The role of evolutionary time, diversification rates and dispersal in determining the global diversity of a large radiation of passerine birds

Aim: Variation in species diversity among different geographic areas may result from differences in speciation and extinction rates, immigration and time for diversification. An area with high species diversity may be the result of a high net diversification rate, multiple immigration events from adjacent regions,anda long time available for the accumulation of species (know as the "time-for-speciation effect"). Here, we examine the relative importance of the three aforementionedprocesses in shaping the geographic diversity patterns of a large radiation of passerine birds. Location: Global Time period: Early Miocene to present Major taxa studied: Babblers (Aves: Passeriformes) Methods: Using a comprehensive phylogeny of extant species (~90% sampled) and distributions of the world's babblers, we reconstructed their biogeographic history and analysed the diversification dynamics. We examined how species richness correlates with the timing of regional colonization, the number of immigration events and the rate of speciation within all 13 geographic distribution regions. Results: We found thatbabblers likely originated in the Sino-Himalayan Mountains (SHM) in the early Miocene, suggesting a long time for diversification and species accumulation within the SHM. Regression analyses showed the regional diversity of babblers can be well explained by the timing of the first colonization within of these areas, while differences in rates of speciation or immigration have far weaker effects. Nonetheless, the rapid speciation of Zosteropsduring the Pleistocene has accounted for the increased diversification and accumulation of species in the oceanic islands. Main conclusions: Our results suggest that the global diversity patterns of babblers have predominantly been shaped by the time-for-speciation effect. Our findings also support an origin centred in tropical and subtropical parts of the SHM, with a cradle of recent diversification in the oceanic islands of the Indo-Pacific region, which provides new insights into the generation of global biodiversity hotspots.A near-complete phylogeny of babblers has been reconstructed in BEAST 1.8.4 based on 12 gene loci

Morphological diversity and altitudinal differentiation of Aethopyga species

Abstract The morphological characteristics of birds are an important tool for studying their adaptation and evolution. The morphological evolution of a clade is not only constrained by the phylogenetic relationship, but also influenced by ecological factors and interspecific competition. Aethopyga is a group of small nectar‐eating birds with obvious sexual dimorphism. They have slender and decurved beaks, which reflect their unique diet and foraging mode. Traditional and geometric morphometrics were combined to characterize the body morphology and beak shape of six species of Aethopyga distributed in China. We aim to assess the roles of phylogeny, altitude, and species interactions to morphological evolution. The main distinguishing characteristic among these six species were overall body size, the ratio of body weight, culmen and tarsal length to body length, tail length and wing length, and beak shape (slender/straight vs. thick/decurved). Although these dimensions cannot distinguish all species, they can show a clear distribution trend, and there is a significant Mahalanobis distance between each pair of species. There were no significant phylogenetic signals in morphological traits. The results of PGLS analysis show that altitude is significantly correlated with log‐transformed tarsus length and beak‐shaped PC1 (slender/straight vs thick/decurved dimensions) across the six species analyzed. Mantel test shows that the distance matrix of beak morphological characteristics showed a significant correlation with the altitudinal distance matrix. The results indicated no significant phylogenetic signal in the morphological characteristics of six species. In terms of beak shape, species with greater overlap in elevation distribution have more similar morphological characteristics, that is, less morphological differentiation

Complete mitochondrial genome of fire-tailed myzornis (Myzornis pyrrhoura) and white-browed fulvetta (Fulvetta vinipectus)

In this study, the complete mitochondrial genomes of Myzornis pyrrhoura and Fulvetta vinipectus were sequenced and described for the first time. The whole mitochondrial genomes of M. pyrrhoura and F. vinipectus are 17,397 bp and 16,961 bp in length, with the G + C percentage 46.34% and 47.36%, respectively. Both genomes contain 13 protein-coding genes, 22 transfer RNA genes, 2 ribosome RNA genes, and 1 non-coding control region. The arrangement of genes is identical to mitochondrial genomes of Sylviidae species reported previously. A phylogenetic reconstruction supported that M. pyrrhoura and F. vinipectus are members of family Sylviidae. The mitochondrial genomes of these two species reported here would be helpful in better understanding the phylogeny and evolution of Sylviidae

