schaechter.asmblog.org

On April 5th, the eminent biologist Sydney Brenner died aged 92. During his decades-long scienti­fic career, he had a lasting impact on biology by introducing C

The Red Queen of Lewis Carroll's Through the Looking Glass is a prominent figure among evolutionary biolo­gists. Her line to Alice, "‘Now, here, you see, it takes all the running you can do to keep in the same place" struck the biologist Leigh Van Valen as an apt metaphor for the need for species to constantly adapt to the changing en­vironment in order to survive

The clincher was that the Maa­løe lab had just published a tantalizing article on synchronous division in bacteria, a subject that I was drawn to. We soon bought two big old black bicycles at the Police auction and were ready to go, to liver som Danskere (live like Danes). We spent the morning analyzing the data from the day before and, after lunch, were ready for a new expe­riment. Lunch at the Serum Institute was at the Laegernes Frokostue (the doctors' lunch room), where I usu­ally had an ost smørrebrød med spejlaeg paa (open faced cheese sandwich topped by a fried egg).

It enhances carbon fixation by the classic carbon-fixing enzyme RuBisCO, which it accomplishes by raising intracellular CO concentration up to 180 times, reducing Rubisco's negative oxygenase activity, and helping to by­pass the issue of limited CO availability in aquatic condi­tions. The group performed a fluorescence recovery after photobleaching (FRAP) ex­periment and discovered that, indeed like a liquid, the Chlamydomonas pyrenoid matrix undergoes internal mix­ing when triggered by cell division and high CO levels. Many of these proteins are involved in funct­ions already known to be carried out by the pyrenoid, like carbon fixation, but the group also uncovered surprise proteins implicated in unexpected funct­ions such as chlorophyll synthesis and amino acid metabolism. Closer inspection of individual species revealed that some hornworts lacking pyrenoids flourished in periods with very low atmo­sphe­ric CO while species with abundant pyrenoids diminish­ed in periods of high atmosphe­ric CO.