1
|
Ludington AJ, Hammond JM, Breen J, Deveson IW, Sanders KL. New chromosome-scale genomes provide insights into marine adaptations of sea snakes (Hydrophis: Elapidae). BMC Biol 2023; 21:284. [PMID: 38066641 PMCID: PMC10709897 DOI: 10.1186/s12915-023-01772-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Sea snakes underwent a complete transition from land to sea within the last ~ 15 million years, yet they remain a conspicuous gap in molecular studies of marine adaptation in vertebrates. RESULTS Here, we generate four new annotated sea snake genomes, three of these at chromosome-scale (Hydrophis major, H. ornatus and H. curtus), and perform detailed comparative genomic analyses of sea snakes and their closest terrestrial relatives. Phylogenomic analyses highlight the possibility of near-simultaneous speciation at the root of Hydrophis, and synteny maps show intra-chromosomal variations that will be important targets for future adaptation and speciation genomic studies of this system. We then used a strict screen for positive selection in sea snakes (against a background of seven terrestrial snake genomes) to identify genes over-represented in hypoxia adaptation, sensory perception, immune response and morphological development. CONCLUSIONS We provide the best reference genomes currently available for the prolific and medically important elapid snake radiation. Our analyses highlight the phylogenetic complexity and conserved genome structure within Hydrophis. Positively selected marine-associated genes provide promising candidates for future, functional studies linking genetic signatures to the marine phenotypes of sea snakes and other vertebrates.
Collapse
Affiliation(s)
- Alastair J Ludington
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia.
| | - Jillian M Hammond
- Genomics and Inherited Disease Program, Garvan Institute of Medical Research, Sydney, NSW, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and Murdoch Children's Research Institute, Darlinghurst, Australia
| | - James Breen
- Indigenous Genomics, Telethon Kids Institute, Adelaide, Australia
- John Curtin School of Medical Research, College of Health & Medicine, Australian National University, Canberra, Australia
| | - Ira W Deveson
- Genomics and Inherited Disease Program, Garvan Institute of Medical Research, Sydney, NSW, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and Murdoch Children's Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Kate L Sanders
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia.
- The South Australian Museum, Adelaide, Australia.
| |
Collapse
|
2
|
Rao WQ, Kalogeropoulos K, Allentoft ME, Gopalakrishnan S, Zhao WN, Workman CT, Knudsen C, Jiménez-Mena B, Seneci L, Mousavi-Derazmahalleh M, Jenkins TP, Rivera-de-Torre E, Liu SQ, Laustsen AH. The rise of genomics in snake venom research: recent advances and future perspectives. Gigascience 2022; 11:6562531. [PMID: 35365832 PMCID: PMC8975721 DOI: 10.1093/gigascience/giac024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/12/2022] [Accepted: 02/13/2022] [Indexed: 12/12/2022] Open
Abstract
Snake venoms represent a danger to human health, but also a gold mine of bioactive proteins that can be harnessed for drug discovery purposes. The evolution of snakes and their venom has been studied for decades, particularly via traditional morphological and basic genetic methods alongside venom proteomics. However, while the field of genomics has matured rapidly over the past 2 decades, owing to the development of next-generation sequencing technologies, snake genomics remains in its infancy. Here, we provide an overview of the state of the art in snake genomics and discuss its potential implications for studying venom evolution and toxinology. On the basis of current knowledge, gene duplication and positive selection are key mechanisms in the neofunctionalization of snake venom proteins. This makes snake venoms important evolutionary drivers that explain the remarkable venom diversification and adaptive variation observed in these reptiles. Gene duplication and neofunctionalization have also generated a large number of repeat sequences in snake genomes that pose a significant challenge to DNA sequencing, resulting in the need for substantial computational resources and longer sequencing read length for high-quality genome assembly. Fortunately, owing to constantly improving sequencing technologies and computational tools, we are now able to explore the molecular mechanisms of snake venom evolution in unprecedented detail. Such novel insights have the potential to affect the design and development of antivenoms and possibly other drugs, as well as provide new fundamental knowledge on snake biology and evolution.
