@article {121, title = {Transcriptome profile of the sinoatrial ring reveals conserved and novel genetic programs of the zebrafish pacemaker.}, journal = {BMC Genomics}, volume = {22}, year = {2021}, month = {2021 Oct 02}, pages = {715}, abstract = {

BACKGROUND: Sinoatrial Node (SAN) is part of the cardiac conduction system, which controls the rhythmic contraction of the vertebrate heart. The SAN consists of a specialized pacemaker cell population that has the potential to generate electrical impulses. Although the SAN pacemaker has been extensively studied in mammalian and teleost models, including the zebrafish, their molecular nature remains inadequately comprehended.

RESULTS: To characterize the molecular profile of the zebrafish sinoatrial ring (SAR) and elucidate the mechanism of pacemaker function, we utilized the transgenic line sqet33mi59BEt to isolate cells of the SAR of developing zebrafish embryos and profiled their transcriptome. Our analyses identified novel candidate genes and well-known conserved signaling pathways involved in pacemaker development. We show that, compared to the rest of the heart, the zebrafish SAR overexpresses several mammalian SAN pacemaker signature genes, which include hcn4 as well as those encoding calcium- and potassium-gated channels. Moreover, genes encoding components of the BMP and Wnt signaling pathways, as well as members of the Tbx family, which have previously been implicated in pacemaker development, were also overexpressed in the SAR. Among SAR-overexpressed genes, 24 had human homologues implicated in 104 different ClinVar phenotype entries related to various forms of congenital heart diseases, which suggest the relevance of our transcriptomics resource to studying human heart conditions. Finally, functional analyses of three SAR-overexpressed genes, pard6a, prom2, and atp1a1a.2, uncovered their novel role in heart development and physiology.

CONCLUSION: Our results established conserved aspects between zebrafish and mammalian pacemaker function and revealed novel factors implicated in maintaining cardiac rhythm. The transcriptome data generated in this study represents a unique and valuable resource for the study of pacemaker function and associated heart diseases.

}, keywords = {Animals, Heart Rate, Humans, Sinoatrial Node, Transcriptome, Zebrafish}, issn = {1471-2164}, doi = {10.1186/s12864-021-08016-z}, author = {Minhas, Rashid and Loeffler-Wirth, Henry and Siddiqui, Yusra H and Obr{\k e}bski, Tomasz and Vashisht, Shikha and Nahia, Karim Abu and Paterek, Alexandra and Brzozowska, Angelika and Bugajski, Lukasz and Piwocka, Katarzyna and Korzh, Vladimir and Binder, Hans and Winata, Cecilia Lanny} } @article {113, title = {A novel conserved enhancer at zebrafish zic3 and zic6 loci drives neural expression.}, journal = {Dev Dyn}, volume = {248}, year = {2019}, month = {2019 09}, pages = {837-849}, abstract = {

BACKGROUND: Identifying enhancers and deciphering their putative roles represent a major step to better understand the mechanism of metazoan gene regulation, development, and the role of regulatory elements in disease. Comparative genomics and transgenic assays have been used with some success to identify critical regions that are involved in regulating the spatiotemporal expression of genes during embryogenesis.

RESULTS: We identified two novel tetrapod-teleost conserved noncoding elements within the vicinity of the zic3 and zic6 loci in the zebrafish genome and demonstrated their ability to drive tissue-specific expression in a transgenic zebrafish assay. The syntenic analysis and robust green fluorescent expression in the developing habenula in the stable transgenic line were correlated with known sites of endogenous zic3 and zic6 expression.

CONCLUSION: This transgenic line that expresses green fluorescent protein in the habenula is a valuable resource for studying a specific population of cells in the zebrafish central nervous system. Our observations indicate that a genomic sequence that is conserved between humans and zebrafish acts as an enhancer that likely controls zic3 and zic6 expression.

}, keywords = {Animals, Animals, Genetically Modified, Conserved Sequence, Embryonic Development, Enhancer Elements, Genetic, Gene Expression Regulation, Developmental, Green Fluorescent Proteins, Habenula, Homeodomain Proteins, Humans, Nervous System, Repressor Proteins, Transcription Factors, Zebrafish, Zebrafish Proteins}, issn = {1097-0177}, doi = {10.1002/dvdy.69}, author = {Minhas, Rashid and Paterek, Aleksandra and {\L}api{\'n}ski, Maciej and Baza{\l}a, Micha{\l} and Korzh, Vladimir and Winata, Cecilia L} }