Genome Organization: Human

Abstract

The human nuclear genome is a highly complex arrangement of two sets of 23 chromosomes, or DNA molecules. There are various types of DNA sequences and chromosomal arrangements, including single‐copy protein‐encoding genes, repetitive sequences and spacer DNA.

Keywords: human genome; genome organization; DNA sequence complexity; gene families; chromosomes

Figure 1.

Broad classification of DNA sequences in the human genome. MER, medium reiteration frequency repetitive sequence.

Figure 2.

RNA‐mediated transposable elements in the human genome. Each contains the characteristic flanking direct repeats (arrows). The human endogenous retrovirus containing long terminal repeats (LTRs) (pale green regions), gag (group‐specific antigen gene), pol (polymerase gene) and env (envelope gene). The THE‐1 retrotransposon consists of an open reading frame (ORF) and LTRs. The non‐LTR retrotransposon (L1) contains internal RNA polymerase II promoter sequences (P), two open reading frames, and a poly(A) tail. The Alu element has a dimeric structure of homologous halves separated by a middle A‐rich region (blue). The left half contains A‐ and B‐box RNA polymerase III promoter sequences, and the right half contains an additional internal 31 bp. For L1 and Alu elements, pale green and mauve regions are sequences unique to these elements.

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Further Reading

Li W‐H and Graur D (1991) Fundamentals of Molecular Evolution. Sunderland, MA: Sinauer Associates.

Strachan T and Read AP (1999) Human Molecular Genetics, 2nd edn. Oxford: BIOS Scientific.

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How to Cite close
Kass, David H, and Batzer, Mark A(Mar 2004) Genome Organization: Human. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0003855]