title: Differential viral levels and immune gene expression in three stocks of Apis mellifera induced by different numbers of Varroa destructor.
abstract: The viral levels and immune responses of Italian honey bees (IHB), Russian honey bees (RHB) and an outcross of Varroa Sensitive Hygienic bees (POL) deliberately infested with one or two foundress Varroa were compared. We found that the Deformed wing virus (DWV) level in IHB inoculated with one or two foundress Varroa increased to about 10(3) or 10(5) fold the levels of their uninfested brood. In contrast, POL (10(2) or 10(4) fold) and RHB (10(2) or l0(4) fold) supported a lower increase in DWV levels. The feeding of different stages of Varroa nymphs did not increase DWV levels of their pupal hosts. Analyses of their corresponding Varroa mites showed the same trends: two foundress Varroa yielded higher DWV levels than one foundress, and the addition of nymphs did not increase viral levels. Using the same pupae examined for the presence of viruses, 16 out of 24 genes evaluated showed significant differential mRNA expression levels among the three honey bee stocks. However, only four genes (Defensin, Dscam, PPOact and spaetzle), which were expressed at similar levels in uninfested pupae, were altered by the number of feeding foundress Varroa and levels of DWV regardless of stocks. This research provides the first evidence that immune response profiles of different honey bee stocks are induced by Varroa parasitism.
authors.affiliation: Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Kitiphong
authors.initials: K
authors.lastname: Khongphinitbunjong
authors.affiliation: USDA-ARS, Honey Bee Breeding, Genetics and Physiology Laboratory, 1157 Ben Hur Road, Baton Rouge, LA 70820, USA.
authors.forename: Lilia I
authors.initials: LI
authors.lastname: de Guzman
authors.affiliation: USDA-ARS, Honey Bee Breeding, Genetics and Physiology Laboratory, 1157 Ben Hur Road, Baton Rouge, LA 70820, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Tarver
authors.affiliation: USDA-ARS, Honey Bee Breeding, Genetics and Physiology Laboratory, 1157 Ben Hur Road, Baton Rouge, LA 70820, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rinderer
authors.affiliation: USDA-ARS, Bee Research Laboratory, Bldg. 476, BARC-East, Beltsville, MD 20705, USA.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand. Electronic address: panuwan@gmail.com.
authors.forename: Panuwan
authors.initials: P
authors.lastname: Chantawannakul
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics / Q000276:immunology / Q000469:parasitology* / Q000821:virology*; D005786:Gene Expression Regulation; D006790:Host-Parasite Interactions; D010849:Picornaviridae / Q000502:physiology*; D011679:Pupa / Q000235:genetics / Q000469:parasitology / Q000821:virology; D057077:Varroidae / Q000821:virology*
keywords: Antimicrobial peptide; Apis mellifera; Deformed wing virus; Varroa destructor