J. Krishnamurti (1895-1986) was thought by many to be a modern-day equivalent of the Buddha. In fact, he was once even considered to be the second coming of Christ. While many think it wonderful to live and work in close proximity with such a person, it's difficult to understand the depth of what this means and how challenging this might be. In Knocking at the Open Door, author R.E. Mark Lee provides an ordinary person view of what being close-up (...) and working together with such a man means, how it challenges one at every turn, and how it causes one to question ceaselessly, even more deeply than one ordinarily would. Lee offers an insightful, candid, and heartfelt narrative that reveals various unknown facets of the eminent world teacher J. Krishnamurti and highlights his distinctive vision for education worldwide. This comprehensive volume brings alive the practical and everyday interactions Lee had with Krishnamurti during a twenty-year period in India and the United Sates. Knocking at the Open Door shares a clear and honest account that demonstrates the challenges of working with Krishnamurti in running a school that is true to the teaching and yet able to function in the reality of modern parental, student, and educational establishment expectations. (shrink)

Progressive supranuclear palsy is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP and 3,247 controls followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the (...) stage 1 SNPs that yielded P ≤ 10-3. We found significant previously unidentified signals associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component. © 2011 Nature America, Inc. All rights reserved. (shrink)

We consider the varieties and directions of influence that the source and target domains involved in a conceptual metaphor can have on each other during the course of understanding metaphorical utterances based on the metaphor. Previous studies have been restricted both as to direction of influence and as to type of influence. They have been largely confined to the “forward” (source to target) direction of influence, and they have concentrated on the transfer of features or propositions and (to some extent) (...) the highlighting of aspects of a domain. By contrast, this article stresses the importance both of other varieties of influence (e.g., transfer of queries and uncertainty effects) and of “reverse” influence (target to source). We seek to curb the natural tendency to think that, because metaphor involves an overall move from source to target, therefore all inter-domain influences in the course of understanding go in that direction. The bulk of the article explores the theoretical issues involved. These issues have arisen out of a reasoning-based approach to metaphor, seeking to make best use of information from metaphorical utterance, context, source and target domains, and known metaphorical mappings, by applying a complex overall reasoning process. The article briefly explains the thorough implementation of reverse influence in a computer program for metaphorical reasoning called ATT-Meta, although the theoretical considerations are relevant to all disciplines concerned with metaphor. We make some suggestions for further computational and psychological research on metaphor. (shrink)

Psychedelics have been recognized as model interventions for studying altered states of consciousness. However, few empirical studies of the shamanic state of consciousness, which is anecdotally similar to the psychedelic state, exist. We investigated the neural correlates of shamanic trance using high-density electroencephalography (EEG) in 24 shamanic practitioners and 24 healthy controls during rest, shamanic drumming, and classical music listening, followed by an assessment of altered states of consciousness. EEG data were used to assess changes in absolute power, connectivity, signal (...) diversity, and criticality, which were correlated with assessment measures. We also compared assessment scores to those of individuals in a previous study under the influence of psychedelics. Shamanic practitioners were significantly different from controls in several domains of altered states of consciousness, with scores comparable to or exceeding that of healthy volunteers under the influence of psychedelics. Practitioners also displayed increased gamma power during drumming that positively correlated with elementary visual alterations. Furthermore, shamanic practitioners had decreased low alpha and increased low beta connectivity during drumming and classical music and decreased neural signal diversity in the gamma band during drumming that inversely correlated with insightfulness. Finally, criticality in practitioners was increased during drumming in the low and high beta and gamma bands, with increases in the low beta band correlating with complex imagery and elementary visual alterations. These findings suggest that psychedelic drug-induced and non-pharmacologic alterations in consciousness have overlapping phenomenal traits but are distinct states of consciousness, as reflected by the unique brain-related changes during shamanic trance compared to previous literature investigating the psychedelic state. (shrink)

