What’s up with the title? Well, It’s been months since I’ve publish a blog about science and what has caught up my attention for the past few months I want to share today. As I study different articles, papers and research, this “crunchy” title, CRISPRs, in its expanded for the Clustered Regularly Interspaced Short Palindromic Repeats has been a hot topic these past few years. Forget about what you are studying now, this technology will change the future of health, medicine, agriculture and science in general. The first time I heard this term was back in 2008 during my 3rd year in the university (University of the Philippines Manila). And honestly, I didn’t understand, nor was I, at that time, interested with such complicated topic.
First, let me define CRISPRs in “English” and how I understood it.
Clustered = They are grouped.
Regular = There is a certain pattern.
Interspaced = There is a spacing or a gap.
Short = Less than 30 letters? or much lesser.
Palindromic = The letters can be read backwards. Like “Level” when reversed is “leveL”. Even people can be palindromic. Try look yourself in a mirror.
Repeats = Occurring again and again… and again.
So these are MIRROR-LIKE sequences that are GROUPED with CONSTANT GAPS, and less than 30 characters that occurs again and again. It sounds very simple, but when I was in the university, it drove me so crazy. Anyway, now I understood it better. So what? Well, more than 15 years ago, these CRISPRs are just sequences. How were they discovered is actually further in the past. They were first observed in Escherichia coli K12 back in 1987 (I wasn’t even born that time). Bacteriophage also have CRISPRs, surprisingly, scientist have found that CRISPRs are also in the genome of many bacteria, not just E. coli. However, at that time, no one really knows what they can do or what is the significance of these regularly occurring patterns. In minute organisms, it is has been observed in more than 50% of the bacteria and archaea group (That’s a lot!). So there is definitely something important about these CRISPRs.
However, researchers speculated that if viruses and bacteria have identical sequences, it might be a way for the bacteria to protect itself from viral infection. It’s like bacteria have their own vaccine against viruses. Sorry viruses, you got owned! Pretty cool, eh? It started from that hypothesis. Then a group of scientists, from University of California, Berkeley (and a collaborating European laboratory), MIT and Harvard University, discovered the potential use of these sequences to make “guided” editing of genomic sequences. However, it seems like it’s not really “editing” at this point, because what researchers can do now is to “delete” certain regions of the genome with high accuracy and specificity, not replace them. At least not yet. But I also believe it’s just a matter of time when researchers can exploit the best utility for this genetic tool. I hope I can be part of it someday.
For many years, researchers, including me, we have been struggling to increase the accuracy as well as the specificity of genome editing. Random mutagenesis, RNAi, homologous recombination. They are good tools but not as good as the developed tool from CRISPRs, which I want to talk more later. Dr. Jennifer Duodna and her team at University of California, Berkeley made an astounding work on CRISPR technology. Now, researchers from Harvard can delete genes from pig to make it a suitable organ donor for human transplantation. Thanks to Prof. George Church! Dr. Feng Zhang from Broad Institute actually made the first in vivo experiment in mammalian hosts. And the surge in research has been tremendous over the past 3 years alone! More than 100% increase in CRISPR research, also thanks to Addgene, a repository for plasmid DNAs, bacteriophages and other gene editing tools that are within the reach for many researchers worldwide. I think it’s just cool to live in this period where all the amazing science and technology is just within our reach.