A 4062-nucleotide (nt) fragment of the mitochondrial genome of the cru
stacean Daphnia pulex was sequenced and found to contain the complete
genes for eight tRNAs and five proteins (ATP6, ATP8, COII, COIII, ND3)
and the partial sequence of COI. In combination with data described p
reviously, approximately 50% of the D. pulex mitochondrial genome has
been sequenced. The gene order in this half of the genome is identical
to that of Drosophila yakuba which differs from that of the other com
pletely sequenced crustacean mitochondrial genome, Artemia franciscana
. Comparison of seven mitochondrial proteins among D. pulex, A. franci
scana, D. yakuba, Anopheles gambiae, Locusta migratoria and Apis melli
fera a showed that, with one exception, the D. pulex proteins are most
similar in length and sequence to the proteins of the dipteran insect
s. Conversely, patterns of nucleotide bias at third codon positions in
fourfold degenerate codon families are very similar in the two crusta
ceans but differed substantially from the insects.