Natural variation and dosage of the HEI10 meiotic E3 ligase control Arabidopsis crossover recombination.

During meiosis, homologous chromosomes undergo crossover recombination, which creates genetic diversity and balances homolog segregation. Despite these critical functions, crossover frequency varies extensively within and between species. Although natural crossover recombination modifier loci have been detected in plants, causal genes have remained elusive. Using natural Arabidopsis thaliana accessions, we identified two major recombination quantitative trait loci (rQTLs) that explain 56.9% of crossover variation in Col×Ler F2 populations. We mapped rQTL1 to semidominant polymorphisms in HEI10, which encodes a conserved ubiquitin E3 ligase that regulates crossovers. Null hei10 mutants are haploinsufficient, and, using genome-wide mapping and immunocytology, we show that transformation of additional HEI10 copies is sufficient to more than double euchromatic crossovers. However, heterochromatic centromeres remained recombination-suppressed. The strongest HEI10-mediated crossover increases occur in subtelomeric euchromatin, which is reminiscent of sex differences in Arabidopsis recombination. Our work reveals that HEI10 naturally limits Arabidopsis crossovers and has the potential to influence the response to selection.

Mucopolysaccharidosis (MPS IIIA) mice have increased lung compliance and airway resistance, decreased diaphragm strength, and no change in alveolar structure.

Mucopolysaccharidosis type IIIA (MPS IIIA) is characterized by neurological and skeletal pathologies caused by reduced activity of the lysosomal hydrolase, sulfamidase, and the subsequent primary accumulation of undegraded heparan sulfate (HS). Respiratory pathology is considered secondary in MPS IIIA and the mechanisms are not well understood. Changes in the amount, metabolism, and function of pulmonary surfactant, the substance that regulates alveolar interfacial surface tension and modulates lung compliance and elastance, have been reported in MPS IIIA mice. Here we investigated changes in lung function in 20-wk-old control and MPS IIIA mice with a closed and open thoracic cage, diaphragm contractile properties, and potential parenchymal remodeling. MPS IIIA mice had increased compliance and airway resistance and reduced tissue damping and elastance compared with control mice. The chest wall impacted lung function as observed by an increase in airway resistance and a decrease in peripheral energy dissipation in the open compared with the closed thoracic cage state in MPS IIIA mice. Diaphragm contractile forces showed a decrease in peak twitch force, maximum specific force, and the force-frequency relationship but no change in muscle fiber cross-sectional area in MPS IIIA mice compared with control mice. Design-based stereology did not reveal any parenchymal remodeling or destruction of alveolar septa in the MPS IIIA mouse lung. In conclusion, the increased storage of HS which leads to biochemical and biophysical changes in pulmonary surfactant also affects lung and diaphragm function, but has no impact on lung or diaphragm structure at this stage of the disease.NEW & NOTEWORTHY Heparan sulfate storage in the lungs of mucopolysaccharidosis type IIIA (MPS IIIA) mice leads to changes in lung function consistent with those of an obstructive lung disease and includes an increase in lung compliance and airway resistance and a decrease in tissue elastance. In addition, diaphragm muscle contractile strength is reduced, potentially further contributing to lung function impairment. However, no changes in parenchymal lung structure were observed in mice at 20 wk of age.

MSH2 shapes the meiotic crossover landscape in relation to interhomolog polymorphism in Arabidopsis.

During meiosis, DNA double-strand breaks undergo interhomolog repair to yield crossovers between homologous chromosomes. To investigate how interhomolog sequence polymorphism affects crossovers, we sequenced multiple recombinant populations of the model plant Arabidopsis thaliana. Crossovers were elevated in the diverse pericentromeric regions, showing a local preference for polymorphic regions. We provide evidence that crossover association with elevated diversity is mediated via the Class I crossover formation pathway, although very high levels of diversity suppress crossovers. Interhomolog polymorphism causes mismatches in recombining molecules, which can be detected by MutS homolog (MSH) mismatch repair protein heterodimers. Therefore, we mapped crossovers in a msh2 mutant, defective in mismatch recognition, using multiple hybrid backgrounds. Although total crossover numbers were unchanged in msh2 mutants, recombination was remodelled from the diverse pericentromeres towards the less-polymorphic sub-telomeric regions. Juxtaposition of megabase heterozygous and homozygous regions causes crossover remodelling towards the heterozygous regions in wild type Arabidopsis, but not in msh2 mutants. Immunostaining showed that MSH2 protein accumulates on meiotic chromosomes during prophase I, consistent with MSH2 regulating meiotic recombination. Our results reveal a pro-crossover role for MSH2 in regions of higher sequence diversity in A. thaliana.

