Isolation and characterization of novel microsatellite loci for parentage assessment in the lance‐tailed manakin (Chiroxiphia lanceolata)

The lance‐tailed manakin (Chiroxiphia lanceolata) is a lek‐breeding bird from Central America in which males court females with complex cooperative displays. To resolve detailed patterns of paternity in the wild, we isolated and characterized 12 novel microsatellite loci in this species. Eleven of these loci were polymorphic (five to 14 alleles), with observed heterozygosities ranging from 0.36 to 0.87 (N = 574 individuals). We tested for linkage disequilibrium using randomized subsamples of adults to control for known family structure among long‐lived and sedentary individuals. These loci will be valuable in resolving paternity among many candidate fathers in this species.     

Postdispersal nepotism in male long‐tailed macaques (Macaca fascicularis)

Cooperative behaviors are promoted by kin selection if the costs to the actor are smaller than the fitness benefits to the recipient, weighted by the coefficient of relatedness. In primates, cooperation occurs primarily among female dyads. Due to male dispersal before sexual maturity in many primate species, however, it is unknown whether there are sufficient opportunities for selective tolerance and occasional coalitionary support for kin selection to favor male nepotistic support. We studied the effect of the presence of male kin on correlates of male reproductive success (residence time, duration of high dominance rank) in non‐natal male long‐tailed macaques (Macaca fascicularis). We found that “related” (i.e., related at the half‐sibling level or higher) males in a group have a significantly higher probability to remain in the non‐natal group compared to males without relatives. Moreover, males stayed longer in a group when a relative was present at group entry or joined the same group within 3 months upon arrival. Males with co‐residing relatives also maintained a high rank for longer than those without. To our knowledge, this is the first demonstration of a potential nepotistic effect on residence and rank maintenance among non‐natal males in a social system without long‐term alliances.     

Long‐term mark‐and‐recapture study of a freshwater mussel reveals patterns of habitat use and an association between survival and river discharge

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Long‐chain base phosphates modulate pollen tube growth via channel‐mediated influx of calcium

Long‐chain base phosphates (LCBPs) have been correlated with amounts of crucial biological processes ranging from cell proliferation to apoptosis in animals. However, their functions in plants remain largely unknown. Here, we report that LCBPs, sphingosine‐1‐phosphate (S1P) and phytosphingosine‐1‐phosphate (Phyto‐S1P), modulate pollen tube growth in a concentration‐dependent bi‐phasic manner. The pollen tube growth in the stylar transmitting tissue was promoted by SPHK1 overexpression (SPHK1‐OE) but dampened by SPHK1 knockdown (SPHK1‐KD) compared with wild‐type of Arabidopsis; however, there was no detectable effect on in vitro pollen tube growth caused by misexpression of SPHK1. Interestingly, exogenous S1P or Phyto‐S1P applications could increase the pollen tube growth rate in SPHK1‐OE, SPHK1‐KD and wild‐type of Arabidopsis. Calcium ion (Ca²⁺)‐imaging analysis showed that S1P triggered a remarkable increase in cytosolic Ca²⁺ concentration in pollen. Extracellular S1P induced hyperpolarization‐activated Ca²⁺ currents in the pollen plasma membrane, and the Ca²⁺ current activation was mediated by heterotrimeric G proteins. Moreover, the S1P‐induced increase of cytosolic free Ca²⁺ inhibited the influx of potassium ions in pollen tubes. Our findings suggest that LCBPs functions in a signaling cascade that facilitates Ca²⁺ influx and modulates pollen tube growth.     

The Dynamic of Aggression: How Individual and Group Factors Affect the Long‐Term Interspecific Aggression Between Two Sympatric Species of Dolphin

Interspecific aggression, similar to intergroup conspecific aggression, has been observed in a variety of taxa. The dominant group or individual is determined by multiple aggressive events and can be influenced by the size, age, or group size of the participating individuals. Interspecific aggression between Atlantic bottlenose (Tursiops truncatus) and spotted (Stenella frontalis) dolphins, both resident and sympatric to Little Bahama Bank, the Bahamas has been consistently observed for over two decades. However, it is unclear whether one species is more dominant and little is known about the factors that influence the progression of aggression. For this study, underwater video recordings of 32 aggressive encounters composed of 451 aggressive behavioural events were analysed over a 12‐yr period (1993–2004). These were used to describe the interspecific aggression observed and quantify which factors (the species and age class of the participants or the group size and behaviour of spotted dolphin groups) had the strongest impact on the progression and outcome of aggression. Over the long term, interspecific aggression was bidirectional with neither species being more dominant. During a single encounter, spotted dolphin group synchrony had the strongest impact on the dynamic of aggression, specifically impacting which group (1) initiated aggression, (2) the direction of aggression and (3) the occurrence of dynamic shifts or dominance reversals. This is the first study to quantify the dynamic of aggression for this population, to document bidirectional aggression and dynamic shifts during long‐term interspecific aggression in free‐ranging delphinids, and this study quantifies the role of synchrony during interspecific aggression using underwater observations.     

HULC: an oncogenic long non‐coding RNA in human cancer

Highly up‐regulated in liver cancer (HULC) was originally identified as the most overexpressed long non‐coding RNA in hepatocellular carcinoma. Since its discovery, the aberrant up‐regulation of HULC has been demonstrated in other cancer types, including gastric cancer, pancreatic cancer, osteosarcoma and hepatic metastasis of colorectal cancer. Recent discoveries have also shed new light on the upstream molecular mechanisms underlying HULC deregulation. As an oncogene, HULC promotes tumorigenesis by regulating multiple pathways, such as down‐regulation of EEF1E1, promotion of abnormal lipid metabolism, and up‐regulation of sphingosine kinase 1. Pertinent to clinical practice, a genetic variant in the HULC gene has been found to alter the risk for hepatocellular carcinoma and oesophageal cancer, whereas cancer patients with high or low expression of HULC exhibit different clinical outcome. These findings highlighted the pathogenic role and clinical utility of HULC in human cancers. Further efforts are warranted to promote the development of HULC‐directed therapeutics.     

Long‐term balanced fertilization increases the soil microbial functional diversity in a phosphorus‐limited paddy soil

The influence of long‐term chemical fertilization on soil microbial communities has been one of the frontier topics of agricultural and environmental sciences and is critical for linking soil microbial flora with soil functions. In this study, 16S rRNA gene pyrosequencing and a functional gene array, geochip 4.0, were used to investigate the shifts in microbial composition and functional gene structure in paddy soils with different fertilization treatments over a 22‐year period. These included a control without fertilizers; chemical nitrogen fertilizer (N); N and phosphate (NP); N and potassium (NK); and N, P and K (NPK). Based on 16S rRNA gene data, both species evenness and key genera were affected by P fertilization. Functional gene array‐based analysis revealed that long‐term fertilization significantly changed the overall microbial functional structures. Chemical fertilization significantly increased the diversity and abundance of most genes involved in C, N, P and S cycling, especially for the treatments NK and NPK. Significant correlations were found among functional gene structure and abundance, related soil enzymatic activities and rice yield, suggesting that a fertilizer‐induced shift in the microbial community may accelerate the nutrient turnover in soil, which in turn influenced rice growth. The effect of N fertilization on soil microbial functional genes was mitigated by the addition of P fertilizer in this P‐limited paddy soil, suggesting that balanced chemical fertilization is beneficial to the soil microbial community and its functions.     