The earlier volume in this series dealt with two religions of Indian origin, namely, Buddhism and Jainism. The Indian religious scene, however, is characterized by not only religions which originated in India but also by religions which entered India from outside India and made their home here. Thus religious life in India has been enlivened throughout its history by the presence of religions of foreign origin on its soil almost from the very time they came into existence. This volume covers (...) three such religions—Zoraoastrianism, Judaism, and Islam. In the case of Zoraostianism, even its very beginnings are intertwined with India, as Zoroastrianism reformed a preexisting religion which had strong links to the Vedic heritage of India. This relationship took on a new dimension when a Zoroastrian community, fearing persecution in Persia after its Arab conquest, sought shelter in western India and ultimately went on to produce India’s pioneering nationalist in the figure of Dadabhai Naoroji ( 1825-1917), also known as the Grand Old Man of India. Jews found refuge in south India after the destruction of the Temple by the Romans in 70 C.E. and have remained a part of the Indian religious scene since then, some even returning to Israel after it was founded in 1948. Islam arrived in Kerala as soon as it was founded and one of the earliest mosques in the history of Islam is found in India. Islam differs from the previously mentioned religions inasmuch as it went on to gain political hegemony over parts of the country for considerable periods of time, which meant that its impact on the religious life of the subcontinent has been greater compared to the other religions. It has also meant that Islam has existed in a religiously plural environment in India for a longer period than elsewhere in the world so that not only has Islam left a mark on India, India has also left its mark on it. Indeed all the three religions covered in this volume share this dual feature, that they have profoundly influenced Indian religious life and have also in turn been profoundly influenced by their presence in India. (shrink)

The earlier volume in this series dealt with two religions of Indian origin, namely, Buddhism and Jainism. The Indian religious scene, however, is characterized by not only religions which originated in India but also by religions which entered India from outside India and made their home here. Thus religious life in India has been enlivened throughout its history by the presence of religions of foreign origin on its soil almost from the very time they came into existence. This volume covers (...) three such religions—Zoraoastrianism, Judaism, and Islam. In the case of Zoraostianism, even its very beginnings are intertwined with India, as Zoroastrianism reformed a preexisting religion which had strong links to the Vedic heritage of India. This relationship took on a new dimension when a Zoroastrian community, fearing persecution in Persia after its Arab conquest, sought shelter in western India and ultimately went on to produce India’s pioneering nationalist in the figure of Dadabhai Naoroji ( 1825-1917), also known as the Grand Old Man of India. Jews found refuge in south India after the destruction of the Temple by the Romans in 70 C.E. and have remained a part of the Indian religious scene since then, some even returning to Israel after it was founded in 1948. Islam arrived in Kerala as soon as it was founded and one of the earliest mosques in the history of Islam is found in India. Islam differs from the previously mentioned religions inasmuch as it went on to gain political hegemony over parts of the country for considerable periods of time, which meant that its impact on the religious life of the subcontinent has been greater compared to the other religions. It has also meant that Islam has existed in a religiously plural environment in India for a longer period than elsewhere in the world so that not only has Islam left a mark on India, India has also left its mark on it. Indeed all the three religions covered in this volume share this dual feature, that they have profoundly influenced Indian religious life and have also in turn been profoundly influenced by their presence in India. (shrink)

The coronavirus disease-2019 (COVID-19) has caused shortages of life-sustaining medical resources, and future waves of the virus may cause further scarcity. The Yale New Haven Health System developed a triage protocol to allocate scarce medical resources during the COVID-19 pandemic, with the primary goal of saving the most lives possible, and a secondary goal of making triage assessments and decisions consistent, transparent, and fair. We outline the process of developing the protocol, summarize the protocol, and discuss the major ethical challenges (...) encountered, along with our answers to the challenges. These challenges include (1) the role of age and chronic comorbidities; (2) evaluating children and pregnant patients; (3) racial, ethnic, and socioeconomic disparities in health; (4) prioritization of healthcare workers; and (5) balancing clinical judgment versus protocolized assessments.We conclude with a review of the limitations of our protocol and the lessons learned. We hope that a robust public discussion of such protocols and the ethical challenges they raise will result in the fairest possible processes, less need for triage, and more lives saved during future waves of the pandemic and similar public health emergencies. (shrink)

