Reproductive mode evolution in lizards revisited: updated analyses examining geographic,climatic and phylogenetic effects support the cold‐climate hypothesis

Viviparity, the bearing of live young, has evolved well over 100 times among squamate reptiles. This reproductive strategy is hypothesized to allow maternal control of the foetus' thermal environment and thereby to increase the fitness of the parents and offspring. Two hypotheses have been posited to explain this phenomenon: (i) the cold‐climate hypothesis (CCH), which advocates low temperatures as the primary selective force; and (ii) the maternal manipulation hypothesis (MMH), which advocates temperature variability as the primary selective force. Here, we investigate whether climatic and geographic variables associated with the CCH vs. the MMH best explain the current geographical distributions of viviparity in lizards while incorporating recent advances in comparative methods, squamate phylogenetics and geospatial analysis. To do this, we compared nonphylogenetic and phylogenetic models predicting viviparity based on point‐of‐capture data from 20 994 museum specimens representing 215 lizard species in conjunction with spatially explicit bioclimatic and geographic (elevation and latitude) data layers. The database we analysed emphasized Nearctic lizards from three species‐rich genera (Phrynosoma, Plestiodon and Sceloporus); however, we additionally analysed a less substantial, but worldwide sample of species to verify the universality of our Nearctic results. We found that maximum temperature of the warmest month (and, less commonly, elevation and maximum temperature of the driest quarter) was frequently the best predictor of viviparity and showed an association consistent with the CCH. Our results strongly favour the CCH over the MMH in explaining lizard reproductive mode evolution.     

‘Last In–First Out’: seasonal variations of non‐structural carbohydrates,glucose‐6‐phosphate and ATP in tubers of two Arum species

• Knowledge on the metabolism of polysaccharide reserves in wild species is still scarce. In natural sites we collected tubers of Arum italicum Mill. and A. maculatum L. – two geophytes with different apparent phenological timing, ecology and chorology – during five stages of the annual cycle in order to understand patterns of reserve accumulation and degradation.
• Both the entire tuber and its proximal and distal to shoot portion were utilised. Pools of non‐structural carbohydrates (glucose, sucrose and starch), glucose‐6‐phosphate and ATP were analysed as important markers of carbohydrate metabolism.
• In both species, starch and glucose content of the whole tuber significantly increased from sprouting to the maturation/senescence stages, whereas sucrose showed an opposite trend; ATP and glucose‐6‐phosphate were almost stable and dropped only at the end of the annual cycle. Considering the two different portions of the tuber, both ATP and glucose‐6‐phosphate concentrations were higher in proximity to the shoot in all seasonal stages, except the flowering stage.
• Our findings suggest that seasonal carbon partitioning in the underground organ is driven by phenology and occurs independently of seasonal climate conditions. Moreover, our results show that starch degradation, sustained by elevated ATP and glucose‐6‐phosphate pools, starts in the peripheral, proximal‐to‐shoot portion of the tuber, consuming starch accumulated in the previous season, as a ‘Last In–First Out’ mechanism of carbohydrate storage.

     

Tumour cell‐intrinsic CTLA4 regulates PD‐L1 expression in non‐small cell lung cancer

Cytotoxic T lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD‐1) are immune checkpoint proteins expressed in T cells. Although CTLA4 expression was found in multiple tumours including non‐small cell lung cancer (NSCLC) tissues and cells, its function in tumour cells is unknown. Recently, PD‐1 was found to be expressed in melanoma cells and to promote tumorigenesis. We found that CTLA4 was expressed in a subset of NSCLC cell lines and in a subgroup of cancer cells within the lung cancer tissues. We further found that in NSCLC cells, anti‐CTLA4 antibody can induce PD‐L1 expression, which is mediated by CTLA4 and the EGFR pathway involving phosphorylation of MEK and ERK. In CTLA4 knockout cells, EGFR knockout cells or in the presence of an EGFR tyrosine kinase inhibitor, anti‐CTLA4 antibody was not able to induce PD‐L1 expression in NSCLC cells. Moreover, anti‐CTLA4 antibody promoted NSCLC cell proliferation in vitro and tumour growth in vivo in the absence of adaptive immunity. These results suggest that tumour cell‐intrinsic CTLA4 can regulate PD‐L1 expression and cell proliferation, and that anti‐CTLA4 antibody, by binding to the tumour cell‐intrinsic CTLA4, may result in the activation of the EGFR pathway in cancer cells.     

