Zeitz, C. | Search bioRxiv

bioRxiv2025

Increased sensitivity to myopia and altered retinal ON/OFF balance in a mouse model lacking Dusp4

Myopia, influenced by environmental and genetic factors, occurs when the emmetropization process fails to stop, causing excessive eyeball growth. Highly myopic animal models lacking a functional ON-pathway identified Dusp4 as a potential gene implicated in myopia. Here, we used a mouse model lacking DUSP4 to gain a better understanding of its retinal role and the mechanisms implicated in myopia development. Dusp4-/- mice have a reduced basal level of retinal dopamine and a higher susceptibility to lens-induced myopia. Dusp4 is expressed in ON-bipolar cells and a subset of OFF-bipolar cells in a light dependent manner. The absence of DUSP4 causes a hyperactivation of the MAPK/ERK pathway. Dusp4-/- mice showed reduced optomotor responses, increased ON-bipolar cell depolarization, reduced oscillatory potentials together with altered OFF and ON-OFF RGC responses to light flashes. These data provide insights into retina-driven mechanisms of myopization, nuancing the impact of ON and OFF pathways upon emmetropization.

neuroscience↗

bioRxiv2020

Chromosome-level genome assembly of a benthic associated Syngnathiformes species: the common dragonet, Callionymus lyra

BackgroundThe common dragonet, Callionymus lyra, is one of three Callionymus species inhabiting the North Sea. All three species show strong sexual dimorphism. The males show strong morphological differentiation, e.g., species-specific colouration and size relations, while the females of different species have few distinguishing characters. Callionymus belongs to the benthic associated clade of the order Syngnathiformes. The benthic associated clade so far is not represented by genome data and serves as an important outgroup to understand the morphological transformation in long-snouted syngnatiforms such as seahorses and pipefishes. FindingsHere, we present the chromosome-level genome assembly of C. lyra. We applied Oxford Nanopore Technologies long-read sequencing, short-read DNBseq, and proximity-ligation-based scaffolding to generate a high-quality genome assembly. The resulting assembly has a contig N50 of 2.2 Mbp, a scaffold N50 of 26.7 Mbp. The total assembly length is 568.7 Mbp, of which over 538 Mbp were scaffolded into 19 chromosome-length scaffolds. The identification of 94.5% of complete BUSCO genes indicates high assembly completeness. Additionally, we sequenced and assembled a multi-tissue transcriptome with a total length of 255.5 Mbp that was used to aid the annotation of the genome assembly. The annotation resulted in 19,849 annotated transcripts and identified a repeat content of 27.66%. ConclusionsThe chromosome-level assembly of C. lyra provides a high-quality reference genome for future population genomic, phylogenomic, and phylogeographic analyses.

genomics↗