We investigate the role of personal values in an investment decision in a controlled experimental setting. Participants were asked to choose an investment in a bond issued by a tobacco company or a bond issued by a non-tobacco company that offered an equal or sometimes lower yield. We then surveyed the participants regarding their feelings toward tobacco use to determine whether these values influenced their investment decision. Using factor analysis, we identified investment- and tobacco-related dimensions on which participants’ responses tended (...) to load. Two of these factors, relating to the societal impact of investment decisions and the health effects of tobacco, were highly significant in determining whether participants selected a tobacco or non-tobacco related investment. More importantly, we found that when the rate of return on a tobacco-related investment exceeds the rate of return on an investment not involving tobacco by 1%, the intensity of participant concerns about the societal effects of their investment decisions was especially important in determining investment choices. This finding indicates that traditional wealth-maximization approaches, which do not consider the personal values of the investor, omit an important factor that affects investment decisions. (shrink)

We investigate the role of personal values in an investment decision in a controlled experimental setting. Participants were asked to choose an investment in a bond issued by a tobacco company or a bond issued by a non-tobacco company that offered an equal or sometimes lower yield. We then surveyed the participants regarding their feelings toward tobacco use to determine whether these values influenced their investment decision. Using factor analysis, we identified investment- and tobacco-related dimensions on which participants’ responses tended (...) to load. Two of these factors, relating to the societal impact of investment decisions and the health effects of tobacco, were highly significant in determining whether participants selected a tobacco or non-tobacco related investment. More importantly, we found that when the rate of return on a tobacco-related investment exceeds the rate of return on an investment not involving tobacco by 1%, the intensity of participant concerns about the societal effects of their investment decisions was especially important in determining investment choices. This finding indicates that traditional wealth-maximization approaches, which do not consider the personal values of the investor, omit an important factor that affects investment decisions. (shrink)

This paper responds to the commentaries from Stacy Carter and Alan Cribb. We pick up on two main themes in our response. First, we reflect on how the process of setting standards for empirical bioethics research entails drawing boundaries around what research counts as empirical bioethics research, and we discuss whether the standards agreed in the consensus process draw these boundaries correctly. Second, we expand on the discussion in the original paper of the role and significance of the concept of (...) ‘integrating’ empirical methods and ethical argument as a standard for research practice within empirical bioethics. (shrink)

There is increasing evidence that dynamic changes to chromatin, chromosomes and nuclear architecture are regulated by RNA signalling. Although the precise molecular mechanisms are not well understood, they appear to involve the differential recruitment of a hierarchy of generic chromatin modifying complexes and DNA methyltransferases to specific loci by RNAs during differentiation and development. A significant fraction of the genome-wide transcription of non-protein coding RNAs may be involved in this process, comprising a previously hidden layer of intermediary genetic information that (...) underpins developmental ontogeny and the differences between species, ecotypes and individuals. It is also evident that RNA editing is a primary means by which hardwired genetic information in animals can be altered by environmental signals, especially in the brain, indicating a dynamic RNA-mediated interplay between the transcriptome, the environment and the epigenome. Moreover, RNA-directed regulatory processes may also transfer epigenetic information not only within cells but also between cells and organ systems, as well as across generations. (shrink)

Researchers from diverse disciplines, including organismal and cellular physiology, sports science, human nutrition, evolution and ecology, have sought to understand the causes and consequences of the surprising variation in metabolic rate found among and within individual animals of the same species. Research in this area has been hampered by differences in approach, terminology and methodology, and the context in which measurements are made. Recent advances provide important opportunities to identify and address the key questions in the field. By bringing together (...) researchers from different areas of biology and biomedicine, we describe and evaluate these developments and the insights they could yield, highlighting the need for more standardisation across disciplines. We conclude with a list of important questions that can now be addressed by developing a common conceptual and methodological toolkit for studies on metabolic variation in animals. (shrink)

