Allozyme variation in a natural population of Stryphnodendron adstringens in the Rio Preto State Park, southeastern Brazil

Leaves and fruits from 63 Stryphnodendron adstringens trees were sampled in the Rio Preto State Park to analyze allozyme segregation, tissue specific expression of allozyme loci, and their genetic parameters. The enzyme systems ADH, EST, ACP, PGM, PGI, GDH, G6PDH, GOT, IDH, LAP, MDH, PER and SKDH were assessed by means of starch-gel electrophoresis. The polymorphic systems PGI, IDH, MDH and GOT demonstrated a dimeric quaternary structure, while EST and PER were monomeric. The total expected genetic diversity (H E) for leaves and seeds were 0.325 and 0.244 respectively. The effective number of alleles per locus (A E) was 1.58 in leaves and 1.42 in seeds. The values of H E and A E observed in S. adstringens were comparatively higher than the average values seen in allozyme studies of other woody plants. The values of the fixation indices for the population, considering leaves (f = 0.070) and seeds (f = 0.107), were not significant. The high values of genetic diversity and of effective number of alleles per locus, as well as the non-significant fixation index and the adjustments of the Hardy-Weinberg proportions between generations for the pgi-1, mdh-2 and idh-1 loci, indicated random mating in this population. The enzyme systems EST and PER demonstrated their best resolution in leaf tissues, while the MDH, IDH, PGI and GOT systems demonstrated their best resolution in seed tissues.

Conflicting genomes, the demic theory & biodiversity

Organismic-centered Darwinism, in order to use direct phenotypes to measure natural selection's effect, necessitates genome's harmony and uniform coherence plus large population sizes. However, modern gene-centered Darwinism has found new interpretations to data that speak of genomic incoherence and disharmony. As a result of these two conflicting positions a conceptual crisis in Biology has arisen. My position is that the presence of small, even pocket-size, demes is instrumental in generating divergence and phenotypic crisis. Moreover, the presence of parasitic genomes as in acanthocephalan worms, which even manipulate suicidal behavior in their hosts; segregation distorters that change meiosis and Mendelian ratios; selfish genes and selfish whole chromosomes, such as the case of B-chromosomes in grasshoppers; P-elements in Drosophila; driving Y-chromosomes that manipulate sex ratios making males more frequent, as in Hamilton's X-linked drive; male strategists and outlaw genes, are eloquent examples of the presence of real conflicting genomes and of a non-uniform phenotypic coherence and genome harmony. Thus, we are proposing that overall incoherence and disharmony generate disorder but also more biodiversity and creativeness. Finally, if genes can manipulate natural selection, they can multiply mutations or undesirable characteristics and even lethal or detrimental ones, hence the accumulation of genetic loads. Outlaw genes can change what is adaptively convenient even in the direction of the trait that is away from the optimum. The optimum can be "negotiated" among the variants, not only because pleiotropic effects demand it, but also, in some cases, because selfish, outlaw, P-elements or extended phenotypic manipulation require it. With organismic Darwinism the genome in the population and in the individual was thought to act harmoniously without conflicts, and genotypes were thought to march towards greater adaptability. Modern Darwinism has a gene-centered vision in which genes, as natural selection's objects can move in dissonance in the direction which benefits their multiplication. Thus, we have greater opportunities for genomes in permanent conflict.

Experience with molecular and cytogenetic diagnosis of fragile X syndrome in Brazilian families

