The Coupling of Alternative Splicing and Nonsense-Mediated mRNA Decay

Most human genes exhibit alternative splicing, but not all alternatively spliced transcripts produce functional proteins. Computational and experimental results indicate that a substantial fraction of alternative splicing events in humans result in mRNA isoforms that harbor a premature termination codon (PTC). These transcripts are predicted to be degraded by the nonsense-mediated mRNA decay (NMD) pathway. One explanation for the abundance of PTC-containing isoforms is that they represent splicing errors that are identified and degraded by the NMD pathway. Another potential explanation for this startling observation is that cells may link alternative splicing and NMD to regulate the abundance of mRNA transcripts. This mechanism, which we call "Regulated Unproductive Splicing and Translation" (RUST), has been experimentally shown to regulate expression of a wide variety of genes in many organisms from yeast to human. It is frequently employed for autoregulation of proteins that affect the splicing process itself. Thus, alternative splicing and NMD act together to play an important role in regulating gene expression

Geochemistry Of Tourmalines Associated With Iron Formation And Quartz Veins Of The Morro Da Pedra Preta Formation, Serra Do Itaberaba Group (são Paulo, Brazil)

Tourmalines of intermediate schorl-dravite composition occur in iron formation (including metachert and tourmalinites), metasediments, calc-silicate and metabasic/intermediate rocks of the Morro da Pedra Preta Formation, a volcanic-sedimentary sequence of the Serra do Itaberaba Group (northeast of São Paulo City, southeastern Brazil). The Morro da Pedra Preta Formation is crosscut by quartz veins that contain both intermediate schorl-dravite arid an alkali-deficient, Cr-(V-)bearing tourmaline, in which the occupancy of the X-site is □0.51Ca0.33Na0.15, characterizing it as intermediate to foitite and magnesiofoitite end-members. Mg# values for this tourmaline are higher than those for intermediate schorl-dravite. Raman spectroscopy also confirms the presence of two groups of tourmalines. Stable isotope data indicate sediment waters as fluid sources, rather than fluids from magmatic/post-magmatic sources. Delta18O compositions for tourmalines, host metachert, and quartz veins are similar, showing that fluid equilibration occurred during crystallization of both quartz and tourmaline. Syngenetic, intermediate schorl-dravite tourmalines were formed under submarine, sedimentary-exhalative conditions; amphibolite-grade metamorphism did not strongly affect their compositions. Younger tourmalines of compositions intermediate to foitite and magnesiofoitite reflect the composition of the host rocks of quartz veins, due to fluid percolation along faults and fractures that caused leaching of Cr (and V) and the crystallization of these alkali-deficient, Cr-(V-)bearing tourmalines.752209234Beljavskis, P., Juliani, C., Garda, G.M., Xavier, R.P., Bettencourt, J.S., Overview of the gold mineralization in the metavolcanic-sedimentary sequence of the Serra do Itaberaba Group-São Paulo-Brazil (1999) Mineral Deposits: Processes to Processing, 1, pp. 151-153. , STANLEY CJ ET AL. (Ed.), Rotterdam/Brookfield: BalkemaBeljavskis, P., Garda, G.M., Sayeg, I.J., Application of SEM in the study of gold mineralizations in the Morro da Pedra Preta Formation, Grupo Serra do Itaberaba - São Paulo, Brazil (1999) Acta Microscopica, 8 (SUPPL. A), pp. 