1
|
Yin X, Castro-Claros JD, Griesshaber E, Salas C, Sancho Vaquer A, Checa AG, Schmahl WW. Molluscs generate preferred crystallographic orientation of biominerals by organic templates, the texture and microstructure of Caudofoveata (Aplacophora) shells. Sci Rep 2024; 14:13469. [PMID: 38866846 PMCID: PMC11169368 DOI: 10.1038/s41598-024-63042-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 05/23/2024] [Indexed: 06/14/2024] Open
Abstract
Caudofoveata are molluscs that protect their vermiform body with a scleritome, a mosaic of unconnected blade/lanceolate-shaped aragonite sclerites. For the species Falcidens gutturosus and Scutopus ventrolineatus we studied the crystallographic constitution and crystal orientation texture of the sclerites and the scleritome with electron-backscatter-diffraction (EBSD), laser-confocal-microscopy (LCM) and field-emission electron microscopy (FE-SEM) imaging. Each sclerite is an aragonite single crystal that is completely enveloped by an organic sheath. Adjacent sclerites overlap laterally and vertically are, however, not connected to each other. Sclerites are thickened in their central portion, relative to their periphery. Thickening increases also from sclerite tip towards its base. Accordingly, cross-sections through a sclerite are straight at its tip, curved and bent towards the sclerite base. Irrespective of curved sclerite morphologies, the aragonite lattice within the sclerite is coherent. Sclerite aragonite is not twinned. For each sclerite the crystallographic c-axis is parallel to the morphological long axis of the sclerite, the a-axis is perpendicular to its width and the b-axis is within the width of the sclerite. The single-crystalinity of the sclerites and their mode of organization in the scleritome is outstanding. Sclerite and aragonite arrangement in the scleritome is not given by a specific crystal growth mode, it is inherent to the secreting cells. We discuss that morphological characteristics of the sclerites and crystallographic preferred orientation (texture) of sclerite aragonite is not the result of competitive growth selection. It is generated by the templating effect of the organic substance of the secreting cells and associated extracellular biopolymers.
Collapse
Affiliation(s)
- X Yin
- Bruker, Beijing, Scientific Technology, Minhang District, Shanghai, 200233, China
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, Munich, Germany
| | - J D Castro-Claros
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071, Granada, Spain
| | - E Griesshaber
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, Munich, Germany.
| | - C Salas
- Departmento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain
| | - A Sancho Vaquer
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, Munich, Germany
| | - A G Checa
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071, Granada, Spain
- Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100, Armilla, Spain
| | - W W Schmahl
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, Munich, Germany
| |
Collapse
|
2
|
Castro-Claros JD, Yin X, Salas C, Griesshaber E, Hörl S, Checa AG, Schmahl WW. Biomineral crystallographic preferred orientation in Solenogastres molluscs (Aplacophora) is controlled by organic templating. Sci Rep 2024; 14:10309. [PMID: 38705929 PMCID: PMC11070423 DOI: 10.1038/s41598-024-57754-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 03/21/2024] [Indexed: 05/07/2024] Open
Abstract
Aplacophoran molluscs are shell-less and have a worm-like body which is covered by biomineralized sclerites. We investigated sclerite crystallography and the sclerite mosaic of the Solenogastres species Dorymenia sarsii, Anamenia gorgonophila, and Simrothiella margaritacea with electron-backscattered-diffraction (EBSD), laser-confocal-microscopy and FE-SEM imaging. The soft tissue of the molluscs is covered by spicule-shaped, aragonitic sclerites. These are sub-parallel to the soft body of the organism. We find, for all three species, that individual sclerites are untwinned aragonite single crystals. For individual sclerites, aragonite c-axis is parallel to the morphological, long axis of the sclerite. Aragonite a- and b-axes are perpendicular to sclerite aragonite c-axis. For the scleritomes of the investigated species we find different sclerite and aragonite crystal arrangement patterns. For the A. gorgonophila scleritome, sclerite assembly is disordered such that sclerites with their morphological, long axis (always the aragonite c-axis) are pointing in many different directions, being, more or less, tangential to cuticle surface. For D. sarsii, the sclerite axes (equal to aragonite c-axes) show a stronger tendency to parallel arrangement, while for S. margaritacea, sclerite and aragonite organization is strongly structured into sequential rows of orthogonally alternating sclerite directions. The different arrangements are well reflected in the structured orientational distributions of aragonite a-, b-, c-axes across the EBSD-mapped parts of the scleritomes. We discuss that morphological and crystallographic preferred orientation (texture) is not generated by competitive growth selection (the crystals are not in contact), but is determined by templating on organic matter of the sclerite-secreting epithelial cells and associated papillae.
Collapse
Affiliation(s)
- J D Castro-Claros
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071, Granada, Spain
| | - X Yin
- Bruker Beijing Scientific Technology, Minhang District, Shanghai, 200233, China
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, 80333, Munich, Germany
| | - C Salas
- Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain
| | - E Griesshaber
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, 80333, Munich, Germany.
