Shashi Bhushan / Indian Institute of Technology, Madras. India
Ramamurthy Baskar / Indian Institute of Technology, Madras. India
Amit Kumar Singh / Tel Aviv University
Using a set of Arabidopsis detector lines carrying mutated or truncated GUS reporter gene, we examined if parental reproductive age influences the spontaneous mutation rates in the ensuing filial generations. We scored for functional GUS reversions, which can be monitored in planta as blue spots. Based on the number of blue spots to the total number of seedlings screened, we scored for frameshift, point mutation, transposition, and homologous recombination rates in three consecutive generations. Plants were self-pollinated in four different ages i.e. 38, 43, 48, and 53 days after sowing (DAS) and in the ensuing generations also; the plants were self-fertilized in the same ages. Compared to the first generation, frameshift mutation rates go down but there is no change in point mutation, transposition, and homologous recombination rates. Compared to the first generation, there is a reduction in the expression levels of genes involved in DNA repair such as ATM (ataxia telangiectasia mutated and) small rRNA (5.8S, 25S, and 18S) but the expression levels of BRAC1 (Breast Cancer Gene 1) increased in the subsequent generations. When similar age groups are compared from one generation to the next, there is no significant change in point mutation, homologous recombination, and transposition rates.