125-126Béziat, D., Bourges, F., Debat, P., Fuchs, Y., Lompo, M., Martin, F., Nikiéma, S., Tollon, F., The Guibaré and Fété Kolé gold-bearing tourmaline-quartz veins in the Birimian Greenstone belts of Burkina Faso (1999) Canadian Mineralogist, 37, pp. 575-591Bone, Y., The geological setting of tourmalinite at Rum Jungle, N.T., Australia - Genetic and economic implications (1988) Mineral Deposita, 23, pp. 34-41Cavarretta, G., Puxeddu, M., Schorldravite-ferridravite tourmalines deposited by hydrothermal magmatic fluids during early evolution of the Larderello geothermal field, Italy (1990) Econ Geol, 85, pp. 1236-1251Fallick, A.E., McConville, P., Boyce, A.J., Burgess, R., Kelley, S.P., Laser microprobe stable isotope measurements on geological materials: Some experimental considerations (with special reference to δ 34S in sulphides) (1992) Chem Geol, 101, pp. 53-61Garda, G.M., Beljavskis, P., Sayeg, I.J., Gold mineralization in the Quartzito area, the Serra do Itaberaba Group - São Paulo, Brazil (1999) Acta Microscopica, 8 (SUPPL. A), pp. 127-128Garda, G.M., Beljavskis, P., Juliani, C., Boyce, A.J., Sulfur stable isotope signatures of the Morro da Pedra Preta Formation, Serra do Itaberaba Group, São Paulo State, Brazil (2002) Geochimica Brasiliensis, , in pressGasharova, B., Mihailova, B., Konstantinov, L., Raman spectra of various types of tourmaline (1997) Eur J Mineral, 9, pp. 935-940Hawthorne, F.C., Henry, D.J., Classification of the minerals of the tourmaline group (1999) Eur J Mineral, 11, pp. 201-215Hawthorne, F.C., Selway, J.B., Kato, A., Matsubara, S., Shimizu, M., Grice, J.D., Vajdak, J., Magnesiofoitite, [](Mg2Al)Al6(Si6O 18)(BO3)3(OH)4, a new alkali-deficient tourmaline (1999) Can Mineral, 37, pp. 1439-1443Henry, D.J., Dutrow, B.L., Metamorphic tourmaline and its petrologic applications (1996) Rev Mineral, 33, pp. 503-557. , GREW ES AND ANOVITZ LM (Ed.), Boron-Mineralogy, petrology and geochemistryHenry, D.J., Guidotti, C.V., Tourmaline as a petrogenetic indicator mineral: An example from the staurolite-grade metapelites of NW Maine (1985) Am Mineral, 70, pp. 1-15Janasi, V., Ulbrich, H.H.G.J., Late Proterozoic granitoid magmatism in the state of São Paulo, southeastern Brazil (1991) Precambrian Res, 51, pp. 351-374Juliani, C., (1993) Geologia, Petrogênese e Aspectos Metalogenéticos dos Grupos Serra do Itaberaba e São Roque na Região das Serras do Itaberaba e da Pedra Branca, p. 684. , NE da cidade de São Paulo, SP. São Paulo. Doctorate Thesis. Instituto de Geociências da USPJuliani, C., Beljavskis, P., Revisão da litoestratigrafia da faixa São Roque/Serra do Itaberaba (SP) (1995) Revista do IG, 16 (1-2), pp. 33-58Juliani, C., Hackspacker, P., Dantas, E.L., Fetter, A.H., The Mesoproterozoic volcano-sedimentary Serra do Itaberaba Group of the central Ribeira Belt, São Paulo State, Brazil: Implications for the age of the overlying São Roque Group (2000) Rev Bras Geoc, 30, pp. 82-86Kassoli-Fournaraki, A., Michailidis, K., Chemical composition of tourmaline in quartz veins from Nea Roda and Thasos areas in Macedonia, Northern Greece (1994) Can Mineral, 32, pp. 607-615King, R.W., Kerrich, R., Chromian dravite associated with ultramafic-rock-hosted Archean lode gold deposits, Timmins-Porcupine District, Ontario (1989) Can Mineral, 27, pp. 419-426Kotzer, T.G., Kyser, T.K., King, R.W., Kerrich, R., An empirical oxygen- and hydrogenisotope geothermometer for quartz-tourmaline and tourmaline-water (1993) Geochim Cosmochim Acta, 57, pp. 3421-3426McDonald, D.J., Hawthorne, F.C., Grice, J.D., Foitite, □[(Fe22+(Al,Fe3+)]Al 