PUBLICATION

Teleost Hox code defines regional identities competent for the formation of dorsal and anal fins

Authors
Adachi, U., Koita, R., Seto, A., Maeno, A., Ishizu, A., Oikawa, S., Tani, T., Ishizaka, M., Yamada, K., Satoh, K., Nakazawa, H., Furudate, H., Kawakami, K., Iwanami, N., Matsuda, M., Kawamura, A.
ID
ZDB-PUB-240612-4
Date
2024
Source
Proceedings of the National Academy of Sciences of the United States of America   121: e2403809121e2403809121 (Journal)
Registered Authors
Kawakami, Koichi, Kawamura, Akinori
Keywords
Hox genes, dorsal and anal fins, morphological diversity, vertebrate evolution
MeSH Terms
  • Animal Fins*
  • Animals
  • Body Patterning/genetics
  • Fish Proteins/genetics
  • Fish Proteins/metabolism
  • Gene Expression Regulation, Developmental
  • Genes, Homeobox*/genetics
  • Homeodomain Proteins*/genetics
  • Homeodomain Proteins*/metabolism
  • Oryzias*/genetics
  • Zebrafish*/genetics
PubMed
38861596 Full text @ Proc. Natl. Acad. Sci. USA
Abstract
The dorsal and anal fins can vary widely in position and length along the anterior-posterior axis in teleost fishes. However, the molecular mechanisms underlying the diversification of these fins remain unknown. Here, we used genetic approaches in zebrafish and medaka, in which the relative positions of the dorsal and anal fins are opposite, to demonstrate the crucial role of hox genes in the patterning of the teleost posterior body, including the dorsal and anal fins. By the CRISPR-Cas9-induced frameshift mutations and positional cloning of spontaneous dorsalfinless medaka, we show that various hox mutants exhibit the absence of dorsal or anal fins, or a stepwise posterior extension of these fins, with vertebral abnormalities. Our results indicate that multiple hox genes, primarily from hoxc-related clusters, encompass the regions responsible for the dorsal and anal fin formation along the anterior-posterior axis. These results further suggest that shifts in the anterior boundaries of hox expression which vary among fish species, lead to diversification in the position and size of the dorsal and anal fins, similar to how modulations in Hox expression can alter the number of anatomically distinct vertebrae in tetrapods. Furthermore, we show that hox genes responsible for dorsal fin formation are different between zebrafish and medaka. Our results suggest that a novel mechanism has occurred during teleost evolution, in which the gene network responsible for fin formation might have switched to the regulation downstream of other hox genes, leading to the remarkable diversity in the dorsal fin position.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping