In the last two decades it has become clear that hormones and gene mutations in endocrine signaling pathways can exert major effects on lifespan and related life history traits in worms, flies, mice, and other organisms. While most of this research has focused on insulin/insulin-like growth factor-1 signaling, a peptide hormone pathway, recent work has shown that also lipophilic hormones play a...

The significance of steroid and peptide hormones for tumour initiation and progression in a number of organs and tissues of various species including humans has been demonstrated by numerous experimental and epidemiological studies. More recently different hormone-stimulated signal transduction pathways have been partly unravelled and their components have been identified and characterised. The...

Studies of the biological incorporation of isotopically labeled acetate into steroid hormones have become a well established tool in the field of steroid biochemistry. We have undertaken the study of the incorporation of acetate-l-U4 into the various sterols and steroid hormones of the pregnant mare. This study has been a joint undertaking of the two laboratories and has been the subject of sev...

The salmon louse is a marine ectoparasitic copepod on salmonid fishes. Its lifecycle consists of eight developmental stages, each separated by a molt. In crustaceans and insects, molting and reproduction is controlled by circulating steroid hormones such as 20-hydroxyecdysone. Steroid hormones are synthesized from cholesterol through catalytic reactions involving a 7,8-dehydrogenase Neverland a...

The unicellular Tetrahymena pyriformis was studied for chemotaxis, chemotactic selection, phagocytosis, growth and body shape changes in the presence of water soluble (beta-cyclodextrin-coupled) steroid hormones (testosterone, estradiol, progesterone, hydrocortisone and dexamethasone). Testosterone was chemoattractant over a wide range of concentrations, while progesterone and dexamethasone wer...

Phoenix, Goy, Gerall, and Young first proposed in 1959 the organizational-activational hypothesis of hormone-driven sex differences in brain and behavior. The original hypothesis posited that exposure to steroid hormones early in development masculinizes and defeminizes neural circuits, programming behavioral responses to hormones in adulthood. This hypothesis has inspired a multitude of experi...

Sex steroid hormones released from the gonads play an important role in mediating social behavior across all vertebrates. Many effects of these gonadal hormones are mediated by nuclear steroid hormone receptors, which are crucial for integration in the brain of external (e.g., social) signals with internal physiological cues to produce an appropriate behavioral output. The African cichlid fish ...

Although some DNA methylation patterns are altered by steroid hormone exposure in the developing brain, less is known about how changes in steroid hormone levels influence DNA methylation patterns in the adult brain. Steroid hormones act in the adult brain to regulate gene expression. Specifically, the expression of the socially relevant peptide vasopressin (AVP) within the bed nucleus of the s...

background: enzyme linked immunosorbent assay (elisa) has been described as an alternative to radioimmunoassay for the mammalian and nonmammalian steroids detection. in this study, a simple and rapid elisa is described and validated for 4-pregnen-3,20, dione (progesterone). materials and methods: a general procedure for preparation of the acetylcholinesterase labelled steroid is described which...