Metabolic Resistance to Insecticides: Heterozygosity at the Chromosome II Locus in House Flies, Musca domestica (Diptera: Muscidae)

Cluck, Terry; Plapp, Frederick W.; Johnston, J. Spencer

doi:10.1093/jee/78.5.1015

“…Another cause of cross-resistance is linkage. Genes affecting resistance to one chemical may be located on the chromosomes in close proximity to other genes, so selection for one gene may automatically select genes affecting other traits [16,17].…”

Section: Introductionmentioning

confidence: 99%

Responses to Selection for Cadmium Resistance in the Least Killifish, Heterandria Formosa

Xie¹,

Klerks²

2003

Environ Toxicol Chem

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An artificial selection experiment was conducted for six generations to investigate the responses to selection for cadmium resistance in the least killifish, Heterandria formosa. There was a rapid response to selection. After only one generation of selection, two of the three selection lines had an increased resistance to cadmium, while all three selection lines had an elevated resistance by the next generation. After six generations of selection, fish from the selection lines survived about three times as long as control line fish when exposed to cadmium. Realized heritability for cadmium resistance was estimated to be 0.50. Cross-resistance to copper was studied in the F2, F3, and F6 generations; fish from the cadmium-resistant lines had a longer survival time than those from the control lines. Resistance to heat was investigated in the F2, F3, and F5 generations; the cadmium-resistant lines had a significantly shorter survival time than the control lines. Our results showed that evolution of resistance to cadmium was rapid, that cross-resistance to copper occurred, and that the evolution of resistance to cadmium was accompanied by a trade-off (fitness costs) as evidenced by the reduced heat tolerance.

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“…Another cause of cross‐resistance is linkage. Genes affecting resistance to one chemical may be located on the chromosomes in close proximity to other genes, so selection for one gene may automatically select genes affecting other traits [16,17].…”

Section: Introductionmentioning

confidence: 99%

Responses to selection for cadmium resistance in the least killifish, Heterandria formosa

Xie

¹

,

Klerks

²

2003

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

An artificial selection experiment was conducted for six generations to investigate the responses to selection for cadmium resistance in the least killifish, Heterandria formosa. There was a rapid response to selection. After only one generation of selection, two of the three selection lines had an increased resistance to cadmium, while all three selection lines had an elevated resistance by the next generation. After six generations of selection, fish from the selection lines survived about three times as long as control line fish when exposed to cadmium. Realized heritability for cadmium resistance was estimated to be 0.50. Cross-resistance to copper was studied in the F2, F3, and F6 generations; fish from the cadmium-resistant lines had a longer survival time than those from the control lines. Resistance to heat was investigated in the F2, F3, and F5 generations; the cadmium-resistant lines had a significantly shorter survival time than the control lines. Our results showed that evolution of resistance to cadmium was rapid, that cross-resistance to copper occurred, and that the evolution of resistance to cadmium was accompanied by a trade-off (fitness costs) as evidenced by the reduced heat tolerance.

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The problem of the number of tarsomeres in the regenerated cockroach leg

Akahane

¹

,

Ban

²

1992

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There are 5 tarsomeres in the normal cockroach leg, but this number is often reduced in regenerated legs. In order to examine this complicated situation, fore-, mid-, and hindlegs of German cockroaches were amputated at 11 different tarsal levels and at 18 different times during the last instar. When tarsi were amputated at or proximal to the 3rd tarsomere, 4-segmented tarsi regenerated. When legs were amputated distal to the 3rd tarsomere, the regenerated tarsi had 5 segments. Three-segmented tarsi rarely regenerated when legs were amputated proximal to 3rd tarsomere and in the latter half of the instar period. The lengths of all tarsomeres of regenerated tarsi were measured together with those of unoperated contralateral tarsomeres, and the ratios of the former to the latter were calculated. The ratios ranged from 28 to 138% for the various tarsomeres and levels of amputation. From a comparison of the ratios and morphological observations, it was suggested that the 3rd tarsomere of the normal 5-segmented tarsus has disappeared in the regenerated 4-segmented tarsus. Pads and disto-lateral spines of tarsomeres were observed on unoperated and regenerated tarsi. It was of interest that double spines were often found on the 4-segmented tarsi, mostly on the 2nd tarsomere, just proximal to the position of the missing 3rd tarsomere. This observation supported the idea that the 3rd tarsomere has not simply disappeared, but has probably fused with the 2nd tarsomere.

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Metabolic Resistance to Insecticides: Heterozygosity at the Chromosome II Locus in House Flies, Musca domestica (Diptera: Muscidae)

Cited by 6 publications

References 0 publications

Responses to Selection for Cadmium Resistance in the Least Killifish, Heterandria Formosa

Responses to Selection for Cadmium Resistance in the Least Killifish, Heterandria Formosa

Responses to selection for cadmium resistance in the least killifish, Heterandria formosa

The problem of the number of tarsomeres in the regenerated cockroach leg

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