Extrachromosomal inheritance of carbon dioxide sensitivity in the mosquito Culex quinquefasciatus.
Mosquitoes from a laboratory colony of Culex quinquefasciatus from Matsu Island, China, develop irreversible paralytic symptoms after exposure to carbon dioxide at 1 degree. This CO2 sensitivity is caused by an inherited infectious agent, probably a virus. Crossing studies between CO2-sensitive and -resistant mosquitoes showed that the sensitivity trait is inherited extrachromosomally in a fashion strictly analogous to the hereditary transmission of sigma virus in Drosophila melanogaster. Sensitivity could be maintained through maternal transmission alone, despite nine generations of backcrossing of "stabilized" CO2-sensitive females to males from a resistant strain. CO2-sensitive males crossed to resistant females transmitted sensitivity to a portion of their F1 progeny, and only the female F1 sensitives were capable of further hereditary transmission.--Matsu, or a very similar hereditary infectious agent, is common in natural populations of Cx. quinquefasciatus on Oahu, Hawaii. Fifty-nine percent of the families reared from field-collected egg rafts contained CO2-sensitive mosquitoes, and some families contained only sensitive mosquitoes.
D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology*; D003433:Crosses, Genetic; D003465:Culex / Q000235:genetics*; D004351:Drug Resistance; D005111:Extrachromosomal Inheritance; D005260:Female; D008297:Male
D002245:Carbon Dioxide