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  - 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  -