Meredithe L Applebury

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Mice express S and M opsins that form visual pigments for the detection of light and visual signaling in cones. Here, we show that S opsin transcription is higher than that of M opsin, which supports ultraviolet (UV) sensitivity greater than midwavelength sensitivity. Surprisingly, most cones coexpress both S and M opsins in a common cone cell type(More)
Mice homozygous for the rd mutation display hereditary retinal degeneration and the classic rd lines serve as a model for human retinitis pigmentosa. In affected animals the retinal rod photoreceptor cells begin degenerating at about postnatal day 8, and by four weeks no photoreceptors are left. Degeneration is preceded by accumulation of cyclic GMP in the(More)
The Drosophila ninaE gene was isolated by a multistep protocol on the basis of its homology to bovine opsin cDNA. The gene encodes the major visual pigment protein (opsin) contained in Drosophila photoreceptor cells R1-R6. The coding sequence is interrupted by four short introns. The positions of three introns are conserved with respect to positions in(More)
Chimeric gene fusions between 4.4 kb of rod opsin 5' flanking sequence fused to a diphtheria toxin gene and 4.4 kb or 500 bp of rod opsin 5' flanking sequence fused to the E. coli IacZ gene were used to generate transgenic mice for analysis of cell type-specific expression and temporal and spatial distribution of reporter gene product during retinal(More)
Notch receptor-mediated cell-cell signaling is known to negatively regulate neurogenesis in both vertebrate and invertebrate species, while being implicated in promoting the acquisition of glial fates. We studied Notch1 function directly during retinal neurogenesis by selective Cre/loxP-triggered Notch1 gene inactivation in peripheral retinal progenitor(More)
The wild-type mouse ultraviolet (UV) and bovine blue cone visual pigments have absorption maxima of 358 and 438 nm, respectively, while sharing 87% amino acid identity. To determine the molecular basis underlying the 80 nm spectral shift between these pigments, we selected several amino acids in helices II and III for site-directed mutagenesis. These amino(More)
  • C Bowes, T Li, +4 authors D B Farber
  • Proceedings of the National Academy of Sciences…
  • 1993
Retinal degeneration in the rd mouse is inherited as an autosomal recessive trait and is caused by a defect in the gene encoding the beta subunit of cGMP phosphodiesterase. Recently, a close genetic association of the rd gene with an endogenous xenotropic murine leukemia virus (Xmv-28) was established by linkage analysis using recombinant inbred strains of(More)
Thyroid hormone action is mediated by thyroid hormone receptors (TRs), which are members of the nuclear hormone receptor superfamily. DNA-binding is presumed to be essential for all nuclear actions of thyroid hormone. To test this hypothesis in vivo, the DNA-binding domain of TR-beta was mutated within its P-box (GS mutant) using gene targeting techniques.(More)
A circadian clock regulates a number of diverse physiological functions in the vertebrate eye. In this study, we show that mRNA for the red-sensitive cone pigment, iodopsin, fluctuates with a circadian rhythm in chicken retina. Transcript levels increase in the late afternoon just prior to the time of cone disc shedding. Furthermore, iodopsin mRNA levels(More)
A simple purification method has been developed for isolation of bovine cGMP phosphodiesterase from photoreceptor rod outer segments. The enzyme is peripherally membrane bound in its native state and is present in relatively high concentrations. In the bovine photoreceptors its molar ratio to rhodopsin can be estimated to be as great as 1:40 and not lower(More)