A laboratory investigation into features of morphology and physiology for their potential to predict reproductive success in male frogs.

Amphibian populations are declining globally, however, the contribution of reduced reproduction to declines is unknown. We investigated associations between morphological (weight/snout-vent length, nuptial pad colour/size, forelimb width/size) and physiological (nuptial pad/testis histomorphology, plasma hormones, gene expression) features with reproductive success in males as measured by amplexus success and fertility rate (% eggs fertilised) in laboratory maintained Silurana/Xenopus tropicalis. We explored the robustness of these features to predict amplexus success/fertility rate by investigating these associations within a sub-set of frogs exposed to anti-androgens (flutamide (50 μg/L)/linuron (9 or 45 μg/L)).

Sex-dependent expression of anti-Müllerian hormone (amh) and amh receptor 2 during sex organ differentiation and characterization of the Müllerian duct development in Xenopus tropicalis.

Amphibian gonadal differentiation involves the action of sex steroids. Recent research indicates that the anti-Müllerian hormone (AMH) is involved in testicular development in some lower vertebrate species. For amphibians there is a lack of data on ontogenetic expression of the AMH receptor AMHR2/amhr2 and of progesterone receptors (PGRS/pgrs).

Molecular and histological endpoints for developmental reproductive toxicity in Xenopus tropicalis: Levonorgestrel perturbs anti-Müllerian hormone and progesterone receptor expression.

There is an increasing concern regarding the risks associated with developmental exposure to endocrine disrupting chemicals and the consequences for reproductive capability. The present study aimed to refine the Xenopus (Silurana) tropicalis test system for developmental reproductive toxicity by characterising molecular and histological features of sexual development, and to explore effects of exposure to the progestagen levonorgestrel (LNG). Larvae were exposed to LNG (0, 3, 30, 300 ng/L) over the first three weeks of development, encompassing the beginning of gonadal differentiation.

Mixture effects of levonorgestrel and ethinylestradiol: estrogenic biomarkers and hormone receptor mRNA expression during sexual programming.

Synthetic progesterone (progestins) and estrogens are widely used pharmaceuticals. Given that their simultaneous unintentional exposure occurs in wildlife and also in human infants, data on mixture effects of combined exposures to these hormones during development is needed. Using the Xenopus (Silurana) tropicalis test system we investigated mixture effects of levonorgestrel (LNG) and ethinylestradiol (EE2) on hormone sensitive endpoints.

Presence of alkylresorcinols, potential whole grain biomarkers, in human adipose tissue.

Alkylresorcinols (AR) in plasma samples have been suggested to be short- to medium-term biomarkers of whole grain wheat and rye intake. In the present study, we investigated whether AR are present in human adipose tissues, and if content correlated with long-term whole grain bread intake. Furthermore, we investigated if the relative AR homologue composition reflected what has been found previously in the habitual diet of Swedes.