Age‐related sensitivity to endotoxin‐induced liver inflammation: Implication of inflammasome/IL‐1β for steatohepatitis

Aging is associated with increased vulnerability to inflammatory challenge. However, the effects of altered inflammatory response on the metabolic status of tissues or organs are not well documented. In this study, we present evidence demonstrating that lipopolysaccharide (LPS)-induced upregulation of the inflammasome/IL-1β pathway is accompanied with an increased inflammatory response and abnormal lipid accumulation in livers of aged rats. To monitor the effects of aging on LPS-induced inflammation, we administered LPS (2 mg kg⁻¹) to young (6-month old) and aged (24-month old) rats and found abnormal lipid metabolism in only aged rats with increased lipid accumulation in the liver. This lipid accumulation in the liver was due to the dysregulation of PPARα and SREBP1c. We also observed severe liver inflammation in aged rats as indicated by increased ALT levels in serum and increased Kupffer cells in the liver. Importantly, among many inflammation-associated factors, the aged rat liver showed chronically increased IL-1β production. Increased levels of IL-1β were caused by the upregulation of caspase-1 activity and inflammasome activation. In vitro studies with HepG2 cells demonstrated that treatment with IL-1β significantly induced lipid accumulation in hepatocytes through the regulation of PPARα and SREBP1c. In summary, we demonstrated that LPS-induced liver inflammation and lipid accumulation were associated with a chronically overactive inflammasome/IL-1β pathway in aged rat livers. Based on the present findings, we propose a mechanism of aging-associated progression of steatohepatitis induced by endotoxin, delineating a pathogenic role of the inflammasome/IL-1β pathway involved in lipid accumulation in the liver.     

A single‐nucleotide polymorphism of miR‐146a and psoriasis: an association and functional study

Epidermal growth factor receptor (EGFR), which is overexpressed in psoriatic lesions, has been proven to contribute to the hyperproliferation of keratinocytes in psoriasis. Single nucleotide polymorphisms (SNPs) involved in miRNAs that can regulate the expression of EGFR could potentially influence the development of psoriasis. The present study investigated the association between a functional SNP of rs2910164 in miR‐146a and the risk of psoriasis in the Chinese Han population. A total of 521 Han Chinese patients with psoriasis and 582 healthy controls were recruited in this study. The miR‐146a rs2910164 SNP was genotyped by polymerase chain reaction‐restriction fragment length polymorphism. Overall, a significantly increased risk of psoriasis was associated with the rs2910164 miR‐146a CG and GG genotypes (adjusted OR, 1.38; 95% CI, 1.06–1.80). Furthermore, the rs2910164G allele in miR‐146a attenuated its inhibitory regulation on the expression of EGFR as well as the proliferation of human keratinocytes, and lowered the level of miR‐146a in the psoriatic lesions. These findings indicate that the rs2910164G allele in miR‐146a weakens its suppression on the proliferation of keratinocytes probably through the decreased inhibition of the target gene, EGFR, which may account for the increased risk of psoriasis in this study population.     

PAPP‐A: a promising therapeutic target for healthy longevity

Pregnancy‐associated plasma protein‐A (PAPP‐A) is a proteolytic enzyme that was discovered to increase local insulin‐like growth factor (IGF) availability for receptor activation through cleavage of inhibitory IGF binding proteins (IGFBPs). Reduced IGF signaling has been associated with increased lifespan and healthspan. Therefore, inhibition of PAPP‐A represents a novel approach to indirectly decrease the availability of bioactive IGF. Here, we will review data in support of PAPP‐A as a therapeutic target to promote healthy longevity.     

A test of fundamental questions in mimicry theory using long‐term datasets

Since the phenomenon of mimicry was first described by Bates in 1862 it has become one of the foundational examples of adaptive evolution. Numerous subcategories of mimicry and dozens of hypotheses pertaining to its evolution and maintenance have been proposed. Many of these hypotheses, however, are difficult to test in experimental settings, and data from natural observations are often inadequate. Here we use data from a long‐term survey of butterfly presence and abundance to test several hypotheses pertaining to Batesian and female‐limited polymorphic mimicry (FPM; a special case of Batesian mimicry). We found strong evidence that models outnumber mimics in both mimicry systems, but no evidence for an increase in relative abundance of FPM mimics to their Batesian counterparts. Tests of the early‐emergence/model first hypothesis showed strong evidence that the Batesian mimic routinely emerges after the model, while emergence timing in the FPM system was site specific, suggesting that other ecological factors are at play. These results demonstrate the importance of long‐term field observations for testing evolutionary and ecological hypotheses.     

