Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata

Abstract Background The polyplacophoran mollusks (chitons) possess serially arranged shell plates. This feature is unique among mollusks and believed to be essential to explore the evolution of mollusks as well as their shells. Previous studies revealed several cell populations in the dorsal epithel...

Full description

Bibliographic Details
Main Authors: Yuxiu Xia, Pin Huan, Baozhong Liu
Format: Article
Language:English
Published: BMC 2023-04-01
Series:EvoDevo
Subjects:
Online Access:https://doi.org/10.1186/s13227-023-00209-9
_version_ 1797850024497905664
author Yuxiu Xia
Pin Huan
Baozhong Liu
author_facet Yuxiu Xia
Pin Huan
Baozhong Liu
author_sort Yuxiu Xia
collection DOAJ
description Abstract Background The polyplacophoran mollusks (chitons) possess serially arranged shell plates. This feature is unique among mollusks and believed to be essential to explore the evolution of mollusks as well as their shells. Previous studies revealed several cell populations in the dorsal epithelium (shell field) of polyplacophoran larvae and their roles in the formation of shell plates. Nevertheless, they provide limited molecular information, and shell field morphogenesis remains largely uninvestigated. Results In the present study, we investigated shell field development in the chiton Acanthochitona rubrolineata based on morphological characteristics and molecular patterns. A total of four types of tissue could be recognized from the shell field of A. rubrolineata. The shell field comprised not only the centrally located, alternatively arranged plate fields and ridges, but also the tissues surrounding them, which were the precursors of the girdle and we termed as the girdle field. The girdle field exhibited a concentric organization composed of two circularly arranged tissues, and spicules were only developed in the outer circle. Dynamic engrailed expression and F-actin (filamentous actin) distributions revealed relatively complicated morphogenesis of the shell field. The repeated units (plate fields and ridges) were gradually established in the shell field, seemingly different from the manners used in the segmentation of Drosophila or vertebrates. The seven repeated ridges also experienced different modes of ontogenesis from each other. In the girdle field, the presumptive spicule-formation cells exhibited different patterns of F-actin aggregations as they differentiate. Conclusions These results reveal the details concerning the structure of polyplacophoran shell field as well as its morphogenesis. They would contribute to exploring the mechanisms of polyplacophoran shell development and molluscan shell evolution.
first_indexed 2024-04-09T18:53:40Z
format Article
id doaj.art-3a2410d841154fdeb1d1b3800d57d262
institution Directory Open Access Journal
issn 2041-9139
language English
last_indexed 2024-04-09T18:53:40Z
publishDate 2023-04-01
publisher BMC
record_format Article
series EvoDevo
spelling doaj.art-3a2410d841154fdeb1d1b3800d57d2622023-04-09T11:18:45ZengBMCEvoDevo2041-91392023-04-0114111610.1186/s13227-023-00209-9Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineataYuxiu Xia0Pin Huan1Baozhong Liu2CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesCAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesCAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesAbstract Background The polyplacophoran mollusks (chitons) possess serially arranged shell plates. This feature is unique among mollusks and believed to be essential to explore the evolution of mollusks as well as their shells. Previous studies revealed several cell populations in the dorsal epithelium (shell field) of polyplacophoran larvae and their roles in the formation of shell plates. Nevertheless, they provide limited molecular information, and shell field morphogenesis remains largely uninvestigated. Results In the present study, we investigated shell field development in the chiton Acanthochitona rubrolineata based on morphological characteristics and molecular patterns. A total of four types of tissue could be recognized from the shell field of A. rubrolineata. The shell field comprised not only the centrally located, alternatively arranged plate fields and ridges, but also the tissues surrounding them, which were the precursors of the girdle and we termed as the girdle field. The girdle field exhibited a concentric organization composed of two circularly arranged tissues, and spicules were only developed in the outer circle. Dynamic engrailed expression and F-actin (filamentous actin) distributions revealed relatively complicated morphogenesis of the shell field. The repeated units (plate fields and ridges) were gradually established in the shell field, seemingly different from the manners used in the segmentation of Drosophila or vertebrates. The seven repeated ridges also experienced different modes of ontogenesis from each other. In the girdle field, the presumptive spicule-formation cells exhibited different patterns of F-actin aggregations as they differentiate. Conclusions These results reveal the details concerning the structure of polyplacophoran shell field as well as its morphogenesis. They would contribute to exploring the mechanisms of polyplacophoran shell development and molluscan shell evolution.https://doi.org/10.1186/s13227-023-00209-9PolyplacophoranMolluskShell fieldPlate fieldMorphogenesisEngrailed
spellingShingle Yuxiu Xia
Pin Huan
Baozhong Liu
Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
EvoDevo
Polyplacophoran
Mollusk
Shell field
Plate field
Morphogenesis
Engrailed
title Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
title_full Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
title_fullStr Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
title_full_unstemmed Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
title_short Shell field morphogenesis in the polyplacophoran mollusk Acanthochitona rubrolineata
title_sort shell field morphogenesis in the polyplacophoran mollusk acanthochitona rubrolineata
topic Polyplacophoran
Mollusk
Shell field
Plate field
Morphogenesis
Engrailed
url https://doi.org/10.1186/s13227-023-00209-9
work_keys_str_mv AT yuxiuxia shellfieldmorphogenesisinthepolyplacophoranmolluskacanthochitonarubrolineata
AT pinhuan shellfieldmorphogenesisinthepolyplacophoranmolluskacanthochitonarubrolineata
AT baozhongliu shellfieldmorphogenesisinthepolyplacophoranmolluskacanthochitonarubrolineata