Miracle-dz/UniFAR-FTUs huggingface dataset:
Parallel and nonparallel ecological, morphological and genetic divergence in lake–stream stickleback from a single catchment

Parallel phenotypic evolution in similar environments has been well studied in evolutionary biology; however, comparatively little is known about the influence of determinism and historical contingency on the nature, extent and generality of this divergence. Taking advantage of a novel system containing multiple lake–stream stickleback populations, we examined the extent of ecological, morphological and genetic divergence between three‐spined stickleback present in parapatric environments. Consistent with other lake–stream studies, we found a shift towards a deeper body and shorter gill rakers in stream fish. Morphological shifts were concurrent with changes in diet, indicated by both stable isotope and stomach contents analysis. Performing a multivariate test for shared and unique components of evolutionary response to the distance gradient from the lake, we found a strong signature of parallel adaptation. Nonparallel divergence was also present, attributable mainly to differences between river locations. We additionally found evidence of genetic substructuring across five lake–stream transitions, indicating that some level of reproductive isolation occurs between populations in these habitats. Strong correlations between pairwise measures of morphological, ecological and genetic distance between lake and stream populations supports the hypothesis that divergent natural selection between habitats drives adaptive divergence and reproductive isolation. Lake–stream stickleback divergence in Lough Neagh provides evidence for the deterministic role of selection and supports the hypothesis that parallel selection in similar environments may initiate parallel speciation.
Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity

We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub‐climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub‐climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels.
Disruptive viability selection on adult exploratory behaviour in eastern chipmunks

Heterogeneous forces of selection associated with fluctuating environments are recognized as important factors involved in the maintenance of inter‐individual phenotypic variance within populations. Consistent behavioural differences over time and across situations (e.g. personality) are increasingly cited as examples of individual variation observed within populations. However, the suggestion that heterogeneous selective pressures target different animal personalities remains largely untested in the wild. In this 5‐year study, we investigated the dynamics of viability selection on a personality trait, exploration, in a population of eastern chipmunks (Tamias striatus) experiencing substantial seasonal variations in weather conditions and food availability associated with masting trees. Contrary to our expectations, we found no evidence of fluctuating selection on exploration. Instead, we found strong disruptive viability selection on adult exploration behaviour, independent of seasonal variations. Individuals with either low or high exploration scores were almost twice as likely to survive over a 6‐month period compared with individuals with intermediate scores. We found no evidence of viability selection on juvenile exploration. Our results highlight that disruptive selection might play an important role in the maintenance of phenotypic variance of wild populations through its effect on different personality types across temporally varying environmental conditions.
Pollen feeding, resource allocation and the evolution of chemical defence in passion vine butterflies

Evolution of pollen feeding in Heliconius has allowed exploitation of rich amino acid sources and dramatically reorganized life‐history traits. In Heliconius, eggs are produced mainly from adult‐acquired resources, leaving somatic development and maintenance to larva effort. This innovation may also have spurred evolution of chemical defence via amino acid‐derived cyanogenic glycosides. In contrast, nonpollen‐feeding heliconiines must rely almost exclusively on larval‐acquired resources for both reproduction and defence. We tested whether adult amino acid intake has an immediate influence on cyanogenesis in Heliconius. Because Heliconius are more distasteful to bird predators than close relatives that do not utilize pollen, we also compared cyanogenesis due to larval input across Heliconius species and nonpollen‐feeding relatives. Except for one species, we found that varying the amino acid diet of an adult Heliconius has negligible effect on its cyanide concentration. Adults denied amino acids showed no decrease in cyanide and no adults showed cyanide increase when fed amino acids. Yet, pollen‐feeding butterflies were capable of producing more defence than nonpollen‐feeding relatives and differences were detectable in freshly emerged adults, before input of adult resources. Our data points to a larger role of larval input in adult chemical defence. This coupled with the compartmentalization of adult nutrition to reproduction and longevity suggests that one evolutionary consequence of pollen feeding, shifting the burden of reproduction to adults, is to allow the evolution of greater allocation of host plant amino acids to defensive compounds by larvae.
Lifetime fitness and age‐related female ornament signalling: evidence for survival and fecundity selection in the pied flycatcher

