Michael Axtell

Trans-species microRNA loci in the parasitic plant Cuscuta campestris have a U6-like snRNA promoter

We have posted a new manuscript on bioRXiv by Collin Hudzik et al.

Key findings are:

  • There is no host-specificity in accumulation of Cuscuta campestris microRNAs; they are induced at a certain point in haustorial development.
  • Almost all of the C. campestris genes that encode trans-species microRNAs have a common promoter element. The sequence and context of this element strongly suggest transcription by RNA Polymerase III.
  • All other known plant small RNA precursors are transcribed by either RNA Polymerase II or IV. Thus the C. campestris trans-species microRNAs are quite distinct from “canonical” small RNA genes. We think that might be related to their export from the parasite.