Ho r izontal gene t r ansfe r

1. Horizontal gene transfer  The transfer of genetic information from one genome to another.

2. Conjugation = transfer of DNA from one organism to another by means of a plasmid.

3. Transformation = uptake of free DNA from the environment.

4. Transduction = transfer of DNA from one organism to another by a bacteriophage.

5. Retrotransduction?

6. An organism into which genetic information from a different organism has been incorporated as a stable part of its genome is a transgenic organism. green fluorescent protein (GFP) Aeqorea victoria ANDi

7. Orthology Paralogy Xenology

8. Horizontal gene transfer is suspected when there is a discrepancy between gene phylogeny and species phylogeny, in particular when the tree reflects geographical proximity rather than phylogenetic affinity.

9. Patchy phylogenetic distribution Aedes aegypti

10. cyanobacteria + chloroplast (Fe-SOD) nucleus cytoplasm (CuZn-SOD) bacteria + mitochondria (Mn-SOD) SOD = superoxide dismutase

11. Leiognathus daura Photobacterium leiognathi (CuZnSOD)

13. Crown Gall Disease

14. Agrobacterium tumefaciens

15. Plant Gene

17. P M P elements & hybrid dysgenesis Margaret Kidwell

18. P elements were not found in any D. melanogaster strains collected before 1950, and collections made subsequently showed increasing frequencies of P with decreasing age. North and South America Europe, Africa, Middle East Australia, Far East

19. Two hypotheses: 1. Most D. melanogaster strains in nature carry P elements, but they tend to lose them in the laboratory. 2. P elements were recently introduced into D. melanogaster populations in nature.

20. The recent acquisition hypothesis is supported by: 1. P strains that have been monitored in the lab for ~15 y were never observed to lose P. 2. There is a geographical cline in the temporal appearance of P in nature. 3. There is evidence for horizontal gene transfer.

22. Species tree P-element tree

23. P element Drosophila melanogaster Drosophila willistoni

25. Proctolaelaps regalis

26. Conditions for horizontal P-element transfer: two Drosophila females from the donor and the recipient species must lay eggs in proximity to one another (2) the recipient egg must be less than 3 hours old (< 512 cells) (3) the germline of the recipient embryo must incorporate a complete copy of P (4) the receiving embryo must survive the biting injuries Marilyn A. Houck

27. type-C virogene

30. Informational genes:Genes involved in replication, transcription, reverse transcription, and translation. Operational genes: All others.

31. The complexity hypothesis informational operational

32. Genes move within the genome and between genomes. Genetic “Mutatismutandis.”

33. Promiscuous DNA

34. Einat Hazkani-Covo et al. Mitochondrial-sequence invasions into the nuclear genome

35. Numts* (nuclear mitochondrial DNA sequences) are a type of promiscuous DNA, i.e., nuclear sequences of mitochondrial origin. *pronounced “new mights”

36. The transfer of functional genes from the mitochondria to the nucleus is thought to have has stopped in evolution after the emergence of animals (~1,000MYA).

37. The reason is thought to be the differences between the nuclear and mitochondrial genetic codes.

38. The transfer of nonfunctional pieces of mitochondrial genetic information continues to this day. Numts have been found so far in 83 eukaryote species.

39. Most species whose genomes have been completely sequenced contain very few numts. Saccharomyces cerevisiae 17 numts Caenorhabditis elegans 3 numts Drosophila melanogaster 3 numts Plasmodium falciparum 3 numts

40. In the human genome we find ~1,000 numts total length = 831 Kb ~0.02% of the nuclear genome

41. Numts: Evolution’s misplaced witnesses

43. Junk DNA Domestic Imported