Mass spectrometry imaging protocol for spatial mapping of lipids, N-glycans and peptides in murine lung tissue.

RATIONALE: The application of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to murine lungs is challenging due to the spongy nature of the tissue. Lungs consist of interconnected air sacs (alveoli) lined by a single layer of flattened epithelial cells, which requires inflation to maintain its natural structure. Therefore, a protocol that is compatible with both lung instillation and high spatial resolution is essential to enable multi-omic studies on murine lung disease models using MALDI-MSI. METHODS AND RESULTS: To maintain the structural integrity of the tissue, murine lungs were inflated with 8% (w/v) gelatin for lipid MSI of fresh frozen tissues or 4% (v/v) paraformaldehyde neutral buffer for N-glycan and peptide MSI of FFPE tissues. Tissues were sectioned and prepared for enzymatic digestion and/or matrix deposition. Glycerol-free PNGase F was applied for N-glycan MSI, while Trypsin Gold was applied for peptide MSI using the iMatrixSpray and ImagePrep Station, respectively. For lipid, N-glycan and peptide MSI, α-cyano-4-hydroxycinnamic acid matrix was deposited using the iMatrixSpray. MS data were acquired with 20 µm spatial resolution using a timsTOF fleX MS instrument followed by MS fragmentation of lipids, N-glycans and peptides. For lipid MSI, trapped ion mobility spectrometry was used to separate isomeric/isobaric lipid species. SCiLS™ Lab was used to visualize all MSI data. For analyte identification, MetaboScape®, GlycoMod and Mascot were used to annotate MS fragmentation spectra of lipids, N-glycans and tryptic peptides, respectively. CONCLUSIONS: Our protocol provides instructions on sample preparation for high spatial resolution MALDI-MSI, MS/MS data acquisition and lipid, N-glycan and peptide annotation and identification from murine lungs. This protocol will allow non-biased analyses of diseased lungs from preclinical murine models and provide further insight into disease models.

Facilitators and barriers to home blood pressure monitoring among pregnant women in Ghana: a mixed-methods analysis of patient perspectives.

BACKGROUND: The benefit of home blood pressure monitoring during pregnancy and in low-resource settings is incompletely understood. The objective of this study was to explore the experiences, barriers, and facilitators of home blood pressure monitoring among pregnant women in Ghana. METHODS: This concurrent triangulation mixed-methods study was conducted at an urban tertiary hospital in Ghana. Participants were recruited from adult pregnant women presenting for routine antenatal care. Upon enrollment, participants' demographics and history were collected. At the next study visit, participants received audiovisual and hands-on training on using an automatic blood pressure monitor; they then monitored and logged their blood pressure daily at home for 2-4 weeks. At the final study visit, verbally administered surveys and semi-structured interviews assessed participant's experiences. Quantitative data were analyzed using R version 4.2.2, and frequencies and descriptive statistics were calculated. Qualitative data were imported into DeDoose 9.0.78 for thematic analysis. RESULTS: Of 235 enrolled participants, 194 completed surveys; of those, 33 completed in-depth interviews. Participants' mean age was 31.6 (SD 5.3) years, 32.1% had not previously given birth, and 31.1% had less than a senior high school education. On a 4-point Likert scale, the majority reported they "definitely" were able to remember (n = 134, 69.1%), could find the time (n = 124, 63.9%), had the energy (n = 157, 80.9%), could use the blood pressure monitor without problems (n = 155, 79.9%), and had family approval (n = 182, 96.3%) while engaging in home blood pressure monitoring. 95.88% (n = 186) believed that pregnant women in Ghana should monitor their blood pressure at home. Qualitative thematic analysis demonstrated that most participants liked home blood pressure monitoring because of increased knowledge of their health during pregnancy. While most participants found measuring their blood pressure at home doable, many faced challenges. Participants' experiences with five key factors influenced how easy or difficult their experience was: 1) Time, stress, and daily responsibilities; 2) Perceived importance of BP in pregnancy; 3) Role of family; 4) Capability of performing monitoring; 5) Convenience of monitoring. CONCLUSIONS: Among pregnant women in urban Ghana, home blood pressure monitoring was perceived as positive, important, and doable; however, challenges must be addressed.

