Torbjörn Caspersson
Encyclopedia
Professor Torbjörn Oskar Caspersson (15 October 1910 – 7 December 1997) was a Swedish
cytologist
and geneticist
. He was born in Motala
and attended the University of Stockholm, where he studied medicine
and biophysics
.
Caspersson made several key contributions to biology.
In 1977 he retired as head of the medical cell research and genetics department at the Karolinska Institute in Stockholm
In 1979 Caspersson was awarded the Balzan Prize
for Biology "For his fundamental studies on protein metabolism and nucleic acids, culminating in a method for identifying specific bands on individual chromosomes by ultraviolet microscopy, thereby creating a new tool for the study of evolution" (motivation of the Balzan General Prize Committee).
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
cytologist
Cell biology
Cell biology is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level...
and geneticist
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
. He was born in Motala
Motala
Motala is a locality and the seat of Motala Municipality, Östergötland County, Sweden with 29,798 inhabitants in 2005. It is the third largest city of Östergötland, following Linköping and Norrköping...
and attended the University of Stockholm, where he studied medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
and biophysics
Biophysics
Biophysics is an interdisciplinary science that uses the methods of physical science to study biological systems. Studies included under the branches of biophysics span all levels of biological organization, from the molecular scale to whole organisms and ecosystems...
.
Caspersson made several key contributions to biology.
- In the 1934 he and Einar Hammarsten showed that DNA was a polymer. Previous theories suggested that each molecule was only ten nucleotides long.
- He provided William AstburyWilliam AstburyWilliam Thomas Astbury FRS was an English physicist and molecular biologist who made pioneering X-ray diffraction studies of biological molecules. His work on keratin provided the foundation for Linus Pauling's discovery of the alpha helix...
with well prepared samples of DNADNADeoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
for Astbury's pioneering structural measurements. - In 1936, in his doctoral thesis in chemistry, presented at the Karolinska Institute in Stockholm, he first studied genetic material inside a cellCell (biology)The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
with an ultravioletUltravioletUltraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
microscopeMicroscopeA microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
to determine the nucleic acid content of cellular structures such as the nucleusCell nucleusIn cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
and nucleolusNucleolusThe nucleolus is a non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA is transcribed and assembled within the nucleolus...
using the Feulgen reaction to stain the DNA. - He worked with Jack Schultz in Stockholm from 1937-1939 on protein synthesis is cells and published the work in 1939, where he independent of Jean BrachetJean BrachetJean Louis Auguste Brachet was a Belgian biochemist who made a key contribution in understanding the role of RNA....
, working out the same problem using a different technique, found that cells making proteins are rich in ribonucleic acids RNARNARibonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
, implying that RNA is required to make proteinProteinProteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s. This was summarised in his book 'Cell Growth and Cell Function' (1950). - He received a personal professorship from the Swedish state in 1944.
- He became head of the newly created department for cell research and genetics at the Medical Nobel Institute, at the Karolinska, in 1945.
- He was the first study the giant chromosomes found in insect larvae.
- He studied the role of the nucleolus in protein synthesis.
- He examined the relationship between the quantity of heterochromatin (chromosomes with few genes) and the rate of growth of cancer cells.
- In 1969 when working at the Karolinska Institute, he (with Lore Zech) found that a stain (quinacrine mustard) caused chromosomeChromosomeA chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s to show light and dark lateral bands along their length. This banding method permits the accurate identification of all 22 autosomeAutosomeAn autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
s and the XX chromosomeThe X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
and YY chromosomeThe Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
chromosomes. This technique highlighted slight structural abnormalities and specific identification of the extra chromosomes involved in conditions such as Down's syndrome (see also cytogeneticsCytogeneticsCytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ...
).
In 1977 he retired as head of the medical cell research and genetics department at the Karolinska Institute in Stockholm
In 1979 Caspersson was awarded the Balzan Prize
Balzan Prize
The International Balzan Prize Foundation awards four annual monetary prizes to people or organisations who have made outstanding achievements in the fields of humanities, natural sciences, culture, as well as for endeavours for peace and the brotherhood of man.-Rewards and assets:Each year the...
for Biology "For his fundamental studies on protein metabolism and nucleic acids, culminating in a method for identifying specific bands on individual chromosomes by ultraviolet microscopy, thereby creating a new tool for the study of evolution" (motivation of the Balzan General Prize Committee).