We report on the cytogenetic and DNA analysis of 55 families with the fragile X (FMR-1 locus) mutation (318 individuals and 15 chorionic villi samples). A total of 129 males were investigated, 54 mentally normal and 75 presenting mental retardation. Among the 54 normal males, 11 had the premutation, and none expressed the fragile site. The full mutation was detected in 73 retarded males, and 14 (18%) presented a premutation along with the full mutation (mosaics). All of them manifested the fragile site. The frequencies of fragile site expression correlated positively with the sizes of the expansion of the CGG repeats (D). Among 153 normal females, 85 were found to be heterozygous for the premutation and 15 had the full mutation. In the premutated females the fragile site was not observed or it occurred at frequencies that did not differ from those observed in 53 noncarriers. Cytogenetic analysis was thus ineffective for the diagnosis of premutated males or females. Among the 51 heterozygotes for the full mutation, 36 (70%) had some degree of mental impairment. As in males, a positive correlation was detected between the frequencies of fragile site manifestation and the size of the expansion. However, the cytogenetic test was less effective for the detection of fully mutated females, than in the case of males, since 14% false negative results were found among females. Segregation analysis confirmed that the risk of mental retardation in the offspring of heterozygotes increases with the length of D. The average observed frequency of mental retardation in the offspring of all heterozygotes was 30%. There was no indication of meiotic drive occurring in female carriers, since the number of individuals who inherited the mutation did not differ from the number of those inheriting the normal allele. No new mutations were detected in the 55 genealogies studied here.

Horizontal projections of area 17 in Cebus monkeys: metric features, and modular and laminar distribution

Metric features and modular and laminar distributions of intrinsic projections of area 17 were studied in Cebus apella. Anterogradely and retrogradely labeled cell appendages were obtained using both saturated pellets and iontophoretic injections of biocytin into the operculum. Laminar and modular distributions of the labeled processes were analyzed using Nissl counterstaining, and/or cytochrome oxidase and/or NADPH-diaphorase histochemistry. We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells located in supragranular cortical layers (principally in layers IIIa, IIIb a, IIIb ß and IIIc). Three distinct axon terminal morphologies were found, i.e., Ia, Ib and II located in granular and supragranular layers. Both complete and partial segregation of group I axon terminals relative to the limits of the blobs of V1 were found. The results are compatible with recent evidence of incomplete segregation of visual information flow in V1 of Old and New World primates

Absence of linkage between MHC and a gene involved in susceptibility to human schistosomiasis

Six hundred million people are at risk of infection by Schistosoma mansoni. MHC haplotypes have been reported to segregate with susceptibility to schistosomiasis in murine models. In humans, a major gene related to susceptibility/resistance to infection by S. mansoni (SM1) and displaying the mean fecal egg count as phenotype was detected by segregation analysis. This gene displayed a codominant mode of inheritance with an estimated frequency of 0.20-0.25 for the deleterious allele and accounted for more than 50% of the variance of infection levels. To determine if the SM1 gene segregates with the human MHC chromosomal region, we performed a linkage study by the lod score method. We typed for HLA-A, B, C, DR and DQ antigens in 11 informative families from an endemic area for schistosomiasis in Bahia, Brazil, by the microlymphocytotoxicity technique. HLA-DR typing by the polymerase chain reaction with sequence-specific primers (PCR-SSP) and HLA-DQ were confirmed by PCR-sequence-specific oligonucleotide probes (PCR-SSOP). The lod scores for the different q values obtained clearly indicate that there is no physical linkage between HLA and SM1 genes. Thus, susceptibility or resistance to schistosomiasis, as defined by mean fecal egg count, is not primarily dependent on the host's HLA profile. However, if the HLA molecule plays an important role in specific immune responses to S. mansoni, this may involve the development of the different clinical aspects of the disease such as granuloma formation and development of hepatosplenomegaly.