Benefits and barriers of home blood pressure monitoring in pregnancy: perspectives of obstetric doctors from a Ghanaian tertiary hospital.

BACKGROUND: Delayed diagnosis of preeclampsia contributes to maternal morbidity and mortality. Patient-performed home blood pressure monitoring facilitates more frequent monitoring and earlier diagnosis. However, challenges may exist to implementation in low- and middle income-countries. METHODS: This cross-sectional mixed methods study evaluated obstetric doctors' perspectives on the benefits of and barriers to the implementation of home blood pressure monitoring among pregnant women in Ghana. Participants were doctors providing obstetric care at Korle Bu Teaching Hospital. Electronic surveys were completed by 75 participants (response rate 49.3%), consisting of demographics and questions on attitudes and perceived benefits and challenges of home BP monitoring. Semi-structured interviews were completed by 22 participants to expand on their perspectives. RESULTS: Quantitative and qualitative results converged to highlight that the current state of blood pressure monitoring among pregnant women in Ghana is inadequate. The majority agreed that delayed diagnosis of preeclampsia leads to poor health outcomes in their patients (90.6%, n = 68) and earlier detection would improve outcomes (98.7%, n = 74). Key qualitative benefits to the adoption of home blood pressure monitoring were patient empowerment and trust of diagnosis, more quantity and quality of blood pressure data, and improvement in systems-level efficiency. The most significant barriers were the cost of monitors, lack of a communication system to convey abnormal values, and low health literacy. Overall, doctors felt that most barriers could be overcome with patient education and counseling, and that benefits far outweighed barriers. The majority of doctors (81.3%, n = 61), would use home BP data to inform their clinical decisions and 89% (n = 67) would take immediate action based on elevated home BP values. 91% (n = 68) would recommend home BP monitoring to their pregnant patients. CONCLUSION: Obstetric doctors in Ghana strongly support the implementation of home blood pressure monitoring, would use values to inform their clinical management, and believe it would improve patient outcomes. Addressing the most significant barriers, including cost of blood pressure monitors, lack of a communication system to convey abnormal values, and need for patient education, is essential for successful implementation.

"Once you get one maternal death, it's like the whole world is dropping on you": experiences of managing maternal mortality amongst obstetric care providers in Ghana.

BACKGROUND: Maternal mortality has a significant global impact, especially in low-resource settings. Little prior research has been conducted on the potential effects of poor maternal outcomes on the personal and professional well-being of healthcare providers. This study explores the in-depth experiences and perspectives of obstetric providers in Ghana who work in a setting with frequent maternal mortalities. METHODS: This is a qualitative study of semi-structured interviews conducted at the Komfo Anokye Teaching Hospital in Ghana. Participants were obstetric healthcare providers, defined as midwives, house officers currently rotating on the obstetrics/gynecology service, and obstetrician/gynecologists at any training or practice level (residents, fellows, and specialists). Interviews were audio-recorded, transcribed verbatim, and uploaded into NVivo for qualitative analysis. Using the Attride-Stirling qualitative model, an incremental and iterative process was used to code interviews with keyword phrases and develop a framework of organizing and global themes. RESULTS: Interviews were conducted with 27 participants-15 midwives and 12 physicians (three obstetrician/gynecologist residents, six obstetrician/gynecologist specialists, and three house officers), with sample size determined by data saturation. Obstetric providers' experiences in a setting with frequent maternal mortalities were dependent on their level of preparedness to manage maternal mortalities and the workplace environment. Providers' level of preparedness was dependent on both the training they had received on the medical management of obstetric emergencies, as well as a lack of training on the mental health aspects of coping with maternal mortality. The impact of the workplace environment was dependent on systems failures and limited resources, blame from colleagues and supervisors, and a lack of support in the workplace. In turn, obstetric providers' experiences managing frequent maternal mortalities impacted their clinical care performance and mental health. CONCLUSIONS: Maternal deaths have profound personal and professional impacts on the healthcare providers who manage them. A large need exists for additional institutional training and support for obstetric providers who manage maternal mortality, especially in low-resource settings like Ghana.

"There is no joy in the family anymore": a mixed-methods study on the experience and impact of maternal mortality on families in Ghana.

