Molecular Phylogeny Supports the Validity of Polypedates impresus Yang 2008

The taxonomy of the Asian tree frogs of the Polypedates leucomystax complex, a group of widespread and morphologically similar species, is very controversial. To ascertain the taxonomic status of these species, we investi- gated the historical relationships among representative samples based on - 2 kb of nucleotide sequences from the mito- chondrial 12S rRNA, tRNAvalinc, and 16S rRNA genes. Our phylogeny resolved five well supported lineages （A, B, C, D and E） in the P leucomystax complex. Polypedates impresus from Yunnan, China, Polypedates cf. mutus and Polypedates cf. megacephalus from Guangxi and Yunnan, China, and Laos constructed Clade C, which is monophyletic. In order to recognize the unique position of this clade, we considered P impresus in Clade C as a valid species. Following our phy- logeny, Chinese Polypedates, corresponding to the other four clades, should include four species： P. mutus （Clade A）; P. braueri （Clade B）; P impresus （Clade C） and P. megacephalus （Clade D）. P Ieucomystax （Clade E） is mainly distributed in the Malaysia, Indonesia and Philippines.

Remarkable mechanochromism and force-induced thermally activated delayed fluorescence enhancement from white-light-emitting organic luminogens with aggregation-induced emission

The development of organic materials with white-light emission and thermally activated delayed fluorescence(TADF)properties in the solid state remain a challenge.Herein,a series of white-light-emitting organic luminogens have been developed and are found to show aggregation-induced delayed fluorescence(AIDF)characteristics.The AIDF emitters present dual-emission consisted of prompt fluorescence and TADF in the crystalline state.Their white-light emissions can be easily tuned by altering the chemical structure and connecting position of the heterocyclic aromatic substituent.Under the stimuli of mechanical force and solvent vapor,the compounds exhibit remarkable and reversible mechanochromism,in which their emission colors are switchable between white and yellow.Upon grinding,they also display linearly tunable luminescence colors,as well as force-induced TADF enhancement,which may be associated with the more compact molecular packing and the restriction of intramolecular motions.The results from time-resolved emission scanning and theoretical calculation suggest that the dual-emission of the AIDF luminogens likely results from the twisted intramolecular charge transfer transitions of the molecules,and the reversible mechanochromism properties probably stem from the interconversion of the quasi-axial and the quasi-equatorial conformations.

Isolation of microsatellite loci and reliable genotyping using noninvasive samples of a critically endangered primate, Trachypithecus leucocephalus

Genetic information can be critical in identifying conservation priorities and developing conservation strategies.There is an urgent need for noninvasive genetic tools to study the wild populations of Asian colobine monkeys.The majority of these species are threatened with habitat destruction,population reduction and even extinction,but generally lack information on their genetic diversity and population structure.Genetic sampling and tissue collection have been scarce in these species owing to strict regulations on manipulation of endangered species,and the difficulties and risks associated with capturing these arboreal and fast-moving monkeys in the challeng­ing environments that they inhabit.These difficulties have hindered the development of molecular genetic mark­ers,which are usually derived from tissues or blood.In this study,we present a method for de novo microsatel­lite isolation and genotyping using DNA from noninvasive origins of a critically endangered Asian colobine,the white-headed langur(Trachypithecus leucocephalus).Genomic DNA isolated from hair was shown to be suf­ficient for microsatellite enrichment and isolation,with similar isolation efficiencies as from tissue DNA.We identified and characterized 20 polymorphic microsatellite loci,and evaluated their amplification success and genotyping reliability with 86 field-collected fecal samples.These results show that this panel of loci can pro­duce reliable genotypes from fecal samples,and represent a useful tool for noninvasive investigation of genetic structure,individual identification and kinship assessment in this highly endangered species.Our approach can be applied to conservation genetic studies of other wild species that lack sequence information and tissue sam­ples.