Ravinnekierron sulkemisen haasteet suomalaisessa ruokaketjussa

Suomi on sitoutunut pyrkimään ravinnetalouden mallimaaksi. Tämä diplomityö on osa Suomi kes-tävän ravinnetalouden mallimaaksi -hanketta. Diplomityön tarkoituksena on kartoittaa ravin-teidenkäytön tehokkuuteen liittyvät ongelmakohdat suomalaisessa ruokaketjussa ja selvittää oh-jauskeinot, joilla näihin pullonkauloihin voitaisiin puuttua. Ravinnehäviöt aiheuttavat suuria ympä-ristöhaittoja ja käytettävät primääriravinteet pohjaavat uusiutumattomiin luonnonvaroihin. Ravinnehäviöitä syntyy ruokaketjun jokaisessa osassa, ja ravinnetehokkuutta voidaan parhaiten edistää pyrkimällä kokonaisvaltaisiin ratkaisuihin. Tutkimus suoritettiin haastattelemalla 20:tä ruokaketjun asiantuntijaa. Haastatteluaineistoa tarkasteltiin laadullisen analyysin menetelmin. Haastatteluiden perusteella ruokaketjun suurimmat ongelmakohdat ovat alkutuotannossa, panos-teollisuudessa ja kulutuksessa. Sekä hallinnollisilla, taloudellisilla että informatiivisilla ohjauskei-noilla on kaikilla tärkeä rooli ravinnetehokkuuden edistämisessä.

The expression of the ACTH receptor

Adrenal glucocorticoid secretion is regulated by adrenocorticotropic hormone (ACTH) acting through a specific cell membrane receptor (ACTH-R). The ACTH-R is a member of the G protein superfamily-coupled receptors and belongs to the subfamily of melanocortin receptors. The ACTH-R is mainly expressed in the adrenocortical cells showing a restricted tissue specificity, although ACTH is recognized by the other four melanocortin receptors. The cloning of the ACTH-R was followed by the study of this gene in human diseases such as familial glucocorticoid deficiency (FGD) and adrenocortical tumors. FGD is a rare autosomal recessive disease characterized by glucocorticoid deficiency, elevated plasma ACTH levels and preserved renin/aldosterone secretion. This disorder has been ascribed to an impaired adrenal responsiveness to ACTH due to a defective ACTH-R, a defect in intracellular signal transduction or an abnormality in adrenal cortical development. Mutations of the ACTH-R have been described in patients with FGD in segregation with the disease. The functional characterization of these mutations has been prevented by difficulties in expressing human ACTH-R in cells that lack endogenous melanocortin receptor activity. To overcome these difficulties we used Y6 cells, a mutant variant of the Y1 cell line, which possesses a non-expressed ACTH-R gene allowing the functional study without any background activity. Our results demonstrated that the several mutations of the ACTH-R found in FGD result in an impaired cAMP response or loss of sensitivity to ACTH stimulation. An ACTH-binding study showed an impairment of ligand binding with loss of the high affinity site in most of the mutations studied.

To Divide or Not to Divide; MicroRNAs and Small Compounds as Modulators of Mitosis

Mitosis is under the stringent quality control of the spindle assembly checkpoint (SAC). However, in cancer cells this control can fail, leading to excessive cellular proliferation and ultimately to the formation of a tumor. Novel cancer cell selective therapies are needed to stop the uncontrolled cell proliferation and tumor growth. The aim of the research presented in this thesis was to identify microRNAs (miRNAs) that could play a role in cancer cell proliferation as well as low molecular weight (LMW) compounds that could interfere with cell division. The findings could be used to develop better cancer diagnostics and therapies in the future. First, a high-throughput screen (HTS) was performed to identify LMW compounds that possess a similar chemical interaction field as rigosertib, an anti-cancer compound undergoing clinical trials. A compound termed Centmitor-1 was discovered that phenocopied the cellular impact of rigosertib by affecting the microtubule dynamics. Next, another HTS aimed at identifying compounds that would target the Hec1 protein, which mediates the interaction between spindle microtubules and chromosomes. Perturbation of this connection should prevent cell division and induce cell death. A compound termed VTT-006 was discovered that abrogated mitosis in several cell line models and exhibited binding to Hec1 in vitro. Lastly, using a cell-based HTS two miRNAs were identified that affected cancer cell proliferation via Aurora B kinase, which is an important mitotic regulator. MiR-378a-5p was found to indirectly suppress the production of the kinase whereas let-7b showed direct binding to the 3’UTR of Aurora B mRNA and repressed its translation. The miRNA-mediated perturbation of Aurora B induced defects in mitosis leading to abnormal chromosome segregation and induction of aneuploidy. The results of this thesis provide new information on miRNA signaling in cancer, which could be utilized for diagnostic purposes. Moreover, the thesis introduces two small compounds that may benefit future drug research.

