RRC ID 81340
Author Urara Adachi, Rina Koita, Akira Seto, Akiteru Maeno, Atsuki Ishizu, Sae Oikawa, Taisei Tani, Mizuki Ishizaka, Kazuya Yamada, Koumi Satoh, Hidemichi Nakazawa, Hiroyuki Furudate, Koichi Kawakami, Norimasa Iwanami, Masaru Matsuda, Akinori Kawamura
Title Teleost Hox code defines regional identities competent for the formation of dorsal and anal fins
Journal Proceedings of the National Academy of Sciences
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.
Volume 121
Published 2024-6-18
DOI 10.1073/pnas.2403809121
PMID 38861596
PMC PMC11194558
MeSH 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
Resource
Medaka HdrR-II1 (IB178) HNI-II (IB176) dfl (MT1391) hoxc11a(ins8) (MT1392) hoxc12a(del5) (MT1674) hoxc12a(del11+ins3);hoxc13a(del14) (MT1675)