Dictyostelium discoideum is a soil-living amoeba. A group of
100,000 form a mound as big as a grain of sand. The hereditary
information is carried on six chromosomes with sizes ranging
from 4 to 7 Mb resulting in a total of about 34 Mb of DNA, a
multicopy 90 kb extrachromosomal element that harbors the rRNA
genes, and the 55 kb mitochondrial genome. The estimated number
of genes in the genome is 8,000 to 10,000 and many of the known
genes show a high degree of sequence similarity to genes in
vertebrate species. - NIH Credit: Rex Chisholm, Northwestern
University (NIGMS Image Gallery)