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Microbial Reproductive Modes Fungal Reproduction Week 12, PMB 220 J. Taylor PowerPoint Presentation
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Microbial Reproductive Modes Fungal Reproduction Week 12, PMB 220 J. Taylor

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Microbial Reproductive Modes Fungal Reproduction Week 12, PMB 220 J. Taylor

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  1. Microbial Reproductive Modes Fungal Reproduction Week 12, PMB 220 J. Taylor

  2. The cost of sex is two-fold. Clonal progeny have twice as many parental genes.

  3. The Value of Sex? The Red Queen Hypothesis. "Now, here, you see, it takes all the running you can do, to keep in the same place." Lewis Carroll John Tenniel (illus) 1872.

  4. The Value of Sex? Muller’s Ratchet H. Muller, 1964

  5. Goddard, Godfray Burt. 2005 Nature 434:636-640

  6. Goddard, Godfray Burt Nature 434:636-40 2005

  7. Harsh environment Goddard, Godfray Burt Nature 434:636-40 2005 Benign environment

  8. Sex is nearly ubiquitous. Only the bdelloid rotifers have been claimed to be an old asexual group. Aydin Örstan http://users.unimi.it/ricci/html/bdelloid.htm

  9. Numbers of Species of Fungi Ascomycota 32,267 46.0% Lichenized fungi 13,500 18.7% Basidiomycota 22,244 32.0% Chytridiomycota 793 1.0% Zygomycota 1,056 1.5% Mitosporic fungi 14,104 19.6% Dictionary of the Fungi, Hawksworth et al. 1996

  10. What is a species? How do they reproduce?

  11. Determining thereproductive mode of Microbes: Recombination v. clonality

  12. Clonal: Association of Alleles.

  13. Recombining: Lack of Association

  14. Testing for reproductive mode.

  15. Tree Length Test

  16. Compter sex: Resampling without replacement.

  17. Tree Length Test

  18. Index of Association

  19. Distance matrix

  20. IA

  21. Gene Genealogy Concordance

  22. Computer sex: Shuffling variable nucleotides among genes.

  23. Aspergillus flavus

  24. You have to know the species before you can study reproductive mode.

  25. Example: Coccidioides immitis Vasso Koufopanou Austin Burt Mat Fisher

  26. Distribution of Coccidioides immitis Rippon, 1988

  27. Phylogenetic Species in C. immitis

  28. Finding Single Nucleotide Polymorphisms Agarose and SSCP gels of PCR products

  29. Coccidioides immitis: multilocus genotypes as single nucleotide polymorphisms (SNPs)

  30. Parsimony analysis: Consensus of 62 most parsimonious trees.

  31. Test of association of alleles: Index of Association

  32. Phylogenetic Species in C. immitis

  33. California Coccidioides Fisher et al. 2000

  34. Likelihood ratio tests Kishino-Hasegawa Two different topologies Shimodaira-Hasagawa Multiple topologies

  35. Lichens Scott Kroken Trebouxia and Letharia

  36. Letharia columbiana Question: Are there two species of Letharia, one sexual and the other not? Letharia vulpina

  37. Letharia vulpina • always produces soredia • apothecia are rare • Letharia columbiana • always produces apothecia • sometimes produces isidia • Are they a “species pair” and how do they reproduce?

  38. Distribution of Letharia species Xerox PARC map

  39. Asexual Sexual www.lichen.com Thomas Nash Apothecia, filled with meiotic ascospores Soredia, algal cells wrapped in hyphae

  40. 6 species suggested Kroken and Taylor. 2000. Mycologia 93:38-53

  41. Question: does the lichen outbreed or inbreed?

  42. Fertilization Spermagonium-- produces spermatia Trichogyne-- fuses with spermatium Paternity analysis of lichen apothecia

  43. Parent and progeny

  44. Letharia “lupina” paternity analysis ‘lupina’ locus CS EarI ‘lupina’ ITS 1F/ 2 SacI Mom1 and 7 kids Mom2 and 6 kids Mom1 and 7 kids Mom2 and 6 kids All 36 apothecia in both species are the result of outcrossing Kroken and Taylor 2001 Fungal Genetics & Biology 34:83-92

  45. Outbreeding and separate fertilizations

  46. Dispersal of Letharia vulpina with its alga Xerox PARC map Högberg et al. 2002. Molecular Ecology 11:1191-1196

  47. Recombining and Clonal in Letharia Recombining: North American sorediate Recombining: North American apotheciate Clonal: European and North African sorediate Letharia species

  48. Daubin et al. 2003. Science 301:829-832