The Boveri–Sutton chromosome theory (also known as the chromosome theory of inheritance or the Sutton–Boveri theory) is a fundamental unifying theory of

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...

which identifies

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s as the carriers of

genetic material Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic aci ...

.1902: Theodor Boveri (1862-1915) and Walter Sutton (1877-1916) propose that chromosomes bear hereditary factors in accordance with Mendelian laws
Genetics and Genomics Timeline. Genome News Network an online publication of the J. Craig Venter Institute.
Holmgren Lab Northwestern University.Mader, S. S. (2007). Biology 9th Ed. McGraw Hill Higher Education, Boston, MA, USA. It correctly explains the mechanism underlying the laws of

Mendelian inheritance Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularize ...

by identifying chromosomes with the paired factors (particles) required by Mendel's laws. It also states that chromosomes are linear structures with

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

s located at specific sites called loci along them. It states simply that chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance. Over a period of time random mutation creates changes in the DNA sequence of a gene. Genes are located on chromosomes.

Background

The chromosome theory of inheritance is credited to papers by Walter Sutton in 1902 and 1903, as well as to independent work by Theodor Boveri during roughly the same period. Boveri was studying

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

s, in which he found that all the chromosomes had to be present for proper

embryonic development In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermat ...

to take place. Sutton's work with

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...

s showed that chromosomes occur in matched pairs of maternal and paternal chromosomes which separate during meiosis and "may constitute the physical basis of the Mendelian law of heredity". This groundbreaking work led E.B. Wilson in his classic text to name the chromosome theory of inheritance the "Sutton-Boveri Theory". Wilson was close to both men since the young Sutton was his student and the prominent Boveri was his friend (in fact, Wilson dedicated the aforementioned book to Boveri). Although the naming precedence is now often reversed to "Boveri-Sutton", there are some who argue that Boveri did not actually articulate the theory until 1904.

Verification

The proposal that chromosomes carried the factors of Mendelian inheritance was initially controversial, but in 1905 it gained strong support when Nettie Stevens showed that the "accessory chromosome" of mealworms' sperm cells was decisive in the sex identity of the progeny,NM Stevens, (1905) “Studies in Spermatogenesis, with Especial Reference to the ‘Accessory Chromosome,’” Washington, DC, Carnegie Institution of Washington, Publication 36, NM Stevens, (1906) . “Studies in Spermatogenesis Part II, A Comparative Study of Heterochromosomes in certain Species of Coleoptera, Hemiptera, and Lepidoptera with Especial Reference to Sex Determination,” Washington, DC, Carnegie Institution of Washington, Publication 36, Part II, (1906) a discovery supported by her mentor E.B. Wilson. Later, Eleanor Carothers documented definitive evidence of

independent assortment Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized ...

of chromosomes in a species of grasshopper.Crow, E.W. and Crow, J. F.
100 Years Ago: Walter Sutton and the Chromosome Theory of Heredity
''Genetics,'' Vol. 160, 1-4, January 2002 Debate continued, however, until 1915 when

Thomas Hunt Morgan Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an Americans, American evolutionary biologist, geneticist, Embryology, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries e ...

's work on inheritance and

genetic linkage Genetic linkage is the tendency of Nucleic acid sequence, DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction. Two Genetic marker, genetic markers that are physically near ...

in the fruit fly ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

'' provided incontrovertible evidence for the proposal. The unifying theory stated that inheritance patterns may be generally explained by assuming that genes are located in specific sites on chromosomes.

References

External links

Each Organism's Traits Are Inherited from a Parent through Transmission of DNA
SciTable by Nature Education. {{DEFAULTSORT:Boveri-Sutton Chromosome Theory Biology theories Cell biology History of genetics