p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities.

Stargardt disease (STGD, also known as fundus flavimaculatus; FFM) is an autosomal recessive retinal disorder characterized by a juvenile-onset macular dystrophy, alterations of the peripheral retina, and subretinal deposition of lipofuscin-like material A gene encoding an ATP-binding cassette (ABC) transporter was mapped to the 2-cM (centiMorgan) interval at 1p13-p21 previously shown by linkage analysis to harbour the STGD gene This gene, ABCR, is expressed exclusively and at high levels in the retina, in rod but not cone photoreceptors, as detected by in situ hybridization Mutational analysis of ABCR in STGD families revealed a total of 19 different mutations including homozygous mutations in two families with consanguineous parentage These data indicate that ABCR is the causal gene of STGD/FFM

A photoreceptor cell-specific ATP-binding transporter gene (ABCR) is mutated in recessive Stargardt macular dystrophy

Vanilloid Receptor–Related Osmotically Activated Channel (VR-OAC), a Candidate Vertebrate Osmoreceptor

http://www.tau.ac.il/~karena/papers/Varfolomeev_et_al_1998.pdf

Targeted Disruption of the Mouse Caspase 8 Gene Ablates Cell Death Induction by the TNF Receptors, Fas/Apo1, and DR3 and Is Lethal Prenatally

Cathepsin K is a recently identified lysosomal cysteine proteinase. It is abundant in osteoclasts, where it is believed to play a vital role in the resorption and remodeling of bone. Pycnodysostosis is a rare inherited osteochondrodysplasia that is caused by mutations of the cathepsin-K gene, characterized by osteosclerosis, short stature, and acroosteolysis of the distal phalanges. With a view to delineating the role of cathepsin K in bone resorption, we generated mice with a targeted disruption of this proteinase. Cathepsin-K-deficient mice survive and are fertile, but display an osteopetrotic phenotype with excessive trabeculation of the bone-marrow space. Cathepsin-K-deficient osteoclasts manifested a modified ultrastructural appearance: their resorptive surface was poorly defined with a broad demineralized matrix fringe containing undigested fine collagen fibrils; their ruffled borders lacked crystal-like inclusions, and they were devoid of collagen-fibril-containing cytoplasmic vacuoles. Assaying the resorptive activity of cathepsin-K-deficient osteoclasts in vitro revealed this function to be severely impaired, which supports the contention that cathepsin K is of major importance in bone remodeling.

https://www.pnas.org/content/pnas/95/23/13453.full.pdf

Impaired osteoclastic bone resorption leads to osteopetrosis in cathepsin-K-deficient mice

We established two mouse interspecific backcross DNA panels, one containing 94 N2 animals from the cross (C57BL/6J × Mus spretus)F1 × C57BL/6J, and another from 94 N2 animals from the reciprocal backcross (C57BL/6J × SPRET/Ei)F1 × SPRET/Ei. We prepared large quantities of DNA from most tissues of each animal to create a community resource of interspecific backcross DNA for use by laboratories interested in mapping loci in the mouse. Initial characterization of the genetic maps of both panels has been completed. We used MIT SSLP markers, proviral loci, and several other sequence-defined genes to anchor our maps to other published maps. The BSB panel map (from the backcross to C57BL/6J) contains 215 loci and is anchored by 45 SSLP and 32 gene sequence loci. The BSS panel map (from the backcross to SPRET/Ei) contains 451 loci and is anchored by 49 SSLP loci, 43 proviral loci, and 60 gene sequence loci. To obtain a high density of markers, we used motif-primed PCR to “fingerprint” the panel DNAs. We constructed two maps, each representing one of the two panels. All new loci can be located with a high degree of certainty on the maps at current marker density. Segregation patterns in these data reveal several examples of transmission ratio distortion and permit analysis of the distribution of crossovers on individual chromosomes.

S. J. Thurston

Papers

Maps from two interspecific backcross DNA panels available as a community genetic mapping resource