Quantifying adaptive divergence of the snowfinches in a common landscape

AimSpecies living in a shared environment face similar selective pressures and often evolve adaptive divergence to avoid competition. Quantifying phenotypic divergence and its genetic parallelism among sympatric species is important for understanding of ecologically moderated biodiversity. Here, we integrate ecologic, phenotypic and genomic datasets to study to what extent three sympatrically snowfinches (Montifringilla adamsi, Pyrgilauda ruficollis and Onychostruthus taczanowskii) differ in their adaptations in order to co-exist in a shared environment.LocationQinghai–Tibetan Plateau.MethodsWe used principal component analysis to summarize and compare environmental and phenotypic divergence. We compared phenotypes relevant to body and beak sizes (n = 68) because they are indicators of niche and food segregation, thus critical for establishing co-existence of sympatric birds. We used comparative genomics (n = 33) to identify genetic loci that are highly divergent between species as well as loci unique for each of species. Using vector analyses, we integrated correlation and permutation to quantify parallelism between phenotypic and genetic divergences.ResultsWe found that body and beak sizes are significantly different among three snowfinches. The phenotypic differentiations are greater in species that share similar ecological conditions than in those that do not. We showed that genes related to developmental process are over-represented within highly divergent genomic regions and unique genetic loci of each species. We found that the extent of phenotypic divergence between snowfinch pairs is more strongly correlated with the magnitude of divergence in developmental genes than in the whole genome.Main conclusionsAdaptive divergence of sympatric snowfinches is highly constrained on developmental genes. As this genetic divergence is strongly correlated with divergence of the traits related to segregation in niche and food resources, this correlation reflects either causal effects or indirect consequences of ecological mediated changes. Our study provides novel insights into the mechanisms underlying evolutionary versatility and ecological success among sympatric species

Additional file 4: of Evolution of body morphology and beak shape revealed by a morphometric analysis of 14 Paridae species

Phylogeny of the 14 Paridae species analysed in this study. (TRE 525 bytes

Additional file 1: of Evolution of body morphology and beak shape revealed by a morphometric analysis of 14 Paridae species

Supplementary materials. Included are 10 supplementary tables (Table S1-S10) and 2 supplementary figures (Figures S1-S2). (PDF 2118 kb

Post-transcriptional modification of m6A methylase METTL3 regulates ERK-induced androgen-deprived treatment resistance prostate cancer

Abstract As the most common modification of RNA, N6-methyladenosin (m6A) has been confirmed to be involved in the occurrence and development of various cancers. However, the relationship between m6A and castration resistance prostate cancer (CRPC), has not been fully studied. By m6A-sequencing of patient cancer tissues, we identified that the overall level of m6A in CRPC was up-regulated than castration sensitive prostate cancer (CSPC). Based on the analysis of m6A-sequencing data, we found m6A modification level of HRas proto-oncogene, GTPase (HRAS) and mitogen-activated protein kinase kinase 2 (MEK2 or MAP2K2) were enhanced in CRPC. Specifically, tissue microarray analysis and molecular biology experiments confirmed that METTL3, an m6A “writer” up-regulated after castration, activated the ERK pathway to contribute to malignant phenotype including ADT resistance, cell proliferation and invasion. We revealed that METTL3-mediated ERK phosphorylation by stabilizing the transcription of HRAS and positively regulating the translation of MEK2. In the Enzalutamide-resistant (Enz-R) C4-2 and LNCap cell line (C4-2R, LNCapR) established in the current study, the ERK pathway was confirmed to be regulated by METTL3. We also found that applying antisense oligonucleotides (ASOs) to target the METTL3/ERK axis can restore Enzalutamide resistance in vitro and in vivo. In conclusion, METTL3 activated the ERK pathway and induced the resistance to Enzalutamide by regulating the m6A level of critical gene transcription in the ERK pathway