Purpose: Our aim was to determine if self-determined motivation (SDM) in elite, men’s soccer changes over time and differs as a function of age, skill-grouping, and engagement in soccer play and practice. We tested predictions from the Developmental Model of Sport Participation (DMSP) regarding relations between practice and play and SDM among both elite and non-elite samples. Methods: Elite youth soccer players in the UK (n = 31; from the Under 13/U13 yr and U15 yr age groups) completed practice history (...) and motivation questionnaires at time1 (T1) and ~2 years later (T2: now U15 yr & U17 yr). Non-elite players (n = 32; from U15 yr and U17 yr) completed the same questionnaires at T2 only. Results: For the elite groups, global SDM decreased over time for the current U17 group (from U15), but no change was seen for the current U15 group (from U13). Age group differences at T2 mirrored these data, with U17 players showing lower global SDM and higher controlled motivation than U15 elites. The non-elite players did not show age group differences, but elites scored higher for global SDM and autonomous motivation than non-elites. The recent hours accumulated in practice negatively correlated with global SDM in elite and non-elite groups, but play was unrelated to measures of motivation. Conclusions: Differences in SDM as a function of age and skill point towards the dynamic nature of these motivations over time, likely a result of proximity to external rewards related to professional status. Although high volumes of practice are related to lower global SDM in both skill groups, the absence of any relations between SDM and soccer play does not support a key prediction related to the DMSP. (shrink)

This volume offers insights on experimental and empirical research in theoretical linguistic issues of negation and polarity, focusing on how negation is marked and how negative polarity is emphatic and how it interacts with double negation. Metalinguistic negation and neg-raising are also explored in the volume. Leading specialists in the field present novel ideas by employing various experimental methods in felicity judgments, eye tracking, self-paced readings, prosody and ERP. Particular attention is given to extensive crosslinguistc data from French, Catalan and (...) Korean along with analyses using semantic and pragmatic methods, corpus linguistics, diachronic perspectives, and longitudinal acquisitional studies as well as signed and gestural negation. Each contribution is situated with regards to major previous studies, thereby offering readers insights on the current state of the art in research on negation and negative polarity, highlighting how theory and data together contributes to the understanding of cognition and mind.. (shrink)

Bioethics should update its conception of the geneThe 25th of April marks the 50th anniversary of the publication in Nature of the letter by James Watson and Francis Crick announcing their solution to the structure of deoxyribose nucleic acid .1 By that time, much was known about the role of chromosomes in inheritance, the contribution of DNA to chromosome structure, and the chemistry of DNA.2 The gene concept itself was also well established by then; the principal scientific problem became to (...) specify what genes were in molecular terms and how they functioned in the cell during ordinary function and cell division.The importance of the solution of the structure of DNA was twofold. First, it gave insight into finding a mechanism for DNA replication, as the authors recognised in this famous sentence:"It has not escaped our notice that the specific pairing we have postulated immediately suggests a copying mechanism for the genetic material.3 … ". (shrink)

In seeking to understand the development of philosophy in later antiquity it is important to take account of Clement of Alexandria, perhaps the first Christian writer to be greatly influenced by the systems of Greece. Accordingly in this article certain aspects of Clement's doctrine will be selected for examination where his obligations to the philosophers have apparently hitherto received insufficient attention. In a valuable paper Mr. R. P. Casey has dealt with many important points, but there is room for further (...) exploration, both by the philological method and by a careful comparison of corresponding ideas in Clement and Plotinus. I am here concerned to stress resemblances rather than to prove, for instance, that any direct connection exists between Neoplatonism and Alexandrian theology. It is nevertheless not irrevelant to mention that Ammonius Saccas, the professor whose lectures both Origen the Christian and Plotinus were to attend, and who, besides being a Platonist, if not the founder of Neoplatonism, was also an apostate Christian, had probably begun to attract attention in Alexandria at the time when Clement was head of the Christian School there, in which perhaps Ammonius himself had been originally educated. There seems nothing to prevent the assumption that Ammonius and Clement were known at least by name to each other, and perhaps the philosopher under whom Plotinus was to study for eleven years had even sat by the side of Clement at the feet of Pantaenus, the erstwhile Stoic and founder of the Catechetical School. However that may be, both Neoplatonism and Alexandrian theology show a markedly similar tendency, and in the Enneads and the Stromateis there are many equivalent features. (shrink)

