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This study aimed to describe, using a statewide trauma registry, the incidence, trends, and injuries for tree stand falls while deer hunting in Pennsylvania.Falls from tree stands were abstracted from the Pennsylvania Trauma Systems Foundation registry (1990-2017) and combined with the number of licensed deer hunters, deer hunting days, and deer hunting-related shooting incidents (HRSIs) provided by the Pennsylvania Game Commission to calculate tree stand fall and HRSI rates (per 1 million deer hunting days) and age-group specific fall rates (per 100,000 licensed deer hunters). Poisson regression was used to assess the significance of the annual and age group rate trends (significanceThere were 1229 victims of tree stand falls and 560 victims of HRSIs between 1990 and 2017. Fall rates increased from 1.5 to 10.4 (Tree stand falls are now the leading cause of Pennsylvania deer hunting accidents. Fall victims usually sustain multiple nonfatal but often disabling injuries. Study findings support the need for surveillance of these accidents and additional tree stand safety education.

Apoptosis is a fundamental feature of multicellular animals and is best understood in mammals, flies, and nematodes, with the invertebrate models being thought to represent a condition of ancestral simplicity. However, the existence of a leukemia-like cancer in the softshell clam Mya arenaria provides an opportunity to re-evaluate the evolution of the genetic machinery of apoptosis. Here, we report the whole-genome sequence for M. arenaria which we leverage with existing data to test evolutionary hypotheses on the origins of apoptosis in animals. We show that the ancestral bilaterian p53 locus, a master regulator of apoptosis, possessed a complex domain structure, in contrast to that of extant ecdysozoan p53s. Further, ecdysozoan taxa, but not chordates or lophotrochozoans like M. arenaria, show a widespread reduction in apoptosis gene copy number. Finally, phylogenetic exploration of apoptosis gene copy number reveals a striking linkage with p53 domain complexity across species. Our results challenge the current understanding of the evolution of apoptosis and highlight the ancestral complexity of the bilaterian apoptotic tool kit and its subsequent dismantlement during the ecdysozoan radiation.

The latter subdivisions might be considered as sites for the transduction of environmental and extra- or intragonadal forms of informational and nutritional input to the gametes. Since Ferguson has considered all currently recognized means of transport which might possibly bring nutrients into the gonads, the present chapter will be limited to a discussion of potential mechanisms of intragonadal nutrient receipt, storage, distribution and utilization in all classes of Echinodermata. The major constituent of this epithelium is a layer of interconnected flagellated-collar cells underlain by granule-containing perikarya and nerve tracts; muscle fibers which are thought to be specializations of the basal portions of some flagellated-collar cells have also been seen in the asteroids. The genital coelomic sinus is a fluid-filled space that totally separates the outer and inner sacs from each other in asteroids, ophiuroids, and probably in echinoids. Numerous studies of gametogenesis in both sexes of members of the Ophiuroidea have been made using light microscopy.

Gametogenesis and intragonadal nutrient storage and utilization are linked processes during sea urchin reproduction. Dynamically interacting germinal and somatic cellular populations make up the germinal epithelium of the sea urchin gonad. Uniquely among edible animal reproductive products, sea urchin gonads grow in size not only because gametogenesis increases the size and/or numbers of germinal cells present but also because somatic cells within the germinal epithelium, the nutritive phagocytes, store extensive nutrient reserves before gametogenesis begins. Here we provide an up-to-date discussion of the unique nature of sea urchin gametogenesis, including gonad structure, the dual gametogenic and somatic nutrient storage functions of sea urchin gonads, annual structural and molecular/genomic data and environmental control. Knowledge of these phenomena has led to successful manipulation of sea urchin reproduction and will increasingly provide opportunities for aquaculture worldwide.

The pharmaceutical compound carbamazepine (CBZ) is a contaminant of emerging concern. Wastewater irrigation can be a long-term, frequent source of CBZ; therefore, understanding the fate and transport of CBZ as a result of wastewater reuse practices has important environmental implications. The objective of this study was to estimate long-term soil transport of CBZ originating from treated wastewater irrigation on plots under different land uses. Field data from a previous study comparing CBZ concentrations in soil under different land uses were used in numerical modeling with HYDRUS-2D for the estimation of CBZ soil transport during 20 yr of irrigation with treated wastewater. This study showed high CBZ retention in soil under all investigated land uses. Adequate modeling results were obtained by using soil organic carbon-water partitioning coefficient (Koc ) for the CBZ linear sorption coefficient (Kd ) estimation, yet an underestimation of CBZ concentration in soil was still noted. Thus, results suggest that, although highly important, organic carbon content is probably not the only soil property governing CBZ sorption at this site, indicating the potential research perspective. Modeling results showed wastewater irrigation containing CBZ for 20 yr increased the CBZ concentration in the soil profile and its vertical movement, with the slowest vertical transport rate occurring on the forested plots. Overall results suggest that a beneficial management practice could be to increase soil organic carbon (e.g., compost addition) when using treated wastewater for irrigation in order to retain CBZ in the surface soil and thus limit its leaching through the soil profile.

Somatic portions of gonads in two phanerozonian sea-stars, Ctenodiscus crispatus and Hippasteria phrygiana, were similar in all aspects of gross structure and histology seen previously in both forcipulate and spinulosan asteroids. For the first time, detailed ultrastructural observations have been made of cells and tissues that reveal several features believed to be of universal occurrence in the gonads of asteroids. These include flagellated-collar cells in the visceral peritoneum and other coelomically derived epithelia, muscular-flagellated-collar cells in the visceral peritoneum and genital coelomic (perihaemal) sinus, the digestion of collagen fibers by cells in the connective tissue layer, and the intimate relationship of the genital haemal sinus and the entire germinal epithelium. Structural and functional compartmentalization are discussed in relation to major activities of the gonad throughout the annual reproductive cycle. The distinctive ultrastructure and current generation of flagellated-collar cells found in the visceral peritoneum are analyzed relative to their role in nutrient transport to gonadal tissues. The single flagellum of each flagellated-collar cell beats in coordination with those on neighboring cells to produce extremely rapid, oriented currents of coelomic fluid. The form of beating in an individual flagellum is planar, and the resulting synchronized activity of many adjacent flagella is non-metachronal; both of these characteristic aspects of current production have, thus far, been encountered together only in the Echinodermata. Flagellated-collar cells are efficient in generating currents which mix contents of the coelomic fluid, and they can presumably supply themselves with nutrients. It is concluded that nutrients so obtained are generally not passed through the wall of the gonad to the germinal epithelium and, as a result, have little to do with nutrition of somatic and germinal cells of the germinal epithelium. Alternatively, well-developed genital portions of the haemal system of the sea-star are advanced as the major channels supplying nutrients to germinal epithelia during gametogenesis.

