The Role of Introgression During the Radiation of Endemic Fishes Adapted to Living at Extreme Altitudes in the Tibetan Plateau.

Recent genomic analyses of evolutionary radiations suggest that ancient introgression may facilitate rapid diversification and adaptive radiation. The loach genus Triplophysa, a genus with most species endemic to Tibetan Plateau, shows ecological diversity and rapid evolution and represents a potential example of adaptive radiation linked to the uplift of the Tibetan Plateau. Here, we interrogate the complex evolutionary history of Triplophysa fishes through the analysis of whole-genome sequences.

Multi-omics Investigation of Freeze Tolerance in the Amur Sleeper, an Aquatic Ectothermic Vertebrate.

Freeze tolerance, the ability of an organism to survive internal ice formation, is a striking survival strategy employed by some ectotherms living in cold environments. However, the genetic bases of this remarkable adaptation are largely unknown. The Amur sleeper (Perccottus glenii), the only known freeze-tolerant fish species, can overwinter with its entire body frozen in ice.

Sympatric or micro-allopatric speciation in a glacial lake? Genomic islands support neither.

Apparent cases of sympatric speciation may actually be due to micro-allopatric or micro-parapatric speciation. One way to distinguish between these models is to examine the existence and nature of genomic islands of divergence, wherein divergent DNA segments are interspersed with low-divergence segments. Such islands should be rare or absent under micro-allopatric speciation but common in cases of speciation with gene flow.

Pseudo-chromosome-length genome assembly for a deep-sea eel Ilyophis brunneus sheds light on the deep-sea adaptation.

High hydrostatic pressure, low temperature, and scarce food supply are the major factors that limit the survival of vertebrates in extreme deep-sea environments. Here, we constructed a high-quality genome of the deep-sea Muddy arrowtooth eel (MAE, Ilyophis brunneus, captured below a depth of 3,500 m) by using Illumina, PacBio, and Hi-C sequencing. We compare it against those of shallow-water eel and other outgroups to explore the genetic basis that underlies the adaptive evolution to deep-sea biomes.

Monsoon boosted radiation of the endemic East Asian carps.

Major historical events often trigger the rapid flourishing of a few lineages, which in turn shape established biodiversity patterns. How did this process occur and develop? This study provides a window into this issue. The endemic East Asian carps (EEAC) dominated the ichthyofauna of East Asia and exhibited a high degree of adaptation to monsoonal river-lake ecosystems.

Tracing the genetic footprints of vertebrate landing in non-teleost ray-finned fishes.

Rich fossil evidence suggests that many traits and functions related to terrestrial evolution were present long before the ancestor of lobe- and ray-finned fishes. Here, we present genome sequences of the bichir, paddlefish, bowfin, and alligator gar, covering all major early divergent lineages of ray-finned fishes. Our analyses show that these species exhibit many mosaic genomic features of lobe- and ray-finned fishes.

African lungfish genome sheds light on the vertebrate water-to-land transition.

Lungfishes are the closest extant relatives of tetrapods and preserve ancestral traits linked with the water-to-land transition. However, their huge genome sizes have hindered understanding of this key transition in evolution. Here, we report a 40-Gb chromosome-level assembly of the African lungfish (Protopterus annectens) genome, which is the largest genome assembly ever reported and has a contig and chromosome N50 of 1.

The new chimeric chiron genes evolved essential roles in zebrafish embryonic development by regulating NAD levels.

The origination of new genes is important for generating genetic novelties for adaptive evolution and biological diversity. However, their potential roles in embryonic development, evolutionary processes into ancient networks, and contributions to adaptive evolution remain poorly investigated. Here, we identified a novel chimeric gene family, the chiron family, and explored its genetic basis and functional evolution underlying the adaptive evolution of Danioninae fishes.

Comparative iTRAQ proteomics revealed proteins associated with lobed fin regeneration in Bichirs.

Background: can fully regenerate its pectoral lobed fins, including a complex endoskeleton, with remarkable precision. However, despite the enormous potential of this species for use in medical research, its regeneration mechanisms remain largely unknown.

Methods: To identify the differentially expressed proteins (DEPs) during the early stages of lobed fin regeneration in , we performed a differential proteomic analysis using isobaric tag for relative and absolute quantitation (iTRAQ) approach based quantitative proteome from the pectoral lobed fins at 3 time points.

Massive Loss of Olfactory Receptors But Not Trace Amine-Associated Receptors in the World's Deepest-Living Fish ().

Olfactory receptor repertoires show highly dynamic evolution associated with ecological adaptations in different species. The Mariana snailfish () living below a depth of 6000 m in the Mariana Trench evolved degraded vision and occupies a specific feeding habitat in a dark, low-food environment. However, whether such adaptations involve adaptive changes in the chemosensory receptor repertoire is not known.

Morphology and genome of a snailfish from the Mariana Trench provide insights into deep-sea adaptation.

