scholarly journals POLYMORPHISM OF THE HEREDITARY SIGMA VIRUS IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1980 ◽  
Vol 95 (2) ◽  
pp. 459-465
Author(s):  
Annie Fleuriet
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Common Type ◽  
Co2 Sensitivity ◽  
Genetic Types ◽  
Sigma Virus

ABSTRACT Previous studies have shown that, in natural French populations of Drosophila melanogaster, 10 to 20% of the flies are infected by the noncontagious, hereditary rhabdovirus sigma responsible for CO2 sensitivity. These populations are also polymorphic for two alleles [ref(2)Po and ref(2)Pp of a gene for resistance to the sigma virus. Evidence is given here that two viral genetic types, differing in their response to the ref(2)Pp allele, are present in these populations of flies; the most common type is only slightly sensitive to the ref(2)Pp allele.

scholarly journals REPRODUCTION IN CAGE POPULATIONS OF A POLYMORPHISM REGULARLY OBSERVED IN THE NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER IN FRANCE

Genetics ◽  
1978 ◽  
Vol 88 (4) ◽  
pp. 755-759
Author(s):  
Annie Fleuriet
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Rate Of Return ◽  
Rapid Rate ◽  
Experimental Conditions ◽  
Co2 Sensitivity ◽  
In The Wild ◽  
Strong Forces

ABSTRACT Polymorphism for both alleles of a gene ref(2)P, which is a usual trait of French natural populations of Drosophila melanogaster, can be reproduced in experimental conditions. ref(2)P is a gene for resistance to the hereditary, noncontagious Rhabdovirus α, responsible for CO2 sensitivity in Drosophila melanogaster. The equilibrium frequencies observed in cages are the same as in the wild, whether α virus is present or not. The rapid rate of return to these equilibrium frequencies indicates that strong forces, which remain to be determined, are responsible for the maintenance of this polymorphism.

scholarly journals EXTRACHROMOSOMAL INHERITANCE OF CARBON DIOXIDE SENSITIVITY IN THE MOSQUITO CULEX QUINQUEFASCIATUS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 649-659
Author(s):  
Donald A Shroyer ◽  
Leon Rosen
Keyword(s):  
Carbon Dioxide ◽  
Culex Quinquefasciatus ◽  
Natural Populations ◽  
Infectious Agent ◽  
Maternal Transmission ◽  
Co2 Sensitivity ◽  
Laboratory Colony ◽  
F1 Progeny ◽  
Extrachromosomal Inheritance ◽  
Sigma Virus

ABSTRACT Mosquitoes from a laboratory colony of Culex quinquefasciatus from Matsu Island, China, develop irreversible paralytic symptoms after exposure to carbon dioxide at 1°. 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.

scholarly journals INDEPENDENT PRODUCTION OF CO2 SENSITIVITY BY NUCLEAR GENE DLY AND A TRANSMISSIBLE AGENT FROM DELAYED-RECOVERY DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 92 (2) ◽  
pp. 503-510
Author(s):  
M A Clark ◽  
W B McCrady ◽  
C L Fielding
Keyword(s):  
Carbon Dioxide ◽  
Drosophila Melanogaster ◽  
Nuclear Gene ◽  
Infectious Agent ◽  
Mutant Gene ◽  
Co2 Sensitivity ◽  
The Third ◽  
Male Line ◽  
Delayed Recovery ◽  
Sigma Virus

ABSTRACT Flies of stocks designated delayed-recovery by MCCRADY and SULERUD (1964) remain temporarily paralyzed after exposure to carbon dioxide. This condition is similar to CO2 sensitivity, which occurs in flies infected with the maternally transmitted sigma virus, but is due, at least in part, to the third chromosome mutant gene DlY. Because earlier work indicated that extracts of delayed-recovery flies could occasionally transmit CO2, sensitivity when injected into resistant recipients, we have tested the possibility that some delayed-recovery stocks contain a sigma-like transmissible virus, in addition to the Dly gene. We found that TDR-orange, a stock derived from the original delayed-recovery line, and temperature-cured populations of the same stock, both contain some agent that is transmissible by injection. TDR-BC3f, a stock derived by backcrossing through the male line to eliminate maternally transmitted factors, does not appear to contain such an infectious agent, but remains sensitive to CO2. These observations lead us to the conclusion that the originally described delayed-recovery stocks harbor an infectious extrachromosomal agent, in addition to possessing the Dly gene, and each is capable of producing a sensitivity to carbon dioxide.

scholarly journals Female Genotypes Affect Sperm Displacement in Drosophila

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1487-1493 ◽  
Author(s):  
Andrew G Clark ◽  
David J Begun
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Natural Populations ◽  
Isogenic Line ◽  
Female Fitness ◽  
Sperm Displacement ◽  
Extensive Variation ◽  
Polymorphic Genes ◽  
Displacement Parameter ◽  
Competitive Success

Abstract Differential success of sperm is likely to be an important component of fitness. Extensive variation among male genotypes in competitive success of sperm in multiply mated females has been documented for Drosophila melanogaster. However, virtually all previous studies considered the female to be a passive vessel. Nevertheless, under certain conditions female fitness could be determined by her role in mediating use of sperm from multiple males. Here we ask whether females differ among genotypes in their tendency to exhibit last-male precedence. Competition of sperm from two tester male genotypes (bwD and B3-09, a third-chromosome isogenic line from Beltsville, MD) was quantified by doubly mating female lines that had been rendered homozygous for X, second, or third chromosomes isolated from natural populations. The composite sperm displacement parameter, P2′, was highly heterogeneous among lines, whether or not viability effects were compensated, implying the presence of polymorphic genes affecting access of sperm to eggs. Genetic variation of this type is completely neutral in the absence of pleiotropy or interaction between variation in the two sexes.

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