| 1. |
- Jarvis, Erich D., et al.
(författare)
-
Phylogenomic analyses data of the avian phylogenomics project
- 2015
-
Ingår i: GigaScience. - : Oxford University Press (OUP). - 2047-217X. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Determining the evolutionary relationships among the major lineages of extant birds has been one of the biggest challenges in systematic biology. To address this challenge, we assembled or collected the genomes of 48 avian species spanning most orders of birds, including all Neognathae and two of the five Palaeognathae orders. We used these genomes to construct a genome-scale avian phylogenetic tree and perform comparative genomic analyses. Findings: Here we present the datasets associated with the phylogenomic analyses, which include sequence alignment files consisting of nucleotides, amino acids, indels, and transposable elements, as well as tree files containing gene trees and species trees. Inferring an accurate phylogeny required generating: 1) A well annotated data set across species based on genome synteny; 2) Alignments with unaligned or incorrectly overaligned sequences filtered out; and 3) Diverse data sets, including genes and their inferred trees, indels, and transposable elements. Our total evidence nucleotide tree (TENT) data set (consisting of exons, introns, and UCEs) gave what we consider our most reliable species tree when using the concatenation-based ExaML algorithm or when using statistical binning with the coalescence-based MP-EST algorithm (which we refer to as MP-EST*). Other data sets, such as the coding sequence of some exons, revealed other properties of genome evolution, namely convergence. Conclusions: The Avian Phylogenomics Project is the largest vertebrate phylogenomics project to date that we are aware of. The sequence, alignment, and tree data are expected to accelerate analyses in phylogenomics and other related areas.
|
|
| 2. |
- Nadachowska-Brzyska, Krystyna, et al.
(författare)
-
Temporal Dynamics of Avian Populations during Pleistocene Revealed by Whole-Genome Sequences
- 2015
-
Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 25:10, s. 1375-1380
-
Tidskriftsartikel (refereegranskat)abstract
- Global climate fluctuations have significantly influenced the distribution and abundance of biodiversity [1]. During unfavorable glacial periods, many species experienced range contraction and fragmentation, expanding again during interglacials [2- 4]. An understanding of the evolutionary consequences of both historical and ongoing climate changes requires knowledge of the temporal dynamics of population numbers during such climate cycles. Variation in abundance should have left clear signatures in the patterns of intraspecific genetic variation in extant species, from which historical effective population sizes (Ne) can be estimated [3]. We analyzed whole-genome sequences of 38 avian species in a pairwise sequentially Markovian coalescent (PSMC, [5]) framework to quantitatively reveal changes in Ne from approximately 10 million to 10 thousand years ago. Significant fluctuations in Ne over time were evident for most species. The most pronounced pattern observed in many species was a severe reduction in Ne coinciding with the beginning of the last glacial period (LGP). Among species, Ne varied by at least three orders of magnitude, exceeding 1 million in the most abundant species. Several species on the IUCN Red List of Threatened Species showed long-term reduction in population size, predating recent declines. We conclude that cycles of population expansions and contractions have been a common feature of many bird species during the Quaternary period, likely coinciding with climate cycles. Population size reduction should have increased the risk of extinction but may also have promoted speciation. Species that have experienced long-term declines may be especially vulnerable to recent anthropogenic threats.
|
|
| 3. |
- Ribeiro, Angela M., et al.
(författare)
-
31 degrees South : The physiology of adaptation to arid conditions in a passerine bird
- 2019
-
Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 28:16, s. 3709-3721
-
Tidskriftsartikel (refereegranskat)abstract
- Arid environments provide ideal ground for investigating the mechanisms of adaptive evolution. High temperatures and low water availability are relentless stressors for many endotherms, including birds; yet birds persist in deserts. While physiological adaptation probably involves metabolic phenotypes, the underlying mechanisms (plasticity, genetics) are largely uncharacterized. To explore this, we took an intraspecific approach that focused on a species that is resident over a mesic to arid gradient, the Karoo scrub-robin (Cercotrichas coryphaeus). Specifically, we integrated environmental (climatic and primary productivity), physiological (metabolic rates: a measure of energy expenditure), genotypic (genetic variation underlying the machinery of energy production) and microbiome (involved in processing food from where energy is retrieved) data, to infer the mechanism of physiological adaptation. We that found the variation in energetic physiology phenotypes and gut microbiome composition are associated with environmental features as well as with variation in genes underlying energy metabolic pathways. Specifically, we identified a small list of candidate adaptive genes, some of them with known ties to relevant physiology phenotypes. Together our results suggest that selective pressures on energetic physiology mediated by genes related to energy homeostasis and possibly microbiota composition may facilitate adaptation to local conditions and provide an explanation to the high avian intraspecific divergence observed in harsh environments.
|
|
| 4. |
- Xu, Luohao, et al.
(författare)
-
Dynamic evolutionary history and gene content of sex chromosomes across diverse songbirds
- 2019
-
Ingår i: Nature Ecology & Evolution. - : NATURE PUBLISHING GROUP. - 2397-334X. ; 3:5, s. 834-844
-
Tidskriftsartikel (refereegranskat)abstract
- Songbirds have a species number close to that of mammals and are classic models for studying speciation and sexual selection. Sex chromosomes are hotspots of both processes, yet their evolutionary history in songbirds remains unclear. We characterized genomes of 11 songbird species, with 5 genomes of bird-of-paradise species. We conclude that songbird sex chromosomes have undergone four periods of recombination suppression before species radiation, producing a gradient of pairwise sequence divergence termed ‘evolutionary strata’. The latest stratum was probably due to a songbird-specific burst of retrotransposon CR1-E1 elements at its boundary, instead of the chromosome inversion generally assumed for suppressing sex-linked recombination. The formation of evolutionary strata has reshaped the genomic architecture of both sex chromosomes. We find stepwise variations of Z-linked inversions, repeat and guanine-cytosine (GC) contents, as well as W-linked gene loss rate associated with the age of strata. A few W-linked genes have been preserved for their essential functions, indicated by higher and broader expression of lizard orthologues compared with those of other sex-linked genes. We also find a different degree of accelerated evolution of Z-linked genes versus autosomal genes among species, potentially reflecting diversified intensity of sexual selection. Our results uncover the dynamic evolutionary history of songbird sex chromosomes and provide insights into the mechanisms of recombination suppression.
|
|