Long‐term evolution of the natural isolate of Escherichia coli 536 in the mouse gut colonized after maternal transmission reveals convergence in the constitutive expression of the lactose operon

In vitro experimental evolution has taught us many lessons on the molecular bases of adaptation. To move towards more natural settings, evolution in the mice gut has been successfully performed. Yet, these experiments suffered from the use of laboratory strains as well as the use of axenic or streptomycin‐treated mice to maintain the inoculated strains. To circumvent these limitations, we conducted a one‐year experimental evolution in vivo using a natural isolate of E. coli, strain 536, in conditions mimicking as much as possible natural environment with mother‐to‐offspring microbiota transmission. Mice were then distributed in 24 independent cages and separated into two different diets: a regular one (chow diet, CD) and high‐fat and high‐sugar one (Western Diet, WD). Genome sequences revealed an early and rapid selection during the breastfeeding period that selected the constitutive expression of the well‐characterized lactose operon. E. coli was lost significantly more in CD than WD; however, we could not detect any genomic signature of selection, nor any diet specificities during the later part of the experiments. The apparently neutral evolution presumably due to low population size maintained nevertheless at high frequency the early selected mutations affecting lactose regulation. The rapid loss of lactose operon regulation challenges the idea that plastic gene expression is both optimal and stable in the wild.     

The effectiveness of short‐term fox control in protecting a seasonally vulnerable species,the Eastern Long‐necked Turtle (Chelodina longicollis)

Reducing predation by introduced predators on seasonally vulnerable prey is of interest to biodiversity and game managers around the world. In Australia, the Red Fox (Vulpes vulpes) is a significant predator of freshwater turtle nests, destroying up to 93% of nests. We used a nonrandomized intervention study to assess the effectiveness of a short‐term (3‐week) but broad‐scale baiting operation in reducing the level of nest predation on artificial turtle nests around a complex lake system during a major flooding event in north‐western Victoria. Estimates of fox occupancy declined from 0.58 (0.44–0.70 95% CI) to 0.34 (0.21–0.46 95% CI) following fox control. Modelling of nest‐survival rates indicated there was no significant change in survival rates. Effective short‐term predator control to protect seasonally vulnerable prey is desirable and achievable. Knowledge of underlying predator density, predator–bait encounter and consumption rates, and the optimal duration of short‐term control is needed to reduce the risk to prey.     

Long‐distance dispersal and genetic structure of natural populations: an assessment of the inverse isolation hypothesis in peat mosses

It is well accepted that the shape of the dispersal kernel, especially its tail, has a substantial effect on the genetic structure of species. Theory predicts that dispersal by fat‐tailed kernels reshuffles genetic material, and thus, preserves genetic diversity during colonization. Moreover, if efficient long‐distance dispersal is coupled with random colonization, an inverse isolation effect is predicted to develop in which increasing genetic diversity per colonizer is expected with increasing distance from a genetically variable source. By contrast, increasing isolation leads to decreasing genetic diversity when dispersal is via thin‐tailed kernels. Here, we use a well‐established model group for dispersal biology (peat mosses: genus Sphagnum) with a fat‐tailed dispersal kernel, and the natural laboratory of the Stockholm archipelago to study the validity of the inverse isolation hypothesis in spore‐dispersed plants in island colonization. Population genetic structure of three species (Sphagnum fallax, Sphagnum fimbriatum and Sphagnum palustre) with contrasting life histories and ploidy levels were investigated on a set of islands using microsatellites. Our data show (, amova , IBD) that dispersal of the two most abundant species can be well approximated by a random colonization model. We find that genetic diversity per colonizer on islands increases with distance from the mainland for S. fallax and S. fimbriatum. By contrast, S. palustre deviates from this pattern, owing to its restricted distribution in the region, affecting its source pool strength. Therefore, the inverse isolation effect appears to hold in natural populations of peat mosses and, likely, in other organisms with small diaspores.