Analysis of a shark reveals ancient, Wnt-dependent, habenular asymmetries in vertebrates.

The mode of evolution of left-right asymmetries in the vertebrate habenulae remains largely unknown. Using a transcriptomic approach, we show that in a cartilaginous fish, the catshark Scyliorhinus canicula, habenulae exhibit marked asymmetries, in both their medial and lateral components. Comparisons across vertebrates suggest that those identified in lateral habenulae reflect an ancestral gnathostome trait, partially conserved in lampreys, and independently lost in tetrapods and neopterygians.

Contribution of the eye and of opn4xa function to circadian photoentrainment in the diurnal zebrafish.

The eye is instrumental for controlling circadian rhythms in mice and human. Here, we address the conservation of this function in the zebrafish, a diurnal vertebrate. Using lakritz (lak) mutant larvae, which lack retinal ganglion cells (RGCs), we show that while a functional eye contributes to masking, it is largely dispensable for the establishment of circadian rhythms of locomotor activity.

Protocol to locally express cxcl12a during zebrafish olfactory organ development by combining IR-LEGO with live imaging.

Temporal and spatial regulation of gene expression is crucial for proper embryonic development. Infrared laser-evoked gene operator (IR-LEGO) can provide information for various developmental processes. Here, we present a protocol to locally express cxcl12a during zebrafish olfactory organ development using a combination of IR-LEGO and live imaging.

Diversification of habenular organization and asymmetries in teleosts: Insights from the Atlantic salmon and European eel.

Habenulae asymmetries are widespread across vertebrates and analyses in zebrafish, the reference model organism for this process, have provided insight into their molecular nature, their mechanisms of formation and their important roles in the integration of environmental and internal cues with a variety of organismal adaptive responses. However, the generality of the characteristics identified in this species remains an open question, even on a relatively short evolutionary scale, in teleosts. To address this question, we have characterized the broad organization of habenulae in the Atlantic salmon and quantified the asymmetries in each of the identified subdomains.

Probing small ribosomal subunit RNA helix 45 acetylation across eukaryotic evolution.

NAT10 is an essential enzyme that catalyzes N4-acetylcytidine (ac4C) in eukaryotic transfer RNA and 18S ribosomal RNA. Recent studies suggested that rRNA acetylation is dependent on SNORD13, a box C/D small nucleolar RNA predicted to base-pair with 18S rRNA via two antisense elements. However, the selectivity of SNORD13-dependent cytidine acetylation and its relationship to NAT10's essential function remain to be defined.