6Si6O18(BO3)3(OH) 4, a new alkali-deficient tourmaline: Description and crystal structure (1993) Am Mineral, 78, pp. 1299-1303Plimer, I.R., The association of tourmaline-bearing rocks with mineralization at Broken Hill, N.S.W. (1983) Proc Ann Aus Inst Min Met Conf, pp. 157-176Plimer, I.R., Tourmalinites from the Golden Dyke Dome, Northern Australia (1986) Mineral Deposita, 21, pp. 263-270Plimer, I.R., The association of tourmaline with stratiform scheelite deposits (1987) Mineral Deposita, 22, pp. 282-291Plimer, I.R., Tourmalines associated with Australian Proterozoic submarine exhalative ores (1988) Base Metal Sulfide Deposits in Sedimentary and Volcanic Environments, pp. 255-283. , FRIEDRICH GH AND HERZIG PM. (Eds.). Berlin: Springer-VerlagSlack, J.F., Tourmaline in Appalachian-Caledonian massive sulphide deposits and its exploration significance (1982) Trans Instn Min Metall, 91, pp. B81-B89Slack, J.F., Tourmaline associations with hydrothermal ore deposits (1996) Rev Mineral, 33, pp. 559-643. , GREW ES AND ANOVITZ LM (Ed.), Boron - Mineralogy, petrology and geochemistrySlack, J.F., Herriman, N., Barnes, R.G., Plimer, I.R., Stratiform tourmalines in metamorphic terranes and their geologic significance (1984) Geology, 12, pp. 713-716Taylor, B.E., Slack, J.F., Tourmalines from the Appalachian-Caledonian massive sulfide deposits: Textural, chemical, an isotopic relationships (1984) Econ Geol, 79, pp. 1703-1726Taylor H.P., Jr., Oxygen isotope studies of hydrothermal mineral deposits (1967) Geochemistry of Hydrothermal Ore Deposits, p. 670. , BARNES HL (Ed.). 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Volcanic Tourminalites Of The Morro Da Pedra Petra Of The Serra Do Itaberaba Group (sp): Petrography, Chemical Composition Of Tourmaline And Metalogenetic Implications [turmalinitos Vulcanogênicos Da Formação Morro Da Pedra Petra Do Grupo Serra Do Itaberaba (sp): Petrografia, Composição Química Da Turmalina E Implicações Metalogenéticas]

Tourmalinites associated with amphibolites, metachert, iron formation, metatuffs, metasedimentary, metavolcaniclastic and calc-silicate rocks were found in the Morro da Pedra Preta Formation, basal metavolcano-sedimentary sequence of the Serra do ltaberaba Group (São Paulo State, Brazil). The syn-sedimentary origin of the tourmalinites is attested by the deformation of the alternating tourmaline-rich and quartz-rich layers, the presence of rip-up clasts, and whole-rock chemistry similar to that of surrounding metassedimentary rocks. Microprobe analyses show that the tourmaline compositions are: 1) within the schorl-dravite series, for the examples associated with metatuffs, iron formation, metachert metavolcaniclastic and metasedimentary rocks, and 2) within the dravite-uvite series, for those associated with amphibolites, metatuffs and calcsilicate rocks. The former are characterized by low Ca and high Na and Al contents, with variable Fe and Mg contents (schorl-dravite series), whereas the latter, a F-bearing tourmaline, has low Na and Al and high Mg and Ca contents. The schorl component of the tourmaline of the proximal tourmalinites is indicative of the potential of Morro da Pedra Preta Formation for gold, which contrasts with the conditions required for the formation of volcanic massive sulphide deposits (hypersaline fluids and association with magnesian tourmalites). The tourmaline of the various tourmalinites of the Morro da Pedra Preta Formation is not typically magnesian and its composition was more strongly influenced by the composition of the neighboring rocks than that of the hydrothermal fluids, especially when the tourmalinite was deposited in an intermediate to distal in relation to the volcano-exhalative center.51118Almeida, F.F.M., (1981) A. Mapa Geológico Do Estado De São Paulo, Escala 1:500.000, 1, p. 126. , nota explicativa. 