Pollutants Increase Song Complexity and the Volume of the Brain Area HVC in a Songbird

Environmental pollutants which alter endocrine function are now known to decrease vertebrate reproductive success. There is considerable evidence for endocrine disruption from aquatic ecosystems, but knowledge is lacking with regard to the interface between terrestrial and aquatic ecosystems. Here, we show for the first time that birds foraging on invertebrates contaminated with environmental pollutants, show marked changes in both brain and behaviour. We found that male European starlings (Sturnus vulgaris) exposed to environmentally relevant levels of synthetic and natural estrogen mimics developed longer and more complex songs compared to control males, a sexually selected trait important in attracting females for reproduction. Moreover, females preferred the song of males which had higher pollutant exposure, despite the fact that experimentally dosed males showed reduced immune function. We also show that the key brain area controlling male song complexity (HVC) is significantly enlarged in the contaminated birds. This is the first evidence that environmental pollutants not only affect, but paradoxically enhance a signal of male quality such as song. Our data suggest that female starlings would bias their choice towards exposed males, with possible consequences at the population level. As the starling is a migratory species, our results suggest that transglobal effects of pollutants on terrestrial vertebrate physiology and reproduction could occur in birds

Coordinated Regulation of Niche and Stem Cell Precursors by Hormonal Signaling

In the developing Drosophila ovary, the ecdysone signaling pathway controls the differentiation of both niche and germ line stem cell precursors

Dimerization of Translationally Controlled Tumor Protein Is Essential For Its Cytokine-Like Activity

BACKGROUND:Translationally Controlled Tumor Protein (TCTP) found in nasal lavage fluids of allergic patients was named IgE-dependent histamine-releasing factor (HRF). Human recombinant HRF (HrHRF) has been recently reported to be much less effective than HRF produced from activated mononuclear cells (HRFmn). METHODS AND FINDINGS:We found that only NH(2)-terminal truncated, but not C-terminal truncated, TCTP shows cytokine releasing activity compared to full-length TCTP. Interestingly, only NH(2)-terminal truncated TCTP, unlike full-length TCTP, forms dimers through intermolecular disulfide bonds. We tested the activity of dimerized full-length TCTP generated by fusing it to rabbit Fc region. The untruncated-full length protein (Fc-HrTCTP) was more active than HrTCTP in BEAS-2B cells, suggesting that dimerization of TCTP, rather than truncation, is essential for the activation of TCTP in allergic responses. We used confocal microscopy to evaluate the affinity of TCTPs to its putative receptor. We detected stronger fluorescence in the plasma membrane of BEAS-2B cells incubated with Del-N11TCTP than those incubated with rat recombinant TCTP (RrTCTP). Allergenic activity of Del-N11TCTP prompted us to see whether the NH(2)-terminal truncated TCTP can induce allergic airway inflammation in vivo. While RrTCTP had no influence on airway inflammation, Del-N11TCTP increased goblet cell hyperplasia in both lung and rhinal cavity. The dimerized protein was found in sera from allergic patients, and bronchoalveolar lavage fluids from airway inflamed mice. CONCLUSIONS:Dimerization of TCTP seems to be essential for its cytokine-like activity. Our study has potential to enhance the understanding of pathogenesis of allergic disease and provide a target for allergic drug development

Sequencing of the Sea Lamprey (Petromyzon marinus) Genome Provides Insights into Vertebrate Evolution

Lampreys are representatives of an ancient vertebrate lineage that diverged from our own ∼500 million years ago. By virtue of this deeply shared ancestry, the sea lamprey (P. marinus) genome is uniquely poised to provide insight into the ancestry of vertebrate genomes and the underlying principles of vertebrate biology. Here, we present the first lamprey whole-genome sequence and assembly. We note challenges faced owing to its high content of repetitive elements and GC bases, as well as the absence of broad-scale sequence information from closely related species. Analyses of the assembly indicate that two whole-genome duplications likely occurred before the divergence of ancestral lamprey and gnathostome lineages. Moreover, the results help define key evolutionary events within vertebrate lineages, including the origin of myelin-associated proteins and the development of appendages. The lamprey genome provides an important resource for reconstructing vertebrate origins and the evolutionary events that have shaped the genomes of extant organisms

NOVEL TACHYKININS FROM THE BRAIN OF THE SEA LAMPREY, PETROMYZON-MARINUS, AND THE SKATE, RAJA-RHINA

Using radioimmunoassays for mammalian tachykinins, peptides with substance P-like immunoreactivity and neurokinin A-like immunoreactivity were identified in an extract of the brain of the longnose skate, Raja rhina (elasmobranch) but only a peptide with neurokinin A-like immunoreactivity was identified in the brain of the sea lamprey, Petromyzon marinus (agnathan). The primary structure of the skate peptide with substance P-like immunoreactivity (Ala-Lys-His-Asp-Lys-Phe-Tyr-Gly-Leu-Met-NH2) shows one amino acid substitution (Phe3 → His) compared with scyliorhinin I, previously isolated from dogfish brain and gut. The skate neurokinin A-related peptide (His-Lys-Leu-Gly-Ser-Phe-Val-Gly-Leu-Met-NH2) shows two substitutions (Thr3 → Leu and Asp4 → Gly) compared with mammalian neurokinin A. Although the COOH-terminus of the lamprey tachykinin (Arg-Lys-Pro-His-Pro-Lys-Glu-Phe-Val-Gly-Leu-Met-NH2) resembles neurokinin A, the presence of the strongly conserved Lys/Arg-Pro-Xaa-Pro motif at the NH2-terminus of the peptide indicates greater structural similarity with substance P. The additional arginine residue at position 1 in the peptide suggests that the lamprey is utilizing a site of posttranslational processing in the tachykinin precursor that is different from the equivalent site in mammalian and other lower vertebrate preprotachykinin(s).</p

Ancient origins of metazoan gonadotropin-releasing hormone and their receptors revealed by phylogenomic analyses

The discovery of genes related to gonadotropin-releasing hormones (GnRH) and their receptors from diverse species has driven important advances in comparative endocrinology. However, our view of the evolutionary histories and nomenclature of these gene families has become inconsistent as several different iterations of GnRH and receptor relationships have been proposed. Whole genome sequence data are now available for most of the major lineages of animals, and an exhaustive view of the phylogenies of GnRH and their receptors is now possible. In this paper, we leverage data from publically available whole genome sequences to present a new phylogenomic analysis of GnRH and GnRH receptors and the distant relatives of each across metazoan phylogeny. Our approach utilizes a phylogenomics pipeline that searches data from 36 whole genome sequences and conducts phylogenetic analyses of gene trees. We provide a comprehensive analysis of the major groupings of GnRH peptides, related hormones and their receptors and provide some suggestions for a new nomenclature. Our study provides a framework for understanding the functional diversification of this family of neuromodulatory peptides and their receptors