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發現與再發現之間的事
件與認知
以孟德爾為例子
For lecture only; BC Yang
 In 1833, even before Schleiden and Schwann
had presented their cell theory, Robert Brown
had described an ovoid in the cell as the
"nucleus", and Dumortier and von Mohl had
discovered binary fission of the nucleus and
cell. Remak gave the first descriptions of the
changes that occur in the nucleus, and Purkinje
underlined its importance and the requirement
for this organelle throughout the life of a cell.
細節請看: http://www.zoo.uniheidelberg.de/lankenau/Teaching/Vorlesung/stunde16/stunde_16.htm
For lecture only; BC Yang
Francis Galton (1822-1911)
offers a statistical approach to
understanding inheritance.
達爾文的姪子
 Employing impressionistic data about talented individuals and their families,
Galton proposed the "law of ancestral inheritance" in 1876. Revised several
times over the next two decades, Galton's basic conception was that, on
average, each parent provides offspring with one quarter of inherited traits,
while grandparents contribute the rest.
Francis Galton The "law of ancestral heredity," as it turned out, was
mistaken. Although he was interested in individual variations, Galton's
mathematical methods treated them as "errors." In Gregor Mendel's more
carefully conceived experiments with culinary peas, variations represented
the expression of discrete alternative factors or (as we would say today)
genes. Galton, in his personal correspondence with Darwin, came close to
this conception, but never proceeded to a testable formulation.
http://www.genomenewsnetwork.org/timeline/1876_Galton.shtml
For lecture only; BC Yang
 1866, Mendel published his lecture, a work that
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was to establish him as “the father of genetics”.
1869 Johann Friedrich Miescher (nuclein)
1873 Anton Schneider (meiosis)
1879 Walther Flemming (chromaton, mitosis)
1888 Wilhelm von Waldeyer-Hartz, (term
chromosome)
1902 Walter Stanborough Sutton. (chromosomes
carry the units of inheritance)
1904 Theodor Boveri (correlation between
Mendel's factors and chromosomes )
1904 William Bateson (genetics)
1909 Wilhelm Johannasen (gene)
DNA to chromosome to DNA
 1869 Johann Friedrich Miescher identifies a weakly acidic
substance of unknown function in the nuclei of human white
blood cells. This substance will later be called
deoxyribonucleic acid, or DNA.
 1924 Microscope studies using stains for DNA and protein
show that both substances are present in chromosomes.
 1928 Franklin Griffith, a British medical officer, discovers
that genetic information can be transferred from heat-killed
bacteria cells to live ones. This phenomenon, called
transformation, provides the first evidence that the genetic
material is a heat-stable chemical.
 1944 Oswald Avery, Maclyn McCarty, and Colin MacLeod,
identify Griffith's transforming agent as DNA.
Good & simple reference to read:
http://www.csuchico.edu/anth/CASP/Carmosino_P.html
 It was while working on pus cells at Tübingen in 1869
that Miescher made his fundamental discovery. It was
thought that such cells were made largely of protein, but
Miescher noted the presence of something that "cannot
belong among any of the protein substances known
hitherto."
 He showed that the new substance was derived from the
nucleus of the cell alone and consequently named it
'nuclein'.
 Miescher was soon able to show that nuclein could be
obtained from many other cells and was unusual in
Miescher, Johann Friedrich II
containing phosphorus in addition to the usual
1844-1895
ingredients of organic molecules - carbon, oxygen,
Switzerlander
nitrogen, and hydrogen. It was not until 1871 that
Miescher's paper, delayed by Hoppe-Seyler (who wanted
to confirm the results), was published.
http://www.laskerfoundation.org/news/gnn/timeline/1869a.html
For lecture only; BC Yang
1873 and after
 The discovery of chromosomes cannot be
pinpointed to a single person. It was a
consequence of the growing interest in the
division processes of the fertilized egg.
 Scientists on cell division : Anton
Schneider, Eduard Strasburger, Otto
Bütschli, Edouard van Beneden, Leopold
Auerbach, Hermann Fol, Walther
Flemming.
For lecture only; BC Yang
 One of the first discoverers was the zoologist
Anton Schneider in 1873 who showed by
adding acetic acid to fertilized eggs of the
plathelmith Mesostomum Ehrenbergii that the
nucleus disappears and that it changes to a
bulk of thin threads subsequently becoming
thicker and differentiating along an axis
through the cell. The fibers finally separate and
can be followed into each of the new cells
formed from each other by lacing in from the
edges of the original cell.
 Schneider remarked: "These (observations) for
the first time show us how intricate the
metamorphosis of the nucleus (the germ
pustule) is during cell division."
是這個
嗎??
Friedlich Anton Schneider, 1873 Untersuchung
uber Platyhelminthen in: Oberhessischen
Gesellschagt fur Natur-und Heilkinden 14:69-140.
