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Channeled whelk (Busycotypus canaliculatus Linnaeus, 1758) are predatory marine gastropods that are found in intertidal regions of the continental slope along the U.S. Atlantic coast from Cape Cod, Massachusetts to Cape Canaveral, Florida. The channeled whelk is a commercially important species that supports a fishery along the Atlantic coast of the United States. The resource is managed at the state level with minimum landing size (MLS) varying by state. Biological assessments of channeled whelk in the mid-Atlantic and Massachusetts have indicated that females have a low probability of being mature when they enter the fishery. The life history characteristics of channeled whelk including slow growth, late maturation, and direct development paired with unsuitable MLS make this species vulnerable to overexploitation. Currently, the population genetic structure of channeled whelk is unknown, impeding the creation of appropriate management strategies. This study aimed to delineate the population genetic structure of channeled whelk using genotyping-by-sequencing of 252 samples from 10 resource areas from Massachusetts to South Carolina, with fine-scale sampling in the mid-Atlantic region. A total of 2,570 single nucleotide polymorphisms (SNPs) were used to estimate genetic diversity and delineate population structure among resource areas. Analysis of all 10 resource areas revealed four major genetic groups: 1) North and mid-Atlantic resource areas, 2) Pamlico Sound, North Carolina, 3) Wilmington, North Carolina, and 4) Charleston, South Carolina with additional structuring within the north and mid-Atlantic. Analysis North and mid-Atlantic resource samples indicated that Virginia Beach, Virginia was significantly different from all other mid-Atlantic resource areas (FST = 0.001 – 0.016, p < 0.001). Massachusetts and Rhode Island were also significantly different from each other (FST = 0.084, p < 0.001) and from mid-Atlantic samples (FST = 0.031 – 0.128, p < 0.001). Overall, data indicate 7 genetically distinct populations along US East Coast. Estimates of genetic divergence (FST) spanned several orders of magnitude with elevated divergence levels observed when comparing samples from across known biogeographic barriers along the Atlantic coast. FST values were highest (0.150 – 0.465, p <0.001) when comparing samples off Pamlico Sound, North Carolina, off Wilmington, North Carolina, and off Charleston, South Carolina to samples from all other resource areas. The complex population genetic structure revealed by this study underscores the need for further study and for new management strategies for the channeled whelk fishery in resource areas along the Atlantic coast. Results from this study can be used to assess alternative decisions about the appropriate scale for management of the channeled whelk resource in the mid-Atlantic region, which is threatened by overharvest and removal of whelk before they are sexually mature.

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Rapid growth rate and partial sterility have made triploid eastern oysters (Crassostrea virginica) the most popular crop variety for the Virginia oyster aquaculture industry, typically comprising greater than 90% of larvae and juvenile sales. Triploid advantages, however, sometimes come with the disadvantage of higher mortality in late spring and early summer, dubbed “triploid mortality.” In recent years, farms up and down the East Coast, especially Maryland and south into the Gulf of Mexico have experienced triploid mortality. Some of the reports include observations of elevated triploid fecundity. Triploid oysters are created by crossing tetraploids to diploids, and much of the commercial broodstock is acquired through the Virginia Institute of Marine Science Aquaculture Genetics and Breeding Technology Center (ABC). Tetraploid oysters are created from fecund triploid females and propagated favoring the most fertile tetraploids. We hypothesized that heritable fertility may be transferred to the commercial product, possibly yielding fertile triploid oysters. To investigate this possibility, twelve half-sibling families were produced by crossing individual tetraploid males with aliquots from a pooled source of eggs from diploid females. Tetraploid males came from tetraploid lines bred for one, two, five, or eight generations. Two replicates of each family were deployed to two sites: a site known for episodes of triploid mortality on the Eastern Shore of Chesapeake Bay, and at a control site in the Rappahannock River. Temperature and salinity exhibited typical patterns at both sites while oysters were raised to market size. When compared to the control site, cumulative mortality of triploid oysters at the Eastern Shore location was significantly higher, with significantly lower growth rate and fecundity; the latter measured by direct egg counts at peak ripeness. Diploid oysters performed similarly at both sites and exhibited significantly greater fecundity than triploids. Fecundity differed significantly among several triploid families based upon paternal lineage, but fecundity did not vary as a function of tetraploid lineage.