In seeking to understand the development of philosophy in later antiquity it is important to take account of Clement of Alexandria, perhaps the first Christian writer to be greatly influenced by the systems of Greece. Accordingly in this article certain aspects of Clement's doctrine will be selected for examination where his obligations to the philosophers have apparently hitherto received insufficient attention. In a valuable paper Mr. R. P. Casey has dealt with many important points, but there is room for further (...) exploration, both by the philological method and by a careful comparison of corresponding ideas in Clement and Plotinus. I am here concerned to stress resemblances rather than to prove, for instance, that any direct connection exists between Neoplatonism and Alexandrian theology. It is nevertheless not irrevelant to mention that Ammonius Saccas, the professor whose lectures both Origen the Christian and Plotinus were to attend, and who, besides being a Platonist, if not the founder of Neoplatonism, was also an apostate Christian, had probably begun to attract attention in Alexandria at the time when Clement was head of the Christian School there, in which perhaps Ammonius himself had been originally educated. There seems nothing to prevent the assumption that Ammonius and Clement were known at least by name to each other, and perhaps the philosopher under whom Plotinus was to study for eleven years had even sat by the side of Clement at the feet of Pantaenus, the erstwhile Stoic and founder of the Catechetical School. However that may be, both Neoplatonism and Alexandrian theology show a markedly similar tendency, and in the Enneads and the Stromateis there are many equivalent features. (shrink)

Background Over the last decade, the return of results (ROR) in precision medicine research (PMR) has become increasingly routine. Calls for individual rights to research results have extended the “duty to report” from clinically useful genetic information to traits and ancestry results. ROR has thus been reframed as inherently beneficial to research participants, without a needed focus on who benefits and how. This paper addresses this gap, particularly in the context of PMR aimed at increasing participant diversity, by providing investigator (...) and researcher perspectives on and questions about the assumed value of ROR in PMR.Methods Semi-structured interviews with a purposive sample of investigators and researchers across federally funded PMR studies in three national consortia, as well as observations of study activities, focused on how PM researchers conceptualize diversity and implement inclusive practices across research stages, including navigating ROR.Results Interviewees (1) validated the value of ROR as a benefit of PMR, while others (2) questioned the benefit of clinically actionable results to individuals in the absence of sufficient resources for translating findings into health care for diverse and disadvantaged populations; (3) expressed uncertainties in applying the presumed value of ROR as a benefit for non-clinical results; and (4) and debated when the promise of the value of ROR may undermine trust in PMR, and divert efforts to return value beyond ROR.Conclusions Conceptualizations of diversity and inclusion among PM researchers and investigators raise unique ethical questions where unexamined assumptions of the value of ROR inform study recruitment efforts to enroll minoritized and under-represented populations. A lack of consideration for resources and infrastructure necessary to translate ROR into actionable information may hinder trustworthy community-research relationships. Thus, we argue for a more intentional interrogation of ROR practices as an offer of benefit and for whom. (shrink)

Philosophers have long debated whether, if determinism is true, we should hold people morally responsible for their actions since in a deterministic universe, people are arguably not the ultimate source of their actions nor could they have done otherwise if initial conditions and the laws of nature are held fixed. To reveal how non-philosophers ordinarily reason about the conditions for free will, we conducted a cross-cultural and cross-linguistic survey (N = 5,268) spanning twenty countries and sixteen languages. Overall, participants tended (...) to ascribe moral responsibility whether the perpetrator lacked sourcehood or alternate possibilities. However, for American, European, and Middle Eastern participants, being the ultimate source of one’s actions promoted perceptions of free will and control as well as ascriptions of blame and punishment. By contrast, being the source of one’s actions was not particularly salient to Asian participants. Finally, across cultures, participants exhibiting greater cognitive reflection were more likely to view free will as incompatible with causal determinism. We discuss these findings in light of documented cultural differences in the tendency toward dispositional versus situational attributions. (shrink)