Cannibalism of parasitoid‐attacked conspecifics in a non‐carnivorous caterpillar

Cannibalism, the killing and consumption of conspecifics, can even occur in insect species typically considered to be non‐carnivorous. Of particular interest is the cannibalism of parasitoid‐attacked conspecifics, which could reduce parasitism levels in subsequent generations for that conspecific population. This study reports on the occurrence and some of the consequences of cannibalism in parasitoid‐attacked obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). We show that larvae of C. rosaceana, which is considered to be an herbivorous caterpillar species, did not prey upon live conspecifics, but readily consumed conspecifics attacked by Habrobracon gelechiae Ashmead (Hymenoptera: Braconidae). Further examination found that C. rosaceana larvae feeding on parasitoid‐attacked conspecifics, since their fourth instar, suffered a higher mortality and reduction in body size than those fed on plant material only. The cannibalism of attacked conspecifics did not appear to offer any nutrient benefits for the cannibal. To our best knowledge, this is the first empirical example of the occurrence and some of the consequences of cannibalism by a non‐carnivorous insect on its parasitoid‐attacked conspecifics. We discuss the adaptive significance of such cannibalism on parasitoid‐attacked conspecifics with respect to a trans‐generational fitness gain for the population through the killing of the parasitoids, thereby reducing parasitism in subsequent generations.     

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.     

Fine‐scale genetic structuring in a group‐living lizard,the gidgee skink (Egernia stokesii)

By constraining gene flow, group living and natal philopatry can result in fine‐scale genetic structure. Although the genetic structure of some group‐living lizards has been characterised, studies are few compared with those for group‐living bird and mammal species. The Egerniinae group of lizards exhibits a high diversity of social structures, making it a useful group for comparative studies of genetic structure across a broader range of social taxa. A well‐studied member of Egerniinae is Egernia stokesii, a lizard that forms long‐term pair bonds and stable social groups and exhibits natal philopatry and limited dispersal. Evidence exists for consistent E. stokesii social structure across seven close but disconnected rocky outcrops within a 40 × 10 km area. We used summary statistics, analysis of molecular variance, Bayesian clustering, and discriminant analysis of principal components to assess if E. stokesii exhibit a consistent pattern of fine‐scale genetic structure across the same seven outcrops. Due to E. stokesii social structure and constrained dispersal, we predicted significant genetic structuring – based on microsatellite markers – among outcrops. We found significant fine‐scale genetic structuring and evidence for two genetic clusters. We discuss features of E. stokesii biology and ecology that may explain our findings. Some rocky outcrops, and some social groups, contained lizards from both genetic clusters. An examination of the composition of mixed cluster social groups did not detect any notable patterns. Therefore, further work is necessary to identify how the observed patterns may have arisen. Future investigations in E. stokesii and other group‐living lizard species are likely to contribute greatly to our understanding of the genetic consequences of group living.     

Long non‐coding PANDAR as a novel biomarker in human cancer: A systematic review

Objectives

Long non‐coding RNAs (lncRNAs) are characterized as a group of RNAs that more than 200 nucleotides in length and have no protein‐coding function. More and more evidences provided that lncRNAs serve as key molecules in the development of cancer. Deregulation of lncRNAs functions as either oncogenes or tumour suppressor genes in various diseases. Recently, increasing studies about PANDAR in cancer progression were reported. In our review, we will focus on the current research on the character of PANDAR include the clinical management, tumour progression and molecular mechanisms in human cancers.

Materials and methods

We summarize and analyze current studies concerning the biological functions and mechanisms of lncRNA PANDA in tumour development. The related studies were obtained through a systematic search of Pubmed.

