Absence of gemin5 from SMN complexes in nuclear Cajal bodies

<p>Abstract</p> <p>Background</p> <p>Spinal muscular atrophy is caused by reduced levels of the survival of motor neurons (SMN) protein. SMN is found in large complexes with Sm proteins and at least eight other proteins, including seven "gemins". These complexes are involved in the assembly of snRNPs in the cytoplasm and their transport into the nucleus, but the precise roles of the individual protein components are largely unknown.</p> <p>Results</p> <p>We have investigated the subcellular distribution of gemins using novel antibodies against gemins 3–7, and existing mAbs against SMN, gemin2, unrip, fibrillarin and profilin II. Most gemins were equally distributed between nuclear and cytoplasmic fractions of HeLa cells, but gemin5 and unrip were more abundant in the cytoplasm. In a cytoplasmic extract obtained by mild disruption of HeLa cells, nearly all the SMN and gemins 2–4 were in large complexes, but most of the gemin5 sedimented separately with a lower S value. Most of the unrip sedimented with gemins 6 and 7 near the top of the sucrose density gradients, separate from both SMN and gemin5. Anti-SMN mAbs pulled down gemin5 from cytoplasmic extracts, but not from nuclear extracts, and gemin5 did not co-sediment with large SMN complexes in nuclear extracts. These data suggest that gemin5 is easily detached from SMN-gemin complexes in the nucleus. By immuno-histochemistry, gemin5 was rarely detectable in nuclear gems/Cajal bodies, although it was accessible to antibody and easily detectable when present. This suggests that gemin5 is normally absent from SMN complexes in these nuclear storage sites.</p> <p>Conclusion</p> <p>We conclude that SMN complexes usually exist without gemin5 in nuclear gems/Cajal bodies. Gemin5 is believed to be involved in capturing snRNA into SMN complexes in the cytoplasm for transport into the nucleus. We hypothesize that gemin5, though present in the nucleus, is no longer needed for SMN complex function during the time these complexes are stored in gems/Cajal bodies.</p

Seeding Strategies for Multi-Objective Test Case Selection: An Application on Simulation-based Testing

The time it takes software systems to be tested is usually long. This is often caused by the time it takes the entire test suite to be executed. To optimize this, regression test selection approaches have allowed for improvements to the cost-effectiveness of verification and validation activities in the software industry. In this area, multi-objective algorithms have played a key role in selecting the appropriate subset of test cases from the entire test suite. In this paper, we propose a set of seeding strategies for the test case selection problem that generate the initial population of multi-objective algorithms.We integrated these seeding strategies with an NSGA-II algorithm for solving the test case selection problem in the context of simulation-based testing. We evaluated the strategies with six case studies and a total of 21 fitness combinations for each case study (i.e., a total of 126 problems). Our evaluation suggests that these strategies are indeed helpful for solving the multi-objective test case selection problem. In fact, two of the proposed seeding strategies outperformed the NSGA-II algorithm without seeding population with statistical significance for 92.8 and 96% of the problems

Sustainable construction – an international comparison of civil engineering students

Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitudes regarding sustainable construction of civil engineering students at The NUCE (National University of Civil Engineering) in Vietnam, and the Universities of Loughborough and Liverpool in the UK were therefore conducted. Results indicate that students at all three universities appreciate the importance of the development of sustainable construction and have positive attitudes with regards to sustainability. Construction design and appropriate use of materials were two issues generally considered the most important with regards to sustainability, but were also thought to be adequately covered on the courses in all three institutions