Suspected intoxication by Kikuyu grass (Cenchrus clandestinus) of dairy cattle in the Azores, Portugal.

CASE HISTORY: An outbreak of suspected Kikuyu grass (Cenchrus clandestinus) intoxication among dairy cattle occurred on the island of Terceira in the Azores (Portugal), in October 2022. The animals affected were non-lactating dairy cows and heifers from five small farms grazing (free or tethered) a Kikuyu-dominant pasture. Of the 29 animals exposed, 17 were affected, and eight (five heifers and three adult cows) died, resulting in a morbidity rate of 58%, a mortality rate of 28% and a case mortality rate of 47%. CLINICAL FINDINGS AND TREATMENT: The clinical signs were non-specific and inconsistent, and included dry faeces, some with dark red blood; apathy and prostration; abdominal dilatation; tachycardia; tachypnoea; pale or jaundiced mucous membranes; sham drinking; sialorrhoea; and moderate to severe dehydration. Symptomatic treatment was provided but was ineffective. Haematology and serum biochemistry revealed an acute inflammatory leukogram, increased alkaline phosphatase (ALP) activity, decreased gamma-glutamyl transferase (GGT) activity, and azotaemia.The most consistent necropsy findings were haemorrhages in the epicardium and endocardium, an enlarged liver with rounded edges, non-perforated abomasal ulcers, and haemorrhagic lesions in the small and large intestines. Histopathology indicated myocarditis, hepatitis, interstitial nephritis, enteritis and colitis.Several fungal species were isolated from grass samples taken from affected pastures including several Fusarium spp., the genus implicated in Kikuyu toxicosis. Immediate removal of the animals from the pasture with Kikuyu was the only measure that prevented new cases and resulted in the recovery of some of the less affected animals. DIAGNOSIS: The epidemiological features of this outbreak and the clinical signs and micro- and macroscopic lesions observed were highly suggestive of Kikuyu grass poisoning. CLINICAL RELEVANCE: Although the weather conditions varied from other published cases, the grazing conditions (almost exclusive Kikuyu grass) and the post-mortem findings were very similar to those described in the literature, particularly the haemorrhages in the epicardium and endocardium. Kikuyu grass is very invasive and presents many desirable characteristics as cattle feed. Thus, an increase in cases of intoxication may be expected. Practitioners and farmers in areas where Kikuyu grass is abundant should be aware of the potential risks of grazing cattle exclusively on these pastures. They should also be aware of the early and subtle signs of Kikuyu intoxication to allow for timely removal of the animals from pasture.

Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort.

PURPOSE: After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation. METHODS: A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age < 10 and ≥ 14 weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry. RESULTS: Median UIC was 104 µg/L (IQR 62-189) in the overall population (n = 481) of which 19% had UIC < 50 µg/L. Forty three percent (n = 206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146 µg/L (IQR 81-260) and 74 µg/L (IQR 42-113) in ICS users and non-users, respectively (p < 0.001). Not using an ICS was an independent risk factor for iodine insufficiency [adjusted OR (95% CI) = 6.00 (2.74, 13.16); p < 0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p < 0.014). CONCLUSIONS: A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine deficiency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt. Trial registration number NCT04010708, registered on the 8th July 2019.

Early standardized clinical judgement for syncope diagnosis in the emergency department.

BACKGROUND: The diagnosis of cardiac syncope remains a challenge in the emergency department (ED). OBJECTIVE: Assessing the diagnostic accuracy of the early standardized clinical judgement (ESCJ) including a standardized syncope-specific case report form (CRF) in comparison with a recommended multivariable diagnostic score. METHODS: In a prospective international observational multicentre study, diagnostic accuracy for cardiac syncope of ESCJ by the ED physician amongst patients ≥ 40 years presenting with syncope to the ED was directly compared with that of the Evaluation of Guidelines in Syncope Study (EGSYS) diagnostic score. Cardiac syncope was centrally adjudicated independently of the ESCJ or conducted workup by two ED specialists based on all information available up to 1-year follow-up. Secondary aims included direct comparison with high-sensitivity cardiac troponin I (hs-cTnI) and B-type natriuretic peptide (BNP) concentrations and a Lasso regression to identify variables contributing most to ESCJ. RESULTS: Cardiac syncope was adjudicated in 252/1494 patients (15.2%). The diagnostic accuracy of ESCJ for cardiac syncope as quantified by the area under the curve (AUC) was 0.87 (95% CI: 0.84-0.89), and higher compared with the EGSYS diagnostic score (0.73 (95% CI: 0.70-0.76)), hs-cTnI (0.77 (95% CI: 0.73-0.80)) and BNP (0.77 (95% CI: 0.74-0.80)), all P < 0.001. Both biomarkers (alone or in combination) on top of the ESCJ significantly improved diagnostic accuracy. CONCLUSION: ESCJ including a standardized syncope-specific CRF has very high diagnostic accuracy and outperforms the EGSYS score, hs-cTnI and BNP.

New insights about the monomer and homodimer structures of the human AOX1.

Human aldehyde oxidase (hAOX1) is a molybdenum dependent enzyme that plays an important role in the metabolism of various compounds either endogenous or xenobiotics. Due to its promiscuity, hAOX1 plays a major role in the pharmacokinetics of many drugs and therefore has gathered a lot of attention from the scientific community and, particularly, from the pharmaceutical industry. In this work, homology modelling, molecular docking and molecular dynamics simulations were used to study the structure of the monomer and dimer of human AOX. The results with the monomer of hAOX1 allowed to shed some light on the role played by thioridazine and two malonate ions that are co-crystalized in the recent X-ray structure of hAOX1. The results show that these molecules endorse several conformational rearrangements in the binding pocket of the enzyme and these changes have an impact in the active site topology as well as in the stability of the substrate (phthalazine). The results show that the presence of both molecules open two gates located at the entrance of the binding pocket, from which results the flooding of the active site. They also endorse several modifications in the shape of the binding pocket (namely the position of Lys893) that, together with the presence of the solvent molecules, favour the release of the substrate to the solvent. Further insights were also obtained with the assembled homodimer of hAOX1. The allosteric inhibitor (THI) binds closely to the region where the dimerization of both monomers occur. These findings suggest that THI can interfere with protein dimerization.

Using patients as educators for communication skills: Exploring dental students' and patients' views.

TITLE: A qualitative study to explore the issues for patients and students when giving feedback on the communication of dental students. OBJECTIVES: The Department of Health and National Institute for Health Research are committed to involving patients in improving clinical education, research and service delivery. Yet, there is a limited body of evidence on the perceptions of patients when asked to be involved in this way, and specifically when asked to provide feedback on the communication skills of dental students. This study seeks to address this gap and heighten the understanding of the issues faced by patients when asked to be involved in clinical education. METHODS: Data were collected using focus groups with dental students (n=10) and patients (n=8) being treated by these students. Both groups were asked about their thoughts, feelings and beliefs about patients being asked to provide feedback on the communication skills of dental students. Data analysis involved inductive thematic analysis of transcribed audio recordings. RESULTS: Four themes emerged from the data: "legitimacy," "co-educators," "maintaining the equilibrium of the patient-student relationship" and the "timing of patient feedback." Support for involving patients in giving feedback on students' communication skills was established, with patients considering they were best placed to comment on the communication skills of dental students. Patients and students do not want to provide feedback alone and want support to assist them, especially if feedback was negative. Issues of anonymity, confidentiality and ownership of the feedback process were worrisome, and the positioning of patient feedback in the programme was seen as critical. CONCLUSIONS: Patients and students are willing to engage in patient feedback on students' communication skills, and with support and training, the concerns around this are not insurmountable and the benefits could potentially profit both groups. These findings have resonance with other healthcare educators when using patients as educators in the development of communication skills.

Frequent occurrence of trimethoprim-sulfamethoxazole hetero-resistant Staphylococcus aureus isolates in different African countries.