Ornaments displayed by females have often been denied evolutionary interest due to their frequently reduced expression relative to males, habitually attributed to a genetic correlation between the sexes. We estimated annual and lifetime reproductive success of female pied flycatchers (Ficedula hypoleuca) and applied capture–mark–recapture models to analyse annual survival rates in relation to the patterns of expression (absence/presence) of an ornament displayed by all males and a fraction of females. Overall, the likelihood of expressing the ornament increased nonlinearly with female age and was due to within‐individual variation, not to the selective appearance or disappearance of ornament‐related expression of phenotypes in the population. Accordingly, expressing the forehead patch in a given year did not influence survival probability. However, those females expressing the ornament at early ages (1–2 years old) enjoyed survival advantages throughout lifetime. Although ornamented females had higher lifetime fecundity and fledging success, their yearly reproductive performance, in terms of fledging productivity, decreased as they aged so that, late in life, ornamented females reared fewer offspring than nonexpressing females of the same age. In addition, both strategies (expressing vs. not expressing the trait) returned similar fitness payoffs in terms of recruited offspring. Our results support the hypothesis that fecundity and survival selection are involved in the displaying of this ‘male’ ornament by females.
Experimental evidence for trait utility of gill raker number in adaptive radiation of a north temperate fish

North temperate fish in post‐glacial lakes are textbook examples for rapid parallel adaptive radiation into multiple trophic specialists within individual lakes. Speciation repeatedly proceeded along the benthic–limnetic habitat axis, and benthic–limnetic sister species diverge in the number of gill rakers. Yet, the utility of different numbers of gill rakers for consuming benthic vs. limnetic food has only very rarely been experimentally demonstrated. We bred and raised families of a benthic–limnetic species pair of whitefish under common garden conditions to test whether these species (i) show heritable differentiation in feeding efficiency on zooplankton, and (ii) whether variation in feeding efficiency is predicted by variation in gill raker numbers. We used zooplankton of three different size classes to investigate prey size dependency of divergence in feeding efficiency and to investigate the effect strength of variation in the number of gill rakers. Our results show strong interspecific differences in feeding efficiency. These differences are largest when fish were tested with the smallest zooplankton. Importantly, feeding efficiency is significantly positively correlated with the number of gill rakers when using small zooplankton, also when species identity is statistically controlled for. Our results support the hypothesis that a larger number of gill rakers are of adaptive significance for feeding on zooplankton and provide one of the first experimental demonstrations of trait utility of gill raker number when fish feed on zooplankton. These results are consistent with the suggested importance of divergent selection driven feeding adaptation during adaptive radiation of fish in post‐glacial lakes.
Weak impact of fine‐scale landscape heterogeneity on evolutionary potential in Arabidopsis lyrata

Microhabitat heterogeneity can lead to fine‐scale local adaptation when gene flow is restricted, which may be important for the maintenance of genetic variation within populations. This study tested whether microhabitat heterogeneity was associated with trait differences in a population of Arabidopsis lyrata and studied its impact on the genetic variance–covariance (G) matrix. Maternal seed families were collected from dune tops and bottoms, two microhabitats known to vary significantly in water availability. In a common garden experiment, replicate individuals per family were raised under wet and dry conditions, and physiological, morphological and life‐history traits were assessed. Plants from the two microenvironments differed in their response to treatment in two performance components, in stomata density and most strongly in flowering time. Under wet conditions, plants originating from dune bottoms flowered 4 weeks earlier than those from dune tops. Only one of three G‐matrix comparisons revealed that habitat heterogeneity and evolutionary potential were positively linked. The number of independent trait dimensions was larger in the entire population than within subpopulations separated by microhabitat under wet conditions. However, the size of the G‐matrix was no larger in the entire population than within subpopulations separated by microhabitat, and trait correlation structure between microhabitats and treatments was not significantly different. These results indicate that fine‐scale habitat heterogeneity likely led to local adaptation, which weakly affected levels of across‐trait genetic variation.
Heterochrony and post‐natal growth in mammals – an examination of growth plates in limbs

Mammals display a broad spectrum of limb specializations coupled with different locomotor strategies and habitat occupation. This anatomical diversity reflects different patterns of development and growth, including the timing of epiphyseal growth plate closure in the long bones of the skeleton. We investigated the sequence of union in 15 growth plates in the limbs of about 400 specimens, representing 58 mammalian species: 34 placentals, 23 marsupials and one monotreme. We found a common general pattern of growth plate closure sequence, but one that is universal neither between species nor in higher‐order taxa. Locomotor habitat has no detectable correlation with the growth plate closure sequence, but observed patterns indicate that growth plate closure sequence is determined more strongly through phylogenetic factors. For example, the girdle elements (acetabulum and coracoid process) always ossify first in marsupials, whereas the distal humerus is fused before the girdle elements in some placentals. We also found that heterochronic shifts (changes in timing) in the growth plate closure sequence of marsupials occur with a higher rate than in placentals. This presents a contrast with the more limited variation in timing and morphospace occupation typical for marsupial development. Moreover, unlike placentals, marsupials maintain many epiphyses separated throughout life. However, as complete union of all epiphyseal growth plates is recorded in monotremes, the marsupial condition might represent the derived state.
The effects of sexual selection on life‐history traits: an experimental study on guppies

Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To better understand the effect of sexual selection on the fitness of small populations, we compared components of female fitness and the expression of male secondary sexual characters in 19 experimental populations of guppies (Poecilia reticulata) maintained under polygamous or monogamous mating regimes over nine generations. In order to generate treatments that solely differed by their level of sexual selection, the middle‐class neighbourhood breeding design was enforced in the monogamous populations, while in the polygamous populations, all females contributed similarly to the next generation with one male and one female offspring. This experimental design allowed potential sexual conflicts to increase in the polygamous populations because selection could not operate on adult‐female traits. Clutch size and offspring survival showed a weak decline from generation to generation but did not differ among treatments. Offspring size, however, declined across generations, but more in monogamous than polygamous populations. By generation eight, orange‐ and black‐spot areas were larger in males from the polygamous treatment, but these differences were not statistically significant. Overall, these results suggest that neither sexual conflict nor the purging of deleterious mutation had important effects on the fitness of our experimental populations. However, only few generations of enforced monogamy in a benign environment were sufficient to negatively affect offspring size, a trait potentially crucial for survival in the wild. Sexual selection may therefore, under certain circumstances, be beneficial over enforced monogamy during captive breeding.
Molecular mechanisms of nitric oxide‐dependent inhibition of TPA‐induced matrix metalloproteinase‐9 (MMP‐9) in MCF‐7 cells

Matrix metalloproteinase‐9 (MMP‐9) is implicated in the invasion and metastasis of breast cancer cells. We investigated the modulatory effects of nitric oxide (NO) on the 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐induced MMP‐9 expression in MCF‐7 cells. Different chemical NO donors inhibited the extracellular content of TPA‐induced MMP‐9 protein and MMP‐9 activity as assessed by gelatin‐zymography and ELISA, respectively. Concomitant with the reduction in the extracellular MMP‐9 content NO strongly decreased the steady‐state levels of MMP‐9 mRNA which in turn leads to a lower recruitment of MMP‐9 transcripts to polysomes and to a diminished MMP‐9 translation. Reporter gene assays revealed that the inhibition in MMP‐9 expression by NO is mainly attributed to a 0.67 kb fragment of the 5′‐promoter region of the MMP‐9 gene but independent of the 3′untranslated region thus indicating that MMP‐9 suppression by NO mainly results from transcriptional events. Electrophoretic mobility shift assays (EMSA), showed that NO specifically interferes with the TPA‐induced DNA binding affinity of c‐Jun and c‐Fos without affecting the TPA‐induced increase in the levels of the transcription factors. Using pharmacological inhibitors and small interfering (si)RNA we found that PKCδ is indispensably involved in the TPA‐triggered MMP‐9 expression. Concomitantly, the TPA‐evoked increase in total PKC activity was strongly attenuated in the lysates from NO‐treated MCF‐7 cells, thus suggesting that NO attenuates TPA‐triggered MMP‐9 mainly through a direct inhibition of PKCδ. Modulation of MMP‐9 by NO highlights the complex roles of NO in the regulation of MMP‐9 in breast cancer cells. J. Cell. Physiol. 219: 276–287, 2009. © 2009 Wiley‐Liss, Inc.
Wolbachia effects in natural populations of Chorthippus parallelus from the Pyrenean hybrid zone

We evaluate for the first time the effect of Wolbachia infection, involving two different supergroups, on the structure and dynamics of the hybrid zone between two subspecies of Chorthippus parallelus (Orthoptera) in the Pyrenees. Wolbachia infection showed no effects on female fecundity or a slight increment in females infected by F supergroup, although in the last case it has to be well established. Cytoplasmic incompatibility (CI) is confirmed in crosses carried out in the field between individuals from a natural hybrid population. This CI, registered as the relative reduction in embryo production (sh), was of sh = 0.355 and sh = 0.286 in unidirectional crosses involving B and F supergroups, respectively. CI also occurred in bidirectional crosses (sh = 0.147) but with a weaker intensity. The transmission rates of the two Wolbachia strains (B and F) were estimated by the optimization of a theoretical model to reach the infection frequencies observed in certain population. To fit this scenario, both supergroups should present transmission rates close to 1. Further, we have simulated the infection dynamics, and hence, the capacity of Wolbachia to structure the population of the host insects and to affect to reproduction and genetic introgression in the hybrid zone. This represents a first example of the influence of Wolbachia in an insect natural hybrid zone.
Clusterin is a short half‐life, poly‐ubiquitinated protein, which controls the fate of prostate cancer cells