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Genetic and economic implications (1988) Mineralium Deposita, 23, pp. 34-41Cleland, J.M., Morey, G.B., MacSwiggen, P.L., Significance of tourmaline-rich rocks in the North Range Group of the Cuyuna Iron Range, east-central Minnesota (1996) Economic Geology, 91, pp. 1282-1291Ethier, V.G., Campbell, F.A., Tourmaline concentrations in Proterozoic sediments of the southern Cordillera of Canada and their economic significance (1977) Canadian Journal of Earth Sciences, 14, pp. 2348-2363Fleischer, R., Routhier, P., The "consanguineous" origin of the tourmaline-bearing gold deposit: Passagem de Mariana, Brazil (1973) Economic Geology, 68, pp. 11-22Garba, I., Tourmalinization related to Late Proterozoic-Early Paleozoic lode gold mineralization in the Bin Yauri area, Nigeria (1996) Mineralium Deposita, 31, pp. 201-209Garda, G.M., Geochemistry of tourmalines associated with iron formation and quartz veins of the Morro da Pedra Preta Formation, Serra do Itaberaba Group (São Paulo, Brazil) (2003) Anais Da Academia Brasileira De Ciências, 75, pp. 209-234Garda, G.M., Sulfur stable signature of the Morro da Pedra Preta Formation, Serra do Itaberaba Group, Sao Paulo State, Brazil (2002) Geochimica Brasiliensis, 16, pp. 79-97Griffin, W.L., Trace elements from massive sulfide deposits and tourmalinites: Geochemical controls and exploration applications (1996) Economic Geology, 91, pp. 657-675Hawthorne, F.C., Henry, D.J., Classification of the minerals of the tourmaline group (1999) European Journal of Mineralogy, 11, pp. 201-215Hellingwerf, R.H., Tourmaline in central Swedish ore district (1994) Mineralium Deposita, 29, pp. 189-205Henry, D.J., Guidotti, C.V., Tourmaline as a petrogenetic indicator mineral: An example from the staurolite-grade metapelites of NW Maine (1985) American Mineralogist, 70, pp. 1-15Jiang, S.Y., Paragenesis and chemistry of multistage Tourmaline Formation in the Sullivan Pb-Zn-Ag deposit, British Columbia (1998) Economic Geology, 93, pp. 47-67Juliani, C., Geologia, petrogêese e aspectos metalogenéticos dos grupos Serra do Itaberaba e São Roque na região das serras do Itaberaba e da Pedra Branca, NE da cidade de São Paulo, SP 1993 2 v. Tese (Doutorado) - Instituto de Geociências, Universidade de São Paulo, São PauloJuliani, C., Beljavskis, P., Revisão da litoestratigrafia da faixa São Roque/Serra do Itaberaba (SP) (1995) Revista Do Instituto Geológico, 16, pp. 33-58Juliani, C., Beljavskis, P., Schorscher, J.H.D., Petrogênese do vulcanismo e aspectos metalogenéticos associados: Grupo Serra do Itaberaba na região do Grupo São Roque - SP (1986) Congresso Brasileiro De Geologia, 34, pp. 730-745. , Goiârnia. Anais... Goiânia: SBG 1986. v. 2Juliani, C., Pérez-Aguilar, A., Martin, M.A.B., Geotermobarometria e evolução metamórfica P-T-d do Grupo Serra do Itaberaba (SP) (1997) Anais Da Academia Brasileira De Ciências, 69, pp. 441-442Juliani, C., The Mesoproterozoic volcano-sedimentary Serra do Itaberaba Group of the central Ribeira Belt, São Paulo State, Brazil: Implication for the age of overlying São Roque Group (2000) Revista Brasileira De Geociências, 30, pp. 82-86King, R.J., Minerals explained 