| | - S Hörl
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, 80333, Munich, Germany
| | - A G Checa
- Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071, Granada, Spain
- Instituto Andaluz de Ciencias de La Tierra, CSIC-Universidad de Granada, 18100, Armilla, Spain
| | - W W Schmahl
- Department of Geo- and Environmental Sciences, Ludwig Maximillians University Munich, 80333, Munich, Germany
| |
Collapse
|
3
|
Wang Y, Wang M, Li J, Zhang J, Zhang L. A chromosome-level genome assembly of a deep-sea symbiotic Aplacophora mollusc Chaetoderma sp. Sci Data 2024; 11:133. [PMID: 38272948 PMCID: PMC10810820 DOI: 10.1038/s41597-024-02940-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
The worm-shaped, shell-less Caudofoveata is one of the least known groups of molluscs. As early-branching molluscs, the lack of high-quality genomes hinders our understanding of their evolution and ecology. Here, we report a high-quality chromosome-scale genome of Chaetoderma sp. combining PacBio, Illumina, and high-resolution chromosome conformation capture sequencing. The final assembly has a size of 2.45 Gb, with a scaffold N50 length of 141.46 Mb, and is anchored to 17 chromosomes. Gene annotations showed a high level of accuracy and completeness, with 23,675 predicted protein-coding genes and 94.44% of the metazoan conserved genes by BUSCO assessment. We further present 16S rRNA gene amplicon sequencing of the gut microbiota in Chaetoderma sp., which was dominated by the chemoautotrophic bacteria (phylum Gammaproteobacteria). This chromosome-level genome assembly presents the first genome for the Caudofoveata, which constitutes an important resource for studies ranging from molluscan evolution, symposium, to deep-sea adaptation.
Collapse
Affiliation(s)
- Yue Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center of Deep-Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan, 430072, China
- College of Marine Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minxiao Wang
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center of Deep-Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- College of Marine Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center of Deep-Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan, 430072, China
- College of Marine Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junlong Zhang
- College of Marine Science, University of Chinese Academy of Sciences, Beijing, 100049, China
- Department of Marine Organism Taxonomy & Phylogeny, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Linlin Zhang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
- Center of Deep-Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan, 430072, China.
- College of Marine Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
4
|
Paz-Sedano S, Wilson NG, Carmona L, Gosliner TM, Pola M. An ocean yet to be discovered: increasing systematic knowledge of Indo-Pacific Okenia Menke, 1830 (Nudibranchia:Goniodorididae). INVERTEBR SYST 2021. [DOI: 10.1071/is20088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Numerous faunistic and ecological studies have been conducted throughout the Indo-Pacific Ocean to assess its biodiversity. Despite the abundance of research, studies on the species that inhabit the Indo-Pacific are still necessary due to its extent and high species richness. The major species richness of the genus Okenia Menke, 1830 (Nudibranchia, Goniodorididae) is found in the Indo-Pacific Ocean, including 38 of 60 valid species. Nevertheless, this number does not represent the real biodiversity, since at least 20 more species are already reported in field-guides as undescribed species belonging to this genus. The systematics of the genus Okenia are still unclear since it has been the subject of only a few and incomplete studies. In the present paper, we describe five new Okenia species from the coastlines of Japan, Mozambique and Australia: Okenia aurorapapillata sp. nov., Okenia elisae sp. nov., Okenia nakanoae sp. nov., Okenia siderata sp. nov. and Okenia tenuifibrata sp. nov. Moreover, anatomical details not previously described of Okenia atkinsonorum, Okenia barnardi, Okenia cf. echinata, Okenia hallucigenia, Okenia hiroi, Okenia japonica, Okenia pellucida, Okenia pilosa and Okenia rhinorma are provided. New partial sequences of standard markers (COI, 16S rRNA and H3) were obtained and a phylogenetic analysis that included all species with available data was performed.
ZOOBANK urn:lsid:zoobank.org:pub:28AE2536-A264–4194–8AE3-C430620572E7
Collapse
|
5
|
Kocot KM, Todt C, Mikkelsen NT, Halanych KM. Phylogenomics of Aplacophora (Mollusca, Aculifera) and a solenogaster without a foot. Proc Biol Sci 2020; 286:20190115. [PMID: 31064303 PMCID: PMC6532501 DOI: 10.1098/rspb.2019.0115] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent molecular phylogenetic investigations strongly supported the placement of the shell-less, worm-shaped aplacophoran molluscs (Solenogastres and Caudofoveata) and chitons (Polyplacophora) in a clade called Aculifera, which is the sister taxon of all other molluscs. Thus, understanding the evolutionary history of aculiferan molluscs is important for understanding early molluscan evolution. In particular, fundamental questions about evolutionary relationships within Aplacophora have long been unanswered. Here, we supplemented the paucity of available data with transcriptomes from 25 aculiferans and conducted phylogenomic analyses on datasets with up to 525 genes and 75 914 amino acid positions. Our results indicate that aplacophoran taxonomy requires revision as several traditionally recognized groups are non-monophyletic. Most notably, Cavibelonia, the solenogaster taxon defined by hollow sclerites, is polyphyletic, suggesting parallel evolution of hollow sclerites in multiple lineages. Moreover, we describe Apodomenia enigmatica sp. nov., a bizarre new species that appears to be a morphological intermediate between Solenogastres and Caudofoveata. This animal is not a missing link, however; molecular and morphological studies show that it is a derived solenogaster that lacks a foot, mantle cavity and radula. Taken together, these results shed light on the evolutionary history of Aplacophora and reveal a surprising degree of morphological plasticity within the group.
Collapse
Affiliation(s)
- Kevin M Kocot
- 1 The University of Alabama and the Alabama Museum of Natural History , 500 Hackberry Lane, Tuscaloosa, AL 35487 , USA
| | - Christiane Todt
- 2 Rådgivende Biologer AS , Edvard Griegs vei 3, 5059 Bergen , Norway
| | - Nina T Mikkelsen
- 3 University Museum of Bergen, The Natural History Collections, University of Bergen , Allégaten 41, 5007 Bergen , Norway
| | - Kenneth M Halanych
- 4 Department of Biological Sciences, Auburn University , Auburn, AL 36849 , USA
| |
Collapse
|