An official website of the United States government
Islands are well known for their unique biodiversity and significance in evolutionary and ecological studies. Nevertheless, the extinction of island species accounts for most human-caused extinctions in recent time scales, which have accelerated in recent centuries. Pigeons and doves (Columbidae) are noteworthy for the high number of island endemics, as well as for the risks those species have faced since human arrival. On Caribbean islands, no other columbid has generated more phylogenetic interest and uncertainty than the blue-headed quail-dove,Starnoenas cyanocephala. This endangered Cuban endemic has been considered more similar, both behaviourally and phenotypically, to Australasian species than to the geographically closer ‘quail-dove’ (Geotrygons.l.) species of the Western Hemisphere. Here, we use whole genome sequencing fromStarnoenasand other newly sequenced columbids in combination with sequence data from previous publications to investigate its relationships. Phylogenomic analyses, which represent 35 of the 51 genera currently comprising the Columbidae, reveal that the blue-headed quail-dove is the sole representative of a lineage diverging early in the radiation of columbids.Starnoenasis sister to the species-rich subfamily Columbinae, which is found worldwide. As a highly distinctive evolutionary lineage lacking close modern relatives, we recommend elevating the conservation priority ofStarnoenas.
more »
« less
Museum genomics reveals the Xerces blue butterfly ( Glaucopsyche xerces ) was a distinct species driven to extinction
The last Xerces blue butterfly was seen in the early 1940s, and its extinction is credited to human urban development. This butterfly has become a North American icon for insect conservation, but some have questioned whether it was truly a distinct species, or simply an isolated population of another living species. To address this question, we leveraged next-generation sequencing using a 93-year-old museum specimen. We applied a genome skimming strategy that aimed for the organellar genome and high-copy fractions of the nuclear genome by a shallow sequencing approach. From these data, we were able to recover over 200 million nucleotides, which assembled into several phylogenetically informative markers and the near-complete mitochondrial genome. From our phylogenetic analyses and haplotype network analysis we conclude that the Xerces blue butterfly was a distinct species driven to extinction.
more »
« less
- Award ID(s):
- 1922624
- PAR ID:
- 10286929
- Date Published:
- Journal Name:
- Biology Letters
- Volume:
- 17
- Issue:
- 7
- ISSN:
- 1744-957X
- Page Range / eLocation ID:
- 20210123
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract BackgroundThe blue catfish is of great value in aquaculture and recreational fisheries. The F1 hybrids of female channel catfish (Ictalurus punctatus) × male blue catfish (Ictalurusfurcatus) have been the primary driver of US catfish production in recent years because of superior growth, survival, and carcass yield. The channel–blue hybrid also provides an excellent model to investigate molecular mechanisms of environment-dependent heterosis. However, transcriptome and methylome studies suffered from low alignment rates to the channel catfish genome due to divergence, and the genome resources for blue catfish are not publicly available. ResultsThe blue catfish genome assembly is 841.86 Mbp in length with excellent continuity (8.6 Mbp contig N50, 28.2 Mbp scaffold N50) and completeness (98.6% Eukaryota and 97.0% Actinopterygii BUSCO). A total of 30,971 protein-coding genes were predicted, of which 21,781 were supported by RNA sequencing evidence. Phylogenomic analyses revealed that it diverged from channel catfish approximately 9 million years ago with 15.7 million fixed nucleotide differences. The within-species single-nucleotide polymorphism (SNP) density is 0.32% between the most aquaculturally important blue catfish strains (D&B and Rio Grande). Gene family analysis discovered significant expansion of immune-related families in the blue catfish lineage, which may contribute to disease resistance in blue catfish. ConclusionsWe reported the first high-quality, chromosome-level assembly of the blue catfish genome, which provides the necessary genomic tool kit for transcriptome and methylome analysis, SNP discovery and marker-assisted selection, gene editing and genome engineering, and reproductive enhancement of the blue catfish and hybrid catfish.more » « less
-
The dynamics of hybridization between golden-winged (Vermivora chrysoptera) and blue-winged warblers (V. cyanoptera) has been of interest for over a century. Whole genome analysis found only a small number of genomic regions that differed between the species. We previously developed a restriction enzyme-based RFLP approach to genotype large numbers of individuals at each of these loci. Here we extend this approach to an amplicon sequencing method to genotype individuals at these six plumage-associated regions. We demonstrate the efficacy using preliminary data from 4 golden-winged and 4 blue-winged warblers as well as provide the data and scripts necessary to analyze these data for other interested in replicating this approach. Our hope is that these data are useful for other researchers interested in genotyping Vermivora warblers.more » « less
-
The Evolution of Widespread Recombination Suppression on the Dwarf Hamster ( Phodopus ) X ChromosomeMank, Judith (Ed.)Abstract The X chromosome of therian mammals shows strong conservation among distantly related species, limiting insights into the distinct selective processes that have shaped sex chromosome evolution. We constructed a chromosome-scale de novo genome assembly for the Siberian dwarf hamster (Phodopus sungorus), a species reported to show extensive recombination suppression across an entire arm of the X chromosome. Combining a physical genome assembly based on shotgun and long-range proximity ligation sequencing with a dense genetic map, we detected widespread suppression of female recombination across ∼65% of the Phodopus X chromosome. This region of suppressed recombination likely corresponds to the Xp arm, which has previously been shown to be highly heterochromatic. Using additional sequencing data from two closely related species (P. campbelli and P. roborovskii), we show that recombination suppression on Xp appears to be independent of major structural rearrangements. The suppressed Xp arm was enriched for several transposable element families and de-enriched for genes primarily expressed in placenta, but otherwise showed similar gene densities, expression patterns, and rates of molecular evolution when compared to the recombinant Xq arm. Phodopus Xp gene content and order was also broadly conserved relative to the more distantly related rat X chromosome. These data suggest that widespread suppression of recombination has likely evolved through the transient induction of facultative heterochromatin on the Phodopus Xp arm without major changes in chromosome structure or genetic content. Thus, substantial changes in the recombination landscape have so far had relatively subtle influences on patterns of X-linked molecular evolution in these species.more » « less
-
Oleksyk, Taras (Ed.)Abstract The black-footed ferret (Mustela nigripes) narrowly avoided extinction to become an oft-cited example of the benefits of intensive management, research, and collaboration to save a species through ex situ conservation breeding and reintroduction into its former range. However, the species remains at risk due to possible inbreeding, disease susceptibility, and multiple fertility challenges. Here, we report the de novo genome assembly of a male black-footed ferret generated through a combination of linked-read sequencing, optical mapping, and Hi-C proximity ligation. In addition, we report the karyotype for this species, which was used to anchor and assign chromosome numbers to the chromosome-length scaffolds. The draft assembly was ~2.5 Gb in length, with 95.6% of it anchored to 19 chromosome-length scaffolds, corresponding to the 2n = 38 chromosomes revealed by the karyotype. The assembly has contig and scaffold N50 values of 148.8 kbp and 145.4 Mbp, respectively, and is up to 96% complete based on BUSCO analyses. Annotation of the assembly, including evidence from RNA-seq data, identified 21,406 protein-coding genes and a repeat content of 37.35%. Phylogenomic analyses indicated that the black-footed ferret diverged from the European polecat/domestic ferret lineage 1.6 million yr ago. This assembly will enable research on the conservation genomics of black-footed ferrets and thereby aid in the further restoration of this endangered species.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1098/rsbl.2021.0123