Sixty-seven specimens of the common North Atlantic asteroid, Asterias vulgaris, were collected at seasonal intervals over a 2-year period and their testes observed with both light and electron microscopy. In the germinal epithelium, a predictable series of interactions between versatile somatic cells and germinal cells is repeated annually in relation to sequential events in spermatogenesis. For example, massive proliferation and differentiation of spermatogenic cells depend on the elaboration of thousands of spermatogenic columns, which are distinct cellular subdivisions of the germinal epithelium. Each fully developed column is composed of at least one somatic cell surrounded by ≈︁ 400 germinal cells. Such columns form only after intensive spermatogonial mitosis begins in the germinal epithelium. Single annual periods of spermatogenic proliferation and differentiation are initiated from 1 to 3 months out of phase in different individuals and overlap incompletely. Therefore, it is possible to observe testes that are entirely in the proliferative phase, entirely in the differentiative phase, or in both phases simultaneously. Detailed ultrastructural observations and preliminary autoradiographic data demonstrate that columns maintain their height for a variable period of time as germinal cells are generated near their bases, pass along their lengths, and differentiate near their tips; therefore, simultaneous proliferation and differentiation of more than one generation of germinal cells occur in the same column. Finally, formation of primary spermatocytes ceases basally, (terminating proliferation), and remaining columns degrade completely as germinal cells composing them differentiate or are phagocytized (terminating differentiation and spermatogenesis); resulting spermatozoa ultimately accumulate in the expandable lumen. It is proposed that spermatogenic columns provide the structural basis for organization of the microenvironment of small groups of spermatogenic cells (≈︁ 400 at a time) during proliferation and differentiation. Preliminary evidence from A. vulgaris and other species also suggests that somatic cells are temporally pluripotent and are variously involved in the formation, structure, and activities of columns, in extensive phagocytosis, and probably in contributing intrinsic (e.g., 1-methyl adenine and steroids) and mediating extrinsic (e.g., gamete shedding substance and nutrients) microenvironmental factors influential during spermatogenesis in asteroids. The prodigious spermatogenic capabilities of asteroids apparently depend on the generation of spermatogenic columns, on the progressive interaction of germinal and somatic cells before, during, and after columns form, and on the predictable effects of microenvironmental factors received and interpreted at the structural level of the spermatogenic column.

The softshell Mya arenaria is an ecologically and commercially important bivalve mollusc that develops a fatal cancer known as disseminated neoplasia or hemocyte leukemia. This cancer, like many human cancers, involves the master control gene of apoptosis, p53. This gene is also known to interact with retrotransposons, and a growing body of evidence suggests that p53 actually controls retrotransposon expression and subsequently oncogenesis. The recent description of a retrotransposon (i.e., Steamer) in adult M. arenaria and its potential involvement in the oncogenesis of hemocyte leukemia has been suggested. Juvenile clams, previously shown not to develop hemocyte leukemia, were exposed to climate-related changes in seawater temperature and pH predicted for the year 2100. All juvenile softshells do express the retrotransposon Steamer. When juvenile clams are exposed to predicted climate-related changes in temperature and pH in the Gulf of Maine, it significantly induces Steamer expression, specifically in treatments where clams were exposed to low pH. For juvenile individuals of M. arenaria and potentially other bivalves, Steamer may be a candidate biomarker for exposure to ocean acidification conditions.

The fine structure of the male reproductive system of the hermaphroditic brittle-star, Amphipholis squamata, has been studied in specimens from both the Pacific coast (Washington) and the Atlantic coast (New Hampshire). Each testis is a small (100-μm) sphere and is attached to the internal wall of the bursa by peritoneal suspensor cells. Occasional flagellated cells are found on the external surface of the testis. The testicular wall of A. squamata is a multilayered structure, similar to that of other ophiuroids, but the hemal sinus is PAS negative in this species. Germinal cells are surrounded throughout their development by the filopodia of interstitial cells. Adjacent interstitial cells are interconnected, and thus form a structural network within the testis. Positionally and functionally, the interstitial cells resemble Sertoli cells; however, their origin, behavior and ultrastructure are different in many ways. Spermatogenesis includes a series of cyclical changes (aspermatogenic phase, proliferative phase, differentiative phase, and evacuative phase). Within a single testis, the resulting production of sperm is in short pulses, but if all 10 testes are taken together, sperm are produced continuously throughout the year. The events of spermiogenesis closely follow those that have been described in other echinoderms. However, we have provided new information on the release of excess cell membranes and the fusion process of mitochondria. The mature spermatozoa of A. squamata are flagellated and motile, and have “primitive” structural features, in spite of the fact that they fertilize the eggs inside the genital bursae. The spermatozoa do not, as was previously thought, enter the bursa by rupture of the adjacent walls. Instead, they are ejaculated through a gonoduct into the rapid incurrent flow of water entering the bursa. The locomotion of the spermatozoa is in eccentric spirals, due to the unusually large angle at which the flagellum is inserted into the base of the sperm.

The results reported here provide a detailed account of the general morphology and histology of the male and female gonads of the sea-star Asterias vulgaris. The reproductive system of this sea-star (normal five-rayed specimens) consists of 10 separate units, each located proximally on the lateral wall of the ray, one on either side of the ray. Each unit is composed of a gonad, a gonoduct, and genital branches of the aboral haemal and coelomic rings. The gonad is a single bag-like structure with several protrusions (termed major and minor acini) extending from its surface. Its wall is composed of two sacs, one inside the other, separated by the genital coelomic (perihaemal) sinus. The outer sac consists of visceral peritoneum, an elastic-collagenous connective tissue layer, and many epithelial cells and circular muscle fibers. The inner sac comprises epithelial cells and longitudinal muscle fibers, the haemal sinus and contents, and germinal epithelium. The haemal sinus includes the haemal sinus space, filled with granular haemal fluid, cells, and collagen and other fine fibers enclosed by two fibrous laminae. Significant modifications in the form of the gonad and in the condition and relationships of the tissues which compose it occur during the annual reproductive cycle. Both sacs are stretched during growth of the gonad, the outer layers becoming attenuated and the inner layers being pressed against the outer, often obliterating the genital coelomic (perihaemal) sinus. The inner group of tissues is often extensively folded, pushing ridges formed from the inner wall of the haemal sinus and germinal epithelium into the lumen of the gonad. It is pointed out that previous studies on the gonads of asteroids have been relatively few, with no study for any species dealing comprehensively with morphological and histological details of the gonad based on both light and electron microscopy. Comparison of the results of the present study with observations of previous investigators indicates that although significant differences occur (especially in morphological terms), the general features of the histology of the wall of the gonad of many sea-stars are similar. In order to broaden our base for comparative studies, and to pursue significant problems, morphological, histological, histochemical, and ultrastructural investigations should be extended to as many asteroid species as possible.

