A molecular cell biology toolkit for the study of meiosis in the silkworm Bombyx mori

Meiosis is usually described as 4 essential and sequential processes: (1) homolog pairing; (2) synapsis, mediated by the synaptonemal complex; (3) crossing over; and (4) segregation. In this canonical model, the maturation of crossovers into chiasmata plays a vital role in holding homologs together and ensuring their segregation at the first meiotic division. However, Lepidoptera (moths and butterflies) undergo 3 distinct meiotic processes, only one of which is canonical. Lepidoptera males utilize 2 meiotic processes: canonical meiosis that produces nucleated fertile sperm, and a noncanonical meiosis that produces anucleated nonfertile sperm which are nonetheless essential for reproduction. Lepidoptera females, which carry heteromorphic sex chromosomes, undergo a completely achiasmate (lacking crossovers) meiosis, thereby requiring an alternative mechanism to ensure proper homolog segregation. Here, we report that the development of a molecular cell biology toolkit designed to properly analyze features of meiosis, including the synaptonemal complex structure and function, in the silkworm Bombyx mori. In addition to standard homology searches to identify Bombyx orthologs of known synaptonemal complex encoding genes, we developed an ortholog discovery app (Shinyapp) to identify Bombyx orthologs of proteins involved in several meiotic processes. We used this information to clone genes expressed in the testes and then created antibodies against their protein products. We used the antibodies to confirm the localization of these proteins in normal male spermatocytes, as well as using in vitro assays to confirm orthologous interactions. The development of this toolkit will facilitate further study of the unique meiotic processes that characterize meiosis in Lepidoptera.</p

Beyond the call of duty: Why customers contribute to firm-hosted commercial online communities

Firm-hosted commercial online communities, in which customers interact to solve each other's service problems, represent a fascinating context to study the motivations of collective action in the form of knowledge contribution to the community. We extend a model of social capital based on Wasko and Faraj (2005) to incorporate and contrast the direct impact of commitment to both the online community and the host firm, as well as reciprocity, on quality and quantity of knowledge contribution. In addition, we examine the moderating influence of three individual attributes that are particularly relevant to the firm-hosted community context: perceived informational value, sportsmanship, and online interaction propensity. We empirically test our framework using self-reported and objective data from 203 members of a firm-hosted technical support community. In addition to several interesting moderating effects, we find that a customer's online interaction propensity, commitment to the community, and the informational value s/he perceives in the community are the strongest drivers of knowledge contribution

The communibiological perspective: Implications for communication in instruction

Recent advances in neurobiology and psychobiology have raised serious questions about the generality and usefulness of the social learning model upon which a meaningful portion of the curriculum of many communication departments is based. Evidence is accumulating to indicate there is a major role played by genetics in human communication behavior. These developments, and generations of disputes over "nature " vs. "nurture, "have given rise to what has been called the "communibiological perspective."; This paper addresses the implications of the perspective for communication curricula in the 21 st century

It's in our nature: Verbal aggressiveness as temperamental expression

Over the past ten years, a substantial body of research focusing on verbal aggressiveness has accumulated. One major observation emerging from this literature is that some people are more disposed toward aggressive symbolic action than are others. Despite this considerable research effort, why individuals vary in their predispositions toward aggressive communication in interpersonal contexts is not well understood. Current speculation about the origin of verbally aggressive predispositions reflects a long standing paradigm which assigns importance to various learning processes. However, communication scholars have ignored the work of psychobiologists that strongly points to inborn neurobiological bases for human behavior and a trivial impact of environment. In this essay, we propose a theory of verbal aggressiveness supported by the work of psychobiologists as articulated in the temperament literature. We contend that verbal aggressiveness represents expressions of inborn, biological functioning, which is antecedent to social experience and, therefore, independent of social learning processes. In formulating our position, we (1) delineate a metatheoretic rationale for a temperament-based model of verbal aggressiveness, (2) integrate neurologically-based temperament functions into an explanation of research findings regarding verbal aggression, (3) present a working model of verbal aggression, and (4) discuss the implications of our theoretical position