Les gènes de la Drosophile qui interviennent dans la multiplication du virus sigma

Gay, Pierre

doi:10.1007/bf00268263

Cited by 50 publications

(45 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In natural populations of D. melanogaster, there is considerable genetic variation in the susceptibility of flies to infection by sigma viruses, and genetic mapping studies have shown that there are a number of major effect resistance polymorphisms segregating in natural populations [66,67]. Two of the loci that provide resistance to DMelSV have been identified at the molecular level-CHKov and Ref (2) The first of the polymorphisms that provides resistance to DMelSV involves the CHKov1 and CHKov2 genes [69].…”

Section: Resistance To Sigma Virusesmentioning

confidence: 99%

“…The spread of the insensitive viral type was documented in France and Germany over approximately 10 years in the 1980s, with the insensitive virus largely replacing the sensitive viral type over this period [88,89]. Are sigma viruses adapting to overcome the other resistance genes that have been found in host populations [66,67]? Two experiments on paternal transmission-blocking genes have produced contrasting results.…”

Section: Coevolution and Viral Countermeasuresmentioning

confidence: 99%

See 1 more Smart Citation

Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?

Longdon

Jiggins

2012

Proc. R. Soc. B.

View full text Add to dashboard Cite

Insects are host to a wide range of vertically transmitted bacterial endosymbionts, but we know relatively little about their viral counterparts. Here, we discuss the vertically transmitted viral endosymbionts of insects, firstly examining the diversity of this group, and then focusing on the well-studied sigma viruses that infect dipterans. Despite limited sampling, evidence suggests that vertically transmitted viruses may be common in insects. Unlike bacteria, viruses can be transmitted through sperm and eggs, a trait that allows them to rapidly spread through host populations even when infection is costly to the host. Work on Drosophila melanogaster has shown that sigma viruses and their hosts are engaged in a coevolutionary arms race, in which the spread of resistance genes in the host population is followed by the spread of viral genotypes that can overcome host resistance. In the long-term, associations between sigma viruses and their hosts are unstable, and the viruses persist by occasionally switching to new host species. It therefore seems likely that viral endosymbionts have major impacts on the evolution and ecology of insects.

show abstract

Section: Resistance To Sigma Virusesmentioning

confidence: 99%

Section: Coevolution and Viral Countermeasuresmentioning

confidence: 99%

Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?

Longdon

Jiggins

2012

Proc. R. Soc. B.

View full text Add to dashboard Cite

show abstract

“…A few loci (called ref) of the fly are known to confer resistance to the virus (Gay, 1978). Two viral types have been described and the Viral Type II is the most resistant to the effect of the ref(2) P locus (Fleuriet, 1986).…”

Section: Drosophila-sigma Systemmentioning

confidence: 99%

Temporal surveys of French populations of Drosophila melanogaster: P–M system, enzymatic polymorphism and infection by the sigma virus

Anxolabéhère¹,

Charles-Palabost²,

Fleuriet

et al. 1988

Heredity

View full text Add to dashboard Cite

About 120 strains derived from natural populations of D. melanogaster collected between 1983 and 1986 in the Languedoc-Roussillon area (France) were tested for their characteristics in the P-M system, enzymatic polymorphism and infection by the sigma virus. Over these four years, a clear geographical pattern was found for the P-M system over a distance of 250 km, with weak P populations in the northern zone of the area studied, Q populations in the centre and M' populations in the south. This pattern was stable for P sterility potential but a decrease of the M cytotype level was observed in the southernmost zone. During the same period, the frequency of flies infected by the sigma virus also showed a regular geographical pattern with the highest values in the central zone. The frequency of infected flies increased steadily during this period. In the enzymatic study, neither geographical nor temporal trends were detected for the loci analyzed. Correlations among the different systems are discussed.

show abstract

“…F r o m a m u t a g e n e s i s (8) done w i t h 23 S P + ts +, t w o t e m p e r a t u r e -s e n s i t i v e m u t a n t s , ts 10 a n d ts 1 I, h a v e b e e n obtained. These ts m u t a n t s were u n d i s t i n g u i s h a b l e from t h e p a r e n t a l 2 3 S P + ts + at 20 ° C. F r o m t h e same m u t a g e n e s i s a clone was k e p t as a m u t a n t m o r e r e s t r i c t e d t h a n t h e p a r e n t in S t a n d a r d flies a t 20 ° C (previously n a m e d 23hrO e [10]). This clone was used in t h e e x p e r i m e n t s h o w n in Fig.…”

Section: Drosophila and Virus Strainsmentioning

confidence: 98%

The late functions ofDrosophila sigma virus

Contamine

1984

Archives of Virology

View full text Add to dashboard Cite

Several criteria can be used to characterize the temperature-sensitive mutants of sigma virus: the lability of infectious centers initiated by the efficient viral particles following the inoculation; the localization of the temperature-sensitive period; the hereditary transmission of infection in a maternal Drosophila line at high temperature; the evolution of the CO2 sensitivity symptom and of the viral titer per fly for hereditarily infected flies kept at a permissive temperature and shifted to a restrictive one. Experimental data concerning the last two criteria are shown and discussed here. From all the criteria, three classes of ts mutants can be defined: the first class (prototype ts4) are the mutants blocked in hereditary transmission at high temperature. These mutants are affected during the whole viral cycle but the viral maturation is not directly affected. The second class (ts9, haP27) are the mutants directly affected in viral maturation. For these latter, the hereditary transmission in a maternal line is efficient at high temperature, and only a late temperature sensitive period is observed. The third class (prototype haP7) are the mutants for which only an early temperature-sensitive period is observed. In fact, for these mutants, the viral information is strongly heat-sensitive at the beginning of viral cycle. This defect is rapidly corrected, and the hereditary transmission, late viral functions and viral maturation are as efficient as those of wild type virus, at high temperature. Using temperature-sensitive mutants similar to the wild type virus at permissive temperature, a formal description of the viral cycle at 20 degrees C in the standard flies can be obtained. The long period necessary to perform an entire viral cycle (about 60 hours) is a result of the restrictive action on late viral functions at 20 degrees C of the Oe allele of the ref(3)O host gene present in the standard flies.

show abstract

Les gènes de la Drosophile qui interviennent dans la multiplication du virus sigma

Cited by 50 publications

References 13 publications

Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?

Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?

Temporal surveys of French populations of Drosophila melanogaster: P–M system, enzymatic polymorphism and infection by the sigma virus

The late functions ofDrosophila sigma virus

Contact Info

Product

Resources

About