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Osteosarcoma is a rare primary bone tumor for which no significant therapeutic advancement has been made since the late 1980’s despite ongoing efforts. A subset of patients who share good prognosis respond well to the current chemotherapeutic regimen of methotrexate, doxorubicin, and cisplatin. However, pathologically assessed chemotherapy response has thus far failed as a tool to stratify patients to alternate therapies and improve patient outcomes. Aside from chemotherapy response, no other validated prognostic factor exists, and genetic studies have not revealed any actionable drug targets. We and others have previously reported that epigenomic biomarkers may be useful in this disease. We thus investigated the capacity for microRNAs to mark the transition from a chemotherapy sensitive to resistant tumor phenotype. We performed small RNA sequencing on a cohort of paired pre-chemotherapy and post-chemotherapy frozen high-grade osteosarcoma tumor samples and discovered a profile of miRNAs with dynamic expression patterns following chemotherapy exposure in patient samples. An independent dataset of paired pre-chemotherapy and post-chemotherapy formalin fixed paraffin embedded samples we assayed with array-based technology was used to show the miRNA profiles are reproducible. Transcriptional studies of the miRNAs’ target genes contextualize the potential biological role of the miRNAs. In a pharmacogenomic screen, both miRNAs and their target genes predict response to drugs which reverse the chemoresistant phenotype and potentially synergize with chemotherapy in otherwise treatment resistant tumors. / 2026-02-28T00:00:00Z

The Clearnose Skate (Rostroraja eglanteria, Bosc 1800) is a flat, benthic elasmobranch and member of the family Rajidae. They are widely distributed in the coastal waters of the east coast of the United States and in the northeastern Gulf of Mexico. It has been noted that the physical appearance of Clearnose Skate from the southern end of their range near South Carolina is distinct from individuals found in the northern end of their range near Woods Hole, MA, perhaps suggestive of a sub-species, though this observation has not been further investigated. Clearnose Skate are seasonally migratory and are often incidentally caught in bottom trawl fisheries during times of migration and congregation, discarded at sea, and poorly accounted for in catch records. They are managed by the New England Fishery Management Council (NEFMC) as part of a skate complex, which includes six other species of skate, and are not currently managed by the Southeast Fishery Management Council or the Gulf States Fishery Management Council. Continuing to indiscriminately harvest an undermanaged species without knowledge of the underlying population structure can have deleterious effects on scientific, conservation, and management efforts. This study used an interdisciplinary combination of molecular and morphological techniques to better understand the population structure of the Clearnose Skate sampled throughout their geographic range. Specimens were collected by fisheries-independent surveys and categorized into one of three study regions; U.S. East Coast north of Cape Hatteras (NOR), U.S. East Coast from Cape Hatteras to Florida (SOU), and the Gulf of Mexico (GOM). For genetic studies, DNA was extracted from 194 specimens (NOR = 127, SOU = 45, GOM = 22) and shipped to Diversity Arrays Technology for high-throughput genotyping-by-sequencing, resulting in a final filtered dataset of 8,914 loci (outlier and neutral) and 30 outlier loci. For morphological studies, 126 specimens (NOR =57, SOU = 47, GOM = 24) were used to collect 41 morphometric, 9 thorn, and 7 skeletal characters. Results of both genetic and morphological analyses indicate that GOM specimens are distinct from those collected off the U.S East Coast and should be managed as a separate population. This study was unable to definitively resolve whether structure was present in samples collected along the U.S. east coast, but genetic data indicated small but significant differences between samples collected in the South Carolina, Georgia, and Florida region as compared to samples collected from more northern regions based on pairwise FST values. These genetic differences were spatially autocorrelated, indicating a genetic gradient along the East Coast consistent with an isolation-by-distance model. Before management recommendations in this region can be made, more information regarding Clearnose Skate migration and reproduction are needed.