Bats account for one-fifth of mammalian species, are the only mammals with powered flight, and are among the few animals that echolocate. The insect-eating Brandt’s bat (Myotis brandtii) is the longest-lived bat species known to date (lifespan exceeds 40 years) and, at 4–8 g adult body weight, is the most extreme mammal with regard to disparity between body mass and longevity. Here we report sequencing and analysis of the Brandt’s bat genome and transcriptome, which suggest adaptations consistent with echolocation and hibernation, as well as altered metabolism, reproduction and visual function. Unique sequence changes in growth hormone and insulin-like growth factor 1 receptors are also observed. The data suggest that an altered growth hormone/insulin-like growth factor 1 axis, which may be common to other long-lived bat species, together with adaptations such as hibernation and low reproductive rate, contribute to the exceptional lifespan of the Brandt’s bat.

The past two decades has witnessed a remarkable increase in the number of microbial genomes retrieved from marine systems^1,2. However, it has remained challenging to translate this marine genomic diversity into biotechnological and biomedical applications^3,4. Here we recovered 43,191 bacterial and archaeal genomes from publicly available marine metagenomes, encompassing a wide range of diversity with 138 distinct phyla, redefining the upper limit of marine bacterial genome size and revealing complex trade-offs between the occurrence of CRISPR–Cas systems and antibiotic resistance genes. In silico bioprospecting of these marine genomes led to the discovery of a novel CRISPR–Cas9 system, ten antimicrobial peptides, and three enzymes that degrade polyethylene terephthalate. In vitro experiments confirmed their effectiveness and efficacy. This work provides evidence that global-scale sequencing initiatives advance our understanding of how microbial diversity has evolved in the oceans and is maintained, and demonstrates how such initiatives can be sustainably exploited to advance biotechnology and biomedicine.

Subterranean mammals spend their lives in dark, unventilated environments that are rich in carbon dioxide and ammonia and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis) and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber). Comparative genome analyses, along with the transcriptomes of related subterranean rodents, revealed candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, an aberrant melatonin system, pain insensitivity, and unique processing of 28S rRNA. Together, these genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance, and longevity.

Significance: Divergent lineages can respond to common environmental factors through convergent processes involving shared genomic components or pathways, but the molecular mechanisms are poorly understood. Here, we provide genomic resources and insights into the evolution of mammalian lineages adapting to aquatic life. Our data suggest convergent evolution, for example, in association with thermoregulation through genes associated with a surface heat barrier (NFIA) and internal heat exchange (SEMA3E). Combined with the support of previous reports showing that the UCP1 locus has been lost in many marine mammals independently, our results suggest that the thermostatic strategy of marine mammals shifted from enhancing heat production to limiting heat loss.

Cetaceans (whales, dolphins, and porpoises) are a group of mammals adapted to various aquatic habitats, from oceans to freshwater rivers. We report the sequencing, de novo assembly and analysis of a finless porpoise genome, and the re-sequencing of an additional 48 finless porpoise individuals. We use these data to reconstruct the demographic history of finless porpoises from their origin to the occupation into the Yangtze River. Analyses of selection between marine and freshwater porpoises identify genes associated with renal water homeostasis and urea cycle, such as urea transporter 2 and angiotensin I-converting enzyme 2, which are likely adaptations associated with the difference in osmotic stress between ocean and rivers. Our results strongly suggest that the critically endangered Yangtze finless porpoises are reproductively isolated from other porpoise populations and harbor unique genetic adaptations, supporting that they should be considered a unique incipient species.

Background: Ghrelin is a multifunctional peptide hormone expressed in a range of normal tissues and pathologies. It has been reported that the human ghrelin gene consists of five exons which span 5 kb of genomic DNA on chromosome 3 and includes a 20 bp non-coding first exon (20 bp exon 0). The availability of bioinformatic tools enabling comparative analysis and the finalisation of the human genome prompted us to re-examine the genomic structure of the ghrelin locus.Results: We have demonstrated the presence of an additional novel exon (exon -1) and 5' extensions to exon 0 and 1 using comparative in silico analysis and have demonstrated their existence experimentally using RT-PCR and 5' RACE. A revised exon-intron structure demonstrates that the human ghrelin gene spans 7.2 kb and consists of six rather than five exons. Several ghrelin gene-derived splice forms were detected in a range of human tissues and cell lines. We have demonstrated ghrelin gene-derived mRNA transcripts that do not code for ghrelin, but instead may encode the C-terminal region of full-length preproghrelin (C-ghrelin, which contains the coding region for obestatin) and a transcript encoding obestatin-only. Splice variants that differed in their 5' untranslated regions were also found, suggesting a role of these regions in the post-transcriptional regulation of preproghrelin translation. Finally, several natural antisense transcripts, termed ghrelinOS (ghrelin opposite strand) transcripts, were demonstrated via orientation-specific RT-PCR, 5' RACE and in silico analysis of ESTs and cloned amplicons.Conclusion: The sense and antisense alternative transcripts demonstrated in this study may function as non-coding regulatory RNA, or code for novel protein isoforms. This is the first demonstration of putative obestatin and C-ghrelin specific transcripts and these findings suggest that these ghrelin gene-derived peptides may also be produced independently of preproghrelin. This study reveals several novel aspects of the ghrelin gene and suggests that the ghrelin locus is far more complex than previously recognised.