Downloaded from www.microbiologyresearch.org by IP: 23.22.50.124 On: Sun, 29 May 2016 06:58:28 Two viruses that cause salivary gland hypertrophy in Glossina pallidipes and Musca domestica are related and form a distinct phylogenetic clade Alejandra Garcia-Maruniak, 1 3 Adly M. M. Abd-Alla, 2 3 Tamer Z. Salem, 1,3 Andrew G. Parker, 2 Verena-Ulrike Lietze, 1 Monique M. van Oers, 4 James E. Maruniak, 1 Woojin Kim, 5 John P. Burand, 5 Franc ¸ois Cousserans, 6 Alan S. Robinson, 2 Just M. Vlak, 4 Max Bergoin 6 and Drion G. Boucias 1 Correspondence Alejandra Garcia-Maruniak alemar@ufl.edu 1 Department of Entomology and Nematology, PO Box 110620, University of Florida, Gainesville, FL 32611-0620, USA 2 Entomology Unit, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria 3 Department of Microbial Molecular Biology, AGERI, Agricultural Research Center, Giza 12619, Egypt 4 Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands 5 Department of Plant, Soil and Insect Science, University of Massachusetts, Amherst, MA 01003, USA 6 Laboratoire de Pathologie Compare ´ e, Universite ´ Montpellier II, Montpellier, France Received 25 August 2008 Accepted 24 October 2008 Glossina pallidipes and Musca domestica salivary gland hypertrophy viruses (GpSGHV and MdSGHV) replicate in the nucleus of salivary gland cells causing distinct tissue hypertrophy and reduction of host fertility. They share general characteristics with the non-occluded insect nudiviruses, such as being insect-pathogenic, having enveloped, rod-shaped virions, and large circular double-stranded DNA genomes. MdSGHV measures 65¾550 nm and contains a 124 279 bp genome (~44 mol% G+C content) that codes for 108 putative open reading frames (ORFs). GpSGHV, measuring 50¾1000 nm, contains a 190 032 bp genome (28 mol% G+C content) with 160 putative ORFs. Comparative genomic analysis demonstrates that 37 MdSGHV ORFs have homology to 42 GpSGHV ORFs, as some MdSGHV ORFs have homology to two different GpSGHV ORFs. Nine genes with known functions (dnapol, ts, pif-1, pif-2, pif-3, mmp, p74, odv-e66 and helicase-2), a homologue of the conserved baculovirus gene Ac81 and at least 13 virion proteins are present in both SGHVs. The amino acid identity ranged from 19 to 39 % among ORFs. An (A/T/G)TAAG motif, similar to the baculovirus late promoter motif, was enriched 100 bp upstream of the ORF transcription initiation sites of both viruses. Six and seven putative microRNA sequences were found in MdSGHV and GpSGHV genomes, respectively. There was genome. Collinearity between the two SGHVs, but not between the SGHVs and the nudiviruses. Phylogenetic analysis of conserved genes clustered both SGHVs in a single clade separated from the nudiviruses and baculoviruses. Although MdSGHV and GpSGHV are different viruses, their pathology, host range and genome composition indicate that they are related. INTRODUCTION A group of double-stranded (ds) DNA viruses, referred to as salivary gland hypertrophy viruses (SGHV), has been detected in the house fly Musca domestica (Coler et al., 1993), the narcissus bulb fly Merodon equestris (Amargier et al., 1979) and various tsetse fly Glossina species (Jaenson, 1978; Otieno et al., 1980; Gouteux, 1987; Minter- Goedbloed & Minter, 1989; Shaw & Moloo, 1993). SGHV infection in the nuclei of salivary gland cells, leads to salivary gland hypertrophy (SGH). Infected adult house flies do not exhibit any overt disease symptoms, but in 3These authors contributed equally to this work. Supplementary material is available with the online version of this paper. Journal of General Virology (2009), 90, 334–346 DOI 10.1099/vir.0.006783-0 334 006783 G 2009 SGM Printed in Great Britain