High rates of trimethoprim/sulfamethoxazole (SXT) resistance, a combination of two antifolate antibiotics trimethoprim (TMP) and sulfamethoxazole (SMZ), have been reported among Staphylococcus aureus isolates in Portuguese-speaking African countries. Our study aimed to evaluate the occurrence of TMP resistance markers in major SXTR methicillin-resistant S. aureus (MRSA) clones from these countries. We accessed also different fitness traits that could explain the success of these isolates over the Brazilian MRSA (the most successful SXTR MRSA clone worldwide but never identified in these countries). Minimum inhibitory concentrations for SXT, TMP and SMZ were determined, and genes encoding TMP resistance (dfrG, dfrA, dfrK and dfrB) were searched. Representatives of the Brazilian clone and of the major MRSA African clones were evaluated for their fitness by individual growth curves, competition assays, survival under desiccation, autolytic activity, resistance to oxidative stress, and also growth at high osmolarity and in acid and alkaline environments. Although all African isolates showed high-level resistance to TMP, the majority presented hetero-resistance to SXT. TMP resistance was linked to the presence of dfrG (78%), dfrA (19%) or both (3%) genes. Compared to the Brazilian clone, the African isolates showed higher growth rates and autolytic activity, and better survival to desiccation and alkaline conditions. Since isolates exhibiting SXT hetero-resistance are frequent in Africa, the implementation of standardized guidelines to detect this phenomenon is of major interest. The predominant MRSA clones in Portuguese-speaking African countries likely possess significant advantages over other clones, such as the Brazilian MRSA, that may explain their epidemiological success.

Cognitive impairment and magnetic resonance imaging correlates in primary progressive multiple sclerosis.

OBJECTIVES: To characterize cognitive impairment in primary progressive multiple sclerosis (PPMS) and to correlate the pattern of cognitive deficits with brain magnetic resonance imaging (MRI) volumetric data. MATERIALS AND METHODS: In a multicenter cross-sectional study, we recruited consecutive patients with PPMS as well as age, sex, and education level-matched healthy controls (HC). All participants underwent neuropsychological (NP) assessment, and brain MRI was performed in patients with PPMS for analysis of lesion load, subcortical GM volumes, and regional cortical volumes. RESULTS: We recruited 55 patients with PPMS and 36 HC. Thirty-six patients were included in the MRI analysis. Patients with PPMS performed significantly worse than HC in all NP tests. Subcortical GM volume was significantly correlated with all NP tests, except for Stroop Test, with the largest effect for the thalamus (r=-.516 [BVMT-R DR, P=.016 FDR-corrected] to r=.664 [SDMT, P<.001 FDR-corrected]). In the stepwise linear regression model, thalamic volume was the only predictor of performance in all NP tests. CONCLUSION: Cognitive impairment is common in PPMS and affects all evaluated cognitive domains. Subcortical GM volume, particularly of the thalamus, is a strong predictor of cognitive performance, suggesting it has a central role in the pathophysiology of PPMS-related cognitive dysfunction.

Transgenerational effects of a hypercaloric diet.

The effects of a maternal hypercaloric diet (HD) during puberty and early adulthood on neuroimmune aspects in offspring were investigated. In female rats of the F0 generation and male rats of the F1 generation, bodyweight (BW) gain, retroperitoneal fat (RPF) weight, the number of hypodermic adipocytes (HAs) and expression of glial fibrillary acidic protein (GFAP) were measured in hypothalamic astrocytes. On Postnatal Day 50, the F1 pups were challenged with lipopolysaccharide (LPS, 100µgkg-1, s.c.) or an equal volume of saline (S), and behaviour in the open field test was evaluated, as were plasma neuropeptide and cytokine concentrations. The maternal HD caused the female F0 rats to become overweight. The F1 offspring of dams fed the HD and challenged with saline (HDS group) exhibited increases in BW gain, RPF weight and in the number of large HAs and a decrease in GFAP immunoreactivity. F1 offspring of dams fed the HD and challenged with LPS (HDLPS group) exhibited decreases in BW gain, RPF weight and GFAP immunoreactivity, but no differences were observed in the number of larger and small HAs. Plasma tumour necrosis factor-α concentrations were high in the HDS and HDLPS groups. Thus, the maternal HD during puberty and early adulthood caused the F1 generation to become overweight despite the fact that they received a normocaloric diet. These results indicate a transgenerational effect of the HD that may occur, in part, through permanent changes in immune system programming. The attenuation of neuroinflammation biomarkers after LPS administration may have resulted in a decrease in the number of adipocytes, which, in turn, reduced cytokine, adipokine and chemokine levels, which are able to recruit inflammatory cells in adipose tissue.

Maternal food restriction in rats of the F0 generation increases retroperitoneal fat, the number and size of adipocytes and induces periventricular astrogliosis in female F1 and male F2 generations.

The present study investigated whether male offspring (F2 generation) from female rats (F1 generation) whose mothers (F0 generation) were food restricted during gestation inherit a phenotypic transgenerational tendency towards being overweight and obese in the juvenile period, in the absence of food restriction in the F1/F2 generations. Dams of the F0 generation were 40% food restricted during pregnancy. Bodyweight, the number and size of larger and small hypodermal adipocytes (HAs), total retroperitoneal fat (RPF) weight and the expression of glial fibrillary acidic protein (GFAP) in periventricular hypothalamic astrocytes (PHAs), as determined by immunohistochemistry, were evaluated in both generations. In the female F1 generation, there was low bodyweight gain only during the juvenile period (30-65 days of age), a decrease in the size of small adipocytes, an increase in the number of small adipocytes, an increase in RPF weight and an increase in GFAP expression in PHAs at 90-95 days of age. In males of the F2 generation at 50 days of age, there was increased bodyweight and RPF weight, and a small number of adipocytes and GFAP expression in PHAs. These data indicate that the phenotypic transgenerational tendency towards being overweight and obese was observed in females (F1) from mothers (F0) that were prenatally food restricted was transmitted to their male offspring.

Oral creatine supplementation on performance of Quarter Horses used in barrel racing.

The aim of this study was to evaluate the effects of oral creatine supplementation on the athletic performance of equines used for barrel racing. Ten healthy Quarter Horses, or Quarter Horse crossbred, weighing 429.7 ± 25.3 kg and with mean age of 3.8 ± 1.2 years, were used. Animals were evaluated in four different moments (M1, M2, M3, M4), and between M3 and M4, they were supplemented with 28 g of creatine/100 kg of body weight, orally, for 45 days. Although significant alterations for LDH activity, plasma glucose and packed cell volume were observed, it was possible to conclude that there was no improvement in the athletic performance for the animals used on the experiment, as there were no changes in time scores, heart rate and plasma lactate, variables considered as performance indicators, before and after supplementation.

Student perceptions of a spiral curriculum.

AIM: The aim of this study was evaluation of constructive alignment of student perceptions to a spiral curriculum, as a pre-requisite to successful learning. METHOD: A survey was undertaken to evaluate student thoughts and experiences of a spiral curriculum, by participation in an anonymous voluntary questionnaire. Students were asked to rate their thoughts on their understanding, perceived benefit of and confusion with their spiral curriculum at the current time and retrospectively during previous years, and to answer free-text questions on the impact, effects on learning and future suggestions for their spiral curriculum. RESULTS: Sixty (86%) students completed the questionnaire. Understanding the spiral curriculum worked enhanced with time, with the benefit of the spiral curriculum being felt more conclusively in the latter years, and the majority of students not being confused by the spiral curriculum. Those students who were most confused by the spiral curriculum were the ones who were least likely to appreciate its benefits. The opportunity for consolidation of previously visited knowledge was a perceived predominant advantage, with re-visitation of topics helping to deepen understanding and learning. Clarity on the depth of knowledge at each stage prevents information overload. A spiral curriculum must spiral and not be a repetition of previously delivered topics. CONCLUSIONS: This study provided insights into students' perceptions of an integrated spiral curriculum, and whilst predominantly positive, there are challenges to enhance the student experience. The spiral curriculum provides an opportunity to revisit and consolidate learning to the apparent benefit of the student.

Social learning strategies for nut-cracking by tufted capuchin monkeys (Sapajus spp.).

