| Gametophyte development is essential to the sexual reproduction of angiosperms.Currently,the genes and pathways involved in gametophyte development and fertilization process remain largely unknown.A large-scale mutant screen of Ds transposon insertion lines was employed to identify one mutant（KD361）of Arabidopsis thaliana with a distorted segregation ratio of KanR:Kans.Genetic and morphologic analysis indicated that KD361 mutant is partly male and female gametophytic lethal.We analyzed female gametophyte development of KD361 and found that partial female gametophytes were arrested at FG5 as two polar nuclei did not fuse or the fusion was delayed.The male gametophyte analysis suggested that all the male gametophytes could develop into the mature pollen grains,but the growth and adaptability of pollen tube were partially damaged.In addition,we could not get the homozygote of KD361 which indicated KD361 could not form the homozygous zygote or the homozygous zygote was lethal at the very early embryogenesis period.Complete cosegregation of the phenotype with the antibiotic resistance marker and consistent segregation ratios suggested that Ds was tightly linked to or responsible for the reduced genetic transmission.The sequences flanking the Ds element were isolated with TAIL-PCR.The flanking sequences obtained were run against BLAST to identify the genomic location of the Ds element.In KD361,the 3’ of Ds inserts in the upstream of At4g00380,while the 5’ of Ds insert in the upstream of At4g00730.The Ds insertion caused 137258bp deletion containing 39 genes.We selected a gene as our target via consulting papers and the gene library of Arabidopsis thaliana:At4g00620.At4g00620 encodes an amino acid dehydrogenase family protein which involved in folic acid and derivative biosynthetic and metabolic process,the allelic mutant of this gene Sail720G12 has the similar phenotype with the KD361. |
