Basic isoforms of hemolymph storage proteins expressed during larval metamorphosis

Area of Science:

• Biochemistry
• Insect Physiology
• Molecular Biology

Background:

• Insect metamorphosis involves significant physiological and biochemical changes.
• Hemolymph proteins play crucial roles in nutrient transport and developmental regulation.
• Storage proteins are essential for providing amino acids during insect development.

Purpose of the Study:

• To investigate the presence and characteristics of basic variants of normally acidic storage proteins during Trichoplusia ni larval metamorphosis.
• To analyze the immunoreactivity of these protein variants using antisera generated against their acidic forms.
• To identify and characterize a high molecular weight basic protein potentially related to juvenile hormone suppressible proteins.

Main Methods:

• Analysis of hemolymph from metamorphosing Trichoplusia ni final instar larvae.
• Immunochemical techniques, including Western blotting or ELISA, using antisera against specific proteins.
• Assessment of protein molecular weight and charge characteristics.

Main Results:

• Identification of basic forms of arylphorin, a normally positively charged storage protein.
• Detection of basic variants of a normally acidic juvenile hormone suppressible protein.
• Observation of varied immunoreactivity for protein forms with different basic charges.
• Characterization of a high molecular weight (ca. 150,000 M(r)) basic protein cross-reacting with antiserum against a 74,000 M(r) juvenile hormone suppressible protein.

Conclusions:

• Basic variants of normally acidic storage proteins exist in Trichoplusia ni hemolymph during metamorphosis.
• These findings suggest post-translational modifications or alternative splicing may lead to charge heterogeneity in storage proteins.
• The identified high molecular weight basic protein may represent a novel or modified form of a juvenile hormone suppressible protein, impacting developmental regulation.