Horizontal genetic transfer in eukaryotes Jorge Herrero Vicente

Horizontal genetic transfer in eukaryotes Jorge Herrero Vicente Genomics Presentation template by Slides. Carnival

“ Movement of genetic information across normal mating barriers, between more or less distantly related organisms

EUKARYOTE HGT CRITICISMS ◦ Unknown mechanism(s) of HGT ◦ Overestimation of HGT cases ◦ Methodologies insufficient to confirm HGT

HGT MECHANISMS How does HGT happen and what does it need to happen?

HGT MECHANISMS “YOU ARE WHAT YOU EAT” THEORY § Dietary DNA incorporated (more likely host parasite) CONDUIT MEDIATED TRANSFER IN PLANTS § Plasmodesmata § Haustorium INFECTIOUS AGENTS § Retroviruses LTRs § Horizontal transfer of TEs is widespread § P-elements in Drosophila via mite

HGT MECHANISMS “YOU ARE WHAT YOU EAT” THEORY § Dietary DNA incorporated (more likely host parasite) CONDUIT MEDIATED TRANSFER IN PLANTS § Plasmodesmata § Haustorium INFECTIOUS AGENTS § Retroviruses LTRs § Horizontal transfer of TEs is widespread § P-elements in Drosophila via mite

HGT MECHANISMS “YOU ARE WHAT YOU EAT” THEORY § Dietary DNA incorporated (more likely host parasite) CONDUIT MEDIATED TRANSFER IN PLANTS § Plasmodesmata § Haustorium INFECTIOUS AGENTS § Retroviruses (? ) LTRs § Horizontal transfer of TEs is widespread § P-elements in Drosophila via mite

HGT CONDITIONS Close relationship Population genetics Genetic compatibility Deterioration Between donor and recipient, and/or a vector mediating Recipient immune system, nucleases, and proteases. Large effective population size and adaptive trait are best Mutation in different function Difficult to determine HGT

HGT DETECTION METHODS How do we find HGT?

METHODS OF HGT DETECTION PHYLOGENETIC METHODS § Phylogeny incongruences are hints of HGT § Many problems: orthologous genes, phylogenetic lineage sorting, evolutionary rate heterogeneity, gene loss… PHYLOGENY INDEPENDENT METHODS § Codon-based approaches § BLAST similarity § PCR approaches ADDITIONAL METHODS § Beyond routine PCR with multiple tissue samples § Genomic approaches § Biogeographical and ecological data

METHODS OF HGT DETECTION PHYLOGENETIC METHODS § Phylogeny incongruences are hints of HGT § Many problems: orthologous genes, phylogenetic lineage sorting, evolutionary rate heterogeneity, gene loss… PHYLOGENY INDEPENDENT METHODS § Codon-based approaches § BLAST similarity: homology and integration sites § PCR approaches ADDITIONAL METHODS § Beyond routine PCR with multiple tissue samples § Genomic approaches § Biogeographical and ecological data

MITOCHONDRIAL HGT IN PLANTS AND ANIMAL Plants Animals Unusually active Single peculiar study Multiple transfers of Cytochrome B gene in three beetle species Parasitic plants Single-gene cases Exception: Amborella trichopoda multiple donors

HGT BETWEEN HOST AND PARASITE “YOU ARE WHAT YOU EAT” THEORY RED QUEEN HYPOTHESIS § Arms race between host and parasite

HGT IN MEDICINE AND BIOTECHNOLOGY THERAPEUTIC TARGETS § Cryptosporidium bacterial nucleotide salvage pathway HGT MECHANISMS § Correct human genetic disorders by gene integration § TEs as gene delivery systems in transformation experiments

CONCLUSIONS AND PERSPECTIVES HGT in eukaryotes is an actual, pervasive phenomenon It is very hard to confirm HGT cases, multiple methods must be used and each case confirmed individually Massive genome sequencing will help enormously to confirm, discover and study HGT

Thanks! ANY QUESTIONS? You can find me at jorgeherrerovicente@gmail. com