1
|
Farhat S, Bonnivard E, Pales Espinosa E, Tanguy A, Boutet I, Guiglielmoni N, Flot JF, Allam B. Comparative analysis of the Mercenaria mercenaria genome provides insights into the diversity of transposable elements and immune molecules in bivalve mollusks. BMC Genomics 2022; 23:192. [PMID: 35260071 PMCID: PMC8905726 DOI: 10.1186/s12864-021-08262-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/15/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The hard clam Mercenaria mercenaria is a major marine resource along the Atlantic coasts of North America and has been introduced to other continents for resource restoration or aquaculture activities. Significant mortality events have been reported in the species throughout its native range as a result of diseases (microbial infections, leukemia) and acute environmental stress. In this context, the characterization of the hard clam genome can provide highly needed resources to enable basic (e.g., oncogenesis and cancer transmission, adaptation biology) and applied (clam stock enhancement, genomic selection) sciences. RESULTS Using a combination of long and short-read sequencing technologies, a 1.86 Gb chromosome-level assembly of the clam genome was generated. The assembly was scaffolded into 19 chromosomes, with an N50 of 83 Mb. Genome annotation yielded 34,728 predicted protein-coding genes, markedly more than the few other members of the Venerida sequenced so far, with coding regions representing only 2% of the assembly. Indeed, more than half of the genome is composed of repeated elements, including transposable elements. Major chromosome rearrangements were detected between this assembly and another recent assembly derived from a genetically segregated clam stock. Comparative analysis of the clam genome allowed the identification of a marked diversification in immune-related proteins, particularly extensive tandem duplications and expansions in tumor necrosis factors (TNFs) and C1q domain-containing proteins, some of which were previously shown to play a role in clam interactions with infectious microbes. The study also generated a comparative repertoire highlighting the diversity and, in some instances, the specificity of LTR-retrotransposons elements, particularly Steamer elements in bivalves. CONCLUSIONS The diversity of immune molecules in M. mercenaria may allow this species to cope with varying and complex microbial and environmental landscapes. The repertoire of transposable elements identified in this study, particularly Steamer elements, should be a prime target for the investigation of cancer cell development and transmission among bivalve mollusks.
Collapse
Affiliation(s)
- Sarah Farhat
- Marine Animal Disease Laboratory, School of Marine and Atmospheric Sciences, 100 Nicolls Road, Stony Brook University, Stony Brook, NY, 11794-5000, USA
| | - Eric Bonnivard
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, 29688, Roscoff, France
| | - Emmanuelle Pales Espinosa
- Marine Animal Disease Laboratory, School of Marine and Atmospheric Sciences, 100 Nicolls Road, Stony Brook University, Stony Brook, NY, 11794-5000, USA
| | - Arnaud Tanguy
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, 29688, Roscoff, France
| | - Isabelle Boutet
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, 29688, Roscoff, France
| | - Nadège Guiglielmoni
- Université libre de Bruxelles (ULB), Evolutionary Biology & Ecology, Avenue F.D. Roosevelt 50, B-1050, Brussels, Belgium
| | - Jean-François Flot
- Université libre de Bruxelles (ULB), Evolutionary Biology & Ecology, Avenue F.D. Roosevelt 50, B-1050, Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels - (IB)2, B-1050, Brussels, Belgium
| | - Bassem Allam
- Marine Animal Disease Laboratory, School of Marine and Atmospheric Sciences, 100 Nicolls Road, Stony Brook University, Stony Brook, NY, 11794-5000, USA.
