Regulation of hepatic vitellogenin synthesis in the little skate (Raja erinacea): Use of a homologous enzyme-linked immunosorbent assay
✍ Scribed by Perez, Lorelei E. ;Callard, Ian P.
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 927 KB
- Volume
- 266
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
Abstract
An enzyme‐linked immunosorbent assay (ELISA) was developed to detect vitellogenin in skates. The antibody raised against the yolk protein lipovitellin was shown to recognize a sexspecific, estrogen‐inducible 205 kD protein in plasma, previously identified in skate as vitellogenin. The detection limit of the assay was 31.3 ng/ml, similar to that of radioimmunoassays for vitellogenin detection in other species. Using the assay, vitellogenin levels were shown to be highest (241.8 ± 26.5 ug/ml) in the ovarian follicular phase, decreasing approximately 1‐2 days before ovulation to a low (173.1 ± 22.9 ug/ml) during the luteal phase. Vitellogenin levels increased again approximately 1‐2 days before oviposition to 259.8 ± 38.8 ug/ml.
The effects of estrogen and progesterone on hepatic vitellogenin production in normal and hypophysectomized male skates were also investigated. Plasma vitellogenin was not detectable in either intact or hypophysectomised male skates, but increased with estradiol treatment (intact: 48.2 ± 4.9 ug/ml vs. hypophysectomised 252 ± 10.6 ug/ml at day 8). Progesterone treatment significantly (P < .01) attenuated the effect of estrogen on plasma vitellogenin levels in both intact (17 ± 2.1 ug/ml) and hypophysectomized (44.0 ± 9.4 ug/ml) male skates. © 1993 Wiley‐Liss, Inc.