Wolbachia PCR: Discover the Microbes Within!
In this lesson, students use PCR to determine whether or not an insect they have collected is infected with a fascinating bacterial parasite named Wolbachia. The Wolbachia genus of bacteria lives within the reproductive cells of insects and arthropod species, and results in the feminization of host populations. Students will predict the impact of infection on their local insect populations and broader ecosystem where reproductive success of females is tipped in favored over males. Students are also introduced to how Wolbachia is being used to control mosquito-borne diseases like Dengue and Zika.
The idea and methods for this lab are based on the materials developed by Dr. Seth Bordenstein and other scientists of the Wolbachia Project at Woods Hole Marine Biological Laboratory (MBL). We gratefully acknowledge Dr. Bordenstein, Michael Clark, Michele Bahr, and others at MBL for their generous support in developing this curriculum.
- Perform DNA Extraction, PCR, and gel electrophoresis to determine Wolbachia infection rate in local insect populations
- Describe the symbiotic relationship between Wolbachia and its insect hosts including the different reproductive affects of infection
- Explain how Wolbachia infection could affect local insect populations and the ecosystem over time and communicate this information by creating an infographic
- Experience with DNA extraction, micropipetting and gel electrophoresis
- Definition of biological sex in relation to genotype and phenotype
- Levels of organization in an ecosystem
Disciplinary Core Ideas:
LS2.A – Interdependent Relationships in Ecosystems
“…this tension affects the abundance (number of individuals) of species in any given ecosystem.”
LS3.B – Variation of Traits
“…environmental factors affect expression of traits…”
LS4.C – Adaptation
“..changes in environment have contributed to the expansion of some species, the emergence of new distinct species as populations diverge under different conditions, and the decline–and sometimes the extinction–of some species.”
Science and Engineering Practices:
Analyzing and Interpreting Data
Students analyze PCR data to determine the Wolbachia infection rate of local insect populations. They then use this evidence to explain how this may affect insect populations and the ecosystem over time and make an infographic to communicate their ideas.
Cause and Effect
Students identify patterns in their Wolbachia infection data and describe cause and effect relationships between Wolbachia, its individual insect host, insect populations, and ecosystems.