Collapse
Affiliation(s)
- Wei-Qiao Rao
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark.,Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Konstantinos Kalogeropoulos
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Morten E Allentoft
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Kent Street, 6102, Bentley Perth, Australia.,Globe Institute, University of Copenhagen, Øster Voldgade 5, 1350, Copenhagen, Denmark
| | - Shyam Gopalakrishnan
- Globe Institute, University of Copenhagen, Øster Voldgade 5, 1350, Copenhagen, Denmark
| | - Wei-Ning Zhao
- Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Christopher T Workman
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Belén Jiménez-Mena
- DTU Aqua, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Lorenzo Seneci
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Mahsa Mousavi-Derazmahalleh
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Kent Street, 6102, Bentley Perth, Australia
| | - Timothy P Jenkins
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Esperanza Rivera-de-Torre
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Si-Qi Liu
- Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| |
Collapse
|
3
|
Galbraith JD, Ludington AJ, Sanders KL, Amos TG, Thomson VA, Enosi Tuipulotu D, Dunstan N, Edwards RJ, Suh A, Adelson DL. Horizontal Transposon Transfer and Its Implications for the Ancestral Ecology of Hydrophiine Snakes. Genes (Basel) 2022; 13:genes13020217. [PMID: 35205262 PMCID: PMC8872380 DOI: 10.3390/genes13020217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/23/2022] [Accepted: 01/23/2022] [Indexed: 02/04/2023] Open
Abstract
Transposable elements (TEs), also known as jumping genes, are sequences able to move or copy themselves within a genome. As TEs move throughout genomes they often act as a source of genetic novelty, hence understanding TE evolution within lineages may help in understanding environmental adaptation. Studies into the TE content of lineages of mammals such as bats have uncovered horizontal transposon transfer (HTT) into these lineages, with squamates often also containing the same TEs. Despite the repeated finding of HTT into squamates, little comparative research has examined the evolution of TEs within squamates. Here we examine a diverse family of Australo-Melanesian snakes (Hydrophiinae) to examine if the previously identified, order-wide pattern of variable TE content and activity holds true on a smaller scale. Hydrophiinae diverged from Asian elapids ~30 Mya and have since rapidly diversified into six amphibious, ~60 marine and ~100 terrestrial species that fill a broad range of ecological niches. We find TE diversity and expansion differs between hydrophiines and their Asian relatives and identify multiple HTTs into Hydrophiinae, including three likely transferred into the ancestral hydrophiine from fish. These HTT events provide the first tangible evidence that Hydrophiinae reached Australia from Asia via a marine route.
Collapse
Affiliation(s)
- James D. Galbraith
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; (J.D.G.); (A.J.L.); (K.L.S.); (V.A.T.)
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Alastair J. Ludington
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; (J.D.G.); (A.J.L.); (K.L.S.); (V.A.T.)
| | - Kate L. Sanders
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; (J.D.G.); (A.J.L.); (K.L.S.); (V.A.T.)
| | - Timothy G. Amos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; (T.G.A.); (D.E.T.)
- Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Vicki A. Thomson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; (J.D.G.); (A.J.L.); (K.L.S.); (V.A.T.)
| | - Daniel Enosi Tuipulotu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; (T.G.A.); (D.E.T.)
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | | | - Richard J. Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; (T.G.A.); (D.E.T.)
- Correspondence: (R.J.E.); (A.S.); (D.L.A.)
| | - Alexander Suh
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TU, UK
- Department of Organismal Biology-Systematic Biology, Evolutionary Biology Centre, Uppsala University, SE-752 36 Uppsala, Sweden
- Correspondence: (R.J.E.); (A.S.); (D.L.A.)
| | - David L. Adelson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; (J.D.G.); (A.J.L.); (K.L.S.); (V.A.T.)
- South Australian Museum, Adelaide, SA 5000, Australia
- Correspondence: (R.J.E.); (A.S.); (D.L.A.)
| |
Collapse
|
4
|
Iannucci A, Benazzo A, Natali C, Arida EA, Zein MSA, Jessop TS, Bertorelle G, Ciofi C. Population structure, genomic diversity and demographic history of Komodo dragons inferred from whole-genome sequencing. Mol Ecol 2021; 30:6309-6324. [PMID: 34390519 PMCID: PMC9292392 DOI: 10.1111/mec.16121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023]
Abstract
Population and conservation genetics studies have greatly benefited from the development of new techniques and bioinformatic tools associated with next-generation sequencing. Analysis of extensive data sets from whole-genome sequencing of even a few individuals allows the detection of patterns of fine-scale population structure and detailed reconstruction of demographic dynamics through time. In this study, we investigated the population structure, genomic diversity and demographic history of the Komodo dragon (Varanus komodoensis), the world's largest lizard, by sequencing the whole genomes of 24 individuals from the five main Indonesian islands comprising the entire range of the species. Three main genomic groups were observed. The populations of the Island of Komodo and the northern coast of Flores, in particular, were identified as two distinct conservation units. Degrees of genomic divergence among island populations were interpreted as a result of changes in sea level affecting connectivity across islands. Demographic inference suggested that Komodo dragons probably experienced a relatively steep population decline over the last million years, reaching a relatively stable Ne during the Saalian glacial cycle (400-150 thousand years ago) followed by a rapid Ne decrease. Genomic diversity of Komodo dragons was similar to that found in endangered or already extinct reptile species. Overall, this study provides an example of how whole-genome analysis of a few individuals per population can help define population structure and intraspecific demographic dynamics. This is particularly important when applying population genomics data to conservation of rare or elusive endangered species.