Peruskoulun yläkouluvalinnat Turussa. Perheiden yläkouluvalintojen rakentuminen äitien puheissa ja toimissa

Tutkimuksessa tarkastellaan peruskoulun yläkouluvalintoja Turussa. Tarkastelun keskiössä ovat vuonna 1997 syntyneiden turkulaislasten vanhempien yläkouluvalintaa koskeva yleinen sekä omaan lapseen kiinnittyvä puhe ja toimijuus paikallisessa institutionaalisessa kouluvalintatilassa sekä vanhempien lapsen koulutukseen ja kouluvalintaan liittämät perustelut, merkitykset, arvot ja arvostukset. Tämän lisäksi tutkimuksessa tarkastellaan puheesta ja toimista rakentuvia perheiden kouluvalintastrategioita, joita peilataan äitien koulutuksellisiin ja sosiaalisiin resursseihin sekä paikalliseen toimintapolitiikkaan. Tutkimus ei kerro ainoastaan paikallisessa kontekstissa tapahtuvista kouluvalinnoista, vaan laajemmin yhteiskunnassa vallitsevista hierarkioista ja arvoista sekä koulutukseen ja sosioekonomiseen asemaan linkittyvistä normatiivisista toimintatavoista. Tutkimuksessa käytetään haastattelu- ja kyselyaineistoja. Aineistot kerättiin osana kahta laajempaa Suomen Akatemian rahoittamaa Helsingin ja Turun yliopistojen kanssa yhteistyössä tehtyä tutkimusprojektia Vanhemmat ja kouluvalinta – Perheiden koulutusstrategiat, eriarvoistuminen ja paikalliset koulupolitiikat suomalaisessa peruskoulussa (VAKOVA) 2009–2012 sekä Parents and School Choice. Family Strategies, Segregation and School Policies in Chilean and Finnish Basic Schooling (PASC) 2010–2013. Tutkimusaineistot koostuvat 87 turkulaisäidin haastattelusta ja kyselyaineistosta. Kyselyaineiston analyysissä on käytetty kuvailevia tilastollisia menetelmiä, ja sitä käytetään ensisijaisesti taustoittamaan haastatteluaineistoa. Haastatteluaineiston analyysi perustuu pääasiallisesti teema-analyysiin, mutta toimija-asema-analyysin osalta myös diskursiiviseen lähestymistapaan. Haastatteluaineiston pohjalta esiin nousseiden lasten koulutusta ja kouluvalintoja koskevien kuvausten perusteella perheiden yläkouluvalinnat jaettiin kolmeen erityyppiseen valintastrategiaan: perinteiseen lähikouluvalintastrategiaan (n=41), ambivalenttiseen kouluvalintastrategiaan (n=23) ja päämäärätietoiseen kouluvalintastrategiaan (n=23). Jokainen kolmesta strategiasta piti sisällään kahdenlaista toimijuutta kouluvalintakentällä. Ryhmittely kouluvalintastrategioittain ja toimija-asemittain perustui äitien puhetapaan kouluvalinnoista ja yleisemmin koulutukseen liitetyistä merkityksistä ja arvoista sekä konkreettiseen toimintaan kouluvalinnan suhteen. Lähikouluvalintastrategiaa suosivien jälkeläiset siirtyivät koulunsa yleisluokalle. Perheet toimivat valintakentällä kaupungin rajaavan toimintapolitiikan ohjaamina, jolloin kouluvalinta näytti passiiviselta. Osoitteenmukaiseen kouluun siirtymistä perusteltiin praktisilla syillä; koulumatkan