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Tools for genetics and genomics: Model systems

Robert D Blank, MD, PhD
Section Editor
Benjamin A Raby, MD, MPH
Deputy Editor
Jennifer S Tirnauer, MD


Even a complete knowledge of the entire three billion base pairs that make up the human genome (as provided by the Human Genome Project) is insufficient to understand the genetic basis of disease [1]. The sequence data are far more informative if they can be correlated with functional information. This correlation is most readily accomplished through the use of model systems. Thus, it is best to consider the topics of genomics and model systems together.

This topic summarizes some of the most useful on-line sources of genomic information and analysis, and presents selected examples of the use of model systems to explore the relationship between genetic constitution and function. (See "Principles of molecular genetics".)


The genome is the full complement of genetic information encoded on a complete, haploid set of chromosomes. The human DNA sequence, as defined by the genome project, represents a composite compiled by studying DNA obtained from many individuals. While these data include considerable information regarding sequence variation among individuals, inter-individual variation remains incompletely cataloged.

Efforts to define variation between individuals and to relate such variation to disease risk remain central tasks for human geneticists.

Much of this investigation is focused upon single nucleotide polymorphisms (SNPs), sequence variations which occur roughly once in several hundred bases [2]. (See "Overview of genetic variation".)

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Literature review current through: Nov 2017. | This topic last updated: Oct 17, 2017.
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