Immaculate mice

Immaculate mice

Don’t let the understated headline in the August 1 issue of the journal Cell fool you.

If the paper “Post-Gastrulation Synthetic Embryos Generated Ex Utero from Mouse Naïve ESCs” is to be believed — and given the stature of the journal, and the track record of Dr. Jacob Hanna of Weizmann’s molecular genetics department, who led the team of two dozen Israeli scientists who cowrote the paper — it seems that the Start Up Nation is now on the cutting edge of immaculate conception — a field where Israel’s reputation has loomed large, despite little tangible evidence.

(Photo courtesy of Weizmann Institute)

Now, according to their report, the Weizmann researchers have grown synthetic embryo models of mice from stem cells cultured in a petri dish.

That is to say, no sex cells — neither sperm nor eggs — were used in the making of the protomice.

The researchers say that their goal is to study how stem cells form various organs in the developing embryo, with the aim of someday being able to grow human tissue and organs for transplants.

“The embryo is the best organ-making machine and the best 3D bioprinter. We tried to emulate what it does,” Dr. Hanna explained, apparently unaware of the implications for Christian theology of the possibility of growing people from stem cells, rather than through sex cells tainted by original sin.

Hanna’s work built on two previous advances from his lab: an efficient method for reprogramming stem cells back to their earliest stage and an electronically controlled device for growing natural mouse embryos outside the womb.

In the current experiment, 50 of around 10,000 stem cells successfully developed into embryo-like structures. By eight and a half days later — nearly half of the mouse’s 20-day gestation — each embryo had formed a beating heart, blood stem cell circulation, a brain with well-shaped folds, a neural tube, and an intestinal tract.

The synthetic models were judged to be 95 percent identical to natural mouse embryos in terms of the shape of internal structures and the gene expression patterns of different cell types.

Issues of immaculate conception aside, growing synthetic embryos solely from stem cells cultured in a petri dish could, to a large extent, help researchers avoid the technical and ethical issues involved in using human embryos in research and biotechnology — a particular concern, now that moves are being made to define embryos as fully human in the eyes of the law in some states.

Even with mice, certain experiments now are impossible because they would require thousands of embryos. The stem-cell embryos could be grown in incubators by the millions.

Larry Yudelson &

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