The specific accumulation of yolk proteins by the oocyte is a cornerstone of egg maturation and, therefore, a key element of reproductive physiology. The research proposed here concerns the elucidation of the molecular mechanism governing this process. We have generated a library of monoclonal antibodies against yolk protein at different processing stages in the mosquito oocyte. This gives us a powerful tool to analyse the mechanism of yolk accumulation and develop specific molecular probes. Purified vitellogenin (VG) will be labeled with radio-, fluorescent, and EM markers, and then used for binding and structural studies of its receptor. I intend to investigate the role of hormones and other factors in yolk accumulation. Radioligand binding assay will be used to determine the affinity and number of VG receptors on the oocyte membrane as well as the influence of various factors on these characteristics. I will study the nature of VG epitopes responsible for its recognition by the oocyte. Also, I propose to develop a probe specific for mosquito clathrin, a major component of coated vesicles, and then to study the developmental aspects of their biogenesis. I wish to determine: (1) when both VG receptors and clathrin are synthesized, and (2) what factors govern their production. An understanding of the VG-receptor system will set the stage for our next goal, purification and study of the molecular properties of the VG receptor. Information on the nature of VG recognition and its accumulation by the oocyte, as well as factors affecting this process, will provide an essential background in the search for new approaches in the control of this important arthropod vector.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI032154-08
Application #
2067075
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1987-07-01
Project End
1996-05-31
Budget Start
1994-06-01
Budget End
1995-05-31
Support Year
8
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Michigan State University
Department
Zoology
Type
Schools of Arts and Sciences
DUNS #
193247145
City
East Lansing
State
MI
Country
United States
Zip Code
48824
Cheon, H M; Seo, S J; Sun, J et al. (2001) Molecular characterization of the VLDL receptor homolog mediating binding of lipophorin in oocyte of the mosquito Aedes aegypti. Insect Biochem Mol Biol 31:753-60
Cho, W L; Tsao, S M; Hays, A R et al. (1999) Mosquito cathepsin B-like protease involved in embryonic degradation of vitellin is produced as a latent extraovarian precursor. J Biol Chem 274:13311-21
Sappington, T W; Raikhel, A S (1998) Molecular characteristics of insect vitellogenins and vitellogenin receptors. Insect Biochem Mol Biol 28:277-300
Snigirevskaya, E S; Sappington, T W; Raikhel, A S (1997) Internalization and recycling of vitellogenin receptor in the mosquito oocyte. Cell Tissue Res 290:175-83
Snigirevskaya, E S; Hays, A R; Raikhel, A S (1997) Secretory and internalization pathways of mosquito yolk protein precursors. Cell Tissue Res 290:129-42
Kokoza, V A; Raikhel, A S (1997) Ovarian- and somatic-specific transcripts of the mosquito clathrin heavy chain gene generated by alternative 5'-exon splicing and polyadenylation. J Biol Chem 272:1164-70
Kokoza, V A; Snigirevskaya, E S; Raikhel, A S (1997) Mosquito clathrin heavy chain: analysis of protein structure and developmental expression in the ovary during vitellogenesis. Insect Mol Biol 6:357-68
Sappington, T W; Kokoza, V A; Cho, W L et al. (1996) Molecular characterization of the mosquito vitellogenin receptor reveals unexpected high homology to the Drosophila yolk protein receptor. Proc Natl Acad Sci U S A 93:8934-9
Sappington, T W; Hays, A R; Raikhel, A S (1995) Mosquito vitellogenin receptor: purification, developmental and biochemical characterization. Insect Biochem Mol Biol 25:807-17
Raikhel, A S; Dhadialla, T S (1992) Accumulation of yolk proteins in insect oocytes. Annu Rev Entomol 37:217-51

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