Current Biology最新文献

Light pollution is a major contributing factor to declines in global biodiversity^1,2 that is steadily increasing in both severity and spatial extent.^3,4,5 Artificial light at night degrades the natural visual environment by distorting and masking information vital to various nocturnal animal behaviors. In this study, we demonstrate that multiple discrete behavioral impacts of light pollution can occur simultaneously in different ecological contexts, potentially amplifying the negative consequences of light at night. We detail how artificial light at the ecologically critical transition between day and night modifies the nocturnal activity patterns of two ecologically distinct and phylogenetically distant terrestrial nocturnal arthropods: the long-distance migratory moth Helicoverpa armigera and the central-place foraging spider Drassodes. Moreover, we show that the same timing and levels of light pollution disrupt the celestial nocturnal pattern of polarized light, a visual cue used by these and other species for navigation.^{6,7,8,9,10,11,12,13,14} We suggest that the concurrent effects of a single anthropogenic stressor can be synergistic and stress the importance of reviewing the relationships between the multiple effects of single stressors when evaluating their impacts.

Innovative birds are seen as more attractive and often achieve higher mating success.^1,2,3,4 Assuming this to be a general phenomenon, selection should promote high levels of innovation that allow birds and other animals to solve novel problems or apply new solutions to old ones.⁵ However, animal populations show substantial variation in this trait, as not all individuals, even in the same population, innovate at the same rate or even innovate at all. It remains unclear which forces of selection maintain these differences. Here, we show that female mate choice and male trade-offs between innovation and competitive ability can maintain this variation in innovation in wild house mice. By combining observational data from semi-natural enclosures with experimental mate choice tests, we found that female wild house mice with different innovative abilities consistently preferred males with opposing skills, with innovative females choosing based on physical size, regardless of innovative ability, and non-innovative females choosing innovative males regardless of size. This disassortative preference in laboratory conditions resulted in disassortative mating under more natural conditions. Males faced a trade-off between innovation and size, a predictor of competitive potential. By taking females' innovation propensity into account, we demonstrate how female preference and male innovation-competition trade-offs create the conditions necessary for sexual selection to maintain variation in innovation.

Tissues and organs grow to a characteristic final size during animal development. A hallmark of tissues reaching their final size is the cessation of cell-cycle progression. However, the mechanisms by which cell-cycle progression is halted in tissues reaching their final size remain largely unknown. Here, we show that the extracellular matrix (ECM) is necessary and sufficient to halt cell-cycle progression at G2 phase in Drosophila late-larval-stage wing discs reaching their final size. Depleting ECM in late-larval-stage wing discs leads to nuclear accumulation of the co-transcriptional activator Yorkie (YAP and TAZ in mammals) and to a Yorkie-dependent release of cells from G2-phase arrest. Conversely, increasing ECM thickness induces precocious G2-phase accumulation, which is overcome by expression of an activated form of Yorkie. Furthermore, we show that programmed ECM degradation is necessary for the normal resumption of cell-cycle progression during later pupal stages and for proper adult wing size. Our work identifies a critical role for ECM in restraining cell-cycle progression in tissues reaching their final size and reveals ECM-mediated nuclear exclusion of Yorkie as a key mechanism.

Red flowers are typically pollinated by birds. A new study demonstrates that UV-absorbing phenylpropanoid pigments represent a potential 'magic trait' in the evolution of red flowers in bird-pollinated species, conferring a threefold advantage by enhancing bird attraction, deterring bees, and protecting pollen from ultraviolet radiation.

How do organisms partition a multinucleated compartment into individual cells, each enclosing a single nucleus? While the best-studied organisms form orderly surface monolayers, a new report now describes the process of cellularization deep into the chytrid sporangium.

Color provides an important visual dimension for object detection and classification. In most animals, color and motion vision are largely separated throughout early stages of visual processing. However, accumulating evidence indicates crosstalk between chromatic and achromatic pathways. Here, we investigate the spectral sensitivity of the motion-vision pathway at the level of pre-motor descending neurons (DNs) in two butterfly species with different retinal compositions and wing coloration. Butterflies engage in fast, agile flight within often colorful visual ecologies, which may heighten evolutionary pressure to integrate color and motion vision. Indeed, we observed a separation of spectral sensitivities that matches the functional properties of butterfly DNs, such that wide-field, optic flow-sensitive DNs involved in stabilization reflexes have effective broadband spectral responses, while target-selective DNs involved in target tracking are comparatively narrowband and match conspecific wing coloration. Our findings demonstrate the spectral tuning of motion vision within a pre-motor neuronal bottleneck that controls behavior. VIDEO ABSTRACT.

In angiosperms, dioecy has evolved thousands of times, and the pathways underlying the required floral changes are therefore expected to exhibit diversity as well as parallelism. Here we investigate Itoa orientalis, a dioecious Salicaceae in which immature flowers are bisexual, but the stamens or pistils then abort. This contrasts with the floral development in dioecious species of Populus and Salix, which lack any morphologically bisexual stage. A haplotype-resolved Itoa genome assembly revealed an XY system of sex determination with a sex-determining region (SDR) spanning ∼6 Mb and encompassing the centromere. In females, the SDR contains an 11-bp deletion in the TAPETAL DEVELOPMENT and FUNCTION 1 (TDF1) gene that results in multiple premature stop codons. Experimental silencing of TDF1 in males led to defective stamens, providing direct evidence that TDF1 is a regulator of male function as it is in the phylogenetically distant dioecious Asparagus officinalis. A candidate gene for suppression of female function is the MINI ZINC FINGER 2 (MIF2) gene. These findings reveal that the Salicaceae family has both an ARR17-based one-gene sex-determining system in Populus and Salix, and a two-gene system in Itoa.

Adaptive behavior enables individuals to respond flexibly to environmental changes by forming expectations based on experience within the new environment. Beta oscillations (13-30 Hz), with their widespread distribution,^{1,2,3,4,5,6,7,8,9,10,11,12} play a central role in this process.^{13,14,15,16,17,18,19,20} Specifically, beta synchronization occurring 2 s before movement initiation is modulated by prior errors^21,22,23 and may reflect predictions based on past outcomes.^24,25,26,27 Yet, the spatiotemporal dynamics of pre-movement beta oscillations, as well as their roles in detecting environmental changes and in iteratively updating motor plans to optimize and stabilize performance, remain elusive. Here, we reveal that beta oscillations emerge in a cerebello-cortical network 2 s before action initiation and progressively build up across trials as environmental features are learned and behavioral outcomes become more stable. Within this network, directional connectivity analyses reveal that the cerebellum initially drives prefrontal activity during the pre-movement period, with this influence reversing near movement onset. Finally, using a single-trial approach, we establish that, before action initiation, beta bursts in this network predict performance in the upcoming trial based on previous outcomes. These findings identify pre-movement beta oscillations within a cerebello-cortical network as a neural substrate supporting predictive processes that stabilize motor performance across changing environments. They emphasize the contribution of cerebellar networks to cognitive aspects of motor control up to 2 s before movement onset.

The diversity of life we observe today is the product of deep-time diversification and extinction dynamics unfolding over hundreds of millions of years. Modeling these dynamics requires both phylogenies and fossil data, yet fossils are notoriously uneven in their temporal and taxonomic distribution. In their recent analysis of Hymenoptera, one of the great insect radiations, Jouault et al.¹ employed Bayesian Brownian Bridge (BBB) and PyRate² to estimate origination and extinction patterns. PyRate models diversification rates directly from fossil occurrence data, and the PyRate results appear to be dominated by gaps in the fossil record (Figure 1), suggesting that the inferred extinction events likely reflect overfitting to a sparse fossil record rather than robust signal of extinction.

Contractile tubes must establish organized actomyosin networks. A new study in Caenorhabditis elegans reports that a transient cell polarizes and shapes a valve cell, by both connecting at a junction that slides to expand the apical region of the valve cell as well as providing resistance to organize myosin recruitment to the valve.