1.1 - Introduction To Cytogentics Flashcards
It is the branch of genetics that studies the structure of DNA within the cell nucleus
Cytogenetics
Cytogenetics studies the number and morphology of ________.
Chromosomes
What are the two types Cytogenetics?
- Classical Cytogenetics
- Molecular Cytogenetics
Fluorescently labeled probes are under what type of Cytogenetics?
Molecular Cytogenetics
What is the summarization of the development of Cytogenetics?
A. Cell Discovery
B. Chromosome structure & components discovery
C. Human Cytogenetics emergence
Who observed the section of cork by a primitive type of microscope and found that it was made up of small hollow units like honey comb — he termed the structural unit as cell
Robert Hooke
Who published microscopic anatomy of plants and advanced a theory that the stamen corresponds to male, while pistil corresponds to female reproductive organ?
Nehemiah Grew
- Who improved the microscope by the technique of grinding the lens?
- He also reported the studies on free cells such as protozoa and bacteria and thus opened the door to a new world of microorganisms. He also studied blood cells
- Labeled microorganisms as animalcule
Anthony van Leeuwenhoek
- He showed the presence of sex in plants.
- Seeds are not produced unless pollen is applied to the pistil.
- He concluded that pollen is the male element, while pistil is the female element.
Rudolf Jacob Camerarius
- He published the information on his work of plant hybridization
- He made hybrids between different varieties of tobacco and between some plant genera.
- By using reciprocal crosses, he showed the equal contribution of male and female parents to their offspring
Joseph Gottlieb Kolreuter
He proposed a theory of evolution known as Theory of Inheritance of Acquired Characters
Jean Baptiste Lamarck
According to the Theory of Inheritance of Acquired Characters, what are the factors that brings about the variations in an individual?
a. Conscious effort
b. Reaction to environment
c. Use and disuse of organ
According to the Theory of Inheritance of Acquired Characters, what are the two variables that affect one’s inheritance/heredity?
- Variation in an individual is brought about by:
(a) conscious effort,
(b) reaction to environment, and
(c) use and disuse of the organ. - Heredity carries forward the changes that are acquired during the life time of the individual.
- He studied plant cells and discovered nucleus in Tradescantia.
- He described it as a central feature of living cells
Robert Brown
He described cell division and showed that cells arise through partition walls formed between preexisting cells.
Hugo von Mohl
They put forth the cell theory on the basis of accumulated experimental results:
- The cell is the smallest structural element of a multicellular organism and as a unit, it is itself an elementary organism.
- In a multicellular organism, every cell has a specific function to perform, and represents a working unit.
- A cell can only be produced from another cell by cell division.
Matthias Jacob Schleiden & Theodor Schwann
He is the 1st to discover chromosomes in pollen
Karl Nägeli
He introduced aniline staining to observe chromosomes during cell deivision
Walther Flemming
He coined the term “chromosome” after staining techniques had been developed
Henrich Waldeyer
He derived an estimate of 48 chromosomes using images of nuclei reconstructed from thin sections of human testicular tissue embedded in paraffin and stained with iron hematoxylin
Theophilus Painter
Theophilus Painter initially thought that humans contain 24 pairs of chromosomes (48 chromosomes); However it was discovered that _____ contains 48 chromosomes and not humans
Chimpanzees, gorillas
Who corrected the notion that humans contain 24 pairs of chromosomes to 23 pairs chromosomes (46 chromosomes)?
Joe Hin Tijo & Levan (thru somatic cells)
In what year did Cytogenetic technique improvements (use of colchicines to arrest cells in metaphase) occur?
1950
In 1960, the __________ method of Moorehead et al. was adopted by many cytogenetics
Peripheral Leukocyte Culture
What type of anti-gout drug was used to arrest cells in the metaphase stage?
Colchicine
Enumerate the steps in Peripheral Leukocyte Culture Method
- Collect blood (e.g. 5 mL venous blood)
- Add phytohemagglutinin and culture medium
- Culture at 37°C for 3 days
- Add colchicine and hypotonic saline
- Cells fixed
- Spread cells onto slide by dropping
- Digest w trypsin & stain with Giemsa
- Analyze metaphase spread
- Karyotype
In the process of Peripheral Leukocyte Culture Method, what is the purpose of adding phytohemagglutinin?