28: The tourmaline group (2000) Geology Today, 16 (PART 1), pp. 35-37King, R.W., Geochemical characteristics of tourmaline from Superior Province Archean lode gold deposits: Implications for source regions and processes (1988), (22), pp. 445-447. , Geological Society of Australia Abstract Series. Presented in Bicentennial Gold 88King, R.W., Kerrich, R., Chromian dravite associated with ultramafic-rock-hosted Archean lode gold deposits, Timmins-Porcupine District, Ontario (1989) Canadian Mineralogist, 27, pp. 419-426Mao, J.W., Tourmalinite from northern Guangxi, China (1995) Mineralium Deposita, 30, pp. 235-245MacArdle, P., Tourmalinite as a potential host rock for gold Caledonides of southeast Ireland (1989) Mineralium Deposita, 24, pp. 154-159Pirajno, F., Smithies, R.H., The FeO/(FeO + MgO) ratio of tourmaline: A useful indicator of spatial variations in granite-related hydrothermal mineral deposits (1992) Journal of Geochemical Exploration, 42, pp. 371-381Plimer, I.R., Exhalative Sn and W deposits associated with mafic volcanism as precursors to Sn and W deposits with granites (1980) Mineralium Deposita, 15, pp. 275-289Plimer, I.R., Tourmalinites from the Golden Dyke Dome, Northern Australia (1986) Mineralium Deposita, 21, pp. 263-270Plimer, I.R., Tourmalinites associated with Proterozoic submarine exhalative ores (1988) Base Metal Sulfide Deposits in Sedimentary and Volcanic Environments, pp. 255-283. , FRIEDERICH, G H.HERZIG, P. M. (Ed.). Berlin: Springer-VerlagShaw, D.M., Similarities and contrasts in lunar and terrestrial boron geochemistry (1996) Boron: Mineralogy, Petrology and Geochemistry, pp. 745-769. , GREW, E. S.ANOVITZ, L. M. (Ed.). Washington: The Mineralogical Society of America, (Reviews in Mineralogy, 33)Slack, J.F., Tourmaline in Appalachian-Caledonian massive sulphide deposits and its exploration significance (1982) Institution of Mining and Metallurgy Transactions, 91, pp. B81-B89Slack, J.F., Tourmaline associations with hydrothermal ore deposits (1996) Boron: Mineralogy, Petrology and Geochemistry, pp. 559-643. , GREW, E. S.ANOVITZ, L. M. (Ed.). Washington: The Mineralogical Society of America, (Reviews in Mineralogy, 33)Slack, J.E., Coad, R.P., Multiple hydrothermal and metamorphic events in Kidd Creek volcanogenic massive sulphide deposit, Timmins, Ontario: Evidence from tourmalines and chlorites (1989) Canadian Journal of Earth Sciences, 26, pp. 694-715Slack, J.F., Stratiform tourmalinites in metamorphic terranes and their geologic significance (1984) Geology, 12, pp. 713-716Slack, J.F., Origin and significance of tourmaline-rich rocks in the Broken Hill district, Australia (1993) Economic Geology, 88, pp. 505-541Slack, J.F., Boron-rich mud volcanoes of the Black Sea region: Modern analogues to ancient sea-floor tourmalinites associated with Sullivan-type Pb-Zn deposits? (1998) Geology, 26, pp. 439-442Taylor, R.R., Slack, J.F., Tourmalines from Appalachian-Caledonian massive sulfide deposits: Textural, chemical, and isotopic relationships (1984) Economic Geology, 79, pp. 1703-1726Willner, A.P., Tourmalinites from the stratiform peraluminous metamorphic suite of the Central Namaqua Mobile Belt South Africa (1992) Mineralium Deposita, 27, pp. 304-313Yavuz, E., TOURMAL: Software package for tourmaline, tourmaline-rich rocks and related ore deposits (1997) Computers and Geosciences, 23, pp. 947-959Yavuz, F., Tourmaline compositions from the Salikvan porphyry Cu-Mo deposit and vicinity, northeastern Turkey (1999) The Canadian Mineralogist, 37, pp. 1007-102