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  - Shen, Yingjia
A1  - Chalopin, Domitille
A1  - Garcia, Tzintzuni
A1  - Boswell, Mikki
A1  - Boswell, William
A1  - Shiryev, Sergey A.
A1  - Agarwala, Richa
A1  - Volff, Jean-Nicolas
A1  - Postlethwait, John H.
A1  - Schartl, Manfred
A1  - Minx, Patrick
A1  - Warren, Wesley C.
A1  - Walter, Ronald B.
T1  - X. couchianus and X. hellerii genome models provide genomic variation insight among Xiphophorus species
JF  - BMC Genomics
N2  - Background

Xiphophorus fishes are represented by 26 live-bearing species of tropical fish that express many attributes (e.g., viviparity, genetic and phenotypic variation, ecological adaptation, varied sexual developmental mechanisms, ability to produce fertile interspecies hybrids) that have made attractive research models for over 85 years. Use of various interspecies hybrids to investigate the genetics underlying spontaneous and induced tumorigenesis has resulted in the development and maintenance of pedigreed Xiphophorus lines specifically bred for research. The recent availability of the X. maculatus reference genome assembly now provides unprecedented opportunities for novel and exciting comparative research studies among Xiphophorus species.

Results

We present sequencing, assembly and annotation of two new genomes representing Xiphophorus couchianus and Xiphophorus hellerii. The final X. couchianus and X. hellerii assemblies have total sizes of 708 Mb and 734 Mb and correspond to 98 % and 102 % of the X. maculatus Jp 163 A genome size, respectively. The rates of single nucleotide change range from 1 per 52 bp to 1 per 69 bp among the three genomes and the impact of putatively damaging variants are presented. In addition, a survey of transposable elements allowed us to deduce an ancestral TE landscape, uncovered potential active TEs and document a recent burst of TEs during evolution of this genus.

Conclusions

Two new Xiphophorus genomes and their corresponding transcriptomes were efficiently assembled, the former using a novel guided assembly approach. Three assembled genome sequences within this single vertebrate order of new world live-bearing fishes will accelerate our understanding of relationship between environmental adaptation and genome evolution. In addition, these genome resources provide capability to determine allele specific gene regulation among interspecies hybrids produced by crossing any of the three species that are known to produce progeny predisposed to tumor development.
KW  - Xiphophorus
KW  - X. hellerii
KW  - Annotation
KW  - Single nucleotide change
KW  - Genome comparison
KW  - X. couchianus
KW  - Genome assembly
KW  - NGS
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164582
VL  - 17
ER  -