RITA Levi-Montalcini, a biologist who conducted underground research in defiance of Fascist persecution and went on to win a Nobel prize for helping unlock the mysteries of the cell, has died at her home in Rome. She was 103 and had worked well into her final years.
Rome mayor Gianni Alemanno, announcing her death in a statement on Sunday, called it a great loss ''for all of humanity''.
Italy's so-called ''Lady of the Cells'', a Jew who lived through anti-Semitic discrimination and the Nazi invasion, became one of her country's leading scientists and shared the Nobel medicine prize in 1986 with American biochemist Stanley Cohen for their groundbreaking research carried out in the US. Her research increased the understanding of many conditions, including tumours, developmental malformations and senile dementia.
Italy honoured Dr Levi-Montalcini in 2001 by making her a senator-for-life.
A petite woman with upswept white hair, she kept an intensive work schedule well into old age.
''A beacon of life is extinguished'' with her death, said a niece, Piera Levi-Montalcini, who is a councillor in the northern city of Turin.
Dr Levi-Montalcini was born on April 22, 1909, to a Jewish family in Turin. At the age of 20 she overcame her father's objections that women should not study and obtained a degree in medicine and surgery from Turin University in 1936.
She studied under top anatomist Giuseppe Levi, whom she often credited for her own success and for that of two fellow students and close friends, Salvador Luria and Renato Dulbecco, who also became separate Nobel prize winners. Professor Levi and Dr Levi-Montalcini were not related.
After graduating, Dr Levi-Montalcini began working as a research assistant in neurobiology but lost her job in 1938 when Italy's Fascist regime passed laws barring Jews from universities and major professions.
Her family decided to stay in Italy and, as World War II neared, Dr Levi-Montalcini created a makeshift laboratory in her bedroom, where she began studying the development of chicken embryos, which would later lead to her major discovery of mechanisms that regulate the growth of cells and organs.
With eggs becoming a rarity because of the war, the young scientist biked around the countryside to buy them from farmers. She was soon joined in her secret research by Professor Levi, her university mentor, who was also Jewish.
''She worked in primitive conditions,'' Italian astrophysicist Margherita Hack said in a tribute to her fellow scientist. ''She is really someone to be admired.''
The 1943 German entry into Italy forced the Levi-Montalcini family to flee to Florence and live underground. After the Allies liberated the city, she worked as a doctor at a centre for refugees.
In 1947, Dr Levi-Montalcini was invited to the US, where she remained for more than 20 years, which she called ''the happiest and most productive'' of her life.
During her research at Washington University in St Louis, Missouri, she discovered nerve growth factor, the first substance known to regulate the growth of cells. She showed that when tumours from mice were transplanted to chicken embryos, they induced rapid growth of the embryonic nervous system.
She concluded the tumour released a nerve growth-promoting factor that affected certain types of cells.
The research increased the understanding of many conditions, including tumours, developmental malformations and senile dementia. It also led to the discovery by Professor Cohen of another substance, epidermal growth factor, which stimulates the proliferation of epithelial cells.
The two shared the Nobel prize for medicine in 1986. AP