Jon's interest in the interface between nutritional status and reproductive competence introduced us to a new and intriguing avenue of research. Jon's doctoral work tested the hypothesis that anestrous induced by inadequate nutrition is due to a nutrition-dependent increase in the negative feedback potency of gonadal steroids.

As review of Jon's manuscripts (see Publications for journal reference) will show, Jon's research studies demonstrated that severe weight loss had divergent effects at hypothalamic and pituitary loci; blocking estrogen-induced augmentation GnRH receptor gene expression at the pituitary, while increasing the negative feedback effect of estradiol at hypothalamic sites.

Jon's work represents a major advance in this field and incoming students are continuing these studies.