The spontaneous use of stone tools for cracking nuts by tufted capuchin monkeys, now known to be habitual among wild populations in savanna environments, was first described in a semifree group living in the Tietê Ecological Park (SP, Brazil). Nut-cracking at TEP was first observed by our team in 1995 (Ottoni and Mannu in Int J Primatol 22(3):347-358, 2001), and its ontogeny and associated social dynamics, with inexperienced observers highly interested in the activities of proficient individuals, greatly tolerant to scrounging, support hypotheses about social biases on tool-use learning. Here we further analyze the social learning biases, better characterizing: the social context of nut-cracking in which observation by conspecifics occurs, the quality of the nut-cracking behavior itself and whether scrounging may be the motivation behind this behavior. We confirm that the choice of observational targets is an active one; monkeys do not simply observe those who they are socially close to. We investigate social learning strategies, describing how young capuchins choose to observe older, more proficient and dominant individuals during nut-cracking bouts. Monkeys with higher productivity rates were also more frequently targeted by observers, who were tolerated scroungers, further supporting the scrounging hypothesis. Finally, based on changes of the demographic patterns of tool use and observation, we set to retrace data from 14 years of continuous studies. We argue that we have followed the dissemination of the behavior (Transmission Phase) almost from its beginning, when juveniles were the most frequent nutcrackers, to a more common pattern where adults are the most active tool users (Tradition Phase).

Selection of maize hybrids for tolerance to aluminum in minimal solution.

The aim of this study was to determine the Al concentration and the period of exposure of the roots of maize hybrids in minimal solution for efficient selection of genotypes that are Al-tolerant. Two experiments were performed (48 and 96 h of exposure) with increasing doses of Al in minimal solution; the block design was completely randomized in a split-plot design with 3 replications. By assessing differences in root growth (cm) and the percentage of inhibition of the growth of the main root (%), a marked decrease was observed in maize root growth with increasing Al concentration in the solution. Exposure of the roots to 2 mg/L Al for 48 h in minimal solution was the most efficient for selecting sources of tolerance, particularly for the hybrids H 44 and H 38.

Helicobacter pylori identification: a diagnostic/confirmatory method for evaluation.

The Helicobacter pylori extra gastric reservoir is probably the oral cavity. In order to evaluate the presence of this bacterium in patients with periodontitis and suspicious microbial cultures, saliva was collected from these and non-periodontitis subjects. PCRs targeting 16S rRNA gene and a 860 bp specific region were performed, and digested with the restriction enzyme DdeI. We observed that the PCR-RFLP approach augments the accuracy from 26.2 % (16/61), found in the PCR-based results, to 42.6 % (26/61), which is an excellent indicator for the establishment of this low-cost procedure as a diagnostic/confirmatory method for H. pylori evaluation.

Evaluation and selection of indicators for land degradation and desertification monitoring: methodological approach.

An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification risk, a total of 70 candidate indicators was selected providing information for the biophysical environment, socio-economic conditions, and land management characteristics. The indicators were defined in 1,672 field sites located in 17 study areas in the Mediterranean region, Eastern Europe, Latin America, Africa, and Asia. Based on an existing geo-referenced database, classes were designated for each indicator and a sensitivity score to desertification was assigned to each class based on existing research. The obtained data were analyzed for the various processes of land degradation at farm level. The derived methodology was assessed using independent indicators, such as the measured soil erosion rate, and the organic matter content of the soil. Based on regression analyses, the collected indicator set can be reduced to a number of effective indicators ranging from 8 to 17 in the various processes of land degradation. Among the most important indicators identified as affecting land degradation and desertification risk were rain seasonality, slope gradient, plant cover, rate of land abandonment, land-use intensity, and the level of policy implementation.

Evaluation and selection of indicators for land degradation and desertification monitoring: types of degradation, causes, and implications for management.

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study sites around the world using a wide set of biophysical and socioeconomic indicators. The database described earlier in this issue by Kosmas and others (Environ Manage, 2013) for defining desertification risk was further analyzed to define the most important indicators related to the following degradation processes: water erosion in various land uses, tillage erosion, soil salinization, water stress, forest fires, and overgrazing. A correlation analysis was applied to the selected indicators in order to identify the most important variables contributing to each land degradation process. The analysis indicates that the most important indicators are: (i) rain seasonality affecting water erosion, water stress, and forest fires, (ii) slope gradient affecting water erosion, tillage erosion and water stress, and (iii) water scarcity soil salinization, water stress, and forest fires. Implementation of existing regulations or policies concerned with resources development and environmental sustainability was identified as the most important indicator of land protection.