It removes RBCs leaving only the WBCs
In the process of Peripheral Leukocyte Culture Method, what is the purpose of colchicine?
- It arrest cells during division
- It will stop the cell division in the metaphase
In the process of Peripheral Leukocyte Culture Method, what is the purpose of the hypotonic saline?
It causes swelling/paglobo of the cells so that it is easier to count
In 1960s, In situ hybridization techniques was initially developed by who?
Joseph Gall and Mary Lou Purdue
”Paired factors” was discovered by?
Mendel in 1865
What are the 3 laws under Mendel’s Laws?
- Paired factors are inherited
- Paired factors segregate during gamete formation
- Paired favors independently sort
Who discovered the Chromosome theory of Inheritance?
Sutton & Boveri
According to the Chromosomal Theory of Inheritance, chromosomes occur in _________ & are inherited from parents (the paternal & maternal chromosome)
occur in pairs
According to the Chromosomal Theory of Inheritance, chromosomes segregate in __________ (haploid)
Gamete formation
According to the Chromosomal Theory of Inheritance, chromosome pairs segregate ___________
Independently
Polytene chromosomes were first discovered in ___________ (Balbiani 1881)
Insects (fruit fly)
Who made the first genetic linkage maps from fruit fly?
Morgan, Sturtevant, Bridges and Muller
In 1920, who pioneered plant cytogenetics?
Cyril Darlington
In the genetic transformation experiment, it was proven that ________ is the heredity material and not protein in chromosome
DNA
Who discovered the amount of nitrogen base in chromosome?
Chargaff (Chargaff’s rule)
Who discovered the double helix?
Watson and Crick
In 1961, the discovery of the genetic code in protein synthesis was discovered by who?
Crick, Benner et al.
The first report of CGH analysis (using solid tumors) was made by who?
Kallioniemi and colleagues in 1992
The implementation of array CGH, whereby DNA microarrays are used instead of the traditional metaphase chromosome preparation, was m pioneered by who?
- Solinas-Tolodo et al. in 1997 (in tumor cells)
- Pinkel et al. in 1998 (using breast cancer cells)
This enabled detection of numerical chromosome aberrations
Emergence of Human Cytogenetics
Identify the syndrome
- 45, X
- affects only females
- results when one of the X chromosomes (sex chromosomes) is missing or partially missing
- short height, failure of the ovaries to develop and heart defects
Turner Syndrome
Identify the syndrome
- 47, XXY
- boys and men are born with an extra X chromosome
Klinefelter syndrome
Identify the syndrome
- extra 13th chromosome
Trisomy 13 (Patau syndrome)
Identify the syndrome
- extra copy in the 21st chromosome
- characterized by flattened face, almond-shaped eyes, short neck, small ears, etc
Trisomy 21 (Down syndrome)
Identify the syndrome
- extra copy in the 18th chromosome
- have heart defects, abnormalities of other organs, small, abnormally shaped head, small jaw and mouth, and clenched fists with overlapping fingers
Trisomy 18 (Edward’s syndrome)
This chromosome forms when chromosome 9 and chromosome 22 break and exchange parts (translocation) and is found in patients with chronic myeloid leukemia
Philadelphia chromosome
It was also reported that cells cultured from ________ could be used to determine the chromosome content of the fetus
Amniotic fluid
In what type of cytogenetic does karyotyping belong to?
Classical Cytogenetics
True or False
Shortening of the telomere may result in death
True
True or False
Cytogenetics is important in *pre-natal diagnosis** of the common Aneuploidies
True
95% of the chromosomal aberrations causing live-born birth defects are Aneuploidies chromosomes:
13, 18, 21, X, and Y
Modern detection technique is through interphase FISH prenatal diagnosis with
uncultured amniocytes
True or False
For patients with chronic myeloid leukemia, it has been shown that interphase FISH is highly sensitive in detecting the BCR/ABL fusion
True
True or False
Through the Molecular Cytogenetics, interphase FISH approach,chromosomal aneuploidies can be detected without cell culturing in any given tissue or cell source, such as touch preparations, sections of frozen tumor,and paraffin-embedded tissue.
True
It is the analysis of genomic alterations using mainly in situ hybridization based technology
Molecular Cytogenetics
