Abstract
Vitellogenin (VTG) is a large lipoglycophosphoprotein synthesized in the liver in response to the ovarian hormone estrogen, which is secreted during follicular maturation. VTG travels in the circulation to the ovary where it is processed into yolk proteins that are incorporated in the growing oocyte. The quantification of VTG levels is important for reproductive physiology studies as an indicator of reproductive maturity and activity. An enzyme linked immunosorbent assay (ELISA) for sea turtle VTG was developed using a polyclonal antibody against VTG of a freshwater turtle (Trachemys scripta) and a standard of VTG purified from Kemp's ridley (Lepidochelys kempii) sea turtle plasma. The assay had a sensitivity range of 1.5 - 50 ngVTG/ml plasma. There was no cross reactivity with blood samples from males. The assay showed cross reactivity with six sea turtle species: Lepidochelys kempii, Lepidochelys olivacea, Caretta caretta, Dermochelys coriacea, Chelonia mydas, and Chelonia m. agassizi. Levels of VTG during the annual reproductive cycle of Kemp's ridleys increased during vitellogenesis and ovarian development, as revealed by ultrasound data and ELISA. In addition, in immature ridleys given estrogen treatment the assay revealed increases in VTG levels that persisted for a long period. The assay provides an excellent tool to better understand the dynamics of VTG, a protein that is essential for the nutrition of developing embryos and survival of hatchlings.
Vargas, Patricia (2000). Enzyme linked immunosorbent assay (ELISA) fot vitellogenin in the Kemp's ridley sea turtle, Lepidochelys kempii (Garman, 1880). Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -V37.