TY  - JOUR
A1  - Sendell-Price, Ashley T.
A1  - Tulenko, Frank J.
A1  - Pettersson, Mats
A1  - Kang, Du
A1  - Montandon, Margo
A1  - Winkler, Sylke
A1  - Kulb, Kathleen
A1  - Naylor, Gavin P.
A1  - Phillippy, Adam
A1  - Fedrigo, Olivier
A1  - Mountcastle, Jacquelyn
A1  - Balacco, Jennifer R.
A1  - Dutra, Amalia
A1  - Dale, Rebecca E.
A1  - Haase, Bettina
A1  - Jarvis, Erich D.
A1  - Myers, Gene
A1  - Burgess, Shawn M.
A1  - Currie, Peter D.
A1  - Andersson, Leif
A1  - Schartl, Manfred
T1  - Low mutation rate in epaulette sharks is consistent with a slow rate of evolution in sharks
JF  - Nature Communications
N2  - Sharks occupy diverse ecological niches and play critical roles in marine ecosystems, often acting as apex predators. They are considered a slow-evolving lineage and have been suggested to exhibit exceptionally low cancer rates. These two features could be explained by a low nuclear mutation rate. Here, we provide a direct estimate of the nuclear mutation rate in the epaulette shark (Hemiscyllium ocellatum). We generate a high-quality reference genome, and resequence the whole genomes of parents and nine offspring to detect de novo mutations. Using stringent criteria, we estimate a mutation rate of 7×10\(^{−10}\) per base pair, per generation. This represents one of the lowest directly estimated mutation rates for any vertebrate clade, indicating that this basal vertebrate group is indeed a slowly evolving lineage whose ability to restore genetic diversity following a sustained population bottleneck may be hampered by a low mutation rate.
KW  - evolutionary genetics
KW  - genomics
KW  - molecular evolution
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357827
VL  - 14
ER  - 
TY  - JOUR
A1  - Rhee, Jae-Sung
A1  - Choi, Beom-Soon
A1  - Kim, Jaebum
A1  - Kim, Bo-Mi
A1  - Lee, Young-Mi
A1  - Kim, Il-Chan
A1  - Kanamori, Akira
A1  - Choi, Ik-Young
A1  - Schartl, Manfred
A1  - Lee, Jae-Seong
T1  - Diversity, distribution, and significance of transposable elements in the genome of the only selfing hermaphroditic vertebrate Kryptolebias marmoratus
JF  - Scientific Reports
N2  - The Kryptolebias marmoratus is unique because it is the only selffertilizing hermaphroditic vertebrate, known to date. It primarily reproduces by internal self-fertilization in a mixed ovary/testis gonad. Here, we report on a high-quality genome assembly for the K. marmoratus South Korea (SK) strain highlighting the diversity and distribution of transposable elements (TEs). We find that K. marmoratus genome maintains number and composition of TEs. This can be an important genomic attribute promoting genome recombination in this selfing fish, while, in addition to a mixed mating strategy, it may also represent a mechanism contributing to the evolutionary adaptation to ecological pressure of the species. Future work should help clarify this point further once genomic information is gathered for other taxa of the family Rivulidae that do not self-fertilize. We provide a valuable genome resource that highlights the potential impact of TEs on the genome evolution of a fish species with an uncommon life cycle.
KW  - ecological genetics
KW  - evolutionary genetics
KW  - ichthyology
KW  - Kryptolebias marmoratus
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181329
VL  - 7
ER  - 
TY  - JOUR
A1  - Kim, Bo-Mi
A1  - Amores, Angel
A1  - Kang, Seunghyun
A1  - Ahn, Do-Hwan
A1  - Kim, Jin-Hyoung
A1  - Kim, Il-Chan
A1  - Lee, Jun Hyuck
A1  - Lee, Sung Gu
A1  - Lee, Hyoungseok
A1  - Lee, Jungeun
A1  - Kim, Han-Woo
A1  - Desvignes, Thomas
A1  - Batzel, Peter
A1  - Sydes, Jason
A1  - Titus, Tom
A1  - Wilson, Catherine A.
A1  - Catchen, Julian M.
A1  - Warren, Wesley C.
A1  - Schartl, Manfred
A1  - Detrich, H. William III
A1  - Postlethwait, John H.
