Location: Chemistry Research Unit
Title: Genomic organization and reproductive regulation of a carrier/storage protein in the Varroa Mite, Varroa destructor (Anderson & Trueman) Authors
|Cabrera Cordon, Ana|
|Donohue, Kevin -|
|Grozinger, Christina -|
Submitted to: Insect Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 23, 2013
Publication Date: September 4, 2013
Citation: Cabrera Cordon, A.R., Shirk, P.D., Duehl, A.J., Donohue, K.V., Grozinger, C.M., Evans, J.D., Teal, P.E. 2013. Genomic organization and reproductive regulation of a carrier/storage protein in the Varroa Mite, Varroa destructor (Anderson & Trueman). Insect Molecular Biology. 22(5):505-522. Interpretive Summary: The varroa mite is a major parasite pest of the honey bee in North America. Scientists at the USDA ARS, Center for Medical, Agricultural and Veterinary Entomology identified the gene for the most abundant protein in the varroa mite. The carrier protein was characterized and lacked the capacity to bind heme as did related proteins from ticks. The levels of Vg transcript was found to be decreased during the reproductive period of the female mite. This carrier protein provides a significant target for disruption using molecular techniques to control or disrupt the physiology of the pest varroa mites.
Technical Abstract: The complete genomic region and corresponding transcript of the most abundant protein in the phoretic varroa mite, Varroa destructor (Anderson & Trueman), were sequenced and found to be homologous with hemelipoglyco-proteins (HeLP/CP) of acarines. The genomic arrangement showed the presence of 14 introns and the mature transcript had an open reading frame for a predicted polypeptide of 1,575 amino acid residues that shared a minimum of 25% sequence identity with other CPs. A phylogenetic assessment showed that the VdCP was most closely related to a vitellogenin and HeLP/CP proteins found in ticks which are a branch from the vitellogenin (large lipid transfer gene superfamily) group. However, even though structurally related to the HeLP/CP of ticks, no heme binding by VdCP was detected. Transcript levels of VdCP were 42 and 310 times higher in phoretic female mites compared to males and quiescent deutonymphs, respectively. The reproductive state was a significant regulator of VdCP transcript levels in the female varroa mite. After cell-capping and coincident with initiation of the varroa mite reproductive phase, the VdCP transcript levels declined to a third of the non-reproductive levels and remained low even in early phoretic mites. The function of the VdCP has not been identified but provides an important target to assess for control of the varroa mite using molecular technologies.