Impact of boron deficiency on Xenopus laevis: a summary of biological effects and potential biochemical roles

Biol Trace Elem Res. 2002 Winter;90(1-3):117-42. doi: 10.1385/BTER:90:1-3:117.


The toxicity of boron has been understood for many years. However, limited data currently exist concerning the nutritional essentiality of B in chordates. Results from an ongoing research program evaluating the nutritional essentiality of B in the South African clawed frog, Xenopus laevis, found that X. laevis fed a low-B diet in a low-B culture media produced a substantially higher number of necrotic eggs and fertilized embryos than frogs fed a boron-sufficient diet. Markedly decreased embryo cell counts at mid-blastula transition and an increased frequency of abnormal gastrulation were also noted in embryos from adult frogs fed the B-deficient diet. By 96 h of development, none of the larvae collected from the B-deficient adults and maintained in low-boron culture media developed normally. Reproductive effects associated with B deficiency in female Xenopus included ovary atrophy, oocyte necrosis, and incomplete oocyte maturation. In males, a decrease in testis weight and sperm count was noted. These studies suggest that these adverse effects resulting from B deficiency could be found during gametogenesis, gamete maturation, embryonic development, and larval maturation. The studies also confirmed that B deficiency was capable of interrupting the X. laevis life cycle. Additional studies evaluating the role of B in the thyroid axis and the oocyte plasma membrane progesterone receptor provide the first line of direct evidence for a biochemical role of boron in X. laevis. Combined together, this research program provides firm evidence that B is nutritionally essential in X. laevis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Boron / administration & dosage
  • Boron / deficiency*
  • Boron / pharmacology
  • Embryo, Nonmammalian / drug effects
  • Embryo, Nonmammalian / embryology
  • Growth / drug effects
  • Receptors, Progesterone / metabolism
  • Reproduction / drug effects
  • Thyroid Gland / drug effects
  • Thyroid Gland / physiology
  • Xenopus laevis / embryology
  • Xenopus laevis / growth & development*
  • Xenopus laevis / physiology*


  • Receptors, Progesterone
  • Boron