1. It is the largest genome to be extensively sequenced so far,
being 25 times as large
as any previously sequenced genome and eight times as large as the sum of all such
2. It is the first vertebrate genome to be extensively sequenced.
3. There appear to be about 30,000–40,000 protein-coding genes
in the human
genome—only about twice as many as in worm or fly. However, the genes are
more complex, with more alternative splicing generating a larger number of
4. Hundreds of human genes appear likely to have resulted from
from bacteria at some point in the vertebrate lineage. Dozens of genes appear to
have been derived from transposable elements.
5. Although about half of the human genome derives from transposable
there has been a marked decline in the overall activity of such elements in the
hominid lineage. DNA transposons appear to have become completely inactive
and long-terminal repeat (LTR) retroposons may also have done so.
6. Analysis of the organization of Alu elements explains the longstanding
their surprising genomic distribution, and suggests that there may be strong
selection in favour of preferential retention of Alu elements (a sequence found
in the tissue plasminogen activator gene in chromosome 8) in GC-rich regions
and that these 'selfish' elements may benefit their human hosts.
7. The mutation rate is about twice as high in male as in female
meiosis, showing that
most mutation occurs in males.
8. More than 1.4 million single nucleotide polymorphisms (SNPs)
in the human
genome have been identified. This collection should allow the initiation of
genome-wide linkage disequilibrium mapping of the genes in the human population.