Dermestes maculatus: an intermediate-germ beetle model system for evo-devo. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Xiang, Jie; Forrest, Iain; Pick, Leslie
• Is Part Of: EvoDevo. Volume 6:Issue 1(2015)
• Page Start: 1
• Page End: 17
• Publication Date: 2015-12
• Subjects: Evo-devo -- Segmentation -- Pair-rule patterning -- paired -- RNAi -- Dermestes maculatus; Evolution (Biology) -- Periodicals; Developmental biology -- Periodicals; 576.8
• DOI: 10.1186/s13227-015-0028-0
• Languages: English
• ISSNs: 2041-9139

Abstract

Abstract Background Understanding how genes change during evolution to direct the development of diverse body plans is a major goal of the evo-devo field. Achieving this will require the establishment of new model systems that represent key points in phylogeny. These new model systems must be amenable to laboratory culture, and molecular and functional approaches should be feasible. To date, studies of insects have been best represented by the model systemDrosophila melanogaster . Given the enormous diversity represented by insect taxa, comparative studies within this clade will provide a wealth of information about the evolutionary potential and trajectories of alternative developmental strategies. Results Here we established the beetleDermestes maculatus, a member of the speciose clade Coleoptera, as a new insect model system. We have maintained a continuously breeding culture in the lab and documentedDermestes maculatus embryogenesis using nuclear and phalloidin staining. Anterior segments are specified during the blastoderm stage before gastrulation, and posterior segments are added sequentially during germ band elongation. We isolated and studied the expression and function of the pair-rule segmentation genepaired inDermestes maculatus . In this species, paired is expressed in stripes during both blastoderm and germ band stages: four primary stripes arise prior to gastrulation, confirming an intermediate-germ mode of development for this species. As in other insects, these primary stripes then split into secondary stripes. To study gene function, we established both embryonic and parental RNAi. Knockdown ofDmac -paired with either method resulted in pair-rule-like segmentation defects, including loss of Engrailed expression in alternate stripes. Conclusions These studies establish basic approaches necessary to useDermestes maculatus as a model system. Methods are now available for use of this intermediate-germ insect for future studies of the evolution of regulatory networks controlling insect segmentation, as well as of other processes in development and homeostasis. Consistent with the role ofpaired in long-germDrosophila and shorter-germTribolium, paired functions as a pair-rule segmentation gene inDermestes maculatus. Thus, paired retains pair-rule function in insects with different modes of segment addition.