Identification of new transposable elements in the mutable alleles for flower variegation in the Japanese and common morning glories and transposition of the maize Ac/Ds elements in transgenic rice plants.

日本牵牛花（Pharbitis nil或Ipomoea nil）是日本的传统园艺植物，对该植物进行了广泛的生理和遗传研究。在决定杂色花表型的几个可变位点中，选择了斑点和斑点两个可变等位基因进行了杂色花表型的分子解析。斑点突变体的花为白色，带有彩色斑点和扇形，斑点突变是由转座元件Tpn1整合到花青素色素沉着的DFR基因中引起的。我们还发现，在花色素沉着的CHI基因中，有另一个转座元件Tpn2。常见牵牛花（Pharbitis purpurea或Ipomea purpurea）的可变片状系也有白色的花，有彩色的薄片和扇形，可变片状等位基因被证明是一个新发现的CHS基因，插入了一个新的转座元件Tip100。为了了解转座因子在利用转基因植物的异源系统中的行为，我们还研究了在转基因水稻植株中由活性Ac转座酶介导的非自主Ds因子的体细胞转座。我们目前正在研究Ds元素在体细胞转位中的靶向选择性。

The Japanese Morning glory (Pharbitis nil or Ipomoea nil) is a traditional horticultural plant in Japan, and extensive physiological and geneticalstudies on the plant have been conducted. Among several mutable loci that condition variegated flower phenotypes, two mutable alleles, flecked and speckled have been chosenfor molecular elucidation of the variegated phenotypes. The flecked mutant bears white floweres with colored flecks and sectors, and the flecked mutation was found to be caused by integration of the transposable element, Tpn1, into the DFR gene for anthocyanin pigmentation. We have also found that the seckled mutant also carries another transposable element, Tpn2, in the CHI gene for flower Pigmentation.The mutable flaked line of the common morning glory (Pharbitis purpurea or Ipomea purpurea) also bears white flowers with colored flakes and sectors, and the mutable flaked allele is shown to be a newly identified CHS gene having a new transposable element, Tip100, inserted.To understand the behavior of the transposable elements in heterologous system using transgenic plants, we are also characterizing somatic transposition of a non-autonomous Ds element mediated by the active Ac transposase in transgenic rice plants. We are currently investigating on the target selectivity in the somatic transposition of the Ds element.