BACKGROUND: Maternal mortality has a multifaceted impact on families, especially in low- and middle-income countries, where rates of maternal mortality are high and resources can be lacking. The objective of this study was to explore the ways that maternal mortality influences the physical and emotional wellbeing, financial stability, and caregiving structure of families, and identifies sources of and gaps in support. METHODS: Our study used a mixed-methods design. All maternal mortalities in an 18-month period at a tertiary hospital in Ghana were identified using death certificates. Participants were 51 family members (either husbands or other heads of households) in families affected by maternal mortality. A questionnaire assessed demographic characteristics and changes in family health, income, and family structure. Two validated scales assessing psychological wellbeing were administered: the Patient Health Questionnaire-9 and the Inventory of Complicated Grief. Semi-structured interviews were conducted to assess impact on family wellbeing. RESULTS: Quantitative and qualitative results converged to highlight large, negative impacts of maternal mortality on four areas of family wellbeing: 1) mental health and emotional wellbeing; 2) physical health; 3) family structure; 4) financial stability and security. On the Patient Health Questionnaire-9, 54% (27/50) of participants reported elevated depressive symptoms, with 14% (7/50) of scores falling in the moderately severe or severe ranges. On the Inventory of Complicated Grief, 38% (19/50) exceeded the cutoff for significant impairment in functioning. Worsened family health was associated with greater complicated grief (b = 21.41, p = .004); there were no other significant predictors of depressive symptom severity or complicated grief. Effects on family health centered on concerns about the nutritional status and health of the surviving infant. Family structure was primarily affected by fracturing of the central family unit by sending children to live with relatives. Immense economic strain resulted from hospital bills, funeral expenses, and loss of income. The majority of participants received helpful support from their family (41/51, 80.4%), the community (32/51, 62.7%), and their religious institution (43/51, 84.3%); however, support often stopped soon after the death. CONCLUSIONS: Maternal mortality has profound negative impacts on families in Ghana. Impacts are experienced by husbands and heads of households, as well as surviving children. Both immediate and sustained support is needed for families following a maternal death, especially mental health and financial support.

Community-specific "desired" states for seagrasses through cycles of loss and recovery.

Seagrass habitats provide critical ecosystem services, yet there is ongoing concern over mounting pressures and continuing degradation. Defining a desired state for these habitats is a key step in implementing appropriate management but is often difficult given the challenges of available data and an evaluation of where to set benchmarks. We use more than 20 years of historical seagrass biomass data (1995-2018) for the diverse seagrass communities of Australia's Great Barrier Reef World Heritage Area (GBRWHA) to develop desired state benchmarks. Desired state for seagrass biomass was estimated for 25 of 36 previously defined seagrass communities with the remainder having insufficient data. Desired state varied by more than one order of magnitude between community types and was influenced by the mix of species in the communities and the range of environmental conditions. We identify a historical, decadal-scale cycle of decline with recovery to desired state in coastal intertidal communities. In contrast a number of the estuary and coastal subtidal communities have not recovered to desired state biomass. Understanding a historical context is critically important for setting benchmarks and making informed management decisions on the present state of seagrass in the GBRWHA. The approach we have developed is scalable for monitoring, management and assessment of pressures for other management areas and for other jurisdictions. Our results guide conservation planning through prioritization of the at-risk seagrass communities that are continuing to fall below their desired state.

Attitudes, experiences, and training on comprehensive abortion care: A nationwide survey of trainee physicians in Ghana.

This cross-sectional study assessed attitudes and experiences with abortion care among physician trainees in Ghana. Participants were 27 Obstetrics/Gynecology (OBGYN) residents and 138 house officers. An electronic survey evaluated attitudes, training, clinical experience, and technical skills with abortion care. The majority of participants believe that women should have access to safe abortion. However, only 51.6% of OBGYN residents and 40.9% of house officers want to currently perform abortions as a trainee, primarily due to religious or ethical beliefs. Among house officers, increased likelihood of performing abortions in their future practice is associated with greater exposure to abortion training, (OR 1.40, p=0.032), fewer years practicing medicine (OR 0.26, p=0.010), and believing abortion laws should be liberalized (OR 3.62, p=0.03). Overall, we demonstrate that only two-thirds of physician trainees in Ghana are likely to perform abortion care after completing training, and greater exposure to abortion training is associated with an increased likelihood of performing abortions.

Spectroscopic and Molecular Docking Study of the Interaction between Neutral Re(I) Tetrazolate Complexes and Bovine Serum Albumin.

