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As the single opportunity for plants to move, seed dispersal has an important impact on plant fitness, species distributions and patterns of biodiversity. However, models that predict dynamics such as risk of extinction, range shifts and biodiversity loss tend to rely on the mean value of parameters and rarely incorporate realistic dispersal mechanisms. By focusing on the mean population value, variation among individuals or variability caused by complex spatial and temporal dynamics is ignored. This calls for increased efforts to understand individual variation in dispersal and integrate it more explicitly into population and community models involving dispersal. However, the sources, magnitude and outcomes of intraspecific variation in dispersal are poorly characterized, limiting our understanding of the role of dispersal in mediating the dynamics of communities and their response to global change. In this manuscript, we synthesize recent research that examines the sources of individual variation in dispersal and emphasize its implications for plant fitness, populations and communities. We argue that this intraspecific variation in seed dispersal does not simply add noise to systems, but, in fact, alters dispersal processes and patterns with consequences for demography, communities, evolution and response to anthropogenic changes. We conclude with recommendations for moving this field of research forward.

Diffuse large B‐cell lymphoma (DLBCL) is the most prevalent subtype of non‐Hodgkin lymphoma (NHL) in domestic dogs, with many similarities to its human counterpart. The progression of the disease is rapid, and treatment must be initiated early to achieve cancer remission and extend life. This study examined the relationship between progression‐free survival (PFS) and microRNA (miRNA) expression in dogs with DLBCL. miRNAs are small non‐coding RNA molecules that typically regulate gene expression post‐transcriptionally. They are involved in several pathophysiological processes, including the growth and progression of cancer. Based on the analysis of small RNA sequencing (sRNA‐seq) data, we validated a group of miRNAs in lymph nodes from 44 DLBCL‐affected dogs with known outcomes. We used quantitative PCR to quantify their expression and report a specific subset of miRNAs is associated with decreased PFS in dogs with DLBCL. The miR‐192‐5p and miR‐16‐5p expression were significantly downregulated in dogs with increased PFS. These results indicate that miRNA profiling may potentially identify dogs with DLBCL that will experience poor outcomes following treatment. Identifying specific miRNAs that correlate with the progression of canine DLBCL could aid the development of individualized treatment regimens for dogs. [ABSTRACT FROM AUTHOR]

Lymphoma is among the most common cancer in dogs. Diffuse large B-cell lymphoma (DLBCL) is the predominant type, accounting for up to half of all cases. Definitive diagnosis of DLBCL relies on cytologic evaluation with immunophenotyping, or histopathology and immunohistochemistry when needed. A rapid and specific molecular test aiding in the diagnosis could be beneficial. Noncoding microRNAs (miRNAs) are regulators of gene expression involved in a variety of cellular processes, including cell differentiation, cell cycle progression, and apoptosis. Not surprisingly, miRNA expression is aberrant in diseases such as cancers. Their high stability and abundance in tissues make them promising biomarkers for diagnosing and monitoring diseases. This study aimed to identify miRNA signatures of DLBCL to develop ancillary molecular diagnostic tools. miRNA was isolated from formalin-fixed, paraffin-embedded lymph node tissue from 22 DLBCL and 14 nonneoplastic controls. Relative gene expression of 8 tumor-regulating miRNAs was achieved by RT-qPCR (reverse transcriptase quantitative polymerase chain reaction). The results showed downregulation of the let-7 family of miRNAs and miR-155, whereas miR-34a was upregulated in DLBCL compared to the controls. We demonstrated that the combination of expression levels of miR-34a and let-7f or of let-7b and let-7f achieved 100% differentiation between DLBCL and controls. Furthermore, let-7f alone discriminated DLBCL from nonneoplastic tissue in 97% of cases. Our results represent one step forward in search of a rapid and accurate ancillary diagnostic test for DLBCL in dogs. [ABSTRACT FROM AUTHOR]

Seeds of many hardwood trees are dispersed by scatter-hoarding rodents, and this process is often mediated by the traits of seeds. Although numerous studies have linked seed traits to seed preference by rodents, little is known about how rodents forage for seeds when multiple desirable and undesirable seed traits are available simultaneously. Here, we adopt a novel method of designing choice experiments to study how eastern gray squirrels (Sciurus carolinensis) select for 6 traits (caloric value, protein content, tannin concentration, kernel mass, dormancy period and toughness of shell) among seeds. From n = 426 seed-pair presentations, we found that squirrels preferentially consumed seeds with short dormancy or tougher shells, and preferentially cached seeds with larger kernel mass, tougher shells and higher tannin concentrations. By incorporating random effects, we found that squirrels exhibited consistent preferences for seed traits, which is likely due to the fitness consequences associated with maintaining cached resources. Furthermore, we found that squirrels were willing to trade between multiple traits when caching seeds, which likely results in more seed species being cached in the fall. Ultimately, our approach allowed us to compute the relative values of different seed traits to squirrels, despite covariance among studied traits across seed species. In addition, by investigating how squirrels trade among different seed traits, important insights can be gleaned into behavioral mechanisms underlying seed caching (and, thus, seed survival) dynamics as well as evolutionary strategies adopted by plants to attract seed dispersers. We describe how discrete choice experiments can be used to study resource selection in other ecological systems. [ABSTRACT FROM AUTHOR]