Subcellular partitioning of MRP RNA assessed by ultrastructural and biochemical analysis.

A small RNA encoded within the nucleus is an essential subunit of a RNA processing endonuclease (RNase MRP) hypothesized to generate primers for mitochondrial DNA replication from the heavy strand origin of replication. Controversy has arisen, however, concerning the authenticity of an intramitochondrial pool of MRP RNA, and has called into question the existence of pathways for nucleo-mitochondrial transport of nucleic acids in animal cells. In an effort to resolve this controversy, we combined ultrastructural in situ hybridization and biochemical techniques to assess the subcellular partitioning of MRP RNA. Cryosections of mouse cardiomyocytes were hybridized with biotin-labeled RNA probes complementary to different regions of MRP RNA and varying in length from 115 to 230 nucleotides, followed by immunogold labeling. In addition, we transfected mouse C2C12 myogenic cells with constructs bearing mutated forms of the mouse MRP RNA gene and compared the relative abundance of the resulting transcripts to that of control RNAs within whole cell and mitochondrial fractions. In the former analysis we observed preferential localization of MRP RNA to nucleoli and mitochondria in comparison to the nucleoplasm and cytoplasm. In the latter series of studies we observed that wild-type MRP RNA partitions to the mitochondrial fraction by comparison to other RNA transcripts that are localized to the extramitochondrial cytoplasmic space (28S rRNA) or to the nucleoplasm (U1 snRNA). Deletions within 5' or 3' regions of the MRP RNA gene produced transcripts that remain competent for mitochondrial targeting. In contrast, deletion of the midportion of the coding region (nt 118 to 175) of the MRP RNA gene resulted in transcripts that fail to partition to the mitochondrial fraction. We conclude that an authentic intramitochondrial pool of MRP RNA is present in these actively respiring cells, and that specific structural determinants within the MRP RNA molecule permit it to be partitioned to mitochondria

Blueberry Advisory Committee Research Report

The 1985 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Control of secondary blueberry pest insects 2. Effect of pruning practices on blueberry insect abundance 3. Effect of hexazinone on species distribution in lowbush blueberry fields 4. Dichlobenil for control of bunchberry 5. Evaluation of postemergence herbicides for grass control 6. Hand-wiper applications of herbicides on woody weeds 7. Evaluation of steam as a pruning practice for lowbush blueberry fields 8. Evaluation of glyphosate and 2,4-D applied with a commercial weed roller to control woody weeds 9. Hand-wiping and cutting treatments for dogbane 9. Evaluation of airblast-sprayer application of asulam for bracken fern control 10. Spot treatment of woody weeds with 2,4-D in oil 11. Chemical control of Botrytis blossom blight 12. Evaluation of preliminary steam treatments (1984) at Blueberry Hill Farm 13. Long term effects of N and NPK fertilizer on plant growth and yield 14. Nutritional survey of selected lowbush blueberry fields 15. Interaction of fertility and pruning practices on soil characteristics and lowbush blueberry growth and yield 16. Frequency of fertility application for establishment of lowbush blueberry seedlings 17. Slow release vs. liquid fertilizer for establishment of lowbush blueberry seedlings 18. The effect of several mulches on frost heaving, soil moisture, soil temperature and rhizome development 19. Blueberry product development: raisin-type blueberries 20. Blueberry product development: blueberry puree 21. Addendum: 1985 Report from Moody Trevet

