Genomic in-situ hybridization (GISH) is a cytogenetic technique developed for detecting and localizing specific nucleic acid sequences on chromosomes, using genomic DNA as probes. First established for animal cell hybrids in 1986, GISH was later adapted for plants by M.D. Bennett and involves several steps, including DNA extraction, slide preparation, and visualization under a fluorescence microscope. This method is valuable for identifying chromosomal rearrangements in cancer, studying genome evolution, and understanding the relationships of wild and cultivated plant species.

1. GISH(Genomic In-Situ
Hybridization)
AREEBA FATIMA
2015-UAM-240
CYTOGENETICS AND EVOLUTION OF CROP PLANTS

2. Outline
 What is GISH?
 Who was developed this technique?
 How we apply this technique on sample?
 How many steps?
 Why we use this technique?

3. What is GISH(Genomic In-Situ
Hybridization)?
 Genomic in-situ hybridization(GISH) is a cytogenetic technique that allows the
detection and localization of specific nucleic acid sequences on morphologically
preserved chromosome using genomic DNA of donor species as prob.

4. Introduction
 GISH is quick, accurate, sensitive,
informative and a comparative
approach.
 GISH technique is an advancement in
the fluorescence in situ hybridization
(FISH) technique.

6. Background
 GISH for plants was developed inn 1987 by M.D. Bennett.
 GISH was mainly developed for the animal hybrid cell in 1986
 In 1987, the Plant Breeding institute Cambridge was used this
technique in plants
M.D Bennett

7. Principle
 This technique involves the extraction of labeling DNA of one
organism and to use as a probe to target the genome of another
organism.
 The part of genome that are similar to the probe hybridize to from a
probe target complex.

8. Steps
 Take probe DNA
 Blocking DNA fragmentation
 Preparation of slide
 Denaturation of probe and blocking DNA in the hybridization mixture
 Addition of probe and blocking DNA with the hybridization mixture
 Chromosome DNA denaturation
 Hybridization of blocking DNA and probe in the target sequence of the chromosome
 Detection of the probe in the chromosome of one parent
 Chromosome DNA molecule of thee second parent related to the unlabeled blocking DNA
 Visualization of hybridization signals associated to a probe(green) in fluorescence microscope.
 Unmarked chromosome are visualized with blue color.

11. Why we do GISH?
 It is used to identify chromosomal rearrangements in cancer patients.
 Chromosomal identification in cell.
 Detect the specific nucleotide sequence within cell and tissues.
 Unique point among the studies of cell, biology, cytogenetics and molecular genetics
 It is possible to detect single copy sequence on chromosome with probes.
 genomic in situ hybridization (GISH) is a potentially powerful tool for studying genome
evolution and biosystematics
 It will useful for investigating the origins of wild and cultivated polyploid plant species

12. Thank you