Genetics, Vol 133, 943-954, Copyright © 1993

INVESTIGATIONS

Unusual Variability of the Drosophila melanogaster ref(2)P Protein Which Controls the Multiplication of Sigma Rhabdovirus

P. Dru, F. Bras, S. Dezelee, P. Gay, A. M. Petitjean, A. Pierre-Deneubourg, D. Teninges and D. Contamine
Laboratoire de Genetique des Virus, CNRS, 91198 Gif sur Yvette cedex, France

The ref(2)P gene of Drosophila melanogaster was identified by the discovery of two alleles, P(o) and P(p), respectively, permissive and restrictive for sigma rhabdovirus multiplication. A surprising variability of this gene was first noticed by the observation of size differences between the transcripts of permissive and restrictive alleles. In this paper, another restrictive allele, P(n), clearly distinct from P(p), is described: it exhibits a weaker antiviral effect than P(p) and differs from P(p) by its molecular structure. Five types of alleles were distinguished on the basis of their molecular structure, as revealed by S1 nuclease analysis of 17 D. melanogaster strains; three alleles were permissive and two restrictive. Comparison of the sequences of four haplotypes revealed numerous point mutations, two deletions (21 and 24 bp) and a complex event involving a 3-bp deletion, all affected the coding region. The unusual variability of the ref(2)P locus was confirmed by the high ratio of amino acid replacements to synonymous mutations (7:1), as compared to that of other genes, such as the Adh (2:42). Nevertheless, nucleotide sequence comparison with the Drosophila erecta ref(2)P gene shows that selective pressures are exerted to maintain the existence of a functional protein. The effects of this high variability on the ref(2)P protein are discussed in relation to its specific antiviral properties and to its function in D. melanogaster, where it is required for male fertility.

This article has been cited by other articles:

				J. Bangham, K.-W. Kim, C. L. Webster, and F. M. Jiggins Genetic Variation Affecting Host-Parasite Interactions: Different Genes Affect Different Aspects of Sigma Virus Replication and Transmission in Drosophila melanogaster Genetics, April 1, 2008; 178(4): 2191 - 2199. [Abstract] [Full Text] [PDF]

				A. Carre-Mlouka, S. Gaumer, P. Gay, A. M. Petitjean, C. Coulondre, P. Dru, F. Bras, S. Dezelee, and D. Contamine Control of Sigma Virus Multiplication by the ref(2)P Gene of Drosophila melanogaster: An in Vivo Study of the PB1 Domain of Ref(2)P Genetics, May 1, 2007; 176(1): 409 - 419. [Abstract] [Full Text] [PDF]

				A. Fleuriet Evolution of the Proportions of Two Sigma Viral Types in Experimental Populations of Drosophila melanogaster in the Absence of the Allele That Is Restrictive of Viral Multiplication Genetics, December 1, 1999; 153(4): 1799 - 1808. [Abstract] [Full Text]