Blueberry Advisory Committee Research Report

The 1984 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Control, biology, and ecology of insects affecting lowbush blueberries . 2. Chemical control of mummyberry disease (Monilinia vaccinii-corymbosi) 3. New Fungicides for control of Botrytis blossom blight 4. Nutritional survey of selected lowbush blueberry fields 5. Interaction of fertility and pruning practices on soil characteristics and lowbush blueberry growth and yield 6. Long term effects of N and NPK fertilizer on plant growth and yield 7. The effect of N fertilization on clonal spread 8. Nutritional responses of the lowbush blueberry in new plantings as related to early establishment 9. The effect of several mulches on frost heaving, soil moisture, soil temperature and rhizome development 10. Effectiveness of mulches and planted lowbush blueberry seedlings for stabilizing soils and increasing plant cover 11. Effect of surface mulches on stabilizing lowbush blueberry soil in barren areas 12. Frequency of fertility application for establishment of lowbush blueberry seedlings 13. Slow release vs liquid fertilizer for establishment of lowbush blueberry seedlings 14. Comparison of rooted cuttings and tissue culture propagated lowbush blueberry plants 15. The effect of growth regulator formulations on growth and rhizome production of the lowbush blueberry 16. Unburned, mowed fields 17. Blueberry concentrate 18. Blueberry product development 19. Dehydrated blueberries 20. Low-calorie blueberry jellies 21. Hexazinone and terbacil mixture for weed control 22. Hexazinone and atrazine mixture for weed control 23. Effect of hexazinone and nitrogen or nitrogen-phosphorus fertilizer on lowbush blueberry plants 24. Hand-wiper applications of herbicides on birch, maple and willow 25. Glyphosate applied after leaf drop for bunchberry control 26. Napropamide for seedling weed control 27. PP333 plant growth regulator 28. Dichlobenil for bunchberry control 29. Effect of hexazinone on weed and blueberry populations 30. Fluazifop-butyl for grass control 31. Hand-wiping and cutting treatments for dogbane 32. Evaluation of airblast sprayer application of asulam for bracken fern control 33. Evaluation of spot treatment of woody weeds with 2,4-D in oil 34. Steam heat as a control of mummyberry diseas

Blueberry Progress Reports

The 1983 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Introduction 2. Forest Tent Caterpillar in Blueberries 3. Control, Biology, and Ecology of Insects Affecting Lowbush Blueberries 4. Blueberry Diseases: Incidence and Control 5. Physiology and Culture of the Lowbush Blueberry 6. Weed Control in Lowbush Blueberry Fields 7. Product Development of Lowbush Blueberrie

Blueberry Advisory Committee Extension Report

The 1986 edition of the Blueberry Advisory Committee Extension Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Fertility Levels 2. Insect and Disease Fact Sheets 3. Development of Insect ID Information for Growers 4. Effect of Pruning Practices an Blueberry Insect Abundance 5. Control of Blueberry Maggot (Alternatives to Guthion) 6. Economic Thresholds and Control of Secondary Blueberry Pests 7. Chemical Control of Mummyberry Disease 8. Chemical Control of Botrytis Bloom Blight 9. Effects of Late Summer Fungicide Applications 10. Mowing vs. Burning - Comparisons of Disease Incidence 11. Long-term Effects of N and NPK Fertilizer on Plant Growth and Yield 12. Effect of Several Mulches on Frost Heaving, Soil Moisture, Soil Temperature and Rhizome Development 13. Interaction of Fertility and Pruning Practices on Soil 14. Effect of Block Freezing on Physical Characterization and Sugar Migration on Lowbush Blueberries 15. Demonstration of the Rota-Cone Vacuum Drying Process on Lowbush Blueberries 16. Production of a Blueberry Gelatin 17. Isolation and Characterization of Blueberry Pectin 18. The Effect of pH, Chemicals and Holding time-temperature on the color of Blueberry Puree 19. Effect of Hexazinone on Species Distribution in Lowbush Blueberry Fields 20. Evaluation of Postemergent Herbicides for Grass Control 21. Evaluation of Sulfonyl urea and lmidazoline compounds for Bunchberry Control 22. Use of Mechanical wiper with glyphosate or dicamba for control of dogbane 23. Hand-wiper Applications of Herbicides on Woody Weeds 24. Dogbane Control with 2% Glyphosate 25. Low Volume Solution of Asulam for Bracken Fern Control 26. Integrated Weed Management 27. 1986 Annual Report to the Maine Lowbush Blueberry Commissio