Cariogenic bacteria and dental health status in adolescents: the role of oral health behaviours.

AIM: To evaluate the association between dental health status and levels of cariogenic bacteria in teenagers and the influence of behaviours and socio-demographic background on levels of bacteria. MATERIALS AND METHODS: Study design: A cross-sectional population-based sample of 13-year-old adolescents (112 females and 78 males, total 190) was examined. The number of decayed, missing and filled surfaces (DMFS), plaque and hygiene index were recorded according to the WHO criteria. The saliva samples were collected in a sterile container and then analysed by culture on Mitis Salivarius Bacitracin (MSB) agar for mutans Streptococci and on Man Rogosa Sharp (MRS) agar for Lactobacilli. The levels of bacteria were expressed as the number of colonies forming units per millilitre of saliva (CFU/ml). Associations between levels of mutans Streptococci and Lactobacilli and dental health were estimated by odds ratio (OR) and 95% confidence interval (95% CI) using unconditional logistic regression. RESULTS: No mutans Streptococci were detected in 53.2% of the adolescents but 22.6% presented ≥ 10³ CFU/ml. For Lactobacilli, these values were, respectively 43.7% and 34.7%. After adjustment for gender and social class, the OR (95% CI) for DMFS >5 was 8.66 (3.57-21.02) if mutans Streptococci ≥ 10³ CFU and 2.11 (0.96-4.64) if Lactobacilli ≥ 10³ CFU. CONCLUSION: This data allow us to conclude that hygiene habits and dental visits are not associated with high levels of cariogenic bacteria, but high scores of DMFS were found in adolescents with high levels of mutans Streptococci and lower parents' education.

High prevalence of hospital-associated methicillin-resistant Staphylococcus aureus in the community in Portugal: evidence for the blurring of community-hospital boundaries.

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infection in the community (CA-MRSA), but in spite of its relevance, no data exist concerning its epidemiology in Portugal. In this study, we aimed to evaluate the prevalence, population structure, and origin of MRSA in the Portuguese community. A total of 527 isolates, both methicillin-susceptible S. aureus (MSSA) and MRSA, were collected from individuals with no healthcare-related risk factors attending 16 healthcare institutions in Portugal. Isolates were characterized for the presence of mecA, Panton-Valentine leukocidin (PVL), and arginine catabolic mobile element (ACME), and by staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), spa, and multilocus sequence typing (MLST). Susceptibility to a panel of 13 antibiotics was tested. Isolates relatedness was analyzed by goeBURST and BURP. We found a high frequency (21.6%) of MRSA in the community. However, only 11.4% of the isolates belonged to typical CA-MRSA epidemic clones (USA300, USA400, USA700, Southwest Pacific, European, and ST398). The remaining isolates, which constituted the great majority (88.6%), belonged to hospital-associated MRSA (HA-MRSA) epidemic clones, namely, to the EMRSA-15 clone (77.2%). PVL was rare and carried by 17 isolates only (five MRSA and 12 MSSA). In the whole collection, some MRSA and MSSA were highly related. The high frequency of MRSA in the community in Portugal seems to result mainly from dissemination from the hospital. They might also have emerged from an extant MSSA population, by SCCmec acquisition, or MRSA clonal introduction from abroad.

A proposed model for the flowering signaling pathway of sugarcane under photoperiodic control.

Molecular analysis of floral induction in Arabidopsis has identified several flowering time genes related to 4 response networks defined by the autonomous, gibberellin, photoperiod, and vernalization pathways. Although grass flowering processes include ancestral functions shared by both mono- and dicots, they have developed their own mechanisms to transmit floral induction signals. Despite its high production capacity and its important role in biofuel production, almost no information is available about the flowering process in sugarcane. We searched the Sugarcane Expressed Sequence Tags database to look for elements of the flowering signaling pathway under photoperiodic control. Sequences showing significant similarity to flowering time genes of other species were clustered, annotated, and analyzed for conserved domains. Multiple alignments comparing the sequences found in the sugarcane database and those from other species were performed and their phylogenetic relationship assessed using the MEGA 4.0 software. Electronic Northerns were run with Cluster and TreeView programs, allowing us to identify putative members of the photoperiod-controlled flowering pathway of sugarcane.