Results

PANDAR was a well‐characterized oncogenic lncRNA and widely overexpressed in many tumours. PANDAR is upregulated in many types of cancer, including colorectal cancer, lung cancer, renal cell carcinoma, cholangiocarcinoma, osteosarcoma, thyroid cancer and other cancers. Upregulation of PANDAR was significantly associated with advanced tumour weights, TNM stage and overall survival. Furthermore, repressed of PANDAR would restrain proliferation, migration and invasion.

Conclusion

PANDAR may act as a powerful tumour biomarker for cancer diagnosis and treatment.     

Unique haplotypes in ant‐attended aphids and widespread haplotypes in non‐attended aphids

Aphid species within the genus Tuberculatus Mordvilko (Hemiptera: Aphididae) exhibit a variety of interactions with ants, ranging from close associations to non‐attendance. A previous study indicated that despite wing possession, ant‐attended Tuberculatus species exhibited low dispersal rates compared with non‐attended species. This study examined if presence or absence of mutualistic interactions and habitat continuity of host plants affected intraspecific genetic diversity and genetic differentiation in mitochondrial DNA cytochrome oxidase I (COI) sequences. Sympatric ant‐attended Tuberculatus quercicola (Matsumura) (Hemiptera: Aphididae) and non‐attended Tuberculatus paiki Hille Ris Lambers (Hemiptera: Aphididae) were collected from the daimyo oak Quercus dentata Thunberg (Fagales: Fagaceae) in Japan and examined for haplotype variability. Seventeen haplotypes were identified in 568 T. quercicola individuals representing 23 populations and seven haplotypes in 425 T. paiki representing 19 populations. Haplotype diversity, which indicates the mean number of differences between all pairs of haplotypes in the sample, and nucleotide diversity were higher in T. quercicola than T. paiki. Analysis of molecular variance (AMOVA) showed higher genetic differentiation among populations within groups of T. quercicola (39.8%) than T. paiki (22.6%). The effects of attendant ant species on genetic differentiation in T. quercicola were not distinguishable from geographic factors. Despite low dispersal rates, host plant habitat continuity might facilitate widespread dispersal of a T. quercicola haplotype in Hokkaido. These results suggested that following T. quercicola colonization, gene flow among populations was limited, resulting in genetic drift within populations. However, frequent T. paiki dispersal is clearly evident by low genetic differentiation among populations within groups, resulting in lower haplotype diversity.     

Phytotyping4D: a light‐field imaging system for non‐invasive and accurate monitoring of spatio‐temporal plant growth

Integrative studies of plant growth require spatially and temporally resolved information from high‐throughput imaging systems. However, analysis and interpretation of conventional two‐dimensional images is complicated by the three‐dimensional nature of shoot architecture and by changes in leaf position over time, termed hyponasty. To solve this problem, Phytotyping^4D uses a light‐field camera that simultaneously provides a focus image and a depth image, which contains distance information about the object surface. Our automated pipeline segments the focus images, integrates depth information to reconstruct the three‐dimensional architecture, and analyses time series to provide information about the relative expansion rate, the timing of leaf appearance, hyponastic movement, and shape for individual leaves and the whole rosette. Phytotyping^4D was calibrated and validated using discs of known sizes, and plants tilted at various orientations. Information from this analysis was integrated into the pipeline to allow error assessment during routine operation. To illustrate the utility of Phytotyping^4D, we compare diurnal changes in Arabidopsis thaliana wild‐type Col‐0 and the starchless pgm mutant. Compared to Col‐0, pgm showed very low relative expansion rate in the second half of the night, a transiently increased relative expansion rate at the onset of light period, and smaller hyponastic movement including delayed movement after dusk, both at the level of the rosette and individual leaves. Our study introduces light‐field camera systems as a tool to accurately measure morphological and growth‐related features in plants.     

