Entomological Society of America
St. Louis, Missouri
New techniques for answering old questions: Measuring gene expression in diapausing Megachile rotundata
Poster #: D3072
Monday, November 18th, 9:00am-6:30pm
America’s Center- Exhibit Hall 1 & 2
The alfalfa leafcutting bee, Megachile rotundata, undergoes diapause to survive the winter. Diapause, a non-feeding state, limits energetic resources for metabolism. Insulin signaling is involved with regulation of cell growth and overall metabolism, making it an obvious target for diapause regulation. We hypothesize that the insulin signaling pathway regulates metabolism and development during overwintering. To test this, we need to measure gene expression. The gold standard for measuring gene expression has been quantitative real-time polymerase chain reaction (qRT-PCR). However, qRT-PCR has disadvantages. One drawback is the requirement for having known control genes which can be difficult for non-model organisms. It also limits how many genes can be tested at once. An emerging multiplex technique, NanoString™, works by hybridization and does not require amplification or large quantities of RNA. To test our hypothesis and compare these three techniques, we measured expression of genes in the insulin pathway in either lab- or field-reared M. rotundata during overwintering. First we conducted an Illumina study to get a global view of overall gene expression. Then we performed qRT-PCR on genes in the insulin pathway. Lastly, for NanoString™, we created a custom probe set for genes in the insulin pathway and used the same samples as in the other techniques. If NanoString™ confirms the results of both the Illumina and qRT-PCR studies, the benefits of this emerging technology will allow researchers to more quickly answer questions about how whole pathways change during overwintering and across development, to move the field of insect physiology forward.
Join Liz and her colleagues on November 18th at the Entomological Society of America (ESA) conference in St. Louis, Missouri. Click here for conference details.
© Photo by Meghan Duda

The insulin signaling pathway is involved with many functions such as reproduction, development, and metabolism. This can be important for better understanding how pollinators like the alfalfa leaf cutting bee, Megachile rotundata, survive winter and how changes in climate will impact them. It can also provide insight to key mechanisms that can be used as targets for agricultural pests like the tobacco hornworm, Manduca sexta. With this information, we can help farmers take better care of their bees. Happy bee means there’s food for you and me! Also, although they’re much much smaller, insects have the same insulin pathway we do, which means there’s potential for our research to be translated to other studies like diabetes research.
Liz Cambron is a PhD Candidate at North Dakota State University.