Irreversible inactivation of a transgene in Arabidopsis thaliana
2001
Mirza, B. (Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Biological Sciences)
Plant transformation is now a routine practice in many laboratories around the world. However it has been observed that sometimes the introduced gene becomes inactive. This inactivation could be reversible or irreversible. In this study the genetic behavior of an inactive transgene was observed. For this purpose a wild type chlorophyll gene CH-42 was introduced into a pale (ch-42) mutant Arabidopsis by Agrobacterium mediated transformation. After transformation most of the plants showed green wild type phenotype- However, some transgenic lines did not show the phenotype of the CH-42 transgene and appeared pale in color. Four transgenic lines showing inactive CH-42 transgene were selected to study the segregation of the inactive transgene in the next generations. These transgenic lines with inactive insert were crossed to the wildtype and the CH-42 mutant plants. The F1, plants produced from these crosses were allowed to self fertilize and some of the seeds of these F1 were germinated for analysis of the F2 generation. The results of the reciprocal crosses of all four inactive lines were similar. The inactivation of transgene CH-42 was irreversible and the cellular gene at the CH-42 locus did not have any effect oil the expression of the transgene.
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