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Role of the Corpus Luteum and Progesterone in the Evolution of Vertebrate Viviparity
It is suggested that ovarian progesterone (follicular or luteal in origin) has a dual role in the evolution of viviparity: to inhibit myometrial contractions, thus providing a primary condition for egg retention and v Viviparity.
Caenorhabditis elegans as an Environmental Monitor Using DNA Microarray Analysis
Preliminary results indicate C. elegans may be a useful laboratory and field model for screening EDC and low doses and combinations of EDC need to be tested.
Progesterone and progesterone receptors in reptiles.
Reproductive endocrinology of female elasmobranchs: lessons from the little skate (Raja erinacea) and spiny dogfish (Squalus acanthias).
  • T. Koob, I. Callard
  • Biology, Environmental Science
    The Journal of experimental zoology
  • 1 October 1999
Heterogeneity in ovulatory cycles suggests that the endocrine system evolved a transmutable system for regulating steroidogenesis and the control of the reproductive events in female elasmobranchs.
Effect of cadmium on gonadal development in freshwater turtle (Trachemys scripta, Chrysemys picta) embryos
  • N. Kitana, I. Callard
  • Environmental Science
    Journal of environmental science and health. Part…
  • 17 January 2008
Evidence is provided that environmentally relevant doses of cadmium may affect gonadal developmental processes of freshwater turtles during embryonic and post-natal stages that may result in disruption of reproductive processes later in life.
Gonadal morphology, enzyme histochemistry and plasma steroid levels during the annual reproductive cycle of male and female brown bullhead catfish, Ictalurus nebulosus Lesueur
Significant differences in GSI and plasma steroid levels during the pre-spawning and spawning periods were observed between the two yearly cycles; they may be related to differences in rainfall during these periods.