87. use of inactivated Sendai virus and PEG for fusion of two cells has proved very beneficial in studies for-
(1) Transgenic
(2) Tissue culture
(3) Physical mapping
(4) Recombinant DNA technology
Inactivated Sendai virus and PEG fuse cells by promoting membrane merging, creating hybrid cells that retain specific chromosomes from one parent, aiding genetic studies. This technique mixes cells, applies the fusogen, and selects hybrids using markers like HAT medium for human-mouse fusions. It revolutionized mapping by correlating chromosomes with enzymes.
Option Analysis
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(1) Transgenic: Transgenic organisms incorporate foreign genes via vectors like Agrobacterium or gene guns, not cell fusion. Sendai virus or PEG fusion creates hybrids, not stable gene insertions for inheritance.
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(2) Tissue culture: This propagates cells on media for cloning or regeneration but does not require fusion agents. PEG or virus aids specific hybridoma production, not general culture.
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(3) Physical mapping: Fusion hybrids retain human chromosomes randomly in rodent background, allowing assignment of genes to chromosomes via enzyme assays or markers. Sendai virus enabled early human gene maps.
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(4) Recombinant DNA technology: Involves restriction enzymes, ligases, and vectors for cloning DNA, bypassing cell fusion. Fusion supports hybridomas for antibodies but not core rDNA.
Correct Answer and Explanation
The correct option is (3) Physical mapping. Human-rodent hybrids from Sendai virus or PEG lose human chromosomes selectively, linking retained DNA to phenotypes for synteny groups. This somatic cell genetics mapped hundreds of loci before sequencing. CSIR NET emphasizes this for classical genetics applications.
