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SUMMARY:Endogenous Pararetroviruses Regulate Gene Expression in Hybrids - 
 Dr Sara Lopez Gomollon\, Department of Plant Sciences
DTSTART:20211202T130000Z
DTEND:20211202T140000Z
UID:TALK162109@talks.cam.ac.uk
CONTACT:Kumari Billakurthi
DESCRIPTION:Hybrids (progeny from two different species or genera) may dis
 play characteristics that are out of the range of the parents. For that re
 ason\, hybridisation has been exploited in crop breeding programmes for ce
 nturies to obtain plants that produce more fruits or are more vigorous. \n
 \nInterspecific hybrids may undergo “genomic shock\,” as coined by Bar
 bara McClintock\, leading to perturbation of gene expression and activatio
 n of transposons. Genomic shock can be seen as a source of heritable varia
 tion\, able to trigger extensive phenotypic effects. However\, the molecul
 ar mechanisms associated are not well understood. \n\nWe predict that smal
 l RNAs (sRNAs) may be involved in genomic shock. These 20-24nt long sRNA m
 olecules can mediate gene silencing at transcriptional or posttranscriptio
 nal level. In hybrids\, due to the variability in the sRNA population betw
 een species\, sRNAs from one parent may find new targets in the genome of 
 the other parent\, modifying gene expression.\n\nTo unravel the mechanisms
  of hybridisation-induced genome shock\, we study the F4 generation from a
  cross of tomato and a wild relative. Our results suggest that hybridisati
 on activates integrated viral genomes of EPRVs (endogenous pararetroviruse
 s)\, which are normally latent and found broadly in the plant kingdom. Thi
 s activation leads to an increased production of sRNAs\, as these elements
  are repressed through post-transcriptional gene silencing. \n\nEPRVs are 
 a viral reservoir that upon activation can actually cause viral disease. A
 lthough why some plants show symptoms while others remain healthy is not k
 nown\, we are paving the way: we have identified a mechanism that controls
  the activation of EPRV in hybrids\, mediated by Dicer and sRNAs\, providi
 ng a first molecular handle for EPRV control and the effects of hybridisat
 ion in plant genomes.\n\nThese findings also implicate that hybridization-
 induced genome shock leading to EPRV activation and sRNA silencing\, as ca
 using changes in gene expression. Such hybridization-induced variation in 
 gene expression could increase the range of traits available for selection
  in natural evolution or in breeding for agriculture.\n\nContact reception
 @plantsci.cam.ac.uk for a Zoom link prior to a talk if you are not on our 
 mailing list. Due to having to go online\, we are restricting the talks to
  University of Cambridge and alumni to keep them as informal as possible.
LOCATION:Online
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