Pubertal sexual development and endpoints for disrupted spermatogenesis in the model Xenopus tropicalis

• Peripubertal models to determine effects of anti-androgenic endocrine disrupting chemicals are needed. Using the toxicological model species Xenopus tropicalis, the aims of the study were to 1) provide data on sexual maturation and 2) characterise effects of short-term exposure to an anti-androgenic model substance. Juvenile (2.5 weeks post metamorphosis old) X. tropicalis were exposed to 0, 250, 500 or 1000 & mu;g flutamide/L (nominal) for 2.5 weeks. Upon exposure termination, histology of gonads and Mullerian ducts was characterised in detail. New sperm stages were identified: pale and dark spermatogonial stem cells (SSCs). The testes of control males contained spermatozoa, indicating pubertal onset. The ovaries were immature, and composed of non-follicular and pre-vitellogenic follicular oocytes. The Mullerian ducts were more mature in females than males indicating development/regression in the females and males, respectively. In the 500 & mu;g/L group, the number of dark SSCs per testis area was decreased and the number of secondary spermatogonia was increased. No treatment effects on ovaries or Mullerian ducts were detected. To conclude, our present data provide new knowledge on spermatogenesis, and pubertal onset in X. tropicalis. New endpoints for evaluating spermatogenesis are suggested to be added to existing assays used in endocrine and reproductive toxicology.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine (hsv//eng)

NATURVETENSKAP  -- Biologi -- Annan biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Other Biological Topics (hsv//eng)

NATURVETENSKAP  -- Biologi -- Utvecklingsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Developmental Biology (hsv//eng)

Nyckelord

Spermatogenesis

Oogenesis

Mullerian ducts

Anti-androgen

Reproductive development

Xenopus tropicalis

Publikations- och innehållstyp

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