The Clusterin (CLU) gene produces different forms of protein products, which vary in their biological properties and distribution within the cell. Both the extra‐ and intracellular CLU forms regulate cell proliferation and apoptosis. Dis‐regulation of CLU expression occurs in many cancer types, including prostate cancer. The role that CLU plays in tumorigenesis is still unclear. We found that CLU over‐expression inhibited cell proliferation and induced apoptosis in prostate cancer cells. Here we show that depletion of CLU affects the growth of PC‐3 prostate cancer cells. Following siRNA targeting all CLU mRNA variants, all protein products quickly disappeared, inducing cell cycle progression and higher expression of specific proliferation markers (i.e., H3 mRNA, PCNA, and cyclins A, B1, and D) as detected by RT‐qPCR and Western blot. Quite surprisingly, we also found that the turnover of CLU protein is very rapid and tightly regulated by ubiquitin–proteasome mediated degradation. Inhibition of protein synthesis by cycloheximide showed that CLU half‐life is less than 2 h. CLU protein products were found poly‐ubiquitinated by co‐immuniprecipitation. Proteasome inhibition by MG132 caused stabilization and accumulation of all CLU protein products, including the nuclear form of CLU (nCLU), and committing cells to caspase‐dependent death. In conclusion, proteasome inhibition may induce prostate cancer cell death through accumulation of nCLU, a potential tumor suppressor factor. J. Cell. Physiol. 219: 314–323, 2009. © 2009 Wiley‐Liss, Inc.
The immunoglobulin‐like cell adhesion molecule hepaCAM modulates cell adhesion and motility through direct interaction with the actin cytoskeleton

Previously, we reported the identification of a novel immunoglobulin‐like cell adhesion molecule hepaCAM that promotes cell–extracellular matrix (ECM) interactions including cell adhesion and motility. Cell–ECM interactions are known to be directed by the actin cytoskeleton. In this study, we examined the association of hepaCAM with the actin cytoskeleton. We found that hepaCAM was partially insoluble in Triton X‐100 and colocalized with the actin cytoskeleton on the plasma membrane. Disruption of F‐actin decreased the detergent insolubility and disturbed the subcellular localization of hepaCAM. Coimmunoprecipitation and F‐actin cosedimentation assays revealed that hepaCAM directly bound to F‐actin. In addition, we constructed three N‐ and C‐terminal domain‐deleted mutants of hepaCAM to determine the actin‐binding region as well as to evaluate the effect of the domains on the biological function of hepaCAM. Detergent solubility assays showed that the cytoplasmic domain of hepaCAM might be required for actin association. However, deletion of either the extracellular or the cytoplasmic domain of hepaCAM abolished actin coprecipitation as well as delayed cell–ECM adhesion and cell motility. The data suggest that an intact hepaCAM protein is critical for establishing a stable physical association with the actin cytoskeleton; and such association is important for modulating hepaCAM‐mediated cell adhesion and motility. J. Cell. Physiol. 219: 382–391, 2009. © 2009 Wiley‐Liss, Inc.
Lysophosphatidic acid‐induced ERK activation and chemotaxis in MC3T3‐E1 preosteoblasts are independent of EGF receptor transactivation

Bone‐forming osteoblasts and their progenitors are target cells for the lipid growth factor lysophosphatidic acid (LPA) which is produced by degranulating platelets at sites of tissue injury. LPA is a potent inducer of bone cell chemotaxis, proliferation and survival in vitro, and this lipid factor is an attractive candidate to facilitate preosteoblast migration during skeletal regeneration in vivo. In this study we sought to more clearly define the intracellular signaling pathways mediating the effects of LPA on bone cells. LPA‐treated MC3T3‐E1 preosteoblastic cells exhibited a bimodal activation of extracellular signal‐related kinase (ERK1/2) with maximal phosphorylation at 5 and 60 min. MEK1/2 activation was detected within 2.5 min of LPA exposure and remained elevated for at least an hour. ERK1/2 phosphorylation was not coupled to Ras activation or to LPA‐induced elevations in cytosolic Ca2+. While LPA exposure transactivates the EGF receptor in many cell types, LPA‐stimulated ERK1/2 activation in MC3T3‐E1 cells was unaffected by the inhibition of EGF receptor function. ERK isoforms can function as transcription factors and ERK1/2 rapidly accumulated in the nuclei of LPA‐treated cells, a process that was blocked if ERK1/2 phosphorylation was prevented. Blocking ERK1/2 phosphorylation also led to significant decreases in LPA‐induced MC3T3‐E1 cell chemotaxis, while the inhibition of EGF receptor function had no effect on the stimulation of preosteoblast motility by LPA. Our results identify ERK1/2 activation as a mediator of LPA‐stimulated MC3T3‐E1 cell migration that may be relevant to preosteoblast motility and gene expression during bone repair in vivo. J. Cell. Physiol. 219: 716–723, 2009. © 2009 Wiley‐Liss, Inc.