The common northern sea star Asterias vulgaris is exposed to seasonal variation in temperature from -2 to 17°C. A. vulgaris exhibits an annual reproductive cycle, i.e., the testes increase slowly in size during fall and winter, and reach maximal size in early spring. Slow testicular growth in the winter has been attributed to low field temperatures. Previous studies indicate that the specific activity of ornithine decarboxylase and the levels of the polyamines putrescine, spermidine, and spermine decrease in mid-winter and increase in the spring, coincident with changes in field temperatures. Kinetic studies show that ornithine decarboxylase assayed from individuals collected in March exhibits negative thermal modulation (Km of ornithine is 0.22 mM and 0.65 mM at 15 and 0°C, respectively). Q10 values are highest at low substrate concentrations and at low temperatures. We hypothesize that during the cold winter months a decrease in the amount of ODC and an increase in the apparent Km causes polyamine synthesis to decline, leading to decreased growth and development of the testis. We suggest that thermal modulation of ODC (and polyamine synthesis) is a mechanism by which seasonal temperature fluctuations influence seasonal spermatogenesis in A. vulgaris. We further suggest that growth of various tissues in many other ectothermal invertebrates may be similarly controlled.

Disseminated neoplasia, a diffuse tumor of the hemic system, is character- ized in many bivalve mollusks by hemolymph containing 1-100% mitotic hemocytes. Little is known about the onset and chronic distribution of neoplasia in populations of Mya arenaria (Soft-shell Clam), though studies have reported episodic exposure to environmental contaminants or an infectious agent as a potential cause of this dis- ease. Here we provide the first set of continuous data on neoplasia in Soft-shell Clams, from three sites in New England where sediments have been characterized regarding their granulometry, composition, contaminants, and clam densities. When correlat- ing sediment characteristics to terminal neoplasia (76-100% neoplastic or rounded, unattached hemocytes), New Bedford Harbor, MA, which is the most contaminated site, had the highest frequency of treminal neoplasia (maximum of 9.49% ± 0.78 SE), and the most pristine site, Ogunquit, ME, displayed the lowest frequencies (maximum of 0.47% ± 0.05 SE). Correlations of frequency of neoplasia to known environmental contaminants also suggests that fully neoplastic individuals were found only at sites of increased levels of heavy metals, PCBs, and PAHs. In addition, we documented the highest frequency of clams with terminal neoplasia from New Bedford Harbor in December (9.49% ± 0.78 SE) when seawater temperatures were low, and the lowest frequency in July (1.08 ± 0.4 SE) when seawater temperatures were highest. These results may indicate vulnerability of neoplastic clams to seasonal increases in environ- mental temperature and resulting oxidative stress. Based on shell measurements and a theoretical mathematical age model (which correlates susceptibility to neoplasia with age and sexual maturity), we suggest that the Soft-shell Clam is most susceptible to this disease between one and two years of age (9.5% frequency at 1 year, 22.25% inci- dence at 1.5 years, and 57.14% incidence at 2 years).

Climate change is expected to increase the intensity of precipitation, but our ability to model the consequences for soil respiration are limited by a lack of data from soils that are saturated and draining. In this study, we used large intact soil columns (28 × 30 cm) to 1) quantify changes in CO 2 flux as soils drain from saturated conditions, and 2) to determine which soil water metrics best predict instantaneous maximum CO 2 flux. The columns were from three agricultural landscape positions that vary in soil properties. We simulated water table fluctuations that were observed at the field site (and predicted to increase in future climate scenarios) by flooding the columns from bottom to surface and then allowing the columns to drain for 96 h while monitoring volumetric soil water content (VWC), water filled pore space (WFPS), water content normalized to field capacity, matric potential, and CO 2 flux. Mean cumulative CO 2 flux was 4649 mg CO 2 ―C m − 2 96 h − 1 . Regardless of landscape position, CO 2 flux rates exhibited a single maximum slightly below saturation, near field capacity. This result suggests that many field studies have not captured soil respiration rates when water availability is optimum for heterotrophic respiration. Across landscape positions, matric potential was the most consistent indicator of instantaneous maximum CO 2 flux, with maximum fluxes occurring within the narrow range of − 0.15 to − 4.89 kPa. In contrast, instantaneous maximum CO 2 flux rates occurred between 95 and 131% of water content normalized to field capacity, 72–97% WFPS, and 29–45% VWC. Thus, our data suggest that instantaneous maximum CO 2 flux rates, a key parameter in ecosystem models, can be predicted across an agricultural landscape with diverse soils if matric potential is used as a water scalar.

All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensitivity, respiration, chemoreception and locomotion. In the green sea urchin, the most distal portion of these tube feet contain five ossicles arranged as a light collector with its concave surface facing towards the ambient light. These ossicles are perforated and lined with pigment cells that express a PAX6 protein that is universally involved in the development of eyes and sensory organs in other bilaterians. Polymerase chain reaction (PCR)-based sequencing and real time quantitative PCR (qPCR) also demonstrate the presence and differential expression of a rhabdomeric-like opsin within these tube feet. Morphologically, nerves that could serve to transmit information to the test innervate the tube feet, and the differential expression of opsin transcripts in the tube feet is inversely, and significantly, related to the amount of light that tube feet are exposed to depending on their location on the test. The expression of these genes, the differential expression of opsin based on light exposure and the unique morphological features at the distal portion of the tube foot strongly support the hypothesis that in addition to previously identified functional roles of tube feet they are also photosensory organs that detect and respond to changes in the underwater light field.