pituudella, kulkuyhteyksillä ja lapsen kaverisuhteilla. Hyvinvointivaltion edellytykseksi nähtiin kaikille taattu samanvertainen koulutus ja edelleen luotettiin perinteistä peruskoulua määrittävään mahdollisuuksien tasa-arvoon. Koulutuksen yhdeksi tärkeäksi tehtäväksi nähtiin lapsen kasvattaminen hyvinvoivaksi ja onnelliseksi. Vanhempien toiminta oli perinteisen kouluvalintastrategian mukaista. Ambivalenttista kouluvalintastrategiaa käyttävistä perheistä toiminta kouluvalintakentällä oli kahtalaista. Äidit joko harkitsivat kouluvalintoja tai vertailivat kouluja ja niihin pääsymahdollisuuksia realistisesti tasapainoillen ohjaavan ja mahdollistavan toimintapolitiikan välimaastossa. Tärkeintä oli olla tietoinen kaupungin kouluvalintapolitiikasta sekä siitä, että valinnoilla voi olla merkitystä jälkikasvun koulupolulle. Eri vaihtoehtojen punnitsemisen jälkeen päädyttiin useimmin lähikoulun painotettuun opetukseen. Lapsen peruskoulutusta haluttiin rikastaa painotetulla opetuksella ja hänen toivottiin pääsevän motivoituneeseen ja oppimismyönteiseen koululuokkaan. Valintoja tehtiin paikallisen toimintapolitiikan puitteissa lapsen parasta toivoen. Koulutuksen tehtäväksi nähtiin lapsen intellektuaalinen kasvu kiedottuna koulutuksen tuottamaan hyvinvointiin ja onnellisuuteen. Perheiden valintastrategiaksi muodostui ambivalenttinen strategia motivoituneen oppimisympäristön löytämiseksi. Päämäärätietoista kouluvalintastrategiaa käyttävät vanhemmat hyödynsivät aktiivisesti erilaisia reittejä tiettyihin yläkouluihin pääsemiseksi. Ennakoivien perheiden lapset olivat opiskelleet sellaisessa alakoulussa, joka ei kuulunut yläkoulun oppilasalueelle, mutta takasi lapselle reitin suosittuun yläkouluun. Määrätietoisten perheissä havahduttiin valintoihin puolestaan yläkouluun siirryttäessä, jolloin koulupaikkaa haettiin sopivimman painotetun opetuksen ja koulun maineen mukaan pois lähiyläkoulusta. Lähikoulu -periaate koettiin epäoikeudenmukaiseksi, sillä lapsella tulee olla oikeus toteuttaa omia kykyjään ja lahjakkuuttaan valikoidussa oppilasryhmässä ja perheillä mahdollisuus valita lapsen koulu. Paikallinen toimintapolitiikka ei näyttänyt rajaavan vanhempien kouluvalintoja. Koulutuksen tarkoitukseksi nähtiin intellektuaalinen kasvu ja akateemissivistävä tehtävä. Päämäärätietoisen kouluvalintavalintastrategian tavoitteena oli perheelle sopivan habituksen takaaminen. Paikallinen toimintapolitiikka mahdollisti vanhempien erilaisten kouluvalintastrategioiden rakentumisen ohjaten ensisijaisesti lähiyläkouluun, mutta samalla mahdollistaen koulun valinnan toissijaisen haun kriteerein. Kouluvalintastrategioihin ja toimintatapaan kouluvalintakentällä kytkeytyi vanhempien koulutukseen liittämät arvot sekä kulttuuriset ja sosiaaliset resurssit ja se, miten niitä käytettiin.