Re(I) complexes have potential in biomedical sciences as imaging agents, diagnostics and therapeutics. Thus, it is crucial to understand how Re(I) complexes interact with carrier proteins, like serum albumins. Here, two neutral Re(I) complexes were used (fac-[Re(CO)3 (1,10-phenanthroline)L], in which L is either 4-cyanophenyltetrazolate (1) or 4-methoxycarbonylphenyltetrazole ester (2), to study the interactions with bovine serum albumin (BSA). Spectroscopic measurements, calculations of thermodynamic and Förster resonance energy transfer parameters, as well as molecular modelling, were performed to study differential binding between BSA and complex 1 and 2. Induced-fit docking combined with quantum-polarised ligand docking were employed in what is believed to be a first for a Re(I) complex as a ligand for BSA. Our findings provide a basis for other molecular interaction studies and suggest that subtle functional group alterations at the terminal region of the Re(I) complex have a significant impact on the ability of this class of compounds to interact with BSA.

Effects of ignoring survey design information for data reuse.

Data are currently being used, and reused, in ecological research at an unprecedented rate. To ensure appropriate reuse however, we need to ask the question: "Are aggregated databases currently providing the right information to enable effective and unbiased reuse?" We investigate this question, with a focus on designs that purposefully favor the selection of sampling locations (upweighting the probability of selection of some locations). These designs are common and examples are those designs that have uneven inclusion probabilities or are stratified. We perform a simulation experiment by creating data sets with progressively more uneven inclusion probabilities and examine the resulting estimates of the average number of individuals per unit area (density). The effect of ignoring the survey design can be profound, with biases of up to 250% in density estimates when naive analytical methods are used. This density estimation bias is not reduced by adding more data. Fortunately, the estimation bias can be mitigated by using an appropriate estimator or an appropriate model that incorporates the design information. These are only available however, when essential information about the survey design is available: the sample location selection process (e.g., inclusion probabilities), and/or covariates used in their specification. The results suggest that such information must be stored and served with the data to support meaningful inference and data reuse.

Preeclampsia knowledge among postpartum women treated for preeclampsia and eclampsia at Korle Bu Teaching Hospital in Accra, Ghana.

BACKGROUND: Preeclampsia/eclampsia is a major cause of maternal morbidity and mortality worldwide, yet patients' perspectives about their diagnosis are not well understood. Our study examines patient knowledge among women with preeclampsia/eclampsia in a large urban hospital in Ghana. METHODS: Postpartum women diagnosed with preeclampsia or eclampsia were asked to complete a survey 2-5 days after delivery that assessed demographic information, key obstetric factors, and questions regarding provider counseling. Provider counseling on diagnosis, causes, complications, and future health effects of preeclampsia/eclampsia was quantified on a 4-point scale ('Counseling Composite Score'). Participants also completed an objective knowledge assessment regarding preeclampsia/eclampsia, scored from 0 to 22 points ('Preeclampsia/Eclampsia Knowledge Score' (PEKS)). Linear regression was used to identify predictors of knowledge score. RESULTS: A total of 150 participants were recruited, 88.7% (133) with preeclampsia and 11.3% (17) with eclampsia. Participants had a median age of 32 years, median parity of 2, and mean number of 5.4 antenatal visits. Approximately half of participants reported primary education as their highest level of education. While 74% of women reported having a complication during pregnancy, only 32% of participants with preeclampsia were able to correctly identify their diagnosis, and no participants diagnosed with eclampsia could correctly identify their diagnosis. Thirty-one percent of participants reported receiving no counseling from providers, and only 11% received counseling in all four categories. Even when counseled, 40-50% of participants reported incomplete understanding. Out of 22 possible points on a cumulative knowledge assessment scale, participants had a mean score of 12.9 ± 0.38. Adjusting for age, parity, and the number of antenatal visits, higher scores on the knowledge assessment are associated with more provider counseling (ß 1.4, SE 0.3, p < 0.001) and higher level of education (ß 1.3, SE 0.48, p = 0.008). CONCLUSIONS: Counseling by healthcare providers is associated with higher performance on a knowledge assessment about preeclampsia/eclampsia. Patient knowledge about preeclampsia/eclampsia is important for efforts to encourage informed healthcare decisions, promote early antenatal care, and improve self-recognition of warning signs-ultimately improving morbidity and reducing mortality.

