Zebrafish class 1 phosphatidylinositol transfer proteins: PITPbeta and double cone cell outer segment integrity in retina.

Phosphatidylinositol transfer proteins (PITPs) in yeast co-ordinate lipid metabolism with the activities of specific membrane trafficking pathways. The structurally unrelated metazoan PITPs (mPITPs), on the other hand, are an under-investigated class of proteins. It remains unclear what biological activities mPITPs discharge, and the mechanisms by which these proteins function are also not understood.

Flow of energy in the outer retina in darkness and in light.

Structural features of neurons create challenges for effective production and distribution of essential metabolic energy. We investigated how metabolic energy is distributed between cellular compartments in photoreceptors. In avascular retinas, aerobic production of energy occurs only in mitochondria that are located centrally within the photoreceptor.

Identification of a zebrafish cone photoreceptor-specific promoter and genetic rescue of achromatopsia in the nof mutant.

Purpose: To identify in vivo a promoter fragment that specifically directs transgene expression in all zebrafish cone photoreceptors. This promoter subsequently enables GFP labeling of cones for facile morphologic analysis and purification and genetic rescue of achromatopsia.

Methods: Promoter fragments of the zebrafish cone transducin alpha (TalphaC) gene were subcloned upstream of EGFP and microinjected into one- to two-cell-stage embryos.

The zebrafish nrc mutant reveals a role for the polyphosphoinositide phosphatase synaptojanin 1 in cone photoreceptor ribbon anchoring.

Visual, vestibular, and auditory neurons rely on ribbon synapses for rapid continuous release and recycling of synaptic vesicles. Molecular mechanisms responsible for the properties of ribbon synapses are mostly unknown. The zebrafish vision mutant nrc has unanchored ribbons and abnormal synaptic transmission at cone photoreceptor synapses.

Zebrafish rx3 and mab21l2 are required during eye morphogenesis.

Two alleles of an eyeless mutant, chokh (chk), were identified in ongoing zebrafish F(3) mutagenesis screens. Morphologically, chk mutants can be identified at 15 h post-fertilization by the failure of optic primordia to evaginate from the forebrain. The chk phenotype appears specific, as marker genes in the forebrain, midbrain, and pineal are expressed in normal temporal, spatial, and circadian patterns.