Protein-mediated surface structuring in biomembranes

The lipids and proteins of biomembranes exhibit highly dissimilar conformations, geometrical shapes, amphipathicity, and thermodynamic properties which constrain their two-dimensional molecular packing, electrostatics, and interaction preferences. This causes inevitable development of large local tensions that frequently relax into phase or compositional immiscibility along lateral and transverse planes of the membrane. On the other hand, these effects constitute the very codes that mediate molecular and structural changes determining and controlling the possibilities for enzymatic activity, apposition and recombination in biomembranes. The presence of proteins constitutes a major perturbing factor for the membrane sculpturing both in terms of its surface topography and dynamics. We will focus on some results from our group within this context and summarize some recent evidence for the active involvement of extrinsic (myelin basic protein), integral (Folch-Lees proteolipid protein) and amphitropic (c-Fos and c-Jun) proteins, as well as a membrane-active amphitropic phosphohydrolytic enzyme (neutral sphingomyelinase), in the process of lateral segregation and dynamics of phase domains, sculpturing of the surface topography, and the bi-directional modulation of the membrane biochemical reactivity.

Feasibility of the use of recycled nutrients in fast growing pulpwood production

The application of pulp and paper mill (PPM) sludge in agriculture and forestry has been acknowledged as soil amendments and a plant nutrient source. The main objectives of this study were to evaluate the total cost of the use of recycled nutrients from PPM sludge in fast growing pulpwood production, and the financial profitability of fast growing pulpwood production with the use of these recycled nutrients. The investment and production costs of fast growing pulpwood plantation were directly acquired from a previous research, while the other data was compiled through different studies. The total cost of the use of PPM sludge was evaluated based on assumed factors. Discounted cash flow method was used to evaluate the financial profitability, using NPV and IRR as indicators. The results of estimated sludge nutrient contents were 16.2 g N, 2.9 g P, and 2.4 g K kg-1 of dry sludge. The sludge application rate was estimated at 1.36 Mg/ha in the first year. The total cost of the use of PPM sludge involved transport and spreading cost of US$49.15/dry ton. The fertilization cost applied in the financial model was designed in 3 different options and their results were as follows: option (1) was taken directly from the reference research (US$97/ha); option (2) was the use of sludge alone (US$66.75/ha); and option (3) was the use of sludge and TSP fertilizer (US$83.80/ha). The average NPV without discounting was US$248,180 while the IRRs ranged between approximately 3-4% with an average of 3.63%. Although option (2) and (3) contributed to higher IRRs compared to option (1), this increase was still not significant as the IRR was not sensitive to the total fertilization cost. The advantages are that this practice can be performed at a lower cost and the application rate can be still increased if necessary. It is better for forest plantations compared to agriculture and consequently supports reforestation program. In addition, it can be similarly applied in wood biomass production. A disadvantage is that the IRRs were not very favorable compared to the criterion of 11%. The sludge high in C:N ratio can cause nitrogen immobilization, and regulatory concerns may restrict and complicate the use of sludge landspreading and contribute to additional costs and processes.

Correlation between lactose absorption and the C/T-13910 and G/A-22018 mutations of the lactase-phlorizin hydrolase (LCT) gene in adult-type hypolactasia

The C/T-13910 mutation is the major factor responsible for the persistence of the lactase-phlorizin hydrolase (LCT) gene expression. Mutation G/A-22018 appears to be only in co-segregation with C/T-13910. The objective of the present study was to assess the presence of these two mutations in Brazilian individuals with and without lactose malabsorption diagnosed by the hydrogen breath test (HBT). Ten milk-tolerant and 10 milk-intolerant individuals underwent the HBT after oral ingestion of 50 g lactose (equivalent to 1 L of milk). Analyses for C/T-13910 and G/A-22018 mutations were performed using a PCR-based method. Primers were designed for this study based on the GenBank sequence. The CT/GA, CT/AA, and TT/AA genotypes (lactase persistence) were found in 10 individuals with negative HBT. The CC/GG genotype (lactase non-persistence) was found in 10 individuals, 9 of them with positive HBT results. There was a significant agreement between the presence of mutations in the LCT gene promoter and HBT results (kappa = -0.9, P < 0.001). The CT/AA genotype has not been described previously and seems to be related to lactase persistence. The present study showed a significant agreement between the occurrence of mutations G/A-22018 and C/T-13910 and lactose absorption in Brazilian subjects, suggesting that the molecular test used here could be proposed for the laboratory diagnosis of adult-type primary hypolactasia.