Hairy vetch (Vicia villosa Roth) is a promising winter cover crop for northern climates, but germination can be limited by low soil moisture conditions. Farmers may be reluctant to use hairy vetch, concerned that hard seed will emerge as weeds in succeeding crops. This work examines germination, dormancy, and viability of hairy vetch seeds from nine commercial seed sources, and evaluates the effects of mechanical scarification and ambient temperature hydropriming on the degree of hard-seededness, germination, seed viability and seedling vigor in a range of simulated soil moisture conditions. Hydropriming increased germination by 5% across seed sources and water potentials, but reduced seedling growth by 16%. Mechanical scarification eliminated all hard-seededness, but increased physiologically dormant seed by ∼5% and nonviable seed by ∼2% and reduced seedling growth by 39%. This work indicates that pretreatments may increase germination and reduce hard-seededness, but reduce seed viability and seedling vigor in some seed sources.

Anticipated increases in precipitation intensity due to climate change may affect hydrological controls on soil N 2 O fluxes, resulting in a feedback between climate change and soil greenhouse gas emissions. We evaluated soil hydrologic controls on N 2 O emissions during experimental water table fluctuations in large, intact soil columns amended with 100 kg ha -1 -KNO 3 -N. Soil columns were collected from three landscape positions that vary in hydrological and biogeochemical properties (N = 12 columns). We flooded columns from bottom to surface to simulate water table fluctuations that are typical for this site, and expected to increase given future climate change scenarios. After the soil was saturated to the surface, we allowed the columns to drain freely while monitoring volumetric soil water content, matric potential and N 2 O emissions over 96 h. Across all landscape positions and replicate soil columns, there was a positive linear relationship between total soil N and the log of cumulative N 2 O emissions (r 2 = 0.47; P = 0.013). Within individual soil columns, N 2 O flux was a Gaussian function of water-filled pore space (WFPS) during drainage (mean r 2 = 0.90). However, instantaneous maximum N 2 O flux rates did not occur at a consistent WFPS, ranging from 63% to 98% WFPS across landscape positions and replicate soil columns. In contrast, instantaneous maximum N 2 O flux rates occurred within a narrow range (-1.88 to -4.48 kPa) of soil matric potential that approximated field capacity. The relatively consistent relationship between maximum N 2 O flux rates and matric potential indicates that water filled pore size is an important factor affecting soil N 2 O fluxes. These data demonstrate that matric potential is the strongest predictor of the timing of N 2 O fluxes across soils that differ in texture, structure and bulk density.

Despite improvements in analytical techniques for detecting hormones, such as estrogen in environmental samples, there is conflicting information regarding sample filtration before analyses. In addition, there is little information about estrogen adsorption onto other common laboratory materials, including glass, plastic, or stainless steel. Therefore, we have quantified the adsorption of three different types of estrogen (estrone [E1], 17alpha-ethynylestradiol [EE2], and 17beta-estradiol [E2]) onto 11 different types of filters and six other types of materials used for sample storage and laboratory experiments. We observed significant (p < 0.05) differences in the amount of estrogen adsorbed to the different filters. Glass fiber filters adsorbed the lowest amount, whereas nylon filters adsorbed nearly all of the estrogen that contacted them during filtration. Stainless steel and polycarbonate also adsorbed significant amounts of E1, E2, and EE2. The materials with which estrogen comes into contact should be chosen carefully to avoid potential losses due to sorption.

The purple sea urchin, Strongylocentrotus pur- puratus, is the only non-chordate deuterostome model with a fully sequenced genome. Chromosomal localization of individual genes and resulting gene maps are unavailable for this or for any sea urchin. As a result, the purple sea urchin genome has not been mapped onto specific chromo- somes and remains inaccessible to genome-wide approaches addressing questions that require positional information for particular genes. Here we describe the first successful meth- ods for karyotyping and localizing specific gene loci on chromosomes of Strongylocentrotus purpuratus and those of the phylogenetically related Strongylocentrotus droe- bachiensis. Both species have 42 chromosomes in their diploid genomes (n 21). There are 2 large, 8 medium, and 10 small pairs, plus one putative sex pair. In both species, bindin genes were localized to 2 pair of homologous chro- mosomes by fluorescent in situ hybridization. Fluorescently labeled bacterial artificial chromosome clones generated from S. purpuratus for the functionally related genes brachyury, foxa, and foxb were localized to different chro- mosomes. Our protocols provide previously unavailable tools for developing a gene map for the purple sea urchin genome.

On the northeastern coast of the United States and Canada, Mya arenaria, the soft shell clam, develops a diffuse, hemopoetic tumor (a fatal leukemia-like cancer) resulting from inactivation of p53-like family member pro- teins.These malignant cells provide a model for an unrelated set of human cancer cells that are also characterized by mortalin-based cytoplasmic sequestration of wild-type p53 tumor suppressor protein (mortalin is the mitochondrial Hsp70 protein). Here we describe methods for mass culture and long-term storage of tumor cells from this cancer. These are the first successful efforts at maintaining malignant cells from any marine invertebrate in vitro. Following passage (subculture), these cultures undergo transition from primary cultures to non-immortalized cell lines that continue to proliferate and do not re-differentiate the normal hemocyte phenotype. We also characterize normal clam hemocytes and the pathology of cancerous clam hemocytes in vitro and in vivo using light and electron microscopy, cyto- and immunocytochemistry, molecular biology, and a phagocy- tosis assay. Our protocols provide biomedical and environ- mental researchers with ready access to this naturally oc- curring cancer model. We discuss the clam cancer model regarding (a) human health and disease; (b) animal health, disease, and aquaculture; (c) environmental health monitor- ing; and (d) future research directions.

As Jessani et al.,(1) point out development of cell and animal models that accurately depict human tumorigenesis remains a major goal of cancer research. Clam cancer offers significant advantages over traditional models for genotoxic and non-genotoxic preclinical analysis of treatments for human cancers with a similar molecular basis. The naturally occurring clam model closely resembles an outbreeding, human clinical population and provides both in vitro and in vivo alternatives to those generated from inbred mouse strains or by intentional exposure to known tumor viruses. Fly and worm in vivo models for adult human somatic cell cancers do not exist because their adult somatic cells do not divide. Clam cancer is the best characterized, naturally occurring malignancy with a known molecular basis remarkably similar to those observed in several unrelated human cancers where both genotoxic and non-genotoxic strategies can restore the function of wild-type p53. To further emphasize this point of view, we here demonstrate a p53-induced, mitochondrial-directed mechanism for promoting apoptosis in the clam cancer model that is similar to one recently identified in mammals. Discerning the molecular basis for naturally occurring diseases in non-traditional models and correlating these with related molecular mechanisms responsible for human diseases is a virtually unexplored aspect of toxico-proteomics and genomics and related drug discovery.