Helping decision making for reliable and cost‐effective 2b‐RAD sequencing and genotyping analyses in non‐model species

High‐throughput sequencing has revolutionized population and conservation genetics. RAD sequencing methods, such as 2b‐RAD, can be used on species lacking a reference genome. However, transferring protocols across taxa can potentially lead to poor results. We tested two different IIB enzymes (AlfI and CspCI) on two species with different genome sizes (the loggerhead turtle Caretta caretta and the sharpsnout seabream Diplodus puntazzo) to build a set of guidelines to improve 2b‐RAD protocols on non‐model organisms while optimising costs. Good results were obtained even with degraded samples, showing the value of 2b‐RAD in studies with poor DNA quality. However, library quality was found to be a critical parameter on the number of reads and loci obtained for genotyping. Resampling analyses with different number of reads per individual showed a trade‐off between number of loci and number of reads per sample. The resulting accumulation curves can be used as a tool to calculate the number of sequences per individual needed to reach a mean depth ≥20 reads to acquire good genotyping results. Finally, we demonstrated that selective‐base ligation does not affect genomic differentiation between individuals, indicating that this technique can be used in species with large genome sizes to adjust the number of loci to the study scope, to reduce sequencing costs and to maintain suitable sequencing depth for a reliable genotyping without compromising the results. Here, we provide a set of guidelines to improve 2b‐RAD protocols on non‐model organisms with different genome sizes, helping decision‐making for a reliable and cost‐effective genotyping.     

A morphological,morphometric and histochemical study of the oviduct in pregnant and non‐pregnant females of the plains viscacha (Lagostomus maximus)

The oviduct is a very thin organ with a very tortuous appearance. It is divided into three segments: the infundibulum, the ampulla and the isthmus. Particularly, the oviduct of the viscacha lacks the intramural portion described in other species. The mucosa shows longitudinal pleats. The free edge of the infundibulum ends as small fimbriae that are of variable length and do not completely cover the ovary. The proportion of ciliated and secretory epithelial cells varied both in relation to the segments of the oviduct analysed and to the physiological state (anoestrus, follicular phase, early pregnancy and late pregnancy). The glycocalix and the apical region of the superficial epithelial cells are PAS and alcian‐blue positive. The muscular layers vary in thickness in different regions. Some lectins such as UEA‐1 and DBA showed variations in the binding pattern during the different physiological stages analysed whereas RCA‐1and WGA had a very stable pattern.     

Geographic variation of life‐history traits in the sand lizard,Lacerta agilis: testing Darwin's fecundity‐advantage hypothesis

The fecundity‐advantage hypothesis (FAH) explains larger female size relative to male size as a correlated response to fecundity selection. We explored FAH by investigating geographic variation in female reproductive output and its relation to sexual size dimorphism (SSD) in Lacerta agilis, an oviparous lizard occupying a major part of temperate Eurasia. We analysed how sex‐specific body size and SSD are associated with two putative indicators of fecundity selection intensity (clutch size and the slope of the clutch size–female size relationship) and with two climatic variables throughout the species range and across two widespread evolutionary lineages. Variation within the lineages provides no support for FAH. In contrast, the divergence between the lineages is in line with FAH: the lineage with consistently female‐biased SSD (L. a. agilis) exhibits higher clutch size and steeper fecundity slope than the lineage with an inconsistent and variable SSD (L. a. exigua). L. a. agilis shows lower offspring size (egg mass, hatchling mass) and higher clutch mass relative to female mass than L. a. exigua, that is both possible ways to enhance offspring number are exerted. As the SSD difference is due to male size (smaller males in L. a. agilis), fecundity selection favouring larger females, together with viability selection for smaller size in both sexes, would explain the female‐biased SSD and reproductive characteristics of L. a. agilis. The pattern of intraspecific life‐history divergence in L. agilis is strikingly similar to that between oviparous and viviparous populations of a related species Zootoca vivipara. Evolutionary implications of this parallelism are discussed.     

