Mobile inverted-repeat elements of the Tourist family are associated with the genes of many cereal grasses.

摘要

Tourist was originally described as a 128-bpinsertion mutation in the maize wx-B2 allele. Subsequent analysis revealed thatTourist elements are in the introns or flanking sequences of 11 maize genes anda single barley gene. In this study we report that Tourist elements arefrequently associated with the wild-type genes of two other grasses, rice andsorghum. Six of 35 rice and 5 of 8 sorghum complete gene sequences reported todate contain Tourist elements. Furthermore, 11 additional maize genes have beenfound to contain Tourist elements, bringing the current total of elementsassociated with maize genes to 23. Sequence comparison of Tourist elements hasled to the identification of four subfamilies, designated A-D. Evidence ispresented for the recent mobility of elements in three of these subfamilies andin three of the four grass species. These data suggest that Tourist elements arehighly repetitive in the genomes of some and perhaps all members of thegrasses.