The emergence and exploitation of green fluorescent protein (GFP) has redefined our approach to, and our understanding of, development, homeostasis and disease progression. The utility of fluorescent proteins like GFP has revolutionized experimental approaches in biological research, advancing what is possible. Indeed, developmental biologists today are armed with a bastion of genetically encoded fluorescent proteins and are no longer confined to the study of fixed (i.e. dead) material. Together with recent advances in optical microscopy, fluorescent proteins have become an indispensable tool in a myriad of live imaging experiments. Such experiments now allow us to observe an event as it takes place in situ over time, thereby bringing us closer to understanding exactly how a process of interest actually takes place.FIG1
With Aglow in the Dark, researcher Vincent Pieribone and scientific writer David Gruber have teamed up to produce a book that is both informative and entertaining. It chronicles the history of biofluorescence,and of genetically encoded fluorescent proteins in particular. Albeit an illuminating read (no pun intended!), this is not a textbook, nor a technology guide. Instead it describes an odyssey of discovery that starts with the scientific curiosity that ignited efforts that culminated in the purification of GFP, its subsequent cloning and its later application as a readily visible molecular tag. It details some of the rationale and events that spawned the emergence of today's bumper crop of genetically encoded fluorescent proteins,representing a technicolour palette of increasing complexity. Just over a decade after the cloning of GFP, the use of fluorescent proteins is now commonplace. They represent routine, if not to say essential, tools for many fields of biology, including cell, developmental and neurobiology.
The story told in this book is in itself fascinating, and the authors make sure that the reader is introduced to the protagonists along with their major endeavours. However, as might be expected, and probably in order to make for better reading, many of the events concerned have been streamlined, with the frequent omission of key players, contributions and/or observations. The authors do not delve too deeply into their subject matter, but this may be intentionally to capture a wider audience. Furthermore, the discussion steers clear of the possible double-edged bioethical ramifications of genetically encoded fluorescent protein technology. The text is focused on providing a chronological overview of events, and (unfortunately) a rather superficial description of a few examples of the use of fluorescent proteins to provide the reader with only a glimpse of what might be possible.
In the first chapter, the authors set the stage by discussing bioluminescence, with the basic how and why of this primarily marine phenomenon. They detail how glowing proteins first evolved, and introduce us to the researchers who were inspired by the fluorescence of a variety of animals, including the eponymous jellyfish. They describe the quest to understand the chemical and physical properties of the bioluminescence reaction that led to the isolation of the responsible proteins. Indeed, it was this work that laid the foundations on which the GFP revolution was built, and resulted in the christening of a protein capable of producing green fluorescence when illuminated with ultraviolet light.
Occasionally the transitions between topics are somewhat obtuse, as with the discussion of the basic principles and history of optics, and the science of fluorescence that follows. This is also the case with the introduction of the nematode worm in later chapters.
As the authors continue to weave their story, the reader is taken through the endeavours of many individuals instrumental in taking genetically encoded fluorescent proteins out of their native context and into heterologous systems. The authors review some of the experiments that helped formulate our understanding of how GFP works, and they detail some of the reasons behind the development of an artillery of mutants, each having unique properties suitable for specific applications. The authors digress to mention a few applications,and also to discuss some of the more frivolous uses of fluorescent proteins,which are exemplified by the generation of transgenic `glowing' domestic animals, marketed as pets and/or art.
Albeit an illuminating read...this is not a textbook, nor a technology guide. Instead it describes an odyssey of discovery...
The authors go on to discuss the breakthrough that resulted in an increased assortment of fluorescent proteins being made available as a result of work that identified fluorescent proteins with structural similarity to GFP in non-bioluminescent corals. They also discuss the benefits and shortcomings of fluorescent proteins that exhibited longer wavelength (i.e. red and far-red)excitation and emission spectra. Indeed, we now know that the vivid fluorescent and non-fluorescent colouration of reef Anthozoa is primarily due to a mélange of GFP homologs. And it is the increasing catalogue of cloned GFP homologs that is responsible for the continual expansion of the available genetically encoded colour palette. Here, the authors pause to discuss the diversity of reef corals and highlight the pressing issue of ecological preservation.
The final chapters deal with current and future applications. Ideally, one would have liked to see case studies chosen to reveal the broader impact and potential of the available bounty of fluorescent proteins. Unfortunately, it is here that the authors fail to do the field justice, with vignettes drawn almost exclusively from the field of neurobiology. This section would certainly have benefited from a more expansive discussion of a broader set of applications that would illustrate the true promise of this technology.
That said, as popular science books go, the text is both concise and informative, and certainly worth a leisurely read. It is rather beautifully illustrated, with many of the images resulting from deep-sea excursions courtesy of the authors. Ultimately by telling this story, the authors feed our fascination with all that glows in the dark, and recount the work that laid the foundations of one of the most prolific contributions to modern-day biology.