ers of the next cen­tu­ry will walk into class­rooms in Sep­tem­ber to find thir­ty-five short, thin, red-head­ed boys with freck­les and horn-rimmed glasses.

Woody, oh Woody, where are you now that we need you?

The mind reels at the pos­si­bil­i­ties. We’ve been read­ing late­ly about genes that pre­dis­pose us towards divorce or vio­lence, and genes that deter­mine sex­u­al ori­en­ta­tion. The jour­nal Sci­ence report­ed evi­dence of a gene for “nice­ness.” No kid­ding. A British psy­chol­o­gist admin­is­tered ques­tion­naires to the par­ents of 160 pairs of iden­ti­cal twins and 213 pairs of fra­ter­nal twins aged 5 to 16. Each child was rat­ed for socia­bil­i­ty and pro-social behav­ior. Both iden­ti­cal twins, who share genes and envi­ron­ment, were more like­ly to be nice than fra­ter­nal twins, who share envi­ron­ment only, sug­gest­ing that a pre­dis­po­si­tion towards nice­ness can be genetic.

Mind you, this sort of sci­ence is more appro­pri­ate for a Woody Allen movie than the pres­ti­gious pages of Sci­ence, but you can see what I’m get­ting at. The Sony Ultra­mas­tersperm-jet appa­ra­tus will have a set­ting for niceness.

And now, imag­ine this. Woody in his spermsuit, jog­ging with the oth­er sperm through the dye-room of the appa­ra­tus, bob­bing and weav­ing, try­ing des­per­ate­ly to avoid the dye for “nice.”