89 Interspecific somatic hybridization are often followed
(1) Fusion of paternal chromosome
(2) Fragmentation of Paternal chromosomes
(3) Selective elimination of one of parental chromosome
(4) Fusion of nuclei
Interspecific somatic hybridization fuses protoplasts or cells from different species, often leading to instability where one parent’s chromosomes are preferentially lost over time. This creates asymmetric hybrids useful for gene transfer or mapping, as seen in plant and animal systems.
Option Analysis
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(1) Fusion of paternal chromosome: Chromosome fusion implies end-to-end joining, not typical post-hybridization behavior. Hybrids retain intact chromosomes initially, without paternal-specific fusion.
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(2) Fragmentation of Paternal chromosomes: Fragmentation occurs in some unstable hybrids but affects both parents randomly, not selectively one species. It describes damage, not the common elimination pattern.
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(3) Selective elimination of one of parental chromosome: Human or plant chromosomes from one species eliminate preferentially in rodent or asymmetric hybrids due to genomic shock and instability, stabilizing the hybrid genome.
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(4) Fusion of nuclei: Nuclei merge post-fusion into a single hybrid nucleus, but this precedes chromosome behavior, not what “often follows” hybridization.
Correct Answer and Explanation
The correct option is (3) Selective elimination of one of parental chromosome. In rat-human or plant interspecific fusions, one genome dominates, eliminating excess chromosomes for stability, enabling gene mapping or trait introgression.