Embedding international medical student electives within a 30-year partnership: the Ghana-Michigan collaboration.

BACKGROUND: Global health experiences are an increasingly popular component of medical student curricula. There is little research on the impact of international medical electives embedded within long-standing, sustainable partnerships. Our research explores the University of Michigan medical student elective experience in Ghana within the context of the Ghana-Michigan collaborative. METHODS: Study participants are University of Michigan medical students who completed an international elective in Ghana between March 2006 and June 2017. Post-elective reports were completed by students, including a description of the experience, highlights, disappointments, and the impact of the experience on interest in future international work and future practice of medicine. A retrospective thematic analysis of reports was carried out using NVivo 12 (QSR International, Melbourne, Australia). RESULTS: A total of 57 reports were analyzed. Benefits of the elective experience included building cross-cultural relationships, exposure to different healthcare environments, hands-on clinical and surgical experience, and exposure to different patient populations. Ninety-five percent of students planned to engage in additional international work in the future. Students felt that the long-standing bidirectional exchange allowed them to build cross-cultural relationships and be incorporated as a trusted part of the local clinical team. The partnership modeled collaboration, and many students found inspiration for the direction of their own careers. CONCLUSIONS: Embedding clinical rotations within a well-established, sustained partnerships provides valuable experiences for trainees by modeling reciprocity, program management by local physicians, and cultural humility-all of which can help prepare learners to ethically engage in balanced, long-term partnerships in the future.

A Paradigm in Immunochemistry, Revealed by Monoclonal Antibodies to Spatially Distinct Epitopes on Syntenin-1.

Syntenin-1 is an essential multi-functional adaptor protein, which has multiple roles in membrane trafficking and exosome biogenesis, as well as scaffolding interactions with either the actin cytoskeleton or focal adhesions. However, how this functional multiplicity relates to syntenin-1 distribution in different endosome compartments or other intracellular locations and its underlying involvement in cancer pathogenesis have yet to be fully defined. To help facilitate the investigation of syntenin-1 biology, we developed two specific monoclonal antibodies (Synt-2C6 and Synt-3A11) to spatially distinct linear sequence epitopes on syntenin-1, which were each designed to be unique at the six-amino acid level. These antibodies produced very different intracellular staining patterns, with Synt-2C6 detecting endosomes and Synt-3A11 producing a fibrillar staining pattern suggesting a cytoskeletal localisation. Treatment of cells with Nocodazole altered the intracellular localisation of Synt-3A11, which was consistent with the syntenin-1 protein interacting with microtubules. In prostate tissue biopsies, Synt-3A11 defined atrophy and early-stage prostate cancer, whereas Synt-2C6 only showed minimal interaction with atrophic tissue. This highlights a critical need for site-specific antibodies and a knowledge of their reactivity to define differential protein distributions, interactions and functions, which may differ between normal and malignant cells.

Modification of meiotic recombination by natural variation in plants.

Meiosis is a specialized cell division that produces haploid gametes required for sexual reproduction. During the first meiotic division, homologous chromosomes pair and undergo reciprocal crossing over, which recombines linked sequence variation. Meiotic recombination frequency varies extensively both within and between species. In this review, we will examine the molecular basis of meiotic recombination rate variation, with an emphasis on plant genomes. We first consider cis modification caused by polymorphisms at the site of recombination, or elsewhere on the same chromosome. We review cis effects caused by mismatches within recombining joint molecules, the effect of structural hemizygosity, and the role of specific DNA sequence motifs. In contrast, trans modification of recombination is exerted by polymorphic loci encoding diffusible molecules, which are able to modulate recombination on the same and/or other chromosomes. We consider trans modifiers that act to change total recombination levels, hotspot locations, or interactions between homologous and homeologous chromosomes in polyploid species. Finally, we consider the significance of genetic variation that modifies meiotic recombination for adaptation and evolution of plant species.

Mutations in UPF3B, a member of the nonsense-mediated mRNA decay complex, cause syndromic and nonsyndromic mental retardation.

