We cloned the homologue of the clock gene Bmal from a cephalochordate, Branchiostoma lanceolatum (syn. amphioxus). Amphioxus possesses a single copy of this gene (amphiBmal) that encodes for a protein of 649 amino acids, which is quite similar to BMALs of other chordates. The gene is expressed by a restricted cell group in the anterior vesicle of the neural tube, and its expression site coincides with that of another clock gene, namely, amphiPer. The expression of amphiBmal shows a rhythmic fluctuation that persists under constant darkness and is, thus, circadian. Similar to the situation in craniates, the peak phases of the amphiBmal and amphiPer expression are offset by 12 hours. Based on these observations and the putative homology between the diencephalon of vertebrates and the anterior vesicle of lancelets, we suggest a homology between the suprachiasmatic nucleus of craniates and the amphiBmal/amphiPer-expressing cell group of amphioxus.
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http://dx.doi.org/10.1002/cne.22306 | DOI Listing |
Cell Discov
January 2025
Guangdong Key Laboratory of Pharmaceutical Functional Genes, MOE Key Laboratory of Gene Function and Regulation, MOE Engineering Center of South China Sea Marine Biotechnology, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China.
Apoptotic protease activating factor 1 (Apaf-1) was traditionally defined as a scaffold protein in mammalian cells for assembling a caspase activation platform known as the 'apoptosome' after its binding to cytochrome c. Although Apaf-1 structurally resembles animal NOD-like receptor (NLR) and plant resistance (R) proteins, whether it is directly involved in innate immunity is still largely unknown. Here, we found that Apaf-1-like molecules from lancelets, fruit flies, mice, and humans have conserved DNA sensing functionality.
View Article and Find Full Text PDFJ Exp Biol
January 2025
University of Guelph, 50 Stone Rd E, Guelph, N1G 2M7, Canada.
The timing of metamorphosis and settlement is critical for the survival and reproductive success of marine animals with biphasic life cycles. Thyroid hormones (THs) regulate developmental timing in diverse groups of chordates, including the regulation of metamorphosis in amphibians, teleosts, lancelets, tunicates, and lampreys. Recent evidence suggests a role for TH regulation of metamorphosis outside of the chordates, including echinoderms, annelids, and molluscs.
View Article and Find Full Text PDFSci Adv
December 2024
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Despite their pivotal role, the evolutionary origins of vertebrate digestive systems remain enigmatic. We explored the cellular characteristics of the amphioxus () digestive tract, a model for the presumed primitive chordate digestive system, using bulk tissue companioned with single-cell RNA sequencing. Our findings reveal segmentation and a rich diversity of cell clusters, and we highlight the presence of epithelial-like, ciliated cells in the amphioxus midgut and describe three types of endocrine-like cells that secrete insulin-like, glucagon-like, and somatostatin-like peptides.
View Article and Find Full Text PDFFish Shellfish Immunol
February 2025
Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education), Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, 266237, China. Electronic address:
Nat Commun
October 2024
Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, Prague, Czech Republic.
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