1. DNA trivia: Who are the authors of the 1953 paper on DNA with the following quotes:
“DNA is a helical structure”
with “two co-axial molecules.”
“period is 34 Å”
“one repeating unit contains ten
nucleotides on each of two co-axial molecules.'’
“The phosphate groups lie on the outside of the structural unit, on a helix of diameter about 20 Å”
“the sugar and base groups must accordingly be turned inwards towards the helical axis.”

2. DNA trivia: Who are the authors of the 1953 paper on DNA with the following quotes:
“DNA is a helical structure”
with “two co-axial molecules.”
“period is 34 Å”
“one repeating unit contains ten
nucleotides on each of two co-axial molecules.'’
“The phosphate groups lie on the outside of the structural unit, on a helix of diameter about 20 Å”
“the sugar and base groups must accordingly be turned inwards towards the helical axis.”

4. Also published in the same issue of Nature:

5. If someone gives you data, check with them BEFORE you share it with others.
If it involves human data, you may need approval from the ethics board.
If it involves human data, you may need to keep it secure – i.e, not on an unsecured laptop.

6. Data is NEVER fully anonymized

7.
JAMA. 2013;309(20): doi: /jama
“IN MARCH, THE PUBLICATION OF THE complete genome sequence of cancer cells from a Maryland woman who died in 1951 ignited an ethical firestorm. These cells, called HeLa because they were derived from the cervical tumor of Henrietta Lacks, have been widely cultured in laboratories and used in research.”

8.
1951 Biopsy of Henrietta Lacks’ tumour collected without her knowledge or consent. HeLa cell line soon established.
1971 The journal Obstetrics and Gynecology names Henrietta Lacks as HeLa source; word later spreads in Nature, Science and mainstream press.
1973 Lacks family members learn about HeLa cells. Scientists later collect their blood to map HeLa genes, without proper informed consent.
1996 Lacks family honored at the first annual HeLa Cancer Control Symposium, organized by former student of scientist who isolated HeLa cells.
2013 HeLa genome published without knowledge of the family, which later endorses restricted access to HeLa genome data.

9. http://www. smithsonianmag
…HeLa cells could float on dust particles in the air & travel on unwashed hands and contaminate other cultures. It became an enormous controversy. In the midst of that, one group of scientists tracked down Henrietta’s relatives to take some samples with hopes that they could use the family’s DNA to make a map of Henrietta’s genes so they could tell which cell cultures were HeLa and which weren’t, to begin straightening out the contamination problem.

11.
In the USA, Under GINA (2009), it's (mostly) illegal for
an employer to fire someone based on his genes, and it's illegal for health insurers to raise rates or to deny coverage because of someone's genetic code.
But the law has a loophole: It only applies to health insurance. It doesn't say anything about companies that sell life insurance, disability insurance or long-term-care insurance.”
People who discover they have the gene, ApoE4, associated with Alzheimer’s are 5 times more likely than the average person to go out and buy long-term-care insurance.

13. The boy took the saliva sample late and sent it off to an online genealogy DNA-testing service.
boy's genetic father had never supplied his DNA
2 men on the database matched his Y-chromosome
The two men did not know each other, but shared a surname, albeit with a different spelling.
genetic similarity of their Y-chromosomes suggested a 50% chance that the 2 men & the boy shared the same father, grandfather or great-grandfather.
bought information on everyone born in the same place and on the same date as his father.

14. Science 18 January 2013: Vol. 339 no. 6117 p. 262
NEWS & ANALYSIS GENETICS
Genealogy Databases Enable Naming of Anonymous DNA Donors by John Bohannon
Science 18 January 2013: Vol. 339 no pp
Identifying Personal Genomes by Surname Inference
Melissa Gymrek, Amy L. McGuire, David Golan, Eran Halperin, Yaniv Erlich
able to expose the identity of 50 individuals whose DNA was donated anonymously for scientific study through consortiums such as the 1000 Genomes Project.

17. vol. 110 no. 46, 18566–18571,

18. Background

22. Recombination:

23. Homologous recombination

24. Homologous recombination

25. Homologous recombination

27. Where do we get distances from?
Distances can be derived from Multiple Sequence Alignments (MSAs).
The most basic distance is just a count of the number of sites which differ between two sequences divided by the sequence length. These are sometimes known as p-distances.
Cat
Dog
Rat
Cow
0.2
0.4
0.7
0.5
0.6
0.3
Cat
ATTTGCGGTA
Dog
ATCTGCGATA
Rat
ATTGCCGTTT
Cow
TTCGCTGTTT

30. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

31. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

32. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

33. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

34. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

35. Perfectly “tree-like” distances
Cat
Dog
Rat 3 4 5
Cow 6 7
Cat
Rat 2 1 1 2 4
Dog
Cow

36. Rat Dog Cat Cow Cat Dog Rat 3 4 5 Cow 6 7 Cat Dog Rat Cow Rat Dog Cat1 2 4
Rat
Dog
Cat 3 4 5
Cow 6 7
Rat
Dog
Cat
Cow 1 2 4

37. Rat Dog Cat Cow Cat Dog Rat 3 4 5 Cow 6 7 Cat Dog Rat Cow Cat Dog Rat1 2 4
Cat
Dog
Rat 4
Cow 6 7
Rat
Dog
Cat 3 4 5
Cow 6 7
Rat
Dog
Cat
Cow 1 2 4

38. Multiple sequence alignment

39. Linking algebraic topology to evolution.
Linking algebraic topology to evolution. (A) A tree depicting vertical evolution. (B) A reticulate structure capturing horizontal evolution, as well. (C) A tree can be compressed into a point. (D) The same cannot be done for a reticulate structure without destroying the hole at the center.
Chan J M et al. PNAS 2013;110:
©2013 by National Academy of Sciences

40. Linking algebraic topology to evolution.
Linking algebraic topology to evolution. (A) A tree depicting vertical evolution. (B) A reticulate structure capturing horizontal evolution, as well. (C) A tree can be compressed into a point. (D) The same cannot be done for a reticulate structure without destroying the hole at the center.
Reticulation
Chan J M et al. PNAS 2013;110:
©2013 by National Academy of Sciences

42. Reassortment

43. Homologous recombination

45. Persistent homology characterizes topological features of vertical and horizontal evolution.
Persistent homology characterizes topological features of vertical and horizontal evolution. Evolution was simulated with and without reassortment (SI Appendix, Supplementary Text). (A) A metric space of pairwise genetic distances d(i,j) can be calculated for a given population of genomic sequences g1,…, gn. We visualize these data points using principal coordinate analysis (PCoA) (SI Appendix, Supplementary Text). (B) In the construction of simplicial complexes, two genomes are considered related (joined by a line) if their genetic distance is smaller than ε. Three genomes within ε of each other form a triangle, and so on (SI Appendix, Supplementary Text). From there, we calculate the homology groups at different genetic scales. In the barcode, each bar in different dimensions represents a topological feature of a filtration of simplicial complexes persisting over an interval of ε. A one-dimensional cycle (red highlight) exists at ε = [0.13, 0.16 Hamming distance] and corresponds to a reticulate event. The evolutionary scales I where b1 = 0 are highlighted in gray.
Joseph Minhow Chan et al. PNAS 2013;110:
©2013 by National Academy of Sciences

46. no horizontal transfer (i.e., no homologous recombination)
Reconstructing phylogeny from persistent homology of avian influenza HA. (A) Barcode plot in dimension 0 of all avian HA subtypes.
Influenza:
For a single segment,
no Hk for k > 0
no horizontal transfer
(i.e., no homologous recombination)
Reconstructing phylogeny from persistent homology of avian influenza HA. (A) Barcode plot in dimension 0 of all avian HA subtypes. Each bar represents a connected simplex of sequences given a Hamming distance of ε. When a bar ends at a given ε, it merges with another simplex. Gray bars indicate that two simplices of the same HA subtype merge together at a given ε. Solid color bars indicate that two simplices of different HA subtypes but same major clade merge together. Interpolated color bars indicate that two simplices of different major clades merge together. Colors correspond to known major clades of HA. For specific parameters, see SI Appendix, Supplementary Text. (B) Phylogeny of avian HA reconstructed from the barcode plot in A. Major clades are color-coded. (C) Neighbor-joining tree of avian HA (SI Appendix, Supplementary Text).
©2013 by National Academy of Sciences
Chan J M et al. PNAS 2013;110:

47. Persistent homology of reassortment in avian influenza.
For multiple segments,
non-trivial Hk
k = 1, 2.
Thus
horizontal transfer via reassortment
but not homologous recombination
Persistent homology of reassortment in avian influenza. Analysis of (A) HA and (B) NA reveal no significant one-dimensional topological structure. (C) Concatenated segments reveal rich 1D and 2D topology, indicating reassortment. For specific parameters, see SI Appendix, Supplementary Text. (D) Network representing the reassortment pattern of avian influenza deduced from high-dimensional topology. Line width is determined by the probability that two segments reassort together. Node color ranges from blue to red, correlating with the sum of connected line weights for a given node. For specific parameters, see SI Appendix, Supplementary Text. (E) b2 polytope representing the triple reassortment of H7N9 avian influenza. Concatenated genomic sequences forming the polytope were transformed into 3D space using PCoA (SI Appendix, Supplementary Text). Two-dimensional barcoding was performed using Vietoris–Rips complex and a maximum scale ε of 4,000 nucleotides.
Chan J M et al. PNAS 2013;110:
©2013 by National Academy of Sciences