Genetic linkage map of the Screwworm Fly (Cochliomyia hominivorax) (2n = 12)
The North American Screwworm
fly (Cochliomyia
hominivorax)
is a Dipteran parasite of mammals, including humans and
cattle. The eggs are laid in open wounds, and the
screwworm larvae that hatch out eat the necrotic tissue,
which can cause severe illness (myiasis) or death to the
host. Eradication measures have included large-scale
release of sterile male flies, and identification of
insecticide-resistance genetic markers. As there are
multiple strains of screwworms, biochemical markers can
also be used to identify which strain is present in a
particular area.
Phenotypic markers are shown shaded in blue, biochemical (allozyme) markers are unshaded. Numbers indicate percent recombination between markers.
Note for example the close linkage between the locus for the enzyme phosphoglucomutase (Pgm) and the phenotypic le and wh loci: presence of the latter in heterozygous recessive form can be monitored by screening for the Pgm allele. Note also that markers separated by ~50% recombination (Gpd - re, Cw - ye) will be difficult to distinguish from unlinked markers (50% recombination). Note also that each of the five autosomes are each about 100 cM long.
Phenotypic markers are shown shaded in blue, biochemical (allozyme) markers are unshaded. Numbers indicate percent recombination between markers.
Note for example the close linkage between the locus for the enzyme phosphoglucomutase (Pgm) and the phenotypic le and wh loci: presence of the latter in heterozygous recessive form can be monitored by screening for the Pgm allele. Note also that markers separated by ~50% recombination (Gpd - re, Cw - ye) will be difficult to distinguish from unlinked markers (50% recombination). Note also that each of the five autosomes are each about 100 cM long.