| |
Collapse
|
2
|
Schäfer GG, Grebe LJ, Schinkel R, Lieb B. The Evolution of Hemocyanin Genes in Caenogastropoda: Gene Duplications and Intron Accumulation in Highly Diverse Gastropods. J Mol Evol 2021; 89:639-655. [PMID: 34757470 PMCID: PMC8599328 DOI: 10.1007/s00239-021-10036-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/15/2021] [Indexed: 11/30/2022]
Abstract
Hemocyanin is the oxygen transport protein of most molluscs and represents an important physiological factor that has to be well-adapted to their environments because of the strong influences of abiotic factors on its oxygen affinity. Multiple independent gene duplications and intron gains have been reported for hemocyanin genes of Tectipleura (Heterobranchia) and the caenogastropod species Pomacea canaliculata, which contrast with the uniform gene architectures of hemocyanins in Vetigastropoda. The goal of this study was to analyze hemocyanin gene evolution within the diverse group of Caenogastropoda in more detail. Our findings reveal multiple gene duplications and intron gains and imply that these represent general features of Apogastropoda hemocyanins. Whereas hemocyanin exon–intron structures are identical within different Tectipleura lineages, they differ strongly within Caenogastropoda among phylogenetic groups as well as between paralogous hemocyanin genes of the same species. Thus, intron accumulation took place more gradually within Caenogastropoda but finally led to a similar consequence, namely, a multitude of introns. Since both phenomena occurred independently within Heterobranchia and Caenogastropoda, the results support the hypothesis that introns may contribute to adaptive radiation by offering new opportunities for genetic variability (multiple paralogs that may evolve differently) and regulation (multiple introns). Our study indicates that adaptation of hemocyanin genes may be one of several factors that contributed to the evolution of the large diversity of Apogastropoda. While questions remain, this hypothesis is presented as a starting point for the further study of hemocyanin genes and possible correlations between hemocyanin diversity and adaptive radiation.
Collapse
Affiliation(s)
- Gabriela Giannina Schäfer
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Lukas Jörg Grebe
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Robin Schinkel
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Bernhard Lieb
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany.
| |
Collapse
|
3
|
Schäfer GG, Pedrini-Martha V, Jackson DJ, Dallinger R, Lieb B. The evolution of hemocyanin genes in Tectipleura: a multitude of conserved introns in highly diverse gastropods. BMC Ecol Evol 2021; 21:36. [PMID: 33663373 PMCID: PMC7931591 DOI: 10.1186/s12862-021-01763-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 02/08/2021] [Indexed: 02/07/2023] Open
Abstract
Background Hemocyanin is the oxygen transporter of most molluscs. Since the oxygen affinity of hemocyanin is strongly temperature-dependent, this essential protein needs to be well-adapted to the environment. In Tectipleura, a very diverse group of gastropods with > 27,000 species living in all kinds of habitats, several hemocyanin genes have already been analyzed. Multiple independent duplications of this gene have been identified and may represent potential adaptations to different environments and lifestyles. The aim of this study is to further explore the evolution of these genes by analyzing their exon–intron architectures. Results We have reconstructed the gene architectures of ten hemocyanin genes from four Tectipleura species: Aplysia californica, Lymnaea stagnalis, Cornu aspersum and Helix pomatia. Their hemocyanin genes each contain 53 introns, significantly more than in the hemocyanin genes of Cephalopoda (9–11), Vetigastropoda (15) and Caenogastropoda (28–33). The gene structures of Tectipleura hemocyanins are identical in terms of intron number and location, with the exception of one out of two hemocyanin genes of L. stagnalis that comprises one additional intron. We found that gene structures that differ between molluscan lineages most probably evolved more recently through independent intron gains. Conclusions The strict conservation of the large number of introns in Tectipleura hemocyanin genes over 200 million years suggests the influence of a selective pressure on this gene structure. While we could not identify conserved sequence motifs within these introns, it may be simply the great number of introns that offers increased possibilities of gene regulation relative to hemocyanin genes with less introns and thus may have facilitated habitat shifts and speciation events. This hypothesis is supported by the relatively high number of introns within the hemocyanin genes of Pomacea canaliculata that has evolved independently of the Tectipleura. Pomacea canaliculata belongs to the Caenogastropoda, the sister group of Heterobranchia (that encompass Tectipleura) which is also very diverse and comprises species living in different habitats. Our findings provide a hint to some of the molecular mechanisms that may have supported the spectacular radiation of one of Metazoa’s most species rich groups.
Collapse
Affiliation(s)
- Gabriela Giannina Schäfer
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany.
