Marc Somssich Profile picture
Jan 20 11 tweets 4 min read
Do you know Daisy Roulland-Dussoix? She is one of the discoverers of restriction enzymes, who’s findings paved the way for the development of recombinant DNA and cloning technologies. Accordingly, the finding was rewarded with a #NobelPrize. But the prize didn’t go to her... 🧵👇 A portrait of Daisy Roulland-Dussoix from Wikipedia.
Daisy Roulland-Dussoix worked with Werner Arber to study the mechanism for the observed host-specificity of λ Phages. It was known from an important 1953 paper (Bertani & Weigle) that phages, that had replicated in a certain E. coli strain, could only re-infect the same strain. Title page of the 1953 paper from G. Bertani and J. J. Weigl
Roulland-Dussoix & Arber showed that host-specificity is linked with the phage’s DNA. Using phages carrying radiolabeled DNA, they showed that progeny with 2 parental DNA strands retained specificity, while progeny with newly synthesized daughter strands could adapt to new hosts. Title page of the first paper by Werner Arber and Daisy DussExcerpt from the paper stating ‘(2) All progeny λ K(Pl) p
Back-to-back with this first paper, Roulland-Dussoix & Arber then add that the phage DNA is degraded immediately after injection into the E. coli cell,& that the DNA can be ‘rescued’ by the infection of additional DNA, suggesting competition between the DNA for recognition sites. Title page of the second 1962 paper with the title ‘Host s
It therefore seemed that enzymes, that competitively bind the DNA are involved in this process. These host enzymes are degrading the invasive phage DNA, and are thus ‘restricting’ the phage’s ability to infect the host cell: restriction enzymes.
In 1968 Meselson & Yuan identified the first restriction enzyme, the type I endonuclease EcoK from E. coli, followed by Smith & Wilcox, who identified the type II enzyme HindII in 1970, & Mertz & Davis who found EcoRI in 1972,& also showed that this enzyme produces ‘sticky-ends’. Title pages of the three papers. First, Matthew Meselson & R
The lab of Daniel Nathans then proceeded to use these restriction enzymes to cut up the simian virus 40 genome into 11 defined pieces, followed by gel-separation, demonstrating that endonuclease analysis could be used for DNA mapping of genomes. Figure 3 from the paper, showing the first restriction map o
Then, in 1972/1973, restriction enzymes were used to splice gene fragments into plasmids and shuttled into bacterial cells, where they were replicated and expressed. Molecular cloning was developed,& with it started the Molecular Biology Revolution, changing the world forever. The cloning strategy as outlined in the paper by Peter Berg.Title page of the corresponding 1972 paper showing the title
Accordingly, Nobel Prizes were in order! And the 1978 Prize in Physiology and Medicine "for the discovery of restriction enzymes and their application to problems of molecular genetics" went to Werner Arber, Daniel Nathans & Hamilton O. Smith. Daisy Roulland-Dussoix was ignored. Screenshot from the Nobel Prize page, showing the The Nobel
Thankfully, Daisy Roulland-Dussoix went on to have a long and successful career in science despite this, initially continuing work on restriction enzymes & cloning with Herbert Boyer & eventually becoming a leading expert on mycobacterium/mycoplasmas.
Daisy Roulland-Dussoix died January 5, 2014. I would have liked to end this with a nice obituary for her, but unfortunately I could not find one...

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Marc Somssich

Marc Somssich Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @somssichm

Jan 16
I have done a couple of Twitter threads on interesting researchers worth knowing about. I have compiled them here in this thread and will add more in the future. #SciCom Have a look! 🙂🧵👇
1) Douglas Prasher, the man who cloned the original GFP gene.
2) Albert Coons, the man who developed immunofluorescence microscopy in the throes of World War II.
Read 7 tweets
Dec 2, 2021
#PlantScienceClassics #11: The GUS reporter system. In 1987 Richard Jefferson & colleagues from @michaelbevan565's lab published the first reporter system to monitor promoter activity in planta in the @embojournal: doi.org/10.1002/j.1460… Title page of the paper showing its title “GUS fusions: be
In the 1980s it was possible to express transgenes in cells of different organisms, but visualizing & assaying gene expression was still problematic. The lacZ β-galactosidase was a commonly used reporter, but compromised due to endogenous enzymes breaking down its substrates too.
So Jefferson developed the Escherichia coli uidA-encoded β-glucuronidase (GUS) reporter during his PhD in David Hirsh’s lab @CUBoulder. Adding a GUS-substrate to Caenorhabditis elegans carrying the GUS-reporter led to a colorful precipitate in all tissues with GUS expression. A wild type Caenorhabditis elegans worm and one carrying the
Read 13 tweets
Oct 18, 2021
#PlantScienceClassics #7: The ZigZag Model.15 years ago @jonathandgjones & Jeff Dangl published their @nature review integrating Pattern/PAMP-Triggered Immunity (PTI) & Effector-Triggered Immunity (ETI) into one unified model of ‘The plant immune system’. doi.org/10.1038/nature… A picture showing Jeff Dangl and Jonathan Jones together, in
In the 1980s, with plant molecular biology still in its infancy, the plant immune system was not understood very well at all. Dangl, at the time an immunologist working on mouse/human cells, remembers: ‘I had never considered that plants could recognize pathogens’.
But this fact, that the molecular mechanisms of the plant immune system were still basically a ‘black box’, is exactly what got Dangl interested and motivated to switch fields, and join the group of Klaus Hahlbrock at the @mpipz_cologne to work on plant immunity. An excerpt from the PNAS article 'Profile of Jeffery L. Dang
Read 13 tweets
Jun 3, 2021
Do you know who Douglas Prasher is? He is the person who cloned the original GFP gene in the early 1990s. In my short history of plant light microscopy I also cover a bit of his story - & why he is relatively unknown today, despite the importance of his work. See here: 1/14 🧵 A profile picture of Douglas Prasher from Martin Chalfie's N
2/14 In 1962 Osamu Shimomura et al. identified the bioluminescent Aequorin in the Aequorea jellyfish, as well as a green fluorescent protein, that seemed to act as a FRET-acceptor for the Aequorin 'in jelly' [1][2][3] (REFs at the end). Aequorea victoria jellyfish
3/14 20 years later, Milton Cormier aimed at cloning the Aequorin gene to use it as a bioluminescent marker for use in diagnostics. He hired Douglas Prasher for this job. [4] In 1985, Prasher et al. published the successful cloning, expression and in vitro function Aequorin. [5] Aequorin protein expressed in vitro
Read 16 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!

:(