Collapse
Affiliation(s)
| | - Andrea Benazzo
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Chiara Natali
- Department of BiologyUniversity of FlorenceFirenzeItaly
| | - Evy Ayu Arida
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Moch Samsul Arifin Zein
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Tim S. Jessop
- School of Life and Environmental SciencesDeakin UniversityGeelongVic.Australia
| | - Giorgio Bertorelle
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Claudio Ciofi
- Department of BiologyUniversity of FlorenceFirenzeItaly
| |
Collapse
|
5
|
Lettoof DC, Thomson VA, Cornelis J, Bateman PW, Aubret F, Gagnon MM, von Takach B. Bioindicator snake shows genomic signatures of natural and anthropogenic barriers to gene flow. PLoS One 2021; 16:e0259124. [PMID: 34714831 PMCID: PMC8555784 DOI: 10.1371/journal.pone.0259124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/12/2021] [Indexed: 11/18/2022] Open
Abstract
Urbanisation alters landscapes, introduces wildlife to novel stressors, and fragments habitats into remnant 'islands'. Within these islands, isolated wildlife populations can experience genetic drift and subsequently suffer from inbreeding depression and reduced adaptive potential. The Western tiger snake (Notechis scutatus occidentalis) is a predator of wetlands in the Swan Coastal Plain, a unique bioregion that has suffered substantial degradation through the development of the city of Perth, Western Australia. Within the urban matrix, tiger snakes now only persist in a handful of wetlands where they are known to bioaccumulate a suite of contaminants, and have recently been suggested as a relevant bioindicator of ecosystem health. Here, we used genome-wide single nucleotide polymorphism (SNP) data to explore the contemporary population genomics of seven tiger snake populations across the urban matrix. Specifically, we used population genomic structure and diversity, effective population sizes (Ne), and heterozygosity-fitness correlations to assess fitness of each population with respect to urbanisation. We found that population genomic structure was strongest across the northern and southern sides of a major river system, with the northern cluster of populations exhibiting lower heterozygosities than the southern cluster, likely due to a lack of historical gene flow. We also observed an increasing signal of inbreeding and genetic drift with increasing geographic isolation due to urbanisation. Effective population sizes (Ne) at most sites were small (< 100), with Ne appearing to reflect the area of available habitat rather than the degree of adjacent urbanisation. This suggests that ecosystem management and restoration may be the best method to buffer the further loss of genetic diversity in urban wetlands. If tiger snake populations continue to decline in urban areas, our results provide a baseline measure of genomic diversity, as well as highlighting which 'islands' of habitat are most in need of management and protection.
Collapse
Affiliation(s)
- Damian C. Lettoof
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Vicki A. Thomson
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Jari Cornelis
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Philip W. Bateman
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Fabien Aubret
- Station d’Ecologie Théorique et Expérimentale, CNRS, Moulis, France
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Marthe M. Gagnon
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Brenton von Takach
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
| |
Collapse
|
6
|
Galbraith JD, Ludington AJ, Sanders KL, Suh A, Adelson DL. Horizontal transfer and subsequent explosive expansion of a DNA transposon in sea kraits ( Laticauda). Biol Lett 2021; 17:20210342. [PMID: 34464541 PMCID: PMC8437027 DOI: 10.1098/rsbl.2021.0342] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Transposable elements (TEs) are self-replicating genetic sequences and are often described as important ‘drivers of evolution’. This driving force is because TEs promote genomic novelty by enabling rearrangement, and through exaptation as coding and regulatory elements. However, most TE insertions potentially lead to neutral or harmful outcomes, therefore host genomes have evolved machinery to suppress TE expansion. Through horizontal transposon transfer (HTT) TEs can colonize new genomes, and since new hosts may not be able to regulate subsequent replication, these TEs may proliferate rapidly. Here, we describe HTT of the Harbinger-Snek DNA transposon into sea kraits (Laticauda), and its subsequent explosive expansion within Laticauda genomes. This HTT occurred following the divergence of Laticauda from terrestrial Australian elapids approximately 15–25 Mya. This has resulted in numerous insertions into introns and regulatory regions, with some insertions into exons which appear to have altered UTRs or added sequence to coding exons. Harbinger-Snek has rapidly expanded to make up 8–12% of Laticauda spp. genomes; this is the fastest known expansion of TEs in amniotes following HTT. Genomic changes caused by this rapid expansion may have contributed to adaptation to the amphibious-marine habitat.
Collapse
Affiliation(s)
- James D Galbraith
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Alastair J Ludington
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Kate L Sanders
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Alexander Suh
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TU, UK.,Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre, Uppsala University, Uppsala SE-752 36, Sweden
| | - David L Adelson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| |
Collapse
|