Theodore Boveri, the renowned German cytologist and geneticist, was born on 12 October 1862 in Bamberg, Germany. After completing his elementary education in Bamberg, he studied Latin, Greek, and Science at the Real Gymnasium in Nürnberg and graduated in 1881. He went on to study history and philosophy at Munich University, but soon decided to pursue Natural Science instead. He received a PhD in Medicine in 1885 - his thesis was titled ‘Contributions to the Study of Nerve Fibers’ - and he received his postdoctoral teaching qualification in 1887.
Boveri worked with the German scientist Anton Dohrn in Naples in the winter of 1887-1888. In 1891, he joined Munich University as an Assistant at the Zoological Institute. The following year, he moved to Wurzburg University to take up a position there as the Zoology Professor. Boveri proved to be one of the most popular teachers at Wurzburg. One of his pupils was the American Vassar College Professor, Marcella O’ Grady. He married her on 5 October 1897 in Boston.
Ill-health prevented Boveri from becoming the Director of the Berlin-based Kaiser Wilhelm Institute of Biology in 1912. He died on 15 October 1915.
In the late nineteenth century, genetic research was still in its infancy, and while the presence of chromosomes was known to researchers, they did not know their exact function at different stages of the reproduction process.
Boveri studied the work of the Belgian researcher Edouard van Beneden and used that as a basis for his own research. He carried out scientific research experiments on Ascaris megalocephala (horse roundworm), on sea urchins, and on rabbits.
Edouard van Beneden had discovered the area in the cell that contained the centriole. Boveri found that van Beneden was correct in his assumption that this was the center of cell division and he named it the centrosome.
In his research, he noticed that the roundworm cells, as they divided, showed specific lobes that were then seen in the same order in the newly formed cells. This indicated both chromosomal activity, and that a specific chromosomal sequence was followed during cell division.
Boveri’s scientific research also proved van Beneden’s theory correct that during fertilization the egg and the sperm contributed an equal number of chromosomes to the zygote. If the chromosomal number in divided cells was unequal, as happened when he induced double fertilization in sea urchin eggs, the resultant embryos turned out to be abnormal. This meant that for normal development, specific sets of chromosomes were absolutely necessary, and that in turn meant that individual chromosomes each had specific properties. Boveri published a paper on these experiments in 1902.
In 1903, Theodore Boveri published a paper on the importance of chromosomes in heredity. He proposed that the chromosomes contained genes that were responsible for hereditary characteristics. The American scientist Walter Sutton had independently come to the same conclusion and this hypothesis became known as the Sutton-Boveri theory of heredity. It made the genetics research path easier for geneticists of the twentieth century.
Working with his wife Marcella, Boveri conducted research on cancer causing cells and proposed that there was a genetic cause for cancer. Their research findings showed that cancer was caused by cells with defective chromosomes. The defective chromosomes led to uncontrollable cell division and so to cancer. Research in more modern times appears to agree with their conclusions.