In nature, the soft shell clam, Mya arenaria, develops a fatal blood cancer in which a highly conserved homologue for wild-type human p53 protein is rendered nonfunctional by cytoplasmic sequestration. In untreated leukemic clam hemocytes, p53 is complexed throughout the cytoplasm with overexpressed variants for both clam homologues (full-length variant, 1,200-fold and truncated variant, 620-fold above normal clam hemocytes) of human mortalin, an Hsp70 family protein. In vitro treatment with etoposide only and in vivo treatment with either etoposide or mitoxantrone induces DNA damage, elevates expression (600-fold) and promotes nuclear translocation of p53, and results in apoptosis of leukemic clam hemocytes. Pretreatment with wheat germ agglutinin followed by etoposide treatment induces DNA damage and elevates p53 expression (893-fold) but does not overcome cytoplasmic sequestration of p53 or induce apoptosis. We show that leukemic clam hemocytes have an intact p53 pathway, and that maintenance of this tumor phenotype requires nuclear absence of p53, resulting from its localization in the cytoplasm of leukemic clam hemocytes. The effects of these topoisomerase II poisons may result as mortalin-based cytoplasmic tethering is overwhelmed by de novo expression of p53 protein after DNA damage induced by genotoxic stress. Soft shell clam leukemia provides excellent in vivo and in vitro models for developing genotoxic and nongenotoxic cancer therapies for reactivating p53 transcription in human and other animal cancers displaying mortalin-based cytoplasmic sequestration of the p53 tumor suppressor, such as colorectal cancers and primary and secondary glioblastomas, though not apparently leukemias or lymphomas. [Cancer Res 2008;68(3):777–82]

The germinal epithelium of sea urchin gonads contains two interdependent populations of cells: somatic cells called nutritive phagocytes (NPs) and germ cells—ovarian and testicular gonial cells and their derivatives, gametocytes and gametes. Annually, NPs vary their structure and function to produce a changing microenvironment for germ cells during gametogenesis and after spawning. Here, we describe seasonal changes in the NPs as they interact with germ cells during successive gametogenic stages in both sexes of the green sea urchin, Strongylocentrotus droebachiensis. Monthly samples were collected from the Gulf of Maine at a depth of 10 m and analyzed with light microscopy and stereology. Shorter day length and falling seawater temperatures were correlated with nutrient mobilization from NPs, initiation of gonial cell mitosis, and subsequent gametogenesis. During gametogenesis, NPs in both sexes were depleted of nutrients and eventually phagocytize residual ova or spermatozoa. Observations from this study are important for understanding both the cellular aspects of the reproductive biology of sea urchins and those environmental factors that affect the onset and progress of gametogenesis.

Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years. DOI: http://dx.doi.org/10.7554/eLife.13288.001, eLife digest For millions of years, reef-building stony corals have created extensive habitats for numerous marine plants and animals in shallow tropical seas. Stony corals consist of many small, tentacled animals called polyps. These polyps secrete a mineral called aragonite to create the reef – an external ‘skeleton’ that supports and protects the corals. Photosynthesizing algae live inside the cells of stony corals, and each species depends on the other to survive. The algae produce the coral’s main source of food, although they also produce some waste products that can harm the coral if they build up inside cells. If the oceans become warmer and more acidic, the coral are more likely to become stressed and expel the algae from their cells in a process known as coral bleaching. This makes the coral more likely to die or become diseased. Corals have survived previous periods of ocean warming, although it is not known how they evolved to do so. The evolutionary history of an organism can be traced by studying its genome – its complete set of DNA – and the RNA molecules encoded by these genes. Bhattacharya et al. performed this analysis for twenty stony coral species, and compared the resulting genome and RNA sequences with the genomes of other related marine organisms, such as sea anemones and sponges. In particular, Bhattacharya et al. examined “ortholog” groups of genes, which are present in different species and evolved from a common ancestral gene. This analysis identified the genes in the corals that encode the proteins responsible for constructing the aragonite skeleton. The coral genome also encodes a network of environmental sensors that coordinate how the polyps respond to temperature, light and acidity. Bhattacharya et al. also uncovered a variety of stress-related pathways, including those that detoxify the polyps of the damaging molecules generated by algae, and the pathways that enable the polyps to adapt to environmental stress. Many of these genes were recruited from other species in a process known as horizontal gene transfer. The oceans are expected to become warmer and more acidic in the coming centuries. Provided that humans do not physically destroy the corals’ habitats, the evidence found by Bhattacharya et al. suggests that the genome of the corals contains the diversity that will allow them to adapt to these new conditions. DOI: http://dx.doi.org/10.7554/eLife.13288.002

We have sequenced and characterized the complete mitochondrial genome of the soft-shell clam, Mya arenaria, an important organism for environmental toxicology and aquaculture. Mya arenaria is located in the taxonomic order Myoida, which lacks any member with a completely annotated mitogenome. The M. arenaria mitochondrial genome is 17 947 bp in length. Like most marine bivalves, the circular mitogenome codes entirely on the heavy strand, with no introns. As with other bivalves, the gene order of the mitochondrion is highly rearranged. The mitogenome contains 12 protein-coding genes but ATP8 is missing, consistent with about half of all bivalve genera. Twenty-three tRNAs were identified. Phylogenetic analysis shows that M. arenaria is related most closely with the bivalves Sinonovacula constricta, and Moerella iridescens, of the infraclass Euheterodonta (unassigned). This, along with the close grouping of the phylogenetic trees, confirms a close tie between Myoida and Euheterodonta (unassigned).