Nesfatin‐1, corticotropin‐releasing hormone,thyrotropin‐releasing hormone,and neuronal histamine interact in the hypothalamus to regulate feeding behavior

Nesfatin‐1, corticotropin‐releasing hormone (CRH), thyrotropin‐releasing hormone (TRH), and hypothalamic neuronal histamine act as anorexigenics in the hypothalamus. We examined interactions among nesfatin‐1, CRH, TRH, and histamine in the regulation of feeding behavior in rodents. We investigated whether the anorectic effect of nesfatin‐1, α‐fluoromethyl histidine (FMH; a specific suicide inhibitor of histidine decarboxylase that depletes hypothalamic neuronal histamine), a CRH antagonist, or anti‐TRH antibody affects the anorectic effect of nesfatin‐1, whether nesfatin‐1 increases CRH and TRH contents and histamine turnover in the hypothalamus, and whether histamine increases nesfatin‐1 content in the hypothalamus. We also investigated whether nesfatin‐1 decreases food intake in mice with targeted disruption of the histamine H1 receptor (H1KO mice) and if the H1 receptor (H1‐R) co‐localizes in nesfatin‐1 neurons. Nesfatin‐1‐suppressed feeding was partially attenuated in rats administered with FMH, a CRH antagonist, or anti‐TRH antibody, and in H1KO mice. Nesfatin‐1 increased CRH and TRH levels and histamine turnover, whereas histamine increased nesfatin‐1 in the hypothalamus. Immunohistochemical analysis revealed H1‐R expression on nesfatin‐1 neurons in the paraventricular nucleus of the hypothalamus. These results indicate that CRH, TRH, and hypothalamic neuronal histamine mediate the suppressive effects of nesfatin‐1 on feeding behavior.     

Efficient distinction of invasive aquatic plant species from non‐invasive related species using DNA barcoding

Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non‐invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH‐psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH‐psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics.     

Identification of a recently active Prunus‐specific non‐autonomous Mutator element with considerable genome shaping force

Miniature inverted‐repeat transposable elements (MITEs) are known to contribute to the evolution of plants, but only limited information is available for MITEs in the Prunus genome. We identified a MITE that has been named Falling Stones, FaSt. All structural features (349‐bp size, 82‐bp terminal inverted repeats and 9‐bp target site duplications) are consistent with this MITE being a putative member of the Mutator transposase superfamily. FaSt showed a preferential accumulation in the short AT‐rich segments of the euchromatin region of the peach genome. DNA sequencing and pollination experiments have been performed to confirm that the nested insertion of FaSt into the S‐haplotype‐specific F‐box gene of apricot resulted in the breakdown of self‐incompatibility (SI). A bioinformatics‐based survey of the known Rosaceae and other genomes and a newly designed polymerase chain reaction (PCR) assay verified the Prunoideae‐specific occurrence of FaSt elements. Phylogenetic analysis suggested a recent activity of FaSt in the Prunus genome. The occurrence of a nested insertion in the apricot genome further supports the recent activity of FaSt in response to abiotic stress conditions. This study reports on a presumably active non‐autonomous Mutator element in Prunus that exhibits a major indirect genome shaping force through inducing loss‐of‐function mutation in the SI locus.     

Congruence,non‐homology,and the phylogeny of basal turtles

Joyce, W.G. and Sterli J. 2010. Congruence, non‐homology, and the phylogeny of basal turtles.–Acta Zoologica (Stockholm) Modern cladistic analysis is characterized by the assembly of increasingly larger data sets coupled with the use of congruence as the final test of homology. Some critics of this development have recently called for a return to more detailed primary homology analysis while questioning the utility of congruence. This discussion appears to be central to the debate regarding the phylogenetic relationships of basal turtles, as the large data sets developed by us have been criticized recently for utilizing poorly constructed characters and including too many homoplasy‐prone characters. Our analysis of this critique reveals that (1) new information regarding poorly understood taxa has a greater impact on the outcome of turtle phylogenies than the characters under dispute; (2) most current turtle phylogenies differ in taxon sampling, not character sampling, and so it appears illogical to condemn a particular analysis for its character sampling; (3) even evolutionary taxonomists should agree that key characters utilized to resolve basal turtle relationships cannot be thought to be ‘infallible’; (4) whereas various criteria provide positive evidence for homology, only congruence provides positive evidence for non‐homology; and (5) a stalemate between conflicting camps within a congruence frame work is preferable to the ad hoc dismissal of data sets, because authoritative statements are untestable.