Walther Flemming
1843 - 1905
 1879: he described and
named "chromaton",
"mitosis" and "spireme",
made the first accurate
counts of chromosome
numbers and figured the
longitudinal splitting of
chromosomes.
http://www.nature.com/cgitaf/DynaPage.taf?file=/nrm/journal/v2/n1/full/nrm0101_072a_r.html
For lecture only; BC Yang
 Flemming observed for the
first time that the
chromosomes during cell
division became split along
their longitudinal axis, now
known to consist of
chromatids, and in 1880 he
formulated the sentence:
"Omnis nucleus e nucleo".
 All nuclei come from nuclei
(1863), omnis cellula e cellula
The term chromosome, the name was introduced
in 1888 by von Waldeyer, and the process of cell
division were now well established.
• Waldeyer-Hartz, Wilhelm von
(German). 1888. Über Karyokinese
und ihre Beziehungen zu den
Befruchtungsvorgängen. Archiv für
mikroskopische Anatomie und
Entwicklungsmechanik 32: 1-122
1836-1921
http://vlp.mpiwg-berlin.mpg.de/people/data/per357.html
For lecture only; BC Yang
Walter Stanborough Sutton.
 He was the U.S. geneticist (and also
surgeon) who provided the first conclusive
evidence that chromosomes carry the units
of inheritance and occur in distinct pairs.
 The two papers (Sutton, 1902, 1903)
written as a graduate student under E. B.
Wilson at Columbia University formulated
the concept that chromosomes carried the
units of heredity and explained Mendel's
laws.
1877-1916
http://www.kumc.edu/research/medicine/anatomy/sutton/surgical_career.html
http://post.queensu.ca/~forsdyke/guyer.htm#Chromosomes%20in%20Heredity
For lecture only; BC Yang
I believe this is what Sutton has
seen during his study at
Columbia University
(BC, 2004)
 While he was working as a
graduate student at Columbia
University, studying grasshopper
cells, Sutton observed that
chromosomes occurred in distinct
pairs, and that during meiosis, the
chromosome pairs split, and each
chromosome goes to its own cell.
Sutton announced this discovery in
his 1902 paper On the Morphology
of the Chromosome Group in
Brachyotola.
http://www.kumc.edu/research/medicine/anatomy/sutton/surgical_career.html
For lecture only; BC Yang
 On pages 24-39 of Biological Bulletin, dated October
17th 1902, Sutton noted Montgomery's "suggestion that
maternal chromosomes unite with paternal ones in
synapsis" and briefly called "attention to the probability
that the association of paternal and maternal
chromosomes in pairs and their subsequent separation
during the reducing division ... may constitute the
physical basis of the Mendelian law of heredity."
 This was amplified in the 1903 paper (Biological
Bulletin 1903; 4, 231-251) which, summarizing the
above work and that of Montgomery, Bateson and
Saunders, Bovari, McClung, and himself, set out quite
clearly the idea of the random assortment of paternal
and maternal chromosomes in germ cells where meiosis
is normal (no hybrid sterility).
For lecture only; BC Yang
Theodor Boveri (1862-1915)
 He saw that as egg cells matured, there
comes a point where chromosome numbers
are reduced in half. Boveri was one of the
first to see evidence of the process of meiosis.
(In the late 1880's and early 1890's)
 When Mendel's laws were rediscovered in
1900, Boveri recognized the correlation
between Mendel's factors and the cytology
work being done on chromosomes (1904?).
Some one had already improved the staining technique for chromosomes
http://www.dnaftb.org/dnaftb/concept_8/con8bio.html
For lecture only; BC Yang
 Theodor Boveri, making use of the ideas from
Carl Rabl put forward the hypothesis of the
constancy of the amount of chromosomes and
of their continuity during the Interphase stages
of the nucleus (1887-1888). In 1904 Boveri
already even thought it might be possible that
the pairing of chromosomes would result in an
exchange of genetic substance.
來源資料待查
Bamburg, Deutshland
For lecture only; BC Yang
William Bateson (1861-1926)
William Bateson describes gene linkage, showing that more
than one gene may be required for a particular characteristic or
trait (1904).
A hereditary factor like, for example, the shape of the seed, the
colour of the cotyledons or the colour of the seed shell shall be
called a gene (following a suggestion of BATESON made in
1905).
http://post.queensu.ca/~forsdyke/bateson1.htm
For lecture only; BC Yang
http://www.dnaftb.org/dnaftb/concept_5/con5gallery.html
First page of a 1905 letter written by William Bateson, first Director of the
John Innes Institute, to Adam Sedgewick, Cambridge professor. Bateson
coined the term "genetics" in this letter. he felt the need for a new term to
describe the study of heredity and inherited variations. But the term didn’t
start spreading until Wilhelm Johannsen suggested that the Mendelian
factors of inheritance be called genes.
For lecture only; BC Yang
Wilhelm Johannasen
1857-1927
 Danish botanist Wilhelm Johannsen coined
the word gene (1909) to describe the
Mendelian units of heredity.
 He also made the distinction between the
outward appearance of an individual
(phenotype) and its genetic traits (genotype).
 The proposed word traced from the Greek
word genos, meaning "birth". The word
spawned others, like genome.
http://www.genome.gov/Pages/Education/Kit/main.cfm?pageid=24
For lecture only; BC Yang
Are you satisfied to
accept the Mendel’s
laws?
For lecture only; BC Yang