Genetic Evidence for Differential Regulation of Corneal Epithelial and Stromal Thickness.

Purpose: Central corneal thickness (CCT) is a quantitative trait associated with keratoconus and primary open-angle glaucoma. Although CCT is highly heritable, known genetic variations explain only a fraction of the phenotypic variability. The purpose of this study was to identify additional CCT-influencing loci using inbred strains of mice.

Ketamine/Xylazine-Induced Corneal Damage in Mice.

Purpose: We have observed that the commonly used ketamine/xylazine anesthesia mix can induce a focally severe and permanent corneal opacity. The purpose of this study was to establish the clinical and histological features of this deleterious side effect, its sensitivity with respect to age and anesthesia protocol, and approaches for avoiding it.

Methods: Young C57BL/6J, C57BLKS/J, and SJL/J mice were treated with permutations of anesthesia protocols and compared using slit-lamp exams, optical coherence tomography, histologic analyses, and telemetric measurements of body temperature.

Support and challenges to the melanosomal casing model based on nanoscale distribution of metals within iris melanosomes detected by X-ray fluorescence analysis.

Melanin within melanosomes exists as eumelanin or pheomelanin. Distributions of these melanins have been studied extensively within tissues, but less often within individual melanosomes. Here, we apply X-ray fluorescence analysis with synchrotron radiation to survey the nanoscale distribution of metals within purified melanosomes of mice.

Nano-scale morphology of melanosomes revealed by small-angle X-ray scattering.

Melanosomes are highly specialized organelles that produce and store the pigment melanin, thereby fulfilling essential functions within their host organism. Besides having obvious cosmetic consequences--determining the color of skin, hair and the iris--they contribute to photochemical protection from ultraviolet radiation, as well as to vision (by defining how much light enters the eye). Though melanosomes can be beneficial for health, abnormalities in their structure can lead to adverse effects.

Topical ocular sodium 4-phenylbutyrate rescues glaucoma in a myocilin mouse model of primary open-angle glaucoma.

Purpose: Mutations in the myocilin gene (MYOC) are the most common known genetic cause of primary open-angle glaucoma (POAG). The purpose of this study was to determine whether topical ocular sodium 4-phenylbutyrate (PBA) treatment rescues glaucoma phenotypes in a mouse model of myocilin-associated glaucoma (Tg-MYOC(Y437H) mice).

Methods: Tg-MYOC(Y437H) mice were treated with PBA eye drops (n = 10) or sterile PBS (n = 8) twice daily for 5 months.

Anterior segment dysgenesis and early-onset glaucoma in nee mice with mutation of Sh3pxd2b.

Purpose: Mutations in SH3PXD2B cause Frank-Ter Haar syndrome, a rare condition characterized by congenital glaucoma, as well as craniofacial, skeletal, and cardiac anomalies. The nee strain of mice carries a spontaneously arising mutation in Sh3pxd2b. The purpose of this study was to test whether nee mice develop glaucoma.

Quantitative trait loci associated with murine central corneal thickness.

The cornea is a specialized transparent tissue responsible for refracting light, serving as a protective barrier, and lending structural support to eye shape. Given its importance, the cornea exhibits a surprising amount of phenotypic variability in some traits, including central corneal thickness (CCT). More than a mere anatomic curiosity, differences in CCT have recently been associated with risk for glaucoma.

Tethering recombination initiation proteins in Saccharomyces cerevisiae promotes double strand break formation.

Meiotic recombination in Saccharomyces cerevisiae is initiated by the creation of DNA double strand breaks (DSBs), an event requiring 10 recombination initiation proteins. Published data indicate that these 10 proteins form three main interaction subgroups [(Spo11-Rec102-Rec104-Ski8), (Rec114-Rec107-Mei4), and (Mre11-Rad50-Xrs2)], but certain components from each subgroup may also interact. Although several of the protein-protein interactions have been defined, the mechanism for DSB formation has been challenging to define.