The genome of the pygmy right whale illuminates the evolution of rorquals
(2023) In BMC Biology 21(1).- Abstract
Background: Baleen whales are a clade of gigantic and highly specialized marine mammals. Their genomes have been used to investigate their complex evolutionary history and to decipher the molecular mechanisms that allowed them to reach these dimensions. However, many unanswered questions remain, especially about the early radiation of rorquals and how cancer resistance interplays with their huge number of cells. The pygmy right whale is the smallest and most elusive among the baleen whales. It reaches only a fraction of the body length compared to its relatives and it is the only living member of an otherwise extinct family. This placement makes the pygmy right whale genome an interesting target to update the complex phylogenetic past... (More)
Background: Baleen whales are a clade of gigantic and highly specialized marine mammals. Their genomes have been used to investigate their complex evolutionary history and to decipher the molecular mechanisms that allowed them to reach these dimensions. However, many unanswered questions remain, especially about the early radiation of rorquals and how cancer resistance interplays with their huge number of cells. The pygmy right whale is the smallest and most elusive among the baleen whales. It reaches only a fraction of the body length compared to its relatives and it is the only living member of an otherwise extinct family. This placement makes the pygmy right whale genome an interesting target to update the complex phylogenetic past of baleen whales, because it splits up an otherwise long branch that leads to the radiation of rorquals. Apart from that, genomic data of this species might help to investigate cancer resistance in large whales, since these mechanisms are not as important for the pygmy right whale as in other giant rorquals and right whales. Results: Here, we present a first de novo genome of the species and test its potential in phylogenomics and cancer research. To do so, we constructed a multi-species coalescent tree from fragments of a whole-genome alignment and quantified the amount of introgression in the early evolution of rorquals. Furthermore, a genome-wide comparison of selection rates between large and small-bodied baleen whales revealed a small set of conserved candidate genes with potential connections to cancer resistance. Conclusions: Our results suggest that the evolution of rorquals is best described as a hard polytomy with a rapid radiation and high levels of introgression. The lack of shared positive selected genes between different large-bodied whale species supports a previously proposed convergent evolution of gigantism and hence cancer resistance in baleen whales.
(Less)
- author
- Wolf, Magnus ; Zapf, Konstantin ; Gupta, Deepak Kumar ; Hiller, Michael ; Árnason, Úlfur LU and Janke, Axel LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Cancer resistance, Caperea marginata, Peto’s paradox, Phylogenomics, Positive selection, Pygmy right whale, Rorquals, Whole-genome sequencing
- in
- BMC Biology
- volume
- 21
- issue
- 1
- article number
- 79
- publisher
- BioMed Central (BMC)
- external identifiers
-
- pmid:37041515
- scopus:85152276574
- ISSN
- 1741-7007
- DOI
- 10.1186/s12915-023-01579-1
- language
- English
- LU publication?
- yes
- id
- f280b9a9-a231-4c84-88a9-93178611e7f1
- date added to LUP
- 2023-06-20 12:28:17
- date last changed
- 2024-04-19 22:59:45
@article{f280b9a9-a231-4c84-88a9-93178611e7f1,
abstract = {{<p>Background: Baleen whales are a clade of gigantic and highly specialized marine mammals. Their genomes have been used to investigate their complex evolutionary history and to decipher the molecular mechanisms that allowed them to reach these dimensions. However, many unanswered questions remain, especially about the early radiation of rorquals and how cancer resistance interplays with their huge number of cells. The pygmy right whale is the smallest and most elusive among the baleen whales. It reaches only a fraction of the body length compared to its relatives and it is the only living member of an otherwise extinct family. This placement makes the pygmy right whale genome an interesting target to update the complex phylogenetic past of baleen whales, because it splits up an otherwise long branch that leads to the radiation of rorquals. Apart from that, genomic data of this species might help to investigate cancer resistance in large whales, since these mechanisms are not as important for the pygmy right whale as in other giant rorquals and right whales. Results: Here, we present a first de novo genome of the species and test its potential in phylogenomics and cancer research. To do so, we constructed a multi-species coalescent tree from fragments of a whole-genome alignment and quantified the amount of introgression in the early evolution of rorquals. Furthermore, a genome-wide comparison of selection rates between large and small-bodied baleen whales revealed a small set of conserved candidate genes with potential connections to cancer resistance. Conclusions: Our results suggest that the evolution of rorquals is best described as a hard polytomy with a rapid radiation and high levels of introgression. The lack of shared positive selected genes between different large-bodied whale species supports a previously proposed convergent evolution of gigantism and hence cancer resistance in baleen whales.</p>}},
author = {{Wolf, Magnus and Zapf, Konstantin and Gupta, Deepak Kumar and Hiller, Michael and Árnason, Úlfur and Janke, Axel}},
issn = {{1741-7007}},
keywords = {{Cancer resistance; Caperea marginata; Peto’s paradox; Phylogenomics; Positive selection; Pygmy right whale; Rorquals; Whole-genome sequencing}},
language = {{eng}},
number = {{1}},
publisher = {{BioMed Central (BMC)}},
series = {{BMC Biology}},
title = {{The genome of the pygmy right whale illuminates the evolution of rorquals}},
url = {{http://dx.doi.org/10.1186/s12915-023-01579-1}},
doi = {{10.1186/s12915-023-01579-1}},
volume = {{21}},
year = {{2023}},
}