It is largely unknown how living organisms-especially vertebrates-survive and thrive in the coldness, darkness and high pressures of the hadal zone. Here, we describe the unique morphology and genome of Pseudoliparis swirei-a recently described snailfish species living below a depth of 6,000 m in the Mariana Trench. Unlike closely related shallow sea species, P.

DNA barcoding the ichthyofauna of the Yangtze River: Insights from the molecular inventory of a mega-diverse temperate fauna.

Intensification of inland fisheries and aquatic landscape conversion led to a drastic decline of fish populations in the Yangtze River (YR) during the last decades. This situation urges for the development of a large-scale molecular assessment of YR ichthyofauna to further develop standardized methods of molecular identification for conservation and fisheries management purposes. We present here the results of a large-scale campaign to DNA barcode YR freshwater fishes that succeeded in producing 1,424 new DNA barcodes for 123 species.

Ancient duplications and functional divergence in the interferon regulatory factors of vertebrates provide insights into the evolution of vertebrate immune systems.

Interferon regulatory factors (IRFs) were first discovered as transcription factors that regulate the transcription of human interferon (IFN)-β. Increasing evidence shows that they might be important players involved in Adaptive immune system (AIS) evolution. Although numbers of IRFs have been identified in chordates, the evolutionary history and functional diversity of this gene family during the early evolution of vertebrates have remained obscure.

The first complete mitogenome of the South China deep-sea giant isopod sp. (Crustacea: Isopoda: Cirolanidae) allows insights into the early mitogenomic evolution of isopods.

In this study, the complete mitochondrial (mt) genome sequence of the South China deep-sea giant isopod sp. was determined, and this study is the first to explore in detail the mt genome of a deep-sea member of the order Isopoda. This species belongs to the genus , the members of which are saprophagous residents of the deep-sea benthic environment; based on their large size, is included in the "supergiant group" of isopods.

Genetic diversity and evolutionary history of the Schizothorax species complex in the Lancang River (upper Mekong).

The genus Schizothorax (Cyprinidae), one of the most diverse genera of ichthyofauna of the Qinghai-Tibetan Plateau (QTP), is a good candidate for investigating patterns of genetic variation and evolutionary mechanisms. In this study, sequences from the mitochondrial control region, the cytochrome b gene, and two nuclear genes were used to re-examine the genetic diversity and investigate the evolutionary history of the Schizothorax species complex inhabiting the Lancang River. Three maternal clades were detected in the Schizothorax species complex, but frequent nuclear allele sharing also occurred among the three maternal clades.

Cyprininae phylogeny revealed independent origins of the Tibetan Plateau endemic polyploid cyprinids and their diversifications related to the Neogene uplift of the plateau.

Origin and diversification of the Tibetan polyploid cyprinids (schizothoracins) may help us to explore relationships between diversification of the cyprinids and the Tibetan Plateau uplift. Cyprininae phylogeny was analyzed using mitochondrial and nuclear DNA sequences to trace origins of polyploidy and diversifications of schizothoracins. Ancestral states reconstruction for ploidy levels indicated that the Cyprininae was diploid origin and the schizothoracin clades tetraploid origins.

Comparative population structure of two dominant species, (Munidopsidae: ) and (Mytilidae: ), inhabiting both deep-sea vent and cold seep inferred from mitochondrial multi-genes.

Deep-sea hydrothermal vents and cold seeps, limited environments without sunlight, are two types of extreme habitat for marine organisms. The differences between vents and cold seeps may facilitate genetic isolation and produce population heterogeneity. However, information on such chemosynthetic fauna taxa is rare, especially regarding the population diversity of species inhabiting both vents and cold seeps.

DNA barcoding and evaluation of genetic diversity in Cyprinidae fish in the midstream of the Yangtze River.

The Yangtze River is the longest river in China and is divided into upstream and mid-downstream regions by the Three Gorges (the natural barriers of the Yangtze River), resulting in a complex distribution of fish. Dramatic changes to habitat environments may ultimately threaten fish survival; thus, it is necessary to evaluate the genetic diversity and propose protective measures. Species identification is the most significant task in many fields of biological research and in conservation efforts.

Analysis of the nicotinamide phosphoribosyltransferase family provides insight into vertebrate adaptation to different oxygen levels during the water-to-land transition.

One of the most important events in vertebrate evolutionary history is the water-to-land transition, during which some morphological and physiological changes occurred in concert with the loss of specific genes in tetrapods. However, the molecular mechanisms underlying this transition have not been well explored. To explore vertebrate adaptation to different oxygen levels during the water-to-land transition, we performed comprehensive bioinformatics and experimental analysis aiming to investigate the NAMPT family in vertebrates.

Complete sequence and rearrangement of the mitochondrial genome of Garra qiaojiensis (Cypriniformes: Cyprinidae).

The complete mitochondrial sequence of Garra qiaojiensis was obtained by PCR. It was 17,096 bp in length and comprised 22 transfer RNA genes, 13 protein-coding genes, 2 ribosomal RNA genes and 3 non-coding regions. Unlike the typical mitochondrial genome organization in vertebrate, the mitochondrial genome of G.