Esterases in the house fly. Polymorphisms and inheritance patterns.

Polyacrylamide gel electrophoresis was used to examine the variability and inheritance of esterases in five strains of the house fly, Musca domestica L. Individual zymograms exhibited 8 to 15 bands that could be assigned to one of five zones designated as A through E from anode to cathode. Correlations of P1-F1 banding patterns indicated the existence of at least 3 different loci in zone A. 2 each in zones B and C, and 4 in zone D; no clear inheritance patterns were discernable for the bands of zone E. Only the Es-5 locus of zone C was monomorphic in all of the strains studied. Eight loci possessed null alleles and codominant alleles were detected at six loci. The results suggest that esterases should prove useful for measuring relationships among fly populations or for various studies of population dynamics.

Polymorphisms and inheritance patterns of tetrazolium oxidase and octanol dehydrogenase in the house fly.

Zymogram analyses suggested the existence of two autosomal codominant alleles each at loci controlling the production of tetrazolium oxidase (To1) and octanol dehydrogenase (Odh1) in Texas house flies; an additional variant of the To1 locus was detected in a population from South Dakota. The allozymes of both systems may be dimeric as indicated by the presence of possible heteropolymers in flies heterozygous for To1 and Odh1 allels. Apparent nonsegregating isozymes of To and Odh (To2 and Odh2) were also noted in the zymograms of Texas flies. Some banding forms in the Odh gels could not be interpreted genetically.

Genetics of house flies. Variability studies with North Dakota, Texas, and Florida populations.

Genetic data were used to compare the structure of native house fly populations collected in North Dakota, Texas, and Florida. Recombination studies with mutant markers on chromosomes 3 and 4 indicated a lack of inversion polymorphism among the three populations in those areas of the genetic map studied. Significant differences were observed among flies from the three regions with regard to the frequency of 1) females that produced only male progeny, and 2) male-determining 3rd chromosomes (IIIm chromosomes). However, the North Dakota and Texas flies were more similar to each other than to the Florida flies since populations from the two former areas possessed a low frequency of both male-producing females and IIIm chromosomes; in contrast, the Florida population was void of females that produced males only and a high percentage if not all Florida males appeared to possess the IIIm male-determining mechanism. Tests for recessive lethal 3rd chromosomes showed that there was no significant difference in the frequency of lethal factors recovered from the North Dakota and Texas flies; the presence of IIIm chromosomes in Florida males precluded the recovery of lethal factors from this population by the method employed. The data suggest that house fly strains to be employed in genetic control programs should 1) originate from target control areas to avoid possible behavioral differences existing among flies from different locales, 2) be initiated with as many flies as possible to provide a background for the maintenance of variability, and 3) be renewed periodically with field-collected material since the genotype may be capable of rapid reorganization in response to laboratory selection pressures.

A male-producing strain of the house fly.

An autosome inherited by male offspring only and a temperature-sensitive lethal factor have been combined in a house fly strain which produces both male and female progeny when reared at 25.6 degrees C but only male progeny when reared at 33.3 degrees C.

Genetics and linkage of aldrin resistance in the German cockroach, Blattella germanica (L.).

The inheritance mechanism and linkage association of cyclodiene resistance were studied in 2 cyclodiene-resistant strains of the German cockroach. The resistant strains were crossed to each other, to an unmarked susceptible strain, and to 6 susceptible marker strains. The progeny from succeeding generations were tested for resistance to aldrin using a dipping method or a time-exposure method, and were examined for markers in linkage tests. The results show that cyclodiene resistance (R-Cyclo) is inherited as a simple autosomal semidominant trait which is allelic in the 2 resistant strains. Linkage studies indicate that R-Cyclo is independent of linkage groups II-VI, but is linked with the group VII trait curly wing at a distance of 3.4+/-1.0-6.2+/-1.4.