Sea urchin fisheries are valuable commercial resources in the United States with processed gonads sold in Japanese and American markets and maximum US sales of $150M US dollars in 1996. Wild populations of sea urchins on all coasts of the US have been dramatically over-fished. Aquaculture of sea urchins in land-based facilities can help restore commercial populations and preserve this ecologically important herbivore. In this study, we used invariant summer photoperiod to prevent gametogenesis in the North American green sea urchin (Strongylocentrotus droebachiensis) maintained in a land-based aquaculture system and provided a commercially available formulated feed that promotes maximum growth of intra-gonadal somatic nutrient storage cells called nutritive phagocytes. Results were compared with individuals fed the same formulated feed under ambient photoperiod in cages in the ocean. Monthly samples of gonads from both treatments were evaluated for gonad index, volume fractions of cellular constituents of the germinal epithelium, oocyte diameters and taste. Over the 5 months of this study, gonad indices increased significantly (pb0.001) in both treatments from 4.8%±0.9 (all values±SE) initially to 20.5%±2.1 under invariant and 23.2%±1.4 under ambient photoperiod with no significant difference between treatments (p=0.55). Volume fractions of nutritive phagocytes increased to 80.3%±5.9 (initial 37.9%±7.1) in males and 71.0%±6.7 (initial 10.3%±4.0) in females (pb0.001) only under invariant photoperiod. Nutritive phagocyte lengths increased under both photoperiod treatments, but the volume fraction containing nutrients was higher under invariant photoperiod. Volume fractions of gonial/gametogenic cells increased significantly (pb0.001) only under ambient photoperiod from 20.4%±5.5 to 37.8%±1.8 in males and 0% to 22.6%±3.6 in females. The volume fraction of residual oocytes from last year's oogenesis increased under invariant photoperiod while that of both residual and new oocytes increased under ambient photoperiod. Residual oocyte diameters increased from 56.2 μm±2.2 initially to 93.5 μm±3.7 under invariant and those of residual and new oocytes to 126.0 μm±7.3 under ambient photoperiod. Invariant photoperiod yields gonads in both sexes of S. droebachiensis that do not initiate fall gametogenesis but attain large size as their nutritive phagocytes grow substantially in size. A Canadian study

To connect pedon and landscape scales of soil moisture, a key lies in the distribution of different soils over the landscape. Mapping the fabric of soils over a watershed helps optimal sampling design and appropriate modeling of landscape hydrology. Such a hydropedological perspective is examined in a 7.9-ha forested catchment in central Pennsylvania in order to understand the spatio-temporal organization of soil moisture and its relationships with soil-landscape features. Soil moisture changes at four depth intervals (0–0.06, 0.11–0.29, 0.51–0.69, and 0.91–1.09 m) were monitored at 30 sites in the catchment for over 3 months in 2004. In addition, a reconnaissance campaign was conducted at 189 points on ten days during a 2.5-month period in 2003. Soil distribution and topographic metrics were correlated with the observed soil moisture patterns to reveal their relationships with soil type, depth to bedrock, topographic wetness index, slope, precipitation, and stream discharge. Among the five soil series identified in the catchment, the Ernest soil series (fine-loamy, mixed, superactive, mesic Aquic Fragiudults) remained the wettest throughout the monitoring periods, which was consistent with its morphology and topographic position (e.g., many redox features and a fragipan-like layer starting at 0.3–0.5 m depth). The Weikert soil series (loamy-skeletal, mixed, active, mesic Lithic Dystrudepts) had the driest condition because of its shallow depth to bedrock and steep slopes. Cluster analysis based on soil depth, topographic wetness index, and local slope showed that the 30 monitoring sites could be grouped into wet, moderately wet, moderately dry, and dry locations that exhibited different spatio-temporal patterns of subsurface soil moisture. Such a grouping correlated with the soil series plus local slopes. Because of complex interplays between soils and topography, the individual contributions from soils and topography to the soil moisture grouping were hard to separate. Time series data showed a quick stream flow response to precipitation forcing, indicating the rapid movement of water within the catchment into the stream channel. A conceptual model of hillslope hydrology in this catchment was developed to elaborate the patterns of soil moisture distribution along the hillslope and within soil profiles, their relations to the soil series, and four main flow pathways downslope (i.e., subsurface macropore flow, subsurface lateral flow at A–B horizon interface, return flow at footslope and toeslope, and flow at the soil–bedrock interface). This conceptualization enhances the understanding and modeling of preferential flow dynamics at the small catchment scale, particularly with regard to the role of detailed soil mapping and lateral flow in hillslope hydrology.

Transport properties of sulfonated poly(styrene-b-isobutylene-b-styrene) (S-SIBS) triblock copolymers were examined as a function of ion-exchange capacity (IEC), specifically at high IECs (up to ∼2 mequiv/g). The proton conductivity of S-SIBS was ∼1 order of magnitude higher than sulfonated polystyrene at similar IECs and 3-fold higher than Nafion 117 at an IEC of 2 mequiv/g. However, all polymers in this study possessed similar selectivities (i.e., proton conductivity/methanol permeability) regardless of chemistry or morphology. Small-angle X-ray scattering reveals a periodic-to-nonperiodic transition in S-SIBS with an anisotropic lamellar morphology oriented in the plane of the membrane at IECs ranging from 0.5 to 1 mequiv/g and an isotropic cocontinuous morphology at IECs ranging from 1.1 to 2 mequiv/g. This morphological transition coincides with a discontinuity in the IEC-dependent transport properties. In addition, S-SIBS transport properties were measured after solution casting from 15 different so...

Here we characterize the germinal epithelia of both sexes of Strongylocentrotus droebachiensis, the green sea urchin, throughout its annual gametogenic cycle, using light and electron microscopy and cytochemistry. In both sexes, germinal epithelia include two interacting cellular populations: nutritive phagocytes (NPs) and germ cells. After spring spawning, NPs accumulate nutrients; amitotic oogonia and often mitotic spermatogonia occur in clusters beneath NPs; and subsequent gametogenic stages are residual or absent. During the summer, NP nutrients are mobilized for use in vitellogenesis by residual primary oocytes or to support limited spermatogenesis. In addition, some residual primary oocytes may degenerate and be phagocytized by NPs. Significant nutrient mobilization from NPs and substantial gonial cell mitoses (indicative of new gametogenesis) occur in the fall. In both sexes, all of these changes are facilitated by NPs that form basal incubation chambers near the gonadal wall and within which germ cells are surrounded by nutrients released from the NPs. In females, germ cells at several stages of gametogenesis may be housed in separate chambers in the same NP. Primary oocytes also carry out jelly coat formation, meiosis, and cortical granule translocation within NP incubation chambers. In males, many NPs cooperate to provide large continuous chambers that contain spermatogenic cells at diverse stages. In both sexes these chambers persist throughout the year and isolate gametogenesis from the gonadal lumen. NPs become slender and shorten as their nutrients are depleted. Ova or spermatozoa are stored in the gonadal lumen. Post-spawning, NPs phagocytize differentiated germ cells while simultaneously enclosing intact gonial and residual gametogenic cells in basal chambers near the gonadal wall. In light of our observations, we suggest investigating proteins that may be important in the structural, phagocytic, and nutritive functions of NPs and for which corresponding genes have already been identified in the genome of S. purpuratus, the closely related purple sea urchin.

