Isolation and characterization of novel microsatellite markers and their application for diversity assessment in cultivated groundnut (Arachis hypogaea)

<p>Abstract</p> <p>Background</p> <p>Cultivated peanut or groundnut (<it>Arachis hypogaea </it>L.) is the fourth most important oilseed crop in the world, grown mainly in tropical, subtropical and warm temperate climates. Due to its origin through a single and recent polyploidization event, followed by successive selection during breeding efforts, cultivated groundnut has a limited genetic background. In such species, microsatellite or simple sequence repeat (SSR) markers are very informative and useful for breeding applications. The low level of polymorphism in cultivated germplasm, however, warrants a need of larger number of polymorphic microsatellite markers for cultivated groundnut.</p> <p>Results</p> <p>A microsatellite-enriched library was constructed from the genotype TMV2. Sequencing of 720 putative SSR-positive clones from a total of 3,072 provided 490 SSRs. 71.2% of these SSRs were perfect type, 13.1% were imperfect and 15.7% were compound. Among these SSRs, the GT/CA repeat motifs were the most common (37.6%) followed by GA/CT repeat motifs (25.9%). The primer pairs could be designed for a total of 170 SSRs and were optimized initially on two genotypes. 104 (61.2%) primer pairs yielded scorable amplicon and 46 (44.2%) primers showed polymorphism among 32 cultivated groundnut genotypes. The polymorphic SSR markers detected 2 to 5 alleles with an average of 2.44 per locus. The polymorphic information content (PIC) value for these markers varied from 0.12 to 0.75 with an average of 0.46. Based on 112 alleles obtained by 46 markers, a phenogram was constructed to understand the relationships among the 32 genotypes. Majority of the genotypes representing subspecies <it>hypogaea </it>were grouped together in one cluster, while the genotypes belonging to subspecies <it>fastigiata </it>were grouped mainly under two clusters.</p> <p>Conclusion</p> <p>Newly developed set of 104 markers extends the repertoire of SSR markers for cultivated groundnut. These markers showed a good level of PIC value in cultivated germplasm and therefore would be very useful for germplasm analysis, linkage mapping, diversity studies and phylogenetic relationships in cultivated groundnut as well as related <it>Arachis </it>species.</p

Tropomyosin Regulates Cell Migration during Skin Wound Healing

Precise orchestration of actin polymer into filaments with distinct characteristics of stability, bundling, and branching underpins cell migration. A key regulator of actin filament specialization is the tropomyosin family of actin-associating proteins. This multi-isoform family of proteins assemble into polymers that lie in the major groove of polymerized actin filaments, which in turn determine the association of molecules that control actin filament organization. This suggests that tropomyosins may be important regulators of actin function during physiological processes dependent on cell migration, such as wound healing. We have therefore analyzed the requirement for tropomyosin isoform expression in a mouse model of cutaneous wound healing. We find that mice in which the 9D exon from the TPM3/γTm tropomyosin gene is deleted (γ9D -/-) exhibit a more rapid wound-healing response 7 days after wounding compared with wild-type mice. Accelerated wound healing was not associated with increased cell proliferation, matrix remodeling, or epidermal abnormalities, but with increased cell migration. Rac GTPase activity and paxillin phosphorylation are elevated in cells from γ9D -/- mice, suggesting the activation of paxillin/Rac signaling. Collectively, our data reveal that tropomyosin isoform expression has an important role in temporal regulation of cell migration during wound healing.(NHMRC) grant 51225

Exploring the Oversight of Risk Management in UK Higher Education Institutions: The Case of Audit Committees

We explore how audit committees (ACs) oversee risk management in UK Higher Education Institutions (HEIs), using semi-structured interviews, attendance at AC meetings and documentary analysis. We find that the AC’s oversight seems constrained by a fixation on the process of risk management, an over-reliance on risk registers, and varying levels of emphasis on operational risks. Theoretically, the AC’s oversight reflects different shades of symbolic and substantive activities designed to maintain the HEI’s legitimacy and that of its governing board, hence providing a symbolic representation. We raise concerns as to the AC’s ability to monitor effectively the HEIs’ risk management practices

A ten-year follow-up of a study of memory for the attack of September 11, 2001: Flashbulb memories and memories for flashbulb events.

Within a week of the attack of September 11, 2001, a consortium of researchers from across the United States distributed a survey asking about the circumstances in which respondents learned of the attack (their flashbulb memories) and the facts about the attack itself (their event memories). Follow-up surveys were distributed 11, 25, and 119 months after the attack. The study, therefore, examines retention of flashbulb memories and event memories at a substantially longer retention interval than any previous study using a test-retest methodology, allowing for the study of such memories over the long term. There was rapid forgetting of both flashbulb and event memories within the first year, but the forgetting curves leveled off after that, not significantly changing even after a 10-year delay. Despite the initial rapid forgetting, confidence remained high throughout the 10-year period. Five putative factors affecting flashbulb memory consistency and event memory accuracy were examined: (a) attention to media, (b) the amount of discussion, (c) residency, (d) personal loss and/or inconvenience, and (e) emotional intensity. After 10 years, none of these factors predicted flashbulb memory consistency; media attention and ensuing conversation predicted event memory accuracy. Inconsistent flashbulb memories were more likely to be repeated rather than corrected over the 10-year period; inaccurate event memories, however, were more likely to be corrected. The findings suggest that even traumatic memories and those implicated in a community's collective identity may be inconsistent over time and these inconsistencies can persist without the corrective force of external influences.This is the author accepted manuscript. The final version is available from the American Psychological Association via http://dx.doi.org/10.1037/xge000005