In its quest to answer the question "What is life?" the life sciences have been advancing rapidly with the discovery of various biomolecules and through analysis of their functions. More than 10 years have passed since decoding of a series of important genomes, including that of the human, around the year 2000. As a result of this catalogue of genetic information (the genome) becoming available, developments based on the analysis of individual biological phenomena have accelerated our understanding of the blueprints of the cell, the fundamental unit of life. Among these developments, in vitro reactions of biomolecules have already aided in the successful reconstruction of intracellular phenomena such as replication, transcription, and translation. This type of constructive approach is in its infancy, but even before now, diverse and deep expertise has been acquired on how biomolecules generate cellular functions. Through testing, reconstitution, design and control of cellular functions, opportunities to gain further insight into the design principle of cells have increased both in Japan and overseas. Accordingly, the purpose of this field of study is to establish new trends in the life sciences that may help to advance our understanding of life and provide broad applications through a broad-ranging constructive approach, from molecule design to the composition of non-human embryos.

A constructive (or synthetic) approach encompasses a qualitative understanding of molecular networks and defining sufficient conditions for molecular networks to function. This also differs from the descriptive (or analytical) approach, which emphasizes data collection, in taking an alternative approach that places greater importance on the quantitative predication and verification of the dynamic behavior of biological systems, which also has the benefit of driving forward a cycle of theoretical and experimental development. Furthermore, a constructive approach requires the formularization and quantification of various phenomena, and, through performing experimental verification of theoretical prediction, makes clear the discrepancies between the targeted biological functions and current knowledge and theory. Such discrepancies give rise to new areas for further research, and serve to prompt deep questioning and understanding of the target phenomena, and ultimately we hope, full control over them.

Recently, a larger theme involving the unification of this kind of constitutive approach, namely, "reconstruction and design of cell", has come to be actively discussed both in Japan and overseas. These discussions enforce a constant awareness of the research problem at hand, namely, how do we know whether "cells" are created? It also leads to continuous and active discussion about the fundamental questions in life science, such as "What is a cell?" and "What is life?" For that reason, a constructive approach takes not only a natural science perspective, but also takes into account social and cultural involvement. The size of DNA sequences that can be synthesized is increasing exponentially. To date, the DNA sequence of gene size and virus size have been fully synthesized, and last year in 2010, synthesis of the bacillus genome was accomplished. If the development of DNA synthesis continues at this pace, it may become possible to synthesize genomes the size of the human genome by 2015-2020. What kind of developments in life science will be possible at that point? It is hoped that the birth of "synthetic" life science can be witnessed through participation in this field of study.