| | - Veronika Pedrini-Martha
- Institute of Zoology and Center of Molecular Biosciences, University of Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Daniel John Jackson
- Department of Geobiology, Georg-August-University of Göttingen, Goldschmidtstr. 3, 37077, Göttingen, Germany
| | - Reinhard Dallinger
- Institute of Zoology and Center of Molecular Biosciences, University of Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Bernhard Lieb
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| |
Collapse
|
4
|
Pedrini-Martha V, Schnegg R, Schäfer GG, Lieb B, Salvenmoser W, Dallinger R. Responsiveness of metallothionein and hemocyanin genes to cadmium and copper exposure in the garden snail Cornu aspersum. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 335:228-238. [PMID: 33146003 PMCID: PMC7984241 DOI: 10.1002/jez.2425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022]
Abstract
Terrestrial gastropods express metal-selective metallothioneins (MTs) by which they handle metal ions such as Zn2+ , Cd2+ , and Cu+ /Cu2+ through separate metabolic pathways. At the same time, they depend on the availability of sufficient amounts of Cu as an essential constituent of their respiratory protein, hemocyanin (Hc). It was, therefore, suggested that in snails Cu-dependent MT and Hc pathways might be metabolically connected. In fact, the Cu-specific snail MT (CuMT) is exclusively expressed in rhogocytes, a particular molluscan cell type present in the hemocoel and connective tissues. Snail rhogocytes are also the sites of Hc synthesis. In the present study, possible interactions between the metal-regulatory and detoxifying activity of MTs and the Cu demand of Hc isoforms was explored in the edible snail Cornu aspersum, one of the most common European helicid land snails. This species possesses CdMT and CuMT isoforms involved in metal-selective physiological tasks. In addition, C. aspersum expresses three different Hc isoforms (CaH ɑD, CaH ɑN, CaH β). We have examined the effect of Cd2+ and Cu2+ exposure on metal accumulation in the midgut gland and mantle of C. aspersum, testing the impact of these metals on transcriptional upregulation of CdMT, CuMT, and the three Hc genes in the two organs. We found that the CuMT and CaH ɑD genes exhibit an organ-specific transcriptional upregulation in the midgut gland of Cu-exposed snails. These results are discussed in view of possible interrelationships between the metal-selective activity of snail MT isoforms and the synthesis and metabolism of Hc isoforms.
Collapse
Affiliation(s)
- Veronika Pedrini-Martha
- Department of Zoology and Center of Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Raimund Schnegg
- Department of Zoology and Center of Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | | | - Bernhard Lieb
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Willi Salvenmoser
- Department of Zoology and Center of Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Reinhard Dallinger
- Department of Zoology and Center of Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
5
|
Chiumiento IR, Ituarte S, Sun J, Qiu JW, Heras H, Dreon MS. Hemocyanin of the caenogastropod Pomacea canaliculata exhibits evolutionary differences among gastropod clades. PLoS One 2020; 15:e0228325. [PMID: 31999773 PMCID: PMC6992001 DOI: 10.1371/journal.pone.0228325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/10/2020] [Indexed: 11/20/2022] Open
Abstract
Structural knowledge of gastropod hemocyanins is scarce. To better understand their evolution and diversity we studied the hemocyanin of a caenogastropod, Pomacea canaliculata (PcH). Through a proteomic and genomic approach, we identified 4 PcH subunit isoforms, in contrast with other gastropods that usually have 2 or 3. Each isoform has the typical Keyhole limpet-type hemocyanin architecture, comprising a string of eight globular functional units (FUs). Correspondingly, genes are organized in eight FUs coding regions. All FUs in the 4 genes are encoded by more than one exon, a feature not found in non- caenogastropods. Transmission electron microscopy images of PcH showed a cylindrical structure organized in di, tri and tetra-decamers with an internal collar structure, being the di and tri-decameric cylinders the most abundant ones. PcH is N-glycosylated with high mannose and hybrid-type structures, and complex-type N-linked glycans, with absence of sialic acid. Terminal β-N-GlcNAc residues and nonreducing terminal α-GalNAc are also present. The molecule lacks O-linked glycosylation but presents the T-antigen (Gal-β1,3-GalNAc). Using an anti-PcH polyclonal antibody, no cross-immunoreactivity was observed against other gastropod hemocyanins, highlighting the presence of clade-specific structural differences among gastropod hemocyanins. This is, to the best of our knowledge, the first gene structure study of a Caenogastropoda hemocyanin.
Collapse
Affiliation(s)
- Ignacio Rafael Chiumiento
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
| | - Santiago Ituarte
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
| | - Jin Sun
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jian Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Horacio Heras
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
- Cátedra de Química Biológica, Facultad de Ciencias Naturales y Museo, UNLP, La Plata, Argentina
| | - Marcos Sebastián Dreon
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, UNLP, La Plata, Argentina
- * E-mail:
| |
Collapse
|