High-spin states have been studied in Pr-135(59), populated through the Cd-116(Na-23,4n) reaction at 115 MeV, using the Gammasphere gamma-ray spectrometer. The negative-parity yrast band has been significantly extended to spin similar to 45 (h) over bar and excitation energy 21.5 MeV, showing evidence for several rotational alignments. The positive-parity yrast band of Ce-135(58), populated through the p4n channel of this reaction, was also populated to spin similar to 38 (h) over bar and excitation energy 18 MeV. Cranking calculations indicate that (...) these nuclei are soft with respect to the triaxiality parameter gamma and that several competing nuclear shapes occur at high spin. (shrink)

In the Deese-Roediger/McDermott paradigm, distinctive encoding of list items typically reduces false recognition of critical lures relative to a read-only control. This reduction can be due to enhanced item-specific processing, reduced relational processing, and/or increased test-based monitoring. However, it is unclear whether distinctive encoding reduces false recognition in a selective or global manner. To examine this question, participants studied DRM lists using a distinctive item-specific anagram generation task and then completed a recognition test which included both DRM critical lures and (...) either strongly related lures or weakly related lures. Compared to a read-control group, the generate groups showed increased correct recognition and decreased false recognition of all lure types. We then estimated the separate contributions of encoding and retrieval processes using signal-detection indices. Generation improved correct recognition by both increasing encoding of memory information for list words and by increasing memory monitoring at test. Generation reduced false recognition by reducing the encoding of memory information and by increasing memory monitoring at test. The reduction in false recognition was equivalent for critical lures and related lures, indicating that generation globally reduces the encoding of related non-presented items at study, while globally increasing list-theme-based monitoring at test. (shrink)

Persons registered to vote in Seattle, Washington for the November, 1986 general election and a September, 1987 primary election were randomly assigned to treatments in two telephoneconducted experiments that sought to increase voter tumout. The experiments applied and extended a "self-prophecy” technique, in which respondents are asked simply to predict whether or not they will perform a target action. In the present studies, voting registrants were asked to predict whether or not they would vote in an election that was less (...) than 48 hours away. This technique, which previously increased turnout in a small study done during the 1984 U.S. Presidential election, was again effective among moderate prior-turnout voters in the second of the present much larger experiments. The failure of the effect in Experiment 1 was plausibly a ceiling effect due to very high turnout for a U.S. Senate contest in the 1986 election. Successful applications of the self· prophecy technique are facilitated by social desirability of the target action (which leads subjects to predict that they will perform it). However, social desirability of the target behavior is not a sufficient condition for the effect, as indicated by an unexpected nonoccurrence of the effect among low prior-tumout voters in Experiment 2. (shrink)

Bio-heteronormative conceptions of the family have long reinforced a nuclear ideal of the family as a heterosexual marriage, with children who are the genetic progeny of that union. This ideal, however, has also long been resisted in light of recent social developments, exhibited through the increased incidence and acceptance of step-families, donor-conceived families, and so forth. Although to this end some might claim that the bio-heteronormative ideal is not necessary for a social unit to count as a family, a more (...) systematic conceptualization of the family—the kind of family that matters morally—is relatively underexplored in the philosophical literature. This paper makes a start at developing and defending an account of the family that is normatively attractive and in line with the growing prevalence of non-conventional families and methods of family-formation. Our account, which we call a constitutive-affirmative model of the family, takes the family to be constituted by an ongoing process of relevant affective and affirmative relations between the putative family members. (shrink)

