plants are cloaked in hundreds of tiny projections, known as trichomes. These structures vary in function, shape, size and spacing from species to species, and it’s not known whether similar cellular differentiation programs are responsible for making trichomes in different plants. Trichomes are clearly visible in the scanning electron micrograph of a wild-type Nicotiana tabacum seedling above ...

We studied the evolution of the tobacco Tnt1 retrotransposon by analyzing Tnt1 partial sequences containing both coding domains and U3 regulatory sequences obtained from a number of Nicotiana species. We detected three different subfamilies of Tnt1 elements, Tnt1A, Tnt1B, and Tnt1C, that differ completely in their U3 regions but share conserved flanking coding and LTR regions. U3 divergence bet...