Evolution of salivary glue genes in Drosophila species - BMC Ecology and Evolution Background At the very end of the larval stage Drosophila expectorate a glue secreted by their salivary glands to attach themselves to a substrate while pupariating. The glue is a mixture of apparently unrelated proteins, some of which are highly glycosylated and possess internal repeats. Because species adhere to distinct substrates (i.e. leaves, wood, rotten fruits), glue genes are expected to evolve rapidly. Results We used available genome sequences and PCR-sequencing of regions of interest to investigate the glue genes in 20 Drosophila species. We discovered a new gene in addition to the seven glue genes annotated in D. melanogaster. We also identified a phase 1 intron at a conserved position present in five of the eight glue genes of D. melanogaster, suggesting a common origin for those glue genes. A slightly significant rate of gene turnover was inferred. Both the number of repeats and the repeat sequence were found to diverge rapidly, even between closely related species. We also detected high repeat number variation at the intrapopulation level in D. melanogaster. Conclusion Most conspicuous signs of accelerated evolution are found in the repeat regions of several glue genes.

Evolution of salivary glue genes in Drosophila species bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Taxon-specific expansion and loss of tektins inform metazoan ciliary diversity - BMC Ecology and Evolution Background Cilia and flagella are complex cellular structures thought to have first evolved in a last ciliated eukaryotic ancestor due to the conserved 9 + 2 microtubule doublet structure of the axoneme and associated proteins. The Tektin family of coiled-coil domain containing proteins was previously identified in cilia of organisms as diverse as green algae and sea urchin. While studies have shown that some Tektins are necessary for ciliary function, there has been no comprehensive phylogenetic survey of tektin genes. To fill this gap, we sampled tektin sequences broadly among metazoan and unicellular lineages in order to determine how the tektin gene complements evolved in over 100 different extant species. Results Using Bayesian and Maximum Likelihood analyses, we have ascertained with high confidence that all metazoan tektins arose from a single ancestral tektin gene in the last common ancestor of metazoans and choanoflagellates. Gene duplications gave rise to two tektin genes in the metazoan ancestor, and a subsequent expansion to three and four tektin genes in early bilaterian ancestors. While all four tektin genes remained highly conserved in most deuterostome and spiralian species surveyed, most tektin genes in ecdysozoans are highly derived with extensive gene loss in several lineages including nematodes and some crustaceans. In addition, while tektin-1, − 2, and − 4 have remained as single copy genes in most lineages, tektin-3/5 has been duplicated independently several times, notably at the base of the spiralian, vertebrate and hymenopteran (Ecdysozoa) clades. Conclusions We provide a solid description of tektin evolution supporting one, two, three, and four ancestral tektin genes in a holozoan, metazoan, bilaterian, and nephrozoan ancestor, respectively. The isolated presence of tektin in a cryptophyte and a chlorophyte branch invokes events of horizontal gene transfer, and that the last common ciliated eukaryotic ancestor lacked a tektin gene. Reconstructing the evolutionary history of the tektin complement in each extant metazoan species enabled us to pinpoint lineage specific expansions and losses. Our analysis will help to direct future studies on Tektin function, and how gain and loss of tektin genes might have contributed to the evolution of various types of cilia and flagella.

Taxon-specific expansion and loss of tektins inform metazoan ciliary diversity bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Phylotranscriptomics suggests the jawed vertebrate ancestor could generate diverse helper and regulatory T cell subsets bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Historical biogeography reveals new independent evolutionary lineages in the Pantosteus plebeius-nebuliferus species-group (Actinopterygii: Catostomidae) bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Adaptation and constraint in the evolution of the mammalian backbone bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Dealing with the adaptive immune system during de novo ev... Background The adaptive immune system of vertebrates has ...

Dealing with the adaptive immune system during de novo evolution of genes from intergenic sequences bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

The evolution of a series of behavioral traits is associa... Background An essential question in evolutionary biology ...

The evolution of a series of behavioral traits is associated with autism-risk genes in cavefish bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

The prevalence of terraced treescapes in analyses of phyl... Background The pattern of data availability in a phylogen...

The prevalence of terraced treescapes in analyses of phylogenetic data sets bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Phylogeography of human Y-chromosome haplogroup Q3-L275 f... Background The Y-chromosome haplogroup Q has three major ...

Phylogeography of human Y-chromosome haplogroup Q3-L275 from an academic/citizen science collaboration bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Analysis of a mechanistic Markov model for gene duplicate... Background Gene duplication has been identified as a key ...

Analysis of a mechanistic Markov model for gene duplicates evolving under subfunctionalization bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

PhyInformR: phylogenetic experimental design and phylogen... Background Analyses of phylogenetic informativeness repre...

PhyInformR: phylogenetic experimental design and phylogenomic data exploration in R bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Resolving Cypriniformes relationships using an anchored e... Background Cypriniformes (minnows, carps, loaches, and su...

Resolving Cypriniformes relationships using an anchored enrichment approach bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Phylogenomic analysis of carangimorph fishes reveals flat... Background Flatfish cranial asymmetry represents one of t...

Phylogenomic analysis of carangimorph fishes reveals flatfish asymmetry arose in a blink of the evo... bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

The biodiversity hotspot as evolutionary hot-bed: spectac... Background The disproportionate species richness of the w...

The biodiversity hotspot as evolutionary hot-bed: spectacular radiation of Erica in the Cape Floris... bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Synchrotron imaging of dentition provides insights into t... Background The dentitions of extinct organisms can provid...

Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis,... bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Evolution of the locomotory system in eels (Teleostei: El... Background Living anguilliform eels represent a distinct ...

Evolution of the locomotory system in eels (Teleostei: Elopomorpha) bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Weeds, as ancillary hosts, pose disproportionate risk for... Background The outcome of the arms race between hosts and...

Weeds, as ancillary hosts, pose disproportionate risk for virulent pathogen transfer to crops bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Evidence of positive selection associated with placental ... Background All vertebrates initially feed their offspring...

Evidence of positive selection associated with placental loss in tiger sharks bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Weeds, as ancillary hosts, pose disproportionate risk for... Background The outcome of the arms race between hosts and...

Weeds, as ancillary hosts, pose disproportionate risk for virulent pathogen transfer to crops bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol

Phylogenetic analyses suggest that diversification and bo... Background Skewed body size distributions and the high re...

Phylogenetic analyses suggest that diversification and body size evolution are independent in insects bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-... #bmcevolbiol