Uropygial gland volatiles may code for olfactory information about sex,individual,and species in Bengalese finches Lonchura striata

Over-shadowed by eye-catching vocal and visual signals,chemical communication has long been overlooked in birds.This study aimed at exploring whether volatile composition of the uropygial gland secretion(UGS)of birds was associated with the information about sex,individual and species.By using dichloromethane extraction and gas chromatography-mass spectrometry(GC-MS),we analyzed the UGS volatiles of domesticated Bengalese finches(Lonchura striata,Estrildiea)which is also known as white-rumped munias.We characterized 16 volatile molecules from the UGS,including eight n-alkanols,five diesters,an ester,an aldehyde and a fatty acid,and quantified them in terms of GC peak area percentages(relative abundances).Among these compounds,hexadecanol and octadecanol were major components in both sexes.The former was richer in males than in females and the latter richer in females than in males,suggesting that they might be male and female pheromone candidates,respectively.The high inter-individual variations,in relative abundance,of the UGS volatiles implied that these compounds might carry information about individuality.The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues.Additionally,by comparing with three sympatric passerine species,i.e.,zebra finches Taeniopygia guttata,yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus,we found that the composition of C_ 13-C_ 18 alkanols in the UGS might code for information about species.Our study also showed that quantitative differences(degree)of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species.

Flank gland-secreted putative chemosignals pertaining to photoperiod,endocrine states,and sociosexual behavior in golden hamsters

Behavioral studies have shown that flank glands are involved in chemical communication in golden hamstersMesocricetus auratus but little chemical analysis has been conducted on volatiles arising from these glands. Using gas chromatography-mass spectrometry, we detected compounds from the flank glands of males, only eight of which were also produced infemales. Based on these chemical data we performed a number of further experiments. By manipulating light we found that malesexposed to short-photoperiods developed smaller flank glands than those exposed to long-photoperiods. Six flank gland volatilesreduced in relative abundance, which possibly coded for reproductive status of males of this seasonally breeding hamster species.Through dyadic encounters, we were able to induce the formation of dominant-subordinate relationships and show that two glandularcompounds became high in relative abundance and may function as dominance pheromones. Castration eliminated allmale-specific compounds resulting from flank glands, but bilateral ovariectomies only affected one compound in females. Oncethese ovariectomized females were treated with testosterone, their glandular compounds resembled those of males, suggestingthese compounds are under the main control of androgen. Two female putative pheromones, tetradecanoic acid and hexadecanoicacid, were used in binary choice tests and were both found to attract males over females. Applying a solution of these pheromonecompounds to adult males also suppressed their agonistic

Kinship alters the effects of forced cohabitation on body weight,mate choice and fitness in the rat-like hamster Tscheskia triton

It has been documented that social isolation imparts deleterious effects on gregarious rodents species,but caging in group imparts such effects on solitary rodents. This study was attempted at examining how kinship to affect body weight,behavioral interaction,mate choice and fitness when we caged male and female rat-like hamsters Tscheskia triton in pair,a solitary species. We found that females paired with nonsibling males became heavier than the females paired with sibling males,but both agonistic and amicable behavior between paired males and females did not differ between sibling and nonsibling groups. This indicated that kinship might reduce females' obesity in response to forced cohabitation,and dissociation might exist between physiological and behavioral responses. Furthermore,binary choice tests revealed that social familiarity between either siblings or nonsiblings decreased their investigating time spent in opposite sex conspecific of cage mates and/or their scents as compared with those of non-mates,suggesting effects of social association on mate and kin selection of the hamsters. On the other side,both females and males caged in pair with siblings show a preference between unfamiliar siblings or their scents and the counterparts of nonsiblings after two month separation,indicating that the kin recognition of the hamsters might also rely on phenotype matching. In addition,cohabitation (or permanent presence of fathers) elicited a lower survival of pups in nonsibling pairs than sibling pairs,but did not affect litter size,suggesting that kinship affects fitness when housing male and female ratlike hamsters together. Therefore,inbreeding might be adapted for rare and endangered

Inheritance of social dominance is associated with global sperm DNA methylation in inbred male mice

