30 May | Institute of Cell Biology, University of Bern

Mitochondria, ageing and separate sexes

This seminar was given at the kind invitation of Prof. Dr. Mariusz Nowacki.

I received excellent questions and comments from members of an expert audience. There seemed to be agreement on my view of the experiment we should do next.

It was a pleasure to meet Mariusz’s lab members, including Dr. Estienne Swart and a special host, Dr. Sarah Allen.

I also appreciated the introduction to colleagues. Prof. Dr. André Schneider in particular had fascinating research to report on protein import into mitochondria, with, he believes and I agree, so much to tell us about the origin and evolution of eukaryotes. André thanked me for acknowledging past discussion with Jeff Schatz, whom he knew as his postdoctoral advisor and mentor, and who had provided the first compelling evidence for mitochondrial DNA. In about 1996, in Lund, Sweden, Jeff had recommended not wasting time on Xenopus oocyte mitochondria since they were “really boring; no cytochromes, no ox-phos”. I tried but failed to explain why I thought this was an interesting comment.

André’s comment in Bern was prompted by an acknowledgement slide I’d prepared, and worried about, thanking Jeff and also Lars Ernster for early encouragement. I can’t be sure about Jeff’s view, but Lars definitely liked the mitochondrial theory of ageing, and even showed a summary graphic, Figure 1 from my 1996 Journal of Theoretical Biology paper, in a seminar he later gave in Lund. I recalled apologising to Ernster, an outstanding biochemist and experimentalist, Nobel Chemistry Committee member and spokesman, for proposing “just an hypothesis”.

His reply? – “This is what we do!


Sarah outside the former home of Bern's most famous resident.
Sarah outside the former home of Bern’s most famous resident.
Two members of the Allen family.  Bern, Switzerland, 30th May 2016.
Two members of the Allen family. Bern, Switzerland, 30th May 2016. Photo taken by Estienne Swart.

4 May | Instituto de Neurobiología UNAM

Energy, ageing, fidelity and sex. Oocyte mitochondrial DNA as a protected genetic template

A lively audience packed into a small lecture theatre in the beautiful UNAM Campus Juriquilla.

Good questions introduced many ideas new to me. I thank Dr Alfredo Varela, the newly-appointed director of the Institute of Neurobiology, for generous hospitality. This included an afternoon of presentations and discussion of current research in Alfredo’s laboratory.


Mexico Lectures April–May 2016

Mitochondria, ageing, separate sexes

3 May | Departamento de Bioquímica, CINVESTAV

Regulation of photosynthesis. Control of chloroplast DNA transcription and membrane protein phosphorylation

I felt at home in the research laboratory of Dr. Carlos Gómez of the Department of Biochemistry. I saw a French Press, spectrophotometers and fluorimeters, SDS-PAGE, sucrose gradient centrifugation, and cultures of fascinating cyanobacteria. I learned that Spirulina, once a Mexican speciality and export, is now called Arthrospira. Krisha Rao in King’s College London once gave me a brick-red Spirulina ferredoxin preparation, I seem to recall at 10 mM. I now know Krishna had purified it from Sprulina obtained in Mexico when Krishna worked as a visitor in Carlos’s lab.

Unfortunately I overran again. This seminar was a daunting task, the title requiring me to reach back to a time before most of the audience had been born. It was not all history. The research included Iskander Ibrahim‘s results, published in February this year, on phosphoryl group transfer from cyanobacterial Histidine Kinase 2. So this lecture presented both older and newer work than any lecture in my Mexico tour. An attentive audience again came up with fine questions.

s- dr john f allen

Carlos Gómez and Fanis Missirlis
Carlós Gomez and Fanis Missirlis

Mexico Lectures April–May 2016

Regulation of photosynthesis

29 April | Instituto de Fisiología Celular, Universidad Nacional Autónoma de México

A formidably well-informed audience volunteered numerous good questions during and after my presentation Energy, ageing, fidelity and sex. Oocyte mitochondrial DNA as a protected genetic template. I sensed a degree of polite scepticism. Good. There is no point in explaining things to people who already agree. Such an appreciative and critical audience is definitely good for morale. What a contrast with the department in which Fanis and I were once colleagues.

Lunch was followed by a guided walking tour of the spectacular UNAM campus. Warmly recommended. It’s not my place to comment, but the “Autonomous National University of Mexico” (which it is) should surely be better known internationally. Go there if you ever get the chance. It’s a great place. We’d seen that already on 27 April.

I am most grateful to my host in IFC-UNAM, Xochitl Pérez Martínez, pictured here with Fanis Missirlis.

UNAM lecture 29 April 2016

Mexico Lectures April–May 2016

Mitochondria, ageing, separate sexes

28 April | Fisiología Biofísica y Neurociencias, CINVESTAV

Why chloroplasts and mitochondria retain their own genomes and genetic systems

I felt I had to truncate the advertised title, that of my 2015 PNAS paper. I feared that the original title would put too much text on the first slide, tending to sap the will to live amongst members of a general audience.

I needn’t have worried.

My ever-generous host, Fanis, delivered a fulsome introduction, pointing out that I had changed my title without permission, while being, really, over-complimentary. Where and how we came to be joint authors of a low-impact letter in a high-pact journal is a story in itself, but off-topic, except by distant inference, for the CoRR Hypothesis. Members of the audience seemed to be engaged, some perhaps just waiting for the next joke. But the questions were great, and right on-topic. “What about the kinetoplast?”; “How about mitosomes?”. The message had clearly been received, and understood. I had too much to say, and over-ran; something I regard as serious discourtesy, not say say a sign of terminal self-importance. Perhaps it would be even worse to say “Sorry; no time for questions like that”.

The lunch afterwards was superb, out of doors, and a selection of Mexican foods to go in wraps of tortilla, I think. My family members would have loved it, and known what more of the treats were called than do I.

Such generosity, and such nice people. I wish I’d taken a photo. Specific poster shown here, instead. Thanks to Fanis, too, for that.


Mexico Lectures April–May 2016

Chloroplasts and mitochondria

27 April | Instituto de Ecología, Universidad Nacional Autónoma de México

A redox switch hypothesis for the evolutionary origin of oxygenic photosynthesis

It could be quite wrong. If it is, this great lab may well be the first to find out. I told them this at the outset, and asked them to let me be the first to know. This caused amusement, while I was actually quite serious. I’ll doubt I’ll ever get used to becoming an unintended comedian.

Fantastic place, though. I had a receptive audience. There were perceptive questions and helpful discussions with my host, Valeria Souza, as with five members of her team of talented researchers. They signed my souvenir poster about Cuatro Ciénegas. Maybe that’s an ideal place to look for the protocyanobacterium?

I thank them all.

What a pleasure.

The five talented researchers, plus Fanis and me.
Five talented researchers: Gabriel Ponce, Valerie De Anda, Mirna Vázquez, Marietta Viladornat, Fabricio Romero. Plus Fanis and me.

Mexico Lectures April–May 2016

The origin of atmospheric oxygen