A1  - Park, Hyun
T1  - Antarctic blackfin icefish genome reveals adaptations to extreme environments
JF  - Nature Ecology & Evolution
N2  - Icefishes (suborder Notothenioidei; family Channichthyidae) are the only vertebrates that lack functional haemoglobin genes and red blood cells. Here, we report a high-quality genome assembly and linkage map for the Antarctic blackfin icefish Chaenocephalus aceratus, highlighting evolved genomic features for its unique physiology. Phylogenomic analysis revealed that Antarctic fish of the teleost suborder Notothenioidei, including icefishes, diverged from the stickleback lineage about 77 million years ago and subsequently evolved cold-adapted phenotypes as the Southern Ocean cooled to sub-zero temperatures. Our results show that genes involved in protection from ice damage, including genes encoding antifreeze glycoprotein and zona pellucida proteins, are highly expanded in the icefish genome. Furthermore, genes that encode enzymes that help to control cellular redox state, including members of the sod3 and nqo1 gene families, are expanded, probably as evolutionary adaptations to the relatively high concentration of oxygen dissolved in cold Antarctic waters. In contrast, some crucial regulators of circadian homeostasis (cry and per genes) are absent from the icefish genome, suggesting compromised control of biological rhythms in the polar light environment. The availability of the icefish genome sequence will accelerate our understanding of adaptation to extreme Antarctic environments.
KW  - animal physiology
KW  - evolutionary genetics
KW  - genomics
KW  - ichthyology
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-325811
VL  - 3
ER  - 
TY  - JOUR
A1  - Franchini, Paolo
A1  - Jones, Julia C.
A1  - Xiong, Peiwen
A1  - Kneitz, Susanne
A1  - Gompert, Zachariah
A1  - Warren, Wesley C.
A1  - Walter, Ronald B.
A1  - Meyer, Axel
A1  - Schartl, Manfred
T1  - Long-term experimental hybridisation results in the evolution of a new sex chromosome in swordtail fish
JF  - Nature Communications
N2  - The remarkable diversity of sex determination mechanisms known in fish may be fuelled by exceptionally high rates of sex chromosome turnovers or transitions. However, the evolutionary causes and genomic mechanisms underlying this variation and instability are yet to be understood. Here we report on an over 30-year evolutionary experiment in which we tested the genomic consequences of hybridisation and selection between two Xiphophorus fish species with different sex chromosome systems. We find that introgression and imposing selection for pigmentation phenotypes results in the retention of an unexpectedly large maternally derived genomic region. During the hybridisation process, the sex-determining region of the X chromosome from one parental species was translocated to an autosome in the hybrids leading to the evolution of a new sex chromosome. Our results highlight the complexity of factors contributing to patterns observed in hybrid genomes, and we experimentally demonstrate that hybridisation can catalyze rapid evolution of a new sex chromosome.
KW  - evolutionary genetics
KW  - experimental evolution
KW  - genome evolution
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228396
VL  - 9
ER  - 
TY  - JOUR
A1  - Adolfi, Mateus C.
A1  - Du, Kang
A1  - Kneitz, Susanne
A1  - Cabau, Cédric
A1  - Zahm, Margot
A1  - Klopp, Christophe
A1  - Feron, Romain
A1  - Paixão, Rômulo V.
A1  - Varela, Eduardo S.
A1  - de Almeida, Fernanda L.
A1  - de Oliveira, Marcos A.
A1  - Nóbrega, Rafael H.
A1  - Lopez-Roques, Céline
A1  - Iampietro, Carole
A1  - Lluch, Jérôme
A1  - Kloas, Werner
A1  - Wuertz, Sven
A1  - Schaefer, Fabian
A1  - Stöck, Matthias
A1  - Guiguen, Yann
A1  - Schartl, Manfred
T1  - A duplicated copy of id2b is an unusual sex-determining candidate gene on the Y chromosome of arapaima (Arapaima gigas)
JF  - Scientific Reports
N2  - Arapaima gigas is one of the largest freshwater fish species of high ecological and economic importance. Overfishing and habitat destruction are severe threats to the remaining wild populations. By incorporating a chromosomal Hi-C contact map, we improved the arapaima genome assembly to chromosome-level, revealing an unexpected high degree of chromosome rearrangements during evolution of the bonytongues (Osteoglossiformes). Combining this new assembly with pool-sequencing of male and female genomes, we identified id2bbY, a duplicated copy of the inhibitor of DNA binding 2b (id2b) gene on the Y chromosome as candidate male sex-determining gene. A PCR-test for id2bbY was developed, demonstrating that this gene is a reliable male-specific marker for genotyping. Expression analyses showed that this gene is expressed in juvenile male gonads. Its paralog, id2ba, exhibits a male-biased expression in immature gonads. Transcriptome analyses and protein structure predictions confirm id2bbY as a prime candidate for the master sex-determiner. Acting through the TGF beta signaling pathway, id2bbY from arapaima would provide the first evidence for a link of this family of transcriptional regulators to sex determination. Our study broadens our current understanding about the evolution of sex determination genetic networks and provide a tool for improving arapaima aquaculture for commercial and conservation purposes.
KW  - evolutionary genetics
KW  - genetic markers
KW  - genome
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265672
VL  - 11
IS  - 1
ER  -