T-DNA associated reciprocal translocation reveals differential survival of male and female gametes

Identification and characterization of a female gametophyte defect in sdk1-7 +/- abi3-6 +/- heterozygotes of Arabidopsis thaliana

“…39 Reciprocal chromosome translocations are often observed in Arabidopsis T-DNA insertion lines and known to affect gametophyte development. 28,29,48,49 Consistent with the gamete transmission model for translocation heterozygote, we did not recover any wildtype plants or double homozygotes in our genotypic analysis of the F2 population of the selfed heterozygotes. To our surprise, sdk1-7 homozygous lines crossed with the weaker abi3-8 (Fig S5a) line did not show any fertility or gametophytic defect (Figure 2e).…”

“…Previous studies with Arabidopsis T-DNA insertion lines have reported that T-DNA associated reciprocal translocation events cause differential survival of both male and female gametes. 29 Reciprocal translocations are often known to result in pseudo-linkage. 39 To test this possibility, we performed a segregation analysis of the gametes in F2 from selfed heterozygote (sdk1-7 +/-abi3-6 +/-) for a recombination frequency of 0.05% (Table S3).…”

“…27,28 One type of chromosomal translocation is the reciprocal translocation wherein, the translocation of DNA fragments occurs between non-homologous chromosome. 29 Reciprocal translocation can result in suppression of genetic recombination in the interstitial zone (the chromosome segment between the centromere and the breakpoint) of the translocation heterozygote. This in turn affects the linkage relationships in the translocation heterozygote resulting in "pseudo-linkage" between the genes of the two chromosomes involved in the reciprocal translocation.…”