Dominance relationships between males and their associated traits are usually heritable and have implications for sexual selection in animals.In particular,social dominance and its related male pheromones are heritable in inbred mice;thus,we wondered whether epigenetic changes due to altered levels of DNA methylation determine inheritance.Here,we used C57BL/6 male mice to establish a social dominance-subordination relationship through chronic dyadic encounters,and this relationship and pheromone covariation occurred in their offspring,indicative of heritability.Through transcriptome sequencing and whole-genome DNA methylation profiling of the sperm of both generations,we found that differential methylation of many genes was induced by social dominance-subordination in sires and could be passed on to the offspring.These methylated genes were mainly related to growth and development processes,neurodevelopment,and cellular transportation.The expression of the genes with similar functions in whole-genome methylation/bisulfite sequencing was also differentiated by social dominance-subordination,as revealed by RNA-seq.In particular,the gene Dennd1a,which regulates neural signaling,was differentially methylated and expressed in the sperm and medial prefrontal cortex in paired males before and after dominance-subordination establishment,suggesting the potential epigenetic control and inheritance of social dominance-related aggression.We suggest that social dominance might be passed on to male offspring through sperm DNA methylation and that the differences could potentially affect male competition in offspring by affecting the development of thenervous system.

染料杂化蛋白纳米粒用于肿瘤细胞光热治疗

为了解决花菁类(Cypate)近红外染料作为光热试剂的一些固有缺点,例如疏水性、毒性、不稳定性等,以牛血清白蛋白和Cypate染料作为原料,在水热条件下制备出尺寸较小的稳定杂化纳米粒.纳米结构显著改善了Cypate染料的水溶性,也提升了染料在水相溶液中的稳定性.与小分子染料相比,染料杂化蛋白纳米粒具有良好的生物相容性和光稳定性.此外,蛋白纳米粒具有优于小分子染料的光热转换能力,并展现了良好的光热细胞杀伤能力.

Genetic boundary and gene flow between 2 parapatric subspecies of brown rats

Two parapatric Rattus norvegicus subspecies,R.n.humiliatus(RNH)and R.n.caraco(RNC),are classified accordi ng to morphological diverge nee and are mainly distributed in North and Northeast China.Here,we aimed to explore the population genetic structure,genetic boundary,and gene flow in these rats using 16 microsatellite loci.Structure analysis and principal component an alysis revealed 3 ancestral clusters.We found that the in termediate cluster exhibited higher genetic diversity and a lower in breeding coefficie nt tha n the other 2 clusters.The genetic differentiation between the 3 clusters was significant but weak,with a higher FST value being observed betwee n the clusters on both sides.The subspecies bou ndary inf erred from microsatellite markers may indicate the existence of an admixture or hybridization area covering Liaoning,Inner Mongolia,and Jilin Provinces,rather than corresponding to the administrative provincial boundaries between Liaoning and Jilin.The RNH and RNC subspecies presented moderate gene exchange and an asymmetric bidirectional gene flow pattern,with higher gene flow from the RNH subspecies to the RNC subspecies,constraining speciation.Such genetic characteristics might be explained by biological processes such as dispersal ability,mate choice,and dynamic lineage boundaries.

Inactivation of the bed nucleus of the stria terminalis suppresses the innate fear responses of rats induced by the odor of cat urine

In this study,we investigated whether two brain regions,the bed nucleus of the stria terminalis(BNST)and the basolateral amygdala(BLA),affected male rats(Rattus norvigicus)ability to innately discriminate between a predator odor(cat urine)and female rat urine.Muscimol,a GABAa receptor agonist,was bilaterally microinjected into either the BNST or BLA of rats through

Male pheromones and their reception by females are co-adapted to affect mating success in two subspecies of brown rats

Pheromonal communication plays a key role in the sociosexual behavior of rodents.The coadaptation between pheromones and chemosensory systems has been well illustrated in insects but poorly investigated in rodents and other mammals.We aimed to investigate whether coadaptation between male pheromones and female reception might have occurred in brown rats Rattus norve-gicus.We recently reported that major urinary protein(MUP)pheromones are associated with male mating success in a brown rat subspecies,R.n.humiliatus(Rnh).Here,we discovered that MUPs were less polymorphic and occurred at much lower concentrations in males of a parapatric subspecies,R.n.caraco(Rnc),than in Rnh males,and found no association between pheromones and paternity success.Moreover,the observation of Rnc males that experienced chronic dyadic encounters and established dominance-submission relationships revealed that the dominant males achieved greater mating success than the subordinate males,but their MUP levels did not differ by social status.These findings suggest that male mating success in Rnc rats is related to social rank rather than to pheromone levels and that low concentration of MUPs might not be a reliable signal for mate choice in Rnc rats,which is different from the findings obtained in Rnh rats.In addition,compared with Rnh females,Rnc females exhibited reduced expression of pheromone receptor genes,and a lower number of vomeronasal receptor neurons were activated by MUP pheromones,which imply that the female chemosensory reception of pheromones might be structurally and functionally coadapted with male pheromone signals in brown rats.