Nonsense-mediated mRNA decay (NMD) is of universal biological significance. It has emerged as an important global RNA, DNA and translation regulatory pathway. By systematically sequencing 737 genes (annotated in the Vertebrate Genome Annotation database) on the human X chromosome in 250 families with X-linked mental retardation, we identified mutations in the UPF3 regulator of nonsense transcripts homolog B (yeast) (UPF3B) leading to protein truncations in three families: two with the Lujan-Fryns phenotype and one with the FG phenotype. We also identified a missense mutation in another family with nonsyndromic mental retardation. Three mutations lead to the introduction of a premature termination codon and subsequent NMD of mutant UPF3B mRNA. Protein blot analysis using lymphoblastoid cell lines from affected individuals showed an absence of the UPF3B protein in two families. The UPF3B protein is an important component of the NMD surveillance machinery. Our results directly implicate abnormalities of NMD in human disease and suggest at least partial redundancy of NMD pathways.

Self-regulation of the anterior insula: Reinforcement learning using real-time fMRI neurofeedback.

The anterior insula (AI) plays a key role in affective processing, and insular dysfunction has been noted in several clinical conditions. Real-time functional MRI neurofeedback (rtfMRI-NF) provides a means of helping people learn to self-regulate activation in this brain region. Using the Blood Oxygenated Level Dependant (BOLD) signal from the right AI (RAI) as neurofeedback, we trained participants to increase RAI activation. In contrast, another group of participants was shown 'control' feedback from another brain area. Pre- and post-training affective probes were shown, with subjective ratings and skin conductance response (SCR) measured. We also investigated a reward-related reinforcement learning model of rtfMRI-NF. In contrast to the controls, we hypothesised a positive linear increase in RAI activation in participants shown feedback from this region, alongside increases in valence ratings and SCR to affective probes. Hypothesis-driven analyses showed a significant interaction between the RAI/control neurofeedback groups and the effect of self-regulation. Whole-brain analyses revealed a significant linear increase in RAI activation across four training runs in the group who received feedback from RAI. Increased activation was also observed in the caudate body and thalamus, likely representing feedback-related learning. No positive linear trend was observed in the RAI in the group receiving control feedback, suggesting that these data are not a general effect of cognitive strategy or control feedback. The control group did, however, show diffuse activation across the putamen, caudate and posterior insula which may indicate the representation of false feedback. No significant training-related behavioural differences were observed for valence ratings, or SCR. In addition, correlational analyses based on a reinforcement learning model showed that the dorsal anterior cingulate cortex underpinned learning in both groups. In summary, these data demonstrate that it is possible to regulate the RAI using rtfMRI-NF within one scanning session, and that such reward-related learning is mediated by the dorsal anterior cingulate.

Prostate cell lines as models for biomarker discovery: performance of current markers and the search for new biomarkers.

BACKGROUND: Prostate cancer cell lines have been used in the search for biomarkers that are suitable for prostate cancer diagnosis. Unfortunately, many cell line studies have only involved single cell lines, partially characterized cell lines or were performed without controls, and this may have been detrimental to effective biomarker discovery. We have analyzed a panel of prostate cancer and nonmalignant control cell lines using current biomarkers and then investigated a set of prospective endosomal and lysosomal proteins to search for new biomarkers. METHODS: Western blotting was used to define the amount of protein and specific molecular forms in cell extracts and culture media from a panel of nonmalignant (RWPE-1, PNT1a, PNT2) and prostate cancer (22RV1, CaHPV10, DU-145, LNCaP) cell lines. Gene expression was determined by qRT-PCR. RESULTS: HPV-18 transfected cell lines displayed a different pattern of protein and gene expression when compared to the other cell lines examined, suggesting that these cell lines may not be the most optimal for prostate cancer biomarker discovery. There was an increased amount of prostatic acid phosphatase and kallikrein proteins in LNCaP cell extracts and culture media, but variable amounts of these proteins in other prostate cancer cell lines. There were minimal differences in the amounts of lysosomal proteins detected in prostate cancer cells and culture media, but two endosomal proteins, cathepsin B and acid ceramidase, had increased gene and protein expression, and certain molecular forms showed increased secretion from prostate cancer cells (P ≤ 0.05). LIMP-2 gene and protein expression was significantly increased in prostate cancer compared to nonmalignant cell lines (P ≤ 0.05). CONCLUSIONS: While the existing prostate cancer biomarkers and lysosomal proteins investigated here were not able to specifically differentiate between a panel of nonmalignant and prostate cancer cell lines, endosomal proteins showed some discriminatory capacity. LIMP-2 is a critical regulator of endosome biogenesis and the increased expression observed in prostate cancer cells indicated that other endosome related proteins may also be upregulated and could be investigated as novel biomarkers.