Speciation rates are correlated with changes in plumage color complexity in the largest family of songbirds

Although evolutionary theory predicts an association between the evolution of elaborate ornamentation and speciation, empirical evidence for links between speciation and ornament evolution has been mixed. In birds, the evolution of increasingly complex and colorful plumage may promote speciation by introducing prezygotic mating barriers. However, overall changes in color complexity, including both increases and decreases, may also promote speciation by altering the sexual signals that mediate reproductive choices. Here, we examine the relationship between complex plumage and speciation rates in the largest family of songbirds, the tanagers (Thraupidae). First, we test whether species with more complex plumage coloration are associated with higher speciation rates and find no correlation. We then test whether rates of male or female plumage color complexity evolution are correlated with speciation rates. We find that elevated rates of plumage complexity evolution are associated with higher speciation rates, regardless of sex and whether species are evolving more complex or less complex ornamentation. These results extend to whole-plumage color complexity and regions important in signaling (crown and throat) but not nonsignaling regions (back and wingtip). Our results suggest that the extent of change in plumage traits, rather than overall values of plumage complexity, may play a role in speciation.     

Unique differentiation of radial enamel in Arsinoitherium (Embrithopoda,Tethytheria)

The enamel microstructure in molars of Arsinoitherium is reinvestigated and a new modification of radial enamel (RE), ‘arsinoitheriid radial enamel (ARE)’, is defined. It is characterised by alternating stripes with different organisation of the interprismatic matrix but no prism decussation. Recognition of this new subtype leads to a reinterpretation of structure previously identified as modified radial enamel and of Hunter–Schreger bands in Arsinoitherium. The newly differentiated ARE of Arsinoitherium is more derived in relation to corresponding microstructures of Palaeoamasia and Crivadiatherium. A careful reinvestigation of RE in other Paenungulata will be required to provide additional data bearing on phylogenetic reconstruction. The enamel of Phenacolophus argues against inclusion of this genus in the Embrithopoda.     

CD36 homolog divergence is responsible for the selectivity of carotenoid species migration to the silk gland of the silkworm Bombyx mori

Dietary carotenoids are absorbed in the intestine and delivered to various tissues by circulating lipoproteins; however, the mechanism underlying selective delivery of different carotenoid species to individual tissues remains elusive. The products of the Yellow cocoon (C) gene and the Flesh (F) gene of the silkworm Bombyx mori determine the selectivity for transport of lutein and β-carotene, respectively, to the silk gland. We previously showed that the C gene encodes Cameo2, a CD36 family member, which is thought to function as a transmembrane lipoprotein receptor. Here, we elucidated the molecular identity of the F gene product by positional cloning, as SCRB15, a paralog of Cameo2 with 26% amino acid identity. In the F mutant, SCRB15 mRNA structure was severely disrupted, due to a 1.4 kb genomic insertion in a coding exon. Transgenic expression of SCRB15 in the middle silk gland using the binary GAL4-UAS expression system enhanced selective β-carotene uptake by the middle silk gland, while transgenic expression of Cameo2 enhanced selective lutein uptake under the same GAL4 driver. Our findings indicate that divergence of genes in the CD36 family determines the selectivity of carotenoid species uptake by silk gland tissue and that CD36-homologous proteins can discriminate among carotenoid species.     

Cytogenetic Studies on Workers of the Neotropical Ant Wasmannia auropunctata (Roger 1863) (Hymenoptera: Formicidae: Myrmicinae)

Wasmannia auropunctata is known as one of the worst invasive ants in the World. A cytogenetic study was conducted on two native populations from southeastern Bahia, Brazil. The analysis of the chromosomes observed in mitotic metaphases was made by a combination of methods: Giemsa conventional staining, chromomycin A3 (CMA3) and 4-6-diamidino-2-phenylindole (DAPI) fluorochrome staining, and acridine orange banding. The workers have all the karyotype 2n=32, with ten pairs of metacentric and six pairs of acrocentric chromosomes. One chromosome arm of the pair ten was positive for CMA3 and acridine orange, suggesting the occurrence of a nucleolar organizing region. This region is an interesting marker because is very conservative and seems to constitute an interesting specific taxonomic character. The pericentromeric region of many chromosomes was stained with DAPI, evidencing the occurrence of AT bases rich heterochromatin.     

Enhancement of Mutagenic Activity of 9-Aminoacridine by Introducing a Nitro Group into the Molecule

Mutagenic activity and DNA intercalation were examined for 9-aminoacridine (9-AA) and its derivatives. Introduction of a nitro group into the 9-AA molecule was found to enhance the activity enormously as was detected by the Ames test. Acetylation of amino group at 9-position of acridine ring inhibited the intercalation, the frameshift activity disappearing. Rat liver S9 converted 9-AA metabolically to 9-amino-2-hydroxyacridine.     

High‐throughput instant quantification of protein expression and purity based on photoactive yellow protein turn off/on label

Quantifying the concentration and purity of a target protein is essential for high‐throughput protein expression test and rapid screening of highly soluble proteins. However, conventional methods such as PAGE and dot blot assay generally involve multiple time‐consuming tasks requiring hours or do not allow instant quantification. Here, we demonstrate a new method based on the Photoactive yellow protein turn Off/On Label (POOL) system that can instantly quantify the concentration and purity of a target protein. The main idea of POOL is to use Photoactive Yellow Protein (PYP), or its miniaturized version, as a fusion partner of the target protein. The characteristic blue light absorption and the consequent yellow color of PYP is absent when initially expressed without its chromophore, but can be turned on by binding its chromophore, p‐coumaric acid. The appearance of yellow color upon adding a precursor of chromophore to the co‐expressed PYP can be used to check the expression amount of the target protein via visual inspection within a few seconds as well as to quantify its concentration and purity with the aid of a spectrometer within a few minutes. The concentrations measured by the POOL method, which usually takes a few minutes, show excellent agreement with those by the BCA Kit, which usually takes ～1 h. We demonstrate the applicability of POOL in E. coli, insect, and mammalian cells, and for high‐throughput protein expression screening.