Expression of CaBP transcripts in retinal bipolar cells of developing and adult zebrafish

Abstract

Ca2+-binding proteins play important roles in neuronal function by transducing Ca2+ signals and thereby regulating crucial processes like synaptic signaling and neuronal development, growth and survival. The Ca2+-binding protein (CaBP) subfamily is part of the vast EF-hand containing calmodulin superfamily. Eight genes encoding CaBPs have been identified in zebrafish, and many of them are expressed in specific subpopulations of retinal neurons during development. Among them, cabp2a and cabp5b have been shown to be expressed in the retinal inner nuclear layer (INL). Here, we demonstrate that their paralogues, cabp2b and cabp5a, are also specifically expressed in the INL of the developing retina. By extending expression analysis of cabp2a, cabp2b, cabp5a and cabp5b to the adult retina, we reveal exclusive expression of all four genes in the INL after retinal development is completed. Thus, our findings suggest functions of cabp2a, cabp2b, cabp5a and cabp5b in Ca2+ signaling in mature retinal neurons, besides a role in the developing retina. Triple Blind Peer Review The handling editor, the reviewers, and the authors are all blinded during the review process. Full Open AccessSupported by the Velux Foundation, the University of Zurich, and the EPFL School of Life Sciences. signals and thereby regulating crucial processes like synaptic signaling and neuronal development, growth and survival. The Ca 2+ -binding protein (CaBP) subfamily is part of the vast EF-hand containing calmodulin superfamily. Eight genes encoding CaBPs have been identified in zebrafish, and many of them are expressed in specific subpopulations of retinal neurons during development. Among them, cabp2a and cabp5b have been shown to be expressed in the retinal inner nuclear layer (INL). Here, we demonstrate that their paralogues, cabp2b and cabp5a, are also specifically expressed in the INL of the developing retina. By extending expression analysis of cabp2a, cabp2b, cabp5a and cabp5b to the adult retina, we reveal exclusive expression of all four genes in the INL after retinal development is completed. Thus, our findings suggest functions of cabp2a, cabp2b, cabp5a and cabp5b in Ca 2+ signaling in mature retinal neurons, besides a role in the developing retina. ObjectiveHere, we evaluate expression of cabp5a in the developing zebrafish retina and extend expression analysis of cabp2a, cabp2b, cabp5a and cabp5b to the adult retina.

Partitioning of gene expression among zebrafish photoreceptor subtypes

“…We will discuss this unique opn1mw4 + / opn1lw1 + population in greater detail below. In addition to these photoreceptor clusters, we identified two populations defined by the expression of the bipolar cell marker genes cabp5a and vsx1 39 , 40 (Fig. 1 C,D).…”

Identification of novel circadian transcripts in the zebrafish retina

“…In agreement with our in situ hybridisation results, these cells are located in the INL of the retina. Further, pc10 expressing cells are also positive for Cabp5b, a marker of bipolar cells (Glasauer and Neuhauss 2016).In future, this expression overlap can be used for cell type-specific functional studies. Next, we used the single cell transcriptomics data to identify the cells of the retina where there is the highest convergence of expression of core clock genes.…”

African Arowana Genome Provides Insights on Ancient Teleost Evolution

“…We also found a rough chromosomal one-to-one colinear relationship in Asian arowana itself, whereas more scattered self-syntenic blocks were detected in African arowana genome than in Asian arowana (Figures 2C and 2D). These results provided additional evidences supporting the faster evolution rate of African arowana, which had resulted in more variations in the paralogous chromosomes inheriting from the TS-WGD events ($350 MYA) (Glasauer and Neuhauss, 2014).…”