Download docx - BeanBeetles.org

Protein expression in the life cycle of bean beetles (Callosobruchus maculatus)
Objectives


Design and perform an experiment to compare protein expression at different stages of bean
beetle (Callosobruchus maculatus) development.
Learn methods of protein extraction and comparison.
Introduction
Proteins are one of the fundamental types of macromolecules essential to the workings of individual
cells and thus multicellular organisms. The information for building proteins expressed in a cell is coded
for in the DNA of the cell. This relationship between proteins and DNA is well understood and has been
called the “central dogma” of biology. However, though the DNA of an individual remains relatively
static throughout life, the proteins expressed by that individual will vary based on a number of factors,
including, but not limited to, development, environmental cues, stress, or, in multi-celled organisms, cell
function. For this reason, proteins can be related to changes over time. Conversely, as the gene is a
blueprint for making proteins, a study of proteins also can give insight into the expression of genes.
Proteomics is a relatively new field that maps protein expression and how that expression changes due
to different influences (Anderson and Anderson, 1998; Blackstock and Weir, 1999). It is a complex
subject due to the variety of proteins necessary for life. Yet, it can be useful for comparing organisms in
a variety of ways. Although proteins are coded for in DNA, not all proteins are actively produced in every
cell of an organism or at every stage of development.
The development of bean beetles includes life stages characterized by distinct larval and adult stages.
Eggs that are laid on beans by the adult female hatch and the emergent larva bore into the bean and
begin their development. During this period, the larva will move through four distinct instar stages. The
beetle larva will then pupate before emerging from the bean as a fully formed adult (Beck and Blumer,
2011). In this study, you will address the question, do the proteins expressed by bean beetles change
with developmental stages?
Materials
You will have access to cultures of bean beetles grown on mung beans, adzuki beans, and black-eyed
peas. Each culture will contain beetles at various stages of their life cycle. Also, you will be provided
with supplies necessary for carrying out protein extraction and electrophoresis (Cilia et al, 2009).
Experimental Design
Before coming to class:


review the reading material
design an experiment to compare protein expression in bean beetles



summarize the steps for protein expression and electrophoresis
identify the variables you will be manipulating
predict the outcomes of the experiment
Literature Cited
Anderson NL, Anderson NG (1998). "Proteome and proteomics: new technologies, new concepts, and
new words". Electrophoresis 19 (11): 1853–61.
Beck, C.W. and L.S. Blumer. 2011. A Handbook on Bean Beetles, Callosobruchus maculatus.
www.beanbeetles.org
Blackstock WP, Weir MP (1999). "Proteomics: quantitative and physical mapping of cellular proteins".
Trends Biotechnol. 17 (3): 121–7.
Cilia M, Fish T, Yang X, McLaughlin M, Thannhauser TW, Gray S (2009). “A comparison of protein
extraction methods suitable for gel-based proteomic studies of aphid proteins”. Journal of
Biomolecular Techiques 20 (4): 201-15.
This study was written by T. Ashraf and E. Priddis, 2013 (www.beanbeetles.org).