A novel missense mutation p.L76P in the GJB2 gene causing nonsyndromic recessive deafness in a Brazilian family

Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of nonsyndromic recessive hearing loss in many countries. We report here on a novel point mutation in GJB2, p.L76P (c.227C>T), in compound heterozygosity with a c.35delG mutation, in two Brazilian sibs, one presenting mild and the other profound nonsyndromic neurosensorial hearing impairment. Their father, who carried a wild-type allele and a p.L76P mutation, had normal hearing. The mutation leads to the substitution of leucine (L) by proline (P) at residue 76, an evolutionarily conserved position in Cx26 as well as in other connexins. This mutation is predicted to affect the first extracellular domain (EC1) or the second transmembrane domain (TM2). EC1 is important for connexon-connexon interaction and for the control of channel voltage gating. The segregation of the c.227C>T (p.L76P) mutation together with c.35delG in this family indicates a recessive mode of inheritance. The association between the p.L76P mutation and hearing impairment is further supported by its absence in a normal hearing control group of 100 individuals, 50 European-Brazilians and 50 African-Brazilians.

Multigenerational Brazilian family with malignant hyperthermia and a novel mutation in the RYR1 gene

Malignant hyperthermia (MH) is a pharmacogenetic disease triggered in susceptible individuals by the administration of volatile halogenated anesthetics and/or succinylcholine, leading to the development of a hypermetabolic crisis, which is caused by abnormal release of Ca2+ from the sarcoplasmic reticulum, through the Ca2+ release channel ryanodine receptor 1 (RyR1). Mutations in the RYR1 gene are associated with MH in the majority of susceptible families. Genetic screening of a 5-generation Brazilian family with a history of MH-related deaths and a previous MH diagnosis by the caffeine halothane contracture test (CHCT) in some individuals was performed using restriction and sequencing analysis. A novel missense mutation, Gly4935Ser, was found in an important functional and conserved locus of this gene, the transmembrane region of RyR1. In this family, 2 MH-susceptible individuals previously diagnosed with CHCT carry this novel mutation and another 24 not previously diagnosed members also carry it. However, this same mutation was not found in another MH-susceptible individual whose CHCT was positive to the test with caffeine but not to the test with halothane. None of the 5 MH normal individuals of the family, previously diagnosed by CHCT, carry this mutation, nor do 100 controls from control Brazilian and USA populations. The Gly4932Ser variant is a candidate mutation for MH, based on its co-segregation with disease phenotype, absence among controls and its location within the protein.

Diversity of 16S rRNA genes from bacteria of sugarcane rhizosphere soil

Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire bacterial communities in the environment. In the present study, we have used this approach to assess the bacterial community in the rhizosphere soil of sugarcane at different times and under different nitrogen fertilization conditions. At the high taxonomic level, few differences between samples were observed, with the phylum Proteobacteria (29.6%) predominating, followed by Acidobacteria (23.4%), Bacteroidetes (12.1%), Firmicutes (10.2%), and Actinobacteria (5.6%). The exception was the Verrucomicrobia phylum whose prevalence in N-fertilized soils was approximately 0.7% and increased to 5.2% in the non-fertilized soil, suggesting that this group may be an indicator of nitrogen availability in soils. However, at low taxonomic levels a higher diversity was found associated with plants receiving nitrogen fertilizer. Bacillus was the most predominant genus, accounting for 19.7% of all genera observed. Classically reported nitrogen-fixing and/or plant growth-promoting bacterial genera, such as Azospirillum, Rhizobium, Mesorhizobium, Bradyrhizobium, and Burkholderia were also found although at a lower prevalence.