Changes In Hemolymph During M. sexta
Because Manduca sexta is a holometabolous insect
that has four distinct life stages (egg, caterpillar, pupa,
moth&emdash;see Life Cycle
Stages), it is an excellent model for investigating
changes in gene expression that occur during development.
Numerous researchers are investigating a variety of aspects
of development in M. sexta (for examples, see
Studies Related to Hemolymph Changes
During Development). Gross changes in the proteins
present in hemolymph during larval development and among the
larval, pupal, and moth stages are relatively easy to
demonstrate using common protein analysis techniques such as
determination of total protein concentration and SDS-PAGE
One of the proteins that is readily identifiable in M.
sexta hemolymph is the arylphorin storage protein. This
protein exists in the hemolymph as hexamer composed two
glycosylated subunits of 77 and 72 kDa. The protein is made
by the fat body and secreted into the hemolymph. It
accumulates to high levels during the larval stages. During
the pupal stage, this protein is thought to be degraded and
used for its component amino acids.
Investigating developmental changes:
Collection of M. sexta
Determination of protein
concentration of M. sexta hemolymph.
electrophoresis of M. sexta hemolymph.