In this study, the morphology, transport properties, selectivity, and direct methanol fuel cell (DMFC) performance of a triblock copolymer ionomer, sulfonated poly(styrene–isobutylene–styrene) (S-SIBS), were investigated. The structure of S-SIBS membranes, ranging from 0.5 to 1.0 meq/g, was characterized using small-angle X-ray scattering and revealed a lamellar morphology with a preferred orientation in the plane of the membrane. Subsequently, proton conductivity measured normal to the plane of the membrane was over 10 times lower than when measured in plane , compared to only a 2.5 times difference in conductivity between the two techniques in Nafion 117. When proton conductivity was measured normal to the plane , the resulting selectivities (i.e. proton conductivity/methanol permeability) of S-SIBS membranes are similar to Nafion 117. A previous study [J. Membrane Sci. 217 (2003) 227] reports 5–10 times higher selectivities compared to Nafion 117 when conductivities were measured in plane . In addition, the DMFC performance of S-SIBS (1.0 meq/g) was lower than that of Nafion 117. These significant differences in transport properties and fuel cell performance with respect to polymer structure in S-SIBS membranes provide new insights into designing oriented nanostructures in polymer electrolyte membranes for enhanced transport properties for fuel cell applications.

In this study, the transport properties (i.e. methanol and proton transport) of a triblock copolymer ionomer, sulfonated poly(styrene-isobutylene-styrene) (S-SIBS), at various ion contents were investigated for its application to the direct methanol fuel cell (DMFC). Methanol permeabilities in S-SIBS were more than an order of magnitude lower than Nafion 117, but conductivities were only three-fold less at ambient conditions. S-SIBS was approximately 5–10 times more selective (i.e. proton conductivity/methanol permeability) than Nafion 117 over an ion content range of 0.5–1.0 mmol/g. Also, the transport results follow a power law dependent percolation model, where the critical exponent for diffusion was much lower than those reported in other studies, suggesting a more ordered nanostructure. In addition, transport at higher temperatures (80 °C) was examined. At 80 °C, S-SIBS was only 1.3 times more selective than Nafion 117 at an ion content of 1.0 mmol/g, but was 39 times more selective at an ion content of 0.5 mmol/g.

In order to identify a proton-conducting polymer membrane suitable for replacing Nafion ® 117 in direct methanol fuel cells (DMFC), we prepared a cross-linked copolymer of hydrophilic 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 2-hydroxyethyl methacrylate (HEMA). Fumed silicas were also added in an attempt to increase the amount of water adsorbed by the membrane and to enhance water retention. Hydrated copolymer membranes adsorbed significantly more water than Nafion ® 117, but were no better at retaining water during drying under ambient conditions. Films composed of 4% AMPS—96% HEMA had a room temperature proton conductivity of 0.029 S cm −1 , which increased to 0.06 S cm −1 at 80 °C.

The cell-cycle checkpoint protein p53 both directs terminal differentiation and protects embryos from DNA damage. To study invertebrate p53 during early development, we identified three differentially expressed p53 family members (p53, p97, p120) in the surf clam, Spisula solidissima. In these mollusks, p53 and p97 occur in both embryonic and adult tissue, whereas p120 is exclusively embryonic. We sequenced, cloned, and characterized p120 cDNA. The predicted protein, p120, resembles p53 across all evolutionarily conserved regions and contains a C-terminal extension with a sterile alpha motif (SAM) as in p63 and p73. These vertebrate forms of p53 are required for normal inflammatory, epithelial, and neuronal development. Unlike clam p53 and p97, p120 mRNA and protein levels are temporally expressed in embryos, with mRNA levels decreasing with increasing p120 protein (R(2) = 0.97). Highest surf clam p120 mRNA levels coincide with the onset of neuronal growth. In earlier work we have shown that neuronal development is altered by exposure to polychlorinated biphenyls (PCBs), a neurotoxic environmental contaminant. In this study we show that PCBs differentially affect expression of the three surf clam p53 family members. p120 mRNA and protein are reduced the most and earliest in development, p97 protein shows a smaller and later reduction, and p53 protein levels do not change. For the first time we report that unlike p53 and p97, p120 is specifically embryonic and expressed in a time-dependent manner. Furthermore, p120 responds to PCBs by 48 hr when PCB-induced suppression of the serotonergic nervous system occurs.

Anaerobic, fixed film, bioreactors bioaugmented with a dechlorinating microbial consortium were evaluated as a potential technology for cost effective, sustainable, and reliable treatment of mixed chlorinated ethanes and ethenes in groundwater from a large groundwater recovery system. Bench- and pilot-scale testing at about 3 and 13,500 L, respectively, demonstrated that total chlorinated solvent removal to less than the permitted discharge limit of 100 μg/L. Various planned and unexpected upsets, interruptions, and changes demonstrated the robustness and reliability of the bioreactor system, which handled the operational variations with no observable change in performance. Key operating parameters included an adequately long hydraulic retention time for the surface area, a constant supply of electron donor, pH control with a buffer to minimize pH variance, an oxidation reduction potential of approximately −200 millivolts or lower, and a well-adapted biomass capable of degrading the full suite of chlorinated solvents in the groundwater. Results indicated that the current discharge criteria can be met using a bioreactor technology that is less complex and has less downtime than the sorption based technology currently being used to treat the groundwater.

