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Lampbrush chromosome. Lampbrush chromosome are a special form of chromosome found in the growing oocytes (immature eggs) of most animals, except mammals. They were first described by Walther Flemming and Ruckert in 1882. [1] Lampbrush chromosomes of tailed and tailless amphibians, birds and insects are described best of all.
Lampbrush chromosome from the cell nucleus of an ovarial egg from Triton sp., a salamander. Harold Garnet Callan FRS FRSE (15 March 1917, in Maidenhead – 3 November 1993), [1] known as Mick Callan, was an English zoologist and cytologist. [2] He is especially remembered for his work on Lampbrush chromosomes.
Joseph Grafton Gall (April 14, 1928 – September 12, 2024) was an American cell biologist whose studies revealed many details of chromosome structure and function. Gall's studies were greatly facilitated by his knowledge of many different organisms because he could select the most favorable organism to study when approaching a specific question about nuclear structure.
Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) [2] was an American evolutionary biologist, geneticist, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries elucidating the role that the chromosome plays in heredity.
Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German anatomist, known for summarizing neuron theory [1] and for naming the chromosome. [2] He is also remembered by anatomical structures of the human body which were named after him: Waldeyer's tonsillar ring [ 3 ] (the lymphoid tissue ring of the naso ...
Clarence Erwin McClung (April 5, 1870 – January 17, 1946) was an eminent American zoologist and prairie pioneer cytologist who discovered the role of chromosomes in sex-determination. [ 1 ] [ 2 ] Graduating pharmacy at the University of Kansas in 1892, after a year of teaching he entered the college as a graduate student (A.B.,1896, A.M.,1898 ...
These intensive RNA biosynthese are mirrored in the structure of the chromosomes, which decondense and form lateral loops giving them a lampbrush appearance (see Lampbrush chromosome). Oocyte maturation is the following phase of oocyte development. It occurs at sexual maturity when hormones stimulate the oocyte to complete meiotic division I.
In the 1940s and early 1950s, experiments pointed to DNA as the portion of chromosomes (and perhaps other nucleoproteins) that held genes. A focus on new model organisms such as viruses and bacteria, along with the discovery of the double helical structure of DNA in 1953, marked the transition to the era of molecular genetics.