Proteomics/qPCR protocol to estimate physical ages of wild male oriental fruit flies, Bactrocera dorsalis (Hendel)

Abstract

Laboratory reared fruit flies may have different behavioral phenotypes as compared to the wild in the field. The domesticated lab setting and the absence of factors from the natural environment on lab reared insects may result in different behavioral patterns, such as the length of life cycle. This study was performed to conduct a regression analysis of the ratio of odorant binding protein 99b (OBP99b) expression from 4 to 12-d-old oriental fruit fly males, relative to 1-d-old males to estimate the physical ages of wild male fruit flies. We established two polynomial linear regression equations based on 4–12days old lab-reared flies using proteomics and qPCR. The equations are Y=−0.7768+0.7205X, R2=0.89 (for proteomics) and Y=−0.6478+0.344X, R2=0.64 (for qPCR). We used these equations to estimate the physical ages of wild-caught male fruit flies. These results indicate that despite multiple behavioral differences between laboratory reared and field-caught flies, the physical ages of both groups are identical. We suggest proteomics and qPCR analysis of selected genes and the proteins they encode may be developed into reliable tools for determining the ages of wild-caught animals, including oriental fruit flies.