Tore Samuelsson

After having studied math and chemistry I started out my scientific career as an experimental biochemist. With "experimental" I mean in this case "wetlab" as opposed to the in silico world. For about twenty years I actually did quite a lot of pipetting, mixing, fractionation, purification, and what have you, in order to address different biochemical problems. This was in fact partly in the experimentally difficult days of B.C. ("Before Cloning"). As a consequence a biochemist would at the time often carry out very cumbersome protein purification, starting out with tons of biological raw material and ending up, hopefully, with a few milligrams of reasonably purified protein.

In addition, no one knew about computers in those days. However, I must have had an interest in computational matters because I remember that early during one of my university math courses there was an element of programming and I found that really interesting. The language was called ALGOL, not so popular today. One significant problem at the time was that once having written some code, there was no computer around for trying it out. It was simply a matter of writing pieces of code on a piece of paper. There must have been computers around somewhere but I guess only senior scientific staff had access to those.

Then came the days of cloning and gene technology and I became very interested in analysis of DNA and protein sequences. Eventually I got so much involved in biological sequence analysis that I became a full time bioinformatician. In the early 1990s I started to learn about Unix and Perl. In 2001 an international master's program in bioinformatics was initiated at the Chalmers University of Technology in Gothenburg, Sweden; at that time the first programme of this kind in the country. I was for many years a teacher in that bioinformatics program. I was fortunate to meet a large number of highly motivated international students in that programme.

Quite recently high-throughput sequencing has revolutionized biology and has caused a renewed interest in biological sequence analysis. My book "Genomics and bioinformatics : An introduction to programming tools for life scientists” was published in 2012. In this book a number of specific biological problems are presented and it is demonstrated how these may be addressed using relatively simple Unix and Perl tools. Hence, the reader would be attracted by the biological problem posed and eager to know about the computational stuff needed to tackle it. I also wanted a design with all practical details of the bioinformatics so that a student could follow all the way from problem to final solution.

The more recent textbook title of mine, "The Human Genome in Health and Disease : A Story of Four Letters" was published in February 2019. This book project started out with Garland Science. However, as the book was nearly complete this branch of Taylor and Francis was unfortunately shut down, and the publishing was taken over by CRC Press.

The “Human genome” book attempts to present an accessible account of the molecular sequence information contained in human genome and how it is being used to direct the production of RNA and protein. It addresses the question of what important biological signals are found in the linear sequence of nucleotides in DNA and shows how specific DNA sequences have distinct functions. Such functional sequence elements, may be classified into a number of different functional categories. Examples are the three-nucleotide sequences that specify amino acids, or short DNA sequences that are targets for proteins that regulate transcription.

To provide biological motivation the importance of the DNA sequence for biological function is illustrated with a variety of inherited disorders or with other genetic disorders such as cancer. With such examples different functional elements of a gene, as well as different aspects of genetic information transfer within the cell are introduced. For instance, a point mutation in a coding sequence of a globin gene gives rise to sickle cell anemia, a splicing mutation results in a form of hemophilia, and a mutation in an untranslated region of a mRNA leads to an iron metabolism disorder.

In essence therefore, this book has a molecular sequence perspective and recurring themes are functional DNA sequence elements, illustration of functional impact with genetic disorders, and molecular interactions affected by sequence variation.

Why is it important to know about the different DNA sequence elements of the human genome and their functional impact? There are indeed many medical areas where such knowledge is critical as shown in this book. Examples include pharmacology, gene therapy and the diagnosis of rare inherited disorders and cancer.

Why did this book come about? We currently see a dramatic development in terms of human genome sequencing. Research laboratories around the world generate a wealth of genomic sequence data. Sequencing is becoming widely used in the clinic to analyze a variety of genetic disorders, including cancer. In addition, you can order your own genome sequence from a company ("direct-to-consumer" sequencing). With this wealth of genetic information it becomes increasingly important to know what the human genome sequence is all about, how the sequence should be understood in terms of biological function and how particular variants in the genome should be interpreted. I wanted to write a book providing an introduction to these topics. In the early days of my scientific career I worked as a molecular biologist and eventually I turned to bioinformatics with a focus on molecular sequences. For a long time I have been intrigued by the digital nature of genetic information, that the genome sequence can be handled with computers as a long string of letters, and that computing with molecular sequences may be used to address a variety of biological problems. There are already very good textbooks dealing with the human genome, but this book has a focus on molecular sequences and it examines in a systematic manner the functional role of DNA sequence elements as illustrated with human genetic disorders.