Historically, entities with a vested interest in a product that critics have suggested is harmful have consistently used research to back their claims that the product is safe. Prominent examples are: tobacco, lead, bisphenol A, and atrazine. Research literature indicates that about 80–90% of studies with industry affiliation found no harm from the product, while only about 10–20% of studies without industry affiliation found no harm. In parallel to other historical debates, recent studies examining a possible relationship between mercury exposure (...) and autism spectrum disorder show a similar dichotomy. Studies sponsored and supported by industry or entities with an apparent conflict of interest have most often shown no evidence of harm or no “consistent” evidence of harm, while studies without such affiliations report positive evidence of a Hg/autism association. The potentially causal relationship between Hg exposure and ASD differs from other toxic products since there is a broad coalition of entities for whom a conflict of interest arises. These include influential governmental public health entities, the pharmaceutical industry, and even the coal burning industry. This review includes a systematic literature search of original studies on the potential relationship between Hg and ASD from 1999 to August 2015, finding that of the studies with public health and/or industry affiliation, 86% reported no relationship between Hg and ASD. However, among studies without public health and/or industry affiliation, only 21% find no relationship between Hg and ASD. The discrepancy in these results suggests a bias indicative of a conflict of interest. (shrink)

The origin of marine invertebrate larvae has been an area of controversy in developmental evolution for over a century. Here, we address the question of whether a pelagic “larval” or benthic “adult” morphology originated first in metazoan lineages by testing the hypothesis that particular gene co-option patterns will be associated with the origin of feeding, indirect developing larval forms. Empirical evidence bearing on this hypothesis is derivable from gene expression studies of the sea urchin larval gut of two closely related (...) but differently developing congenerics, Heliocidaris tuberculata (feeding indirect-developing larva) and H. erythrogramma (nonfeeding direct developer), given two subsidiary hypotheses. (1) If larval gut gene expression in H. tuberculata was co-opted from an ancestral adult expression pattern, then the gut expression pattern will remain in adult H. erythrogramma despite its direct development. (2) Genes expressed in the larval gut of H. tuberculata will not have a coordinated expression pattern in H. erythrogramma larvae due to loss of a functional gut. Five structural genes expressed in the invaginating archenteron of H. tuberculata during gastrulation exhibit substantially different expression patterns in H. erythrogramma with only one remaining endoderm specific. Expression of these genes in the adult of H. erythrogramma and larval gut of H. tuberculata, but not in H. erythrogramma larval endoderm, supports the hypothesis that they first played roles in the formation of adult structures and were subsequently recruited into larval ontogeny during the origin and evolution of feeding planktotrophic deuterostome larvae. (shrink)

The larval arms of echinoid plutei are used for locomotion and feeding. They are composed of internal calcite skeletal rods covered by an ectoderm layer bearing a ciliary band. Skeletogenesis includes an autonomous molecular differentiation program in primary mesenchyme cells (PMCs), initiated when PMCs leave the vegetal plate for the blastocoel, and a patterning of the differentiated skeletal units that requires molecular cues from the overlaying ectoderm. The arms represent a larval feature that arose in the echinoid lineage during the (...) Paleozoic and offers a subject for the study of gene co-option in the evolution of novel larval features. We isolated new molecular markers in two closely related but differently developing species, Heliocidaris tuberculata and Heliocidaris erythrogramma. We report the expression of a larval arm-associated ectoderm gene tetraspanin, as well as two new PMC markers, advillin and carbonic anhydrase. Tetraspanin localizes to the animal half of blastula stage H. tuberculata and then undergoes a restriction into the putative oral ectoderm and future location of the postoral arms, where it continues to be expressed at the leading edge of both the postoral and anterolateral arms. In H. erythrogramma, its expression initiates in the animal half of blastulae and expands over the entire ectoderm from gastrulation onward. Advillin and carbonic anhydrase are upregulated in the PMCs postgastrulation and localized to the leading edge of the growing larval arms of H. tuberculata but do not exhibit coordinated expression in H. erythrogramma larvae. The tight spatiotemporal regulation of these genes in H. tuberculata along with other ontogenetic and phylogenetic evidence suggest that pluteus arms are novel larval organs, distinguishable from the processes of skeletogenesis per se. The dissociation of expression control in H. erythrogramma suggest that coordinate gene expression in H. tuberculata evolved as part of the evolution of pluteus arms, and is not required for larval or adult development. (shrink)