Green sea urchins, Strongylocentrotus droebachiensis OF Muller, collected off the coast of New Hampshire, USA, in late February 1995, were brought into the laboratory and fed an artificial diet ad libitum, and subjected to a photoperiod advanced by 4 months. During this study, temperatures and salinities for experimental urchins mirrored those recorded at the collection site. We examined the effects of changes in feeding regime and photoperiod on gametogenesis and compared the experimental urchins with those from the source population. During the 7-month period, experimental urchins showed no detectable changes in mean test height or diameter. Experimental urchins had a significantly higher gonad index (GI) in March, April and May (18 ± 6%) compared with field urchins in March (11 ± 3%). Subsequently, experimental urchins had a mean monthly GI of 25 to 30%, while the mean GI for field urchins was 11 to 13%. Gonial cell mitosis and gametogenesis occurred earlier in experimental male and female urchins compared with field urchins. Stereological and histological observations and stage–frequency data showed that the ovaries of experimental urchins were large because of the accelerated development of nutritive phagocytes, the volume fraction (Vv) of which was 89 to 90% of the gonad, while new vitellogenic primary oocytes occupied

Deep-well injection has been used to dispose of municipal liquid wastes in southwestern Florida since 1988. The liquid wastes are injected into an extremely high-transmissivity zone of fractured dolomite in the Early Eocene Oldsmar Formation of the Floridan aquifer system; this zone is commonly referred to as the Boulder Zone. Data collected during the drilling and operational testing of southwestern Florida injection wells provide insights into the nature of the injection zone and overlying confining beds. The location of high-transmissivity zones that are capable of accepting large quantities of waste water is vertically and horizontally variable and cannot be predicted with certainty. A 40.9-m thick high-permeability interval in one injection well, for example, was absent in a well drilled only 85.4 m away. Some upward migration of low-density injected fluids has occurred, but at no site were the injected liquids detected in deep monitor wells, such as occurred at injection-well sites along the coasts of southeastern, west-central, and east-central Florida. The primary confinement of the injected liquids (i.e., deepest effective confining beds) consists of unfractured beds of low-permeability dolomite within the Oldsmar Formation, whose locations are also laterally and vertically variable. The origin and controls of the distribution of fractures in the Oldsmar Formation are poorly understood.

Leukemia in the soft-shell clam, Mya arenaria, is characterized by tumor cells which are detected initially in the hemolymph. This disease is much more common in clams inhabiting polluted waters, suggesting an environmental component to its pathogenesis. In this study, leukemia cells were identified using a murine monoclonal antibody, 1E10, which recognizes a leukemia-specific protein expressed by tumor cells. Mutant p53 protein was detected using a murine monoclonal antibody (PAb 240) which reacts with mutant p53. Using immunofluorescence, the reactivity of clam cells to the 1E10 antibody was evaluated along with mutant p53 protein reactivity. Reverse transcriptase-polymerase chain reactions followed by sequence analyses were utilized to examine clams with hemocytes reacting with the p53 antibody for possible p53 gene mutations. Mutant p53 protein was expressed by tumor cells from five animals with advanced disease (in which greater than 90% of cells reacted with 1E10). A C → G transversion was detected at the end of exon 6 from two of the five animals that reacted with both the mutant p53 antibody and 1E10. This substitution changes the amino acid of this codon from proline to alanine. Overall, our results suggest that environmentally induced alterations in p53 can contribute to the pathogenesis of leukemia in soft-shell clams inhabiting polluted water and/or sediment.

Gametogenesis and intra-gonadal nutrient storage and utilization are linked processes during sea urchin reproduction. Dynamically interacting germinal and somatic cellular populations make up the germinal epithelium of the sea urchin gonad. Uniquely among edible animal reproductive products, sea urchin gonads grow in size not only because gametogenesis increases the size and/or numbers of germinal cells present, but also because somatic cells within the germinal epithelium, the nutritive phagocytes, store extensive nutrient reserves before gametogenesis begins. Here we provide an up-to-date discussion of the unique nature of sea urchin gametogenesis, including gonad structure, the dual gametogenic and somatic nutrient storage functions of sea urchin gonads, annual structural and molecular/genomic variation and environmental control. Knowledge of these phenomena has led to successful manipulation of sea urchin reproduction and will increasingly provide opportunities for aquaculture worldwide.

Due to its resistance to many wastewater treatment processes, the antiepileptic drug carbamazepine (CBZ) is routinely found in wastewater effluent. Wastewater irrigation is an alternative to stream discharge of wastewater effluent, which utilizes the soil as a tertiary filter to remove excess nutrients and has the potential to remove pharmaceutical compounds. Previous data suggest that CBZ is strongly sorbed to soil; however, it is unknown what its fate is for long periods of irrigation and if land use affects its distribution. Therefore, the objectives of our research were to characterize CBZ concentrations in soils that have been receiving wastewater irrigation for >25 yr under three different land uses: cropped, grassed, and forested. Triplicate soil cores were collected at each of the land uses to a depth of 120 cm. Extractions for CBZ were performed using 5-g soil samples and 20 mL of acetonitrile. The extracted solutions were analyzed on a liquid chromatograph tandem mass spectrometer. The samples were also analyzed for supporting information such as organic carbon, pH, and electrical conductivity. Results suggest that there is accumulation of the CBZ in the surface soils, which have the highest organic carbon content. Average concentrations of CBZ in the surface soils were 4.92, 2.9, and 1.92 ng g, for the forested, grassed, and cropped land uses, respectively. The majority of the CBZ was found in the upper 30 cm of the profile. Our results suggest that the soils adsorb CBZ and slow its movement into groundwater, compared to the movement of nonadsorbed chemicals.

In this chapter we demonstrate the remarkable sequence homology between mortalin proteins from a broad array of invertebrate taxa, including the few species for which functional analyses have been conducted. We also discuss expression and functional data for full-length and truncated clam homologs for human mortalin and their function in cytoplasmic sequestration in cancerous clam hemocytes. Both clam proteins have N-terminal mitochondrial targeting and p53 binding domains, though the truncated variant is missing exon 3 containing the N-terminal ATP/ADP binding and ATPase domains. Both variants are over-expressed and complexed with p53 and both may be responsible for cytoplasmic sequestration of p53 in cancerous clam hemocytes. Clam hemocyte cancer is the only animal model thus far investigated where cytoplasmically sequestered wild-type p53 can be reactivated both in vitro and in vivo using both genotoxic and non-genotoxic therapies. Our results suggest that mortalin-based cytoplasmic sequestration of wild-type p53 in cancerous clam hemocytes can be reversed by treatment with antineoplastic drugs also employed against similar human diseases and will result either in transcription-based apoptosis when the nucleus is accessible or non-transcription-based apoptosis when nuclear access is blocked.