Tag Archives: allele frequency

ASE was ACE

One spin off from the BTOY award was being invited to chair a series of talks on Biology in the Real World at this year’s ASE conference in Birmingham. It was my first time at this event and it was brilliant. Indeed, I’ll be back next year, if I can wangle the time off, as I was only there for the day and didn’t have nearly enough time to explore everything that was going on. But the overall effect was energising, exciting, inspiring – I came back to Oxford buzzing with new ideas and a bag bursting at the seams with bumpf. Many thanks to the Royal Society of Biology for the invite…

The talks were brilliant – here’s the briefest of summaries….

  1. Professor Joanna Verran (Manchester Uni) on Biofilms. Amazing images of e.g. 1000s of bacterial cells on a single grain of sand
    1. www.erc.montana.edu/CBE
    2. https://student.societyforscience.org/articles/slime-cities
    3. I, SuperOrganism – popular book on human body’s biofilms
    4. Fascinating stuff on quorum sensing and possible role in bacterial control
    5. 99% of planet’s bacteria live in biofilm communities.

 

  1. Dr Charles Lane (FERA and SAPS) on Killer Plant Diseases.
    1. Great practical on SAPS website on how to demonstrate Koch’s postulates with rotten apples
    2. Ash dieback first plant disease to be discussed in COBRA meeting

     

    3. Professor Saffron Whitehead (Society of Endocrinology) on Hormones and Homeostasis

    1. Steroids highly conserved – found across Animal Kingdom
    2. Ketoacidosis only occurs in Type 1 Diabetes (because ketone body production inhibited by insulin)
    3. Glycosylated haemoglobin main problem from diabetes leading to similar complications of CVD

4. Professor Greg Hurst (University of Liverpool) on Microbial Partners

  1. e.g. 10-20% of human calorific intake from bacterial digestion in gut (short chain fatty acids – acetate, propionate, butyrate)antibiotics bad for cows/horses because e.g. horses get 80% plus of calories from bacterial digestion. aphids have specialised organ for cultivating symbiotic bacteria that make essential amino acids lacking in phloem – 200 million year old symbiosis. desert rats eat leaves of creosote bush – only because their bacteria detoxify the creosote – a desert rat on antibiotics becomes sensitive to creosote
  2. breast mile contains complex polysaccharides specifically to encourage growth of particular bacteria
  3. aphids not found in tropics because bacteria temperature sensitive
  4. insects dependent on blood/phloem become sterile if fed antibiotics – because they rely on bacteria to produce vital nutrients otherwise lacking in diet
  5. apologising for breaking wind is taking responsibility for the microbial part of you, as methane/hydrogen sulphide are only produced by bacterial enzymes
  6. Review of idea of Holiobionts and how organisms can borrow skills from other Kingdoms by forming a symbiosis/symbiosis opens up new ways of life/niches

5. Dr Ginny Acha (Association of the British Pharmaceutical Industry & British Pharmacological Society) on Personalised Medicines

  1. Interesting data on efficacy of drugs – numbers show percentage of patients who do not respond to drugs for that condition
  • Anti-depressants 38%
  • Diabetes 40%
  • Arthritis 50%
  • Alzheimers 70%
  • Cancer 75%
  • Nice review of history of understanding of blood cancer and how increasing understanding has led to more effective treatment
  • 100 years ago – “disease of blood” – 100% mortality
  • 80 years ago – leukaemia vs lymphoma
  • 60 years ago – 3 types of leukaemia and 2 types of lymphoma
  • Today – too many classifications to note down! 70% survival

Back at school and a lovely lesson with my Year 13s, exploring Genetic Drift through retinitis pigmentosa on Tristan da Cunha (use Google Earth to dramatically show the geographic isolation of this volcanic island)and a rather splendid colour worm game, followed by allele frequency and selection with sickle cell anaemia Sickle Cell Anaemia change in allele freq.

I came up with the idea of applying rates of mutation through Sean B Carroll’s excellent The Making of the Fittest where he does the same with colour vision in birds (brilliant chapter!). It works quite well but, boy, do they struggle with calculating the probabilities! How do you get on?

One way to help is to rephrase the problem. If the rate of mutation was 1 base in 3,000,000,000, what would be the probability of any one person having that mutation? So if the rate is 175 in 3,000,000,000….? And so on. Of course, a point mutation will only have an effect if it’s the right point mutation…. so what do you have to do to the probability?

I send them off to do some homework on Eugenics and applying Hardy Weinberg to the elimination of cystic fibrosis by selective breeding eugenics worksheet with Hardy Weinberg. Yields dramatic results!

I’ll say a bit more about Hardy Weinberg next week, as it’s a nice example of how to make what appears to be dry and theoretical into a hands on, student led learning activity.

But there’s also an Inspection next week, so if it seems a bit rushed, you’ll know why!

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