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L C Erway

Publications and source records attributed to L C Erway.

40 records · Page 3Linked to original sources

Zinc metabolism in lethal-milk mice. Otolith, lactation, and aging effects.

Lethal-milk (lm), a recessive mutation, occurred in the C57BL/6J inbred strain of mice. Lactating lm dams produce a zinc-deficient milk that is lethal to all nursing pups. If foster-nursed on normal dams, lm pups survive and become reproductively mature. Injection of zinc-glycinate into the pups or zinc supplementation of the water of the lactating dams reduces lethality. Other pleiotropic effects in lm mice include congenital otolith defects with delayed righting, "tail-spinning," and abnormal swimming. These effects are diagnostic criteria for segregation of lm mice among backcross progeny. About 40 percent of the expected number of lm pups survive to weaning. Zinc supplementation of the dam improves development of saccular but not of utricular otoliths; zinc does not improve survival of the lm pups among backcross progenies. The lm mice over eight months of age also exhibit extensive hair loss, dermatitis, and skin lesions. Possible roles of metallothionein in zinc and copper metabolism are discussed in regard to the pleiotropic effects of the lethal-milk mutation.

Age Factors↗

Genetic influences in individual susceptibility to noise: a review.

Individual animals and humans show differing susceptibility to noise damage even under very carefully controlled exposure conditions. This difference in susceptibility may be related to unknown genetic components. Common experimental animals (rats, guinea pigs, chinchillas, cats) are outbred-their genomes contain an admixture of many genes. Many mouse strains have been inbred over many generations reducing individual variability, making them ideal candidates for studying the genetic modulation of individual susceptibility. Erway et al. (1993) demonstrated a recessive gene associated with early presbycusis in the C57BL/6J inbred mouse. A series of studies have shown that mice homozygous for Ahl allele are more sensitive to the damaging effects of noise. Recent work has shown that mice homozygous for Ahl are not only more sensitive to noise, but also are probably damaged in a different manner by noise than mice containing the wild-type gene (Davis et al., 2001). Recent work in Noben-Trauth's lab (Di Palma et al., 2001) has shown that the wild-type Ahl gene codes for a hair cell specific cadherin. Cadherins are calcium dependent proteins that hold cells together at adherins junctions to form tissues and organs. The cadherin of interest named otocadherin or CDH23, is localized to the stereocillia of the outer hair cells. Our working hypothesis, suggests that otocadherin may form the lateral links between stereocilia described by Pickles et al (1989). Reduction of, or missing otocadherin weakens the cell and may allow stereocilia to be more easily physically damaged by loud sounds and by aging.

Aging↗

Trace metals and otolith defects in mocha mice.

Mocha mice with pigment anomalies of the coat, eyes, and inner ears also have congenital otolith defects, and they exhibit progressive cochlear degeneration. Mocha mice were first reported to exhibit otolith defects comparable to those of pallid mice. Since manganese supplementation is effective in preventing the otolith defects in pallid mice and in pastel mink, we sought to establish whether or not manganese also might be effective in mocha mice. The otolith defects of mocha mice were prevented or reduced by supplementing the pregnant dams with manganese and/or zinc. The mocha mice also exhibited high perinatal mortality that was not reduced by the supplementary metals. Surviving mocha mice have behavioral anomalies associated with their inner ear defects. Preliminary observations of auditory-evoked brainstem responses and of cochlear degeneration in the mocha mice are discussed.

Abnormalities, Multiple↗