St?©phanie Bayol and Neil Stickland at the Royal Veterinary College, London fed female rats a "junk food" diet of crisps, cheese, muffins and other processed foods throughout pregnancy and lactation.

The offspring, who were overweight at birth, were born with a taste for junk-food themselves. But even when fed a healthy diet, the junk-food babies had a host of medical problems that lasted beyond adolescence into adulthood.

The rats had raised cholesterol and triglyceride levels - both associated with heart disease. Insulin and glucose in the blood were also unusually high, known to be a cause of type-2 diabetes. And the rats remained significantly podgier than normal with extra fat around the kidneys, another diabetes risk-factor.

The female offspring were particularly badly affected, expressing high levels of glucose and the appetite-promoting hormone leptin making them very prone to obesity.

"It seems that a mother's diet whilst pregnant and breastfeeding is very important for the long term health of her child," says Dr Bayol. "This does not mean that obesity and poor health is inevitable and it is important that we take care of ourselves and live a healthy lifestyle. But it does mean that mothers must eat responsibly whilst pregnant."

But will these results translate to humans? Very probably, says Professor Stickland. "Humans share a number of fundamental biological systems with rats, so there is good reason to assume the effects we see in rats may be repeated in humans," he says. "Our research certainly tallies with epidemiological studies linking children's weight to that of their parents."

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Adding protein to the cassava plant has posed a challenge, Sayre said. The scientists discovered that most of the nitrogen required to make the amino acids used for protein synthesis in roots is derived from the cyanogens that also cause cyanide toxicity. So their strategy for increasing protein levels in roots focuses on accelerating the conversion of cyanide-containing compounds into protein rather than completely eliminating cyanogen production, which would hinder the efforts to increase protein production, Sayre explained. To further address the cyanide problem, the scientists have also developed a way to accelerate the processing methods required to remove cyanide - a days-long combination of peeling, soaking and drying the roots before they are eaten.

To strengthen the cassava plant's resistance to viruses, the scientists introduced a protein and small interfering RNA molecules that interfere with the viruses' ability to reproduce.

Prolonging cassava's shelf life has involved the development of a hybrid species that crosses two related plants native to Texas and Brazil. The strategy, still in development, will combine the properties of these plants and additional genes that function as antioxidants, slowing the rotting process that has been traced to the production of free radicals that damage and kill cells in newly harvested cassava roots.

The first cassava product the team plans to develop for investigations in the field will likely include the virus resistance, elevated protein, elevated beta-carotene (pro-vitamin A) and elevated minerals (iron and zinc), Sayre said.

"These traits have been working the best in the greenhouse, and the virus resistance is critical to success in the field," he said. "The thinking behind starting with these four traits is driven by science and by the impact they can have."

The BioCassava Plus project was launched with a $7.5 million grant from the Gates Foundation and recently received an additional $4.6 million in supplemental funding from the foundation to accelerate the application of this research in Africa by African scientists. The supplemental funding will support the training of African scientists so they can produce the transgenic plants in African institutions for use on African farms.

"It will not only be an improved staple crop eaten as a main source of nutrition, but we're also looking at the transformation of cassava from a staple crop to an income-generating crop," Sayre said. "That lifts people out of poverty, allows families to send kids to school and build infrastructure in their villages, so this is an important way to cross cultural barriers. There are many different cultures and languages in Africa, but higher crop yield, productivity, longer shelf life and making money are things that everyone understands."

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