Sex chromosomes evolved from autosomes many times across the eukaryote phylogeny. Several models have been proposed to explain this transition, some involving male and female sterility mutations linked in a region of suppressed recombination between X and Y (or Z/W, U/V) chromosomes. Comparative and experimental analysis of a reference genome assembly for a double haploid YY male garden asparagus (Asparagus officinalis L.) individual implicates separate but linked genes as responsible for sex determination. Dioecy has evolved recently within Asparagus and sex chromosomes are cytogenetically identical with the Y, harboring a megabase segment that is missing from the X. We show that deletion of this entire region results in a male-to-female conversion, whereas loss of a single suppressor of female development drives male-to-hermaphrodite conversion. A single copy anther-specific gene with a male sterile Arabidopsis knockout phenotype is also in the Y-specific region, supporting a two-gene model for sex chromosome evolution.

SummarySex chromosomes have evolved independently in phylogenetically diverse flowering plant lineages. The genes governing sex determination in dioecious species remain unknown, but theory predicts that the linkage of genes influencing male and female function will spur the origin and early evolution of sex chromosomes. For example, in an XY system, the origin of an active Y may be spurred by the linkage of female suppressing and male promoting genes.Garden asparagus (Asparagus officinalis) serves as a model for plant sex chromosome evolution, given that it has recently evolved an XX/XY sex chromosome system. In order to elucidate the molecular basis of gender differences and sex determination, we used RNAsequencing (RNA-Seq) to identify differentially expressed genes between female (XX), male (XY) and supermale (YY) individuals.We identified 570 differentially expressed genes, and showed that significantly more genes exhibited male-biased than female-biased expression in garden asparagus. In the context of anther development, we identified genes involved in pollen microspore and tapetum development that were specifically expressed in males and supermales.Comparative analysis of genes in the Arabidopsis thaliana, Zea mays and Oryza sativa anther development pathways shows that anther sterility in females probably occurs through interruption of tapetum development before microspore meiosis.

The MSQ-BR has adequate internal consistency and test-retest reliability. The MSQ-BR insomnia has adequate internal consistency for use as a separate application. However, the MSQ-BR hypersomnia demonstrated only moderate internal consistency for use as a separate application. Our intention was not to introduce modifications to the questionnaire, but to evaluate the reliability of total MSQ-BR and its subscales. Others studies are needed to assess the consistency of MSQ compared to other instruments.

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Some studies have demonstrated that physiotherapists have a high prevalence of low back pain (LBP). The association between physiotherapy students, who are potentially exposed to the same LBP occupational risks as graduates, and LBP has never been demonstrated. The objective of the study is to evaluate the association between undergraduate physiotherapy study and LBP. The study design includes a cross-sectional study. A questionnairebased study was carried out with physiotherapy and medical students. LBP was measured as lifetime, 1-year and point prevalence. Bivariate and multivariate analyses were performed to find the factors associated with LBP. Bivariate analyses were also performed to assess differences between LBP characteristics in the two courses. 77.9% of the students had LBP at some point in their lives, 66.8% in the last year and 