Ingenious Genes

Ingenious Genes: How Gene Regulation Networks Evolve to Control Development

Roger Sansom
Copyright Date: 2011
Published by: MIT Press,
Pages: 144
https://www.jstor.org/stable/j.ctt5hhm6h
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  • Book Info
    Ingenious Genes
    Book Description:

    Each of us is a collection of more than ten trillion cells, busy performing tasks crucial to our continued existence. Gene regulation networks, consisting of a subset of genes called transcription factors, control cellular activity, producing the right gene activities for the many situations that the multiplicity of cells in our bodies face. Genes working together make up a truly ingenious system. In this book, Roger Sansom investigates how gene regulation works and how such a refined but simple system evolved. Sansom describes in detail two frameworks for understanding gene regulation. The first, developed by the theoretical biologist Stuart Kauffman, holds that gene regulation networks are fundamentally systems that repeat patterns of gene expression. Sansom finds Kauffman's framework an inadequate explanation for how cells overcome the difficulty of development. Sansom proposes an alternative: the connectionist framework. Drawing on work from artificial intelligence and philosophy of mind, he argues that the key lies in how multiple transcription factors combine to regulate a single gene, acting in a way that is qualitatively consistent. This allows the expression of genes to be finely tuned to the variable microenvironments of cells. Because of the nature of both development and its evolution, we can gain insight into the developmental process when we identify gene regulation networks as the controllers of development. The ingenuity of genes is explained by how gene regulation networks evolve to control development.

    eISBN: 978-0-262-29820-9
    Subjects: Ecology & Evolutionary Biology, General Science

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. Preface
    (pp. ix-x)
  4. Acknowledgments
    (pp. xi-xii)
  5. 1 The Problem of the Evolvability of Gene Regulation Networks
    (pp. 1-22)

    Organisms are superbly well engineered to survive and reproduce in their environments. We humans have achieved a wide variety of engineering feats, from computers to space stations, and we have learned to manipulate natural organisms with biotechnology, but it remains well beyond our capacity to build from scratch even simple forms of life capable of surviving and reproducing in a natural environment. The engineering of complex organisms, such as vertebrates, probably will always remain beyond our reach. The only way we can produce a complex organism is the old-fashioned way.

    Explaining the adaptive complexity of organisms has always been a...

  6. 2 Are Gene Regulation Networks Evolvable?
    (pp. 23-36)

    “Exactly how does an egg produce legs, head, eyes, intestine, and get up and start running about?” With this question, Conrad Waddington (1966, p. iv) expresses wonder at both any system that is capable of overcoming the difficulty of development and the difficulty of understanding such a system. The difficulty of a task can be understood in terms of the range of possible physical systems that can overcome that task. For example, opening a particular lock is difficult, because only a relatively small range of systems have the necessary features to be a key that can be inserted and turned...

  7. 3 Kauffman’s Framework for Gene Regulation
    (pp. 37-68)

    Stuart Kauffman’s more comprehensive model of gene regulation is the result of more than thirty years of research. His two books on the subject,The Origins of Order(1993) andAt Home in the Universe(1995), represent the most developed theoretical approach to gene regulation networks. Kauffman’s goal in investigating gene regulation networks is different from mine. He is primarily interested in explaining the complex order of development and of gene regulation; I am primarily interested in explaining the evolvability of development and of gene regulation.

    Organisms are low-entropy states. The second law of thermodynamics tells us low-entropy states are...

  8. 4 The Connectionist Framework for Gene Regulation
    (pp. 69-96)

    At any instance, each cell is faced with a microenvironment and either expresses or does not express each of the organism’s genes. Given that microenvironment, each gene expression and each gene non-expression is either adaptive, maladaptive, or neutral. I consider the adaptivity of a gene regulation network to be determined by the proportion of times that it reacts adaptively to its microenvironment. A gene regulation network isaccurateto the extent that it expresses only the right genes for each microenvironment. The problem of the evolvability of gene regulation networks becomes the question of how gene regulation networks can evolve...

  9. 5 Why Gene Regulation Networks Are the Controllers of Development
    (pp. 97-112)

    Consider a scene that took place on the banks of the Hydaspes River in the Punjab region of India in 326 BC. Nearly 50,000 infantry, more than 10,000 cavalry, and 200 elephants were involved in intense activity that resulted in more than 15,000 deaths. In order to make any sense of what occurred, it is necessary to understand who was controlling what was going on. It turns out that the forces that began on the right bank of the river, under the command of Alexander the Great, were battling the forces of the Punjabi King Porus, which were lined up...

  10. Notes
    (pp. 113-114)
  11. References
    (pp. 115-126)
  12. Index
    (pp. 127-128)