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BackgroundOpsins are the primary proteins responsible for light detection in animals. Cnidarians (jellyfish, sea anemones, corals) have diverse visual systems that have evolved in parallel with bilaterians (squid, flies, fish) for hundreds of millions of years. Medusozoans (e.g. jellyfish, hydroids) have evolved eyes multiple times, each time independently incorporating distinct opsin orthologs. Anthozoans (e.g. corals, sea anemones,) have diverse light-mediated behaviors and, despite being eyeless, exhibit more extensive opsin duplications than medusozoans. To better understand the evolution of photosensitivity in animals without eyes we increased anthozoan representation in the phylogeny of animal opsins and investigated the large but poorly characterized opsin family in the sea anemoneNematostella vectensis.ResultsWe analyzed genomic and transcriptomic data from 16 species of cnidarians to generate a large opsin phylogeny (708 sequences) with the largest sampling of anthozoan sequences to date. We identified 29 opsins fromN. vectensis(NvOpsins) with high confidence, using transcriptomic and genomic datasets. We found that lineage-specific opsin duplications are common across Cnidaria, with anthozoan lineages exhibiting among the highest numbers of opsins in animals. To establish putative photosensory function ofNvOpsins, we identified canonically conserved protein domains and amino acid sequences essential for opsin function in other animal species. We show high sequence diversity amongNvOpsinsat sites important for photoreception and transduction, suggesting potentially diverse functions. We further examined the spatiotemporal expression ofNvOpsinsand found both dynamic expression of opsins during embryonic development and sexually dimorphic opsin expression in adults.ConclusionsThese data show that lineage-specific duplication and divergence has led to expansive diversity of opsins in eyeless cnidarians, suggesting opsins from these animals may exhibit novel biochemical functions. The variable expression patterns of opsins inN. vectensissuggest opsin gene duplications allowed for a radiation of unique sensory cell types with tissue-and stage-specific functions. This diffuse network of distinct sensory cell types could be an adaptive solution for varied sensory tasks experienced in distinct life history stages in Anthozoans.

To fertilize an oocyte, the membrane potential of both mouse and human sperm must hyperpolarize (become more negative inside). Determining the molecular mechanisms underlying this hyperpolarization is vital for developing new contraceptive methods and detecting causes of idiopathic male infertility. In mouse sperm, hyperpolarization is caused by activation of the sperm-specific potassium (K + ) channel SLO3 [C. M. Santi et al. , FEBS Lett. 584 , 1041–1046 (2010)]. In human sperm, it has long been unclear whether hyperpolarization depends on SLO3 or the ubiquitous K + channel SLO1 [N. Mannowetz, N. M. Naidoo, S. A. S. Choo, J. F. Smith, P. V. Lishko, Elife 2 , e01009 (2013), C. Brenker et al. , Elife 3 , e01438 (2014), and S. A. Mansell, S. J. Publicover, C. L. R. Barratt, S. M. Wilson, Mol. Hum. Reprod. 20 , 392–408 (2014)]. In this work, we identified the first selective inhibitor for human SLO3—VU0546110—and showed that it completely blocked heterologous SLO3 currents and endogenous K + currents in human sperm. This compound also prevented sperm from hyperpolarizing and undergoing hyperactivated motility and induced acrosome reaction, which are necessary to fertilize an egg. We conclude that SLO3 is the sole K + channel responsible for hyperpolarization and significantly contributes to the fertilizing ability of human sperm. Moreover, SLO3 is a good candidate for contraceptive development, and mutation of this gene is a possible cause of idiopathic male infertility.

Evidence of the benefits of culinary nutrition education is growing in the literature. Culinary nutrition education programs are naturally experiential, social, skills-based, and effective in improving nutrition-related beliefs, knowledge, and behaviors. In this article, we explore a set of motivational experiences in culinary nutrition education that have been identified as “drivers” of behavior change. These drivers emerged from 20 years of implementation and evaluation of hands-on cooking programs across the life span in more than 30 states within the United States. From these drivers, we developed a framework to guide both new and existing programs that can be best designed to motivate behavior change. These frameworks add value to the work of culinary nutrition educators and will inform and support future culinary nutrition education programs. In future research, health educators implementing skills-based health promotion programs in diverse settings can test the application of this framework to determine its relevance in broader areas.

Neurogenesis, the regulation of cellular proliferation and differentiation in the developing nervous system, is the process that underlies the diversity of size and cell type found in animal nervous systems. Our understanding of how this process has evolved is limited because of the lack of high resolution data and live-imaging methods across species. The retina is a classic model for the study of neurogenesis in vertebrates and live-imaging of the retina has shown that during development, progenitor cells are organized in a pseudostratified neuroepithelium and nuclei migrate in coordination with the cell cycle along the apicobasal axis of the cell, a process called interkinetic nuclear migration. Eventually cells delaminate and differentiate within the boundaries of the epithelium. This process has been considered unique to vertebrates and thought to be important in maintaining organization during the development of a complex nervous system. Coleoid cephalopods, including squid, cuttlefish and octopus, have the largest nervous system of any invertebrate and convergently-evolved camera-type eyes, making them a compelling comparative system to vertebrates. Here we have pioneered live-imaging techniques to show that the squid, Doryteuthis pealeii, displays cellular mechanisms during cephalopod retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo interkinetic nuclear migration until they exit the cell cycle, we identify retinal organization corresponding to progenitor, post-mitotic and differentiated cells, and we find that Notch signaling regulates this process. With cephalopods and vertebrates having diverged 550 million years ago, these results suggest that mechanisms thought to be unique to vertebrates may be common to highly proliferative neurogenic primordia contributing to a large nervous system.

Humans are remarkably efficient at processing natural text. We quantified efficiency for discriminating a sample of meaningful text from a sample of random text by disrupting the meaningful sample, and measuring how much disruption human readers can tolerate before the two samples become indistinguishable. We performed these measurements for a wide range of conditions, involving samples of different lengths and containing letters, words or Chinese characters. We then compared human performance to the best possible performance achieved by a Bayesian estimator under the conditions in which we tested our participants, and in so doing we determined their absolute efficiency. Values were mostly in the range 5–40%, in agreement with reported efficiencies for many visual tasks. Although not intended as a veridical model of human processing, we found that the Bayesian model captured some (but not all) aspects of how humans classified text in our tasks and conditions.