Chronic Feeding of a Low Boron Diet Adversely Affects Reproduction and Development in Xenopus laevis

Abstract

The aims of this work were as follows: 1) to determine whether a purified diet currently used for studies with rats was acceptable for reproductive studies in frogs; and 2) to determine whether frogs are sensitive to a deficit of boron (B) in the diet. Adult Xenopus laevis were fed a nonpurified beef liver and lung (BLL) diet (310 microg B/kg), a purified diet supplemented with boron (+B; 1850 microg B/kg), or a purified diet low in boron (-B; 45 microg B/kg) for 120 d. Frogs fed the BLL and +B diets produced 11.3 and 12.2% necrotic eggs, respectively. Abnormal gastrulation occurred in <4% of the fertilized eggs in both groups, and 96-h larval survival exceeded 75% in both groups. In contrast, frogs fed the -B diet for 120 d produced a high proportion of necrotic eggs (54%). Fertilized embryos from the -B diet-fed frogs showed a high frequency of abnormal gastrulation (26.8%), and >80% of the embryos died before 96 h of development. Mean embryo cell counts at X. laevis developmental stage 7.5 (mid-blastula) were significantly lower in the -B embryos than in the BLL or +B embryos. BLL and -B embryos grown in low boron culture media had a high frequency of malformations compared with embryos grown in boron-supplemented media. These studies show that a purified diet that has been used in rodent studies was acceptable for reproduction studies in X. laevis. This work also demonstrates that a diet low in boron markedly impairs normal reproductive function in adult X. laevis, and that administration of the low boron diet results in an increase in both incidence and severity of adverse effects. In addition, these studies demonstrate the usefulness of the X. laevis model in nutrition studies.

Boron Compounds in the Breast Cancer Cells Chemoprevention and Chemotherapy

“…ATR1 encodes a multidrug resistance transporter and it is widely distributed in bacteria, archaea and lower eukaryotes (Miwa & Fujiwara, 2010). Animals such as zebra, fish, trout and frogs also require boron (Rowe & Eckert, 1999;Fort et al, 1999). Borate ions activate the mitogen-activated protein kinases pathway and stimulate the growth and the proliferation of human embryonic kidney 293 cells (Park et al, 2005).…”

Dietary Boron Intake in the United States: CSFII 1994–1996

“…A Joint FAO/IAEA/WHO Expert Consultation on Trace Elements in Human Nutrition recently declared that boron is ''probably essential'' (WHO, 1996). Recent evidence also suggests that boron is essential for early life stage development in Xenopus frogs (Fort et al, 1999) and zebrafish (Rowe et al, 1998), and boron deficiency resulted in cone photoreceptor dystrophy in the retinas of adult zebrafish (Eckhert and Rowe, 1999).…”

Boron supplementation and activated factor VII in healthy men

“…These include cognitive function (Penland, 1998) and bone formation (Chapin et al, 1998;Armstrong et al, 2000). Embryonic defects related to boron depletion have been reported for zebra fish (Rowe & Eckhert, 1999), frogs (Fort et al, 1998(Fort et al, , 1999(Fort et al, , 2000 and trout (Eckhert, 1998). Boron-related development defects, however, have not been observed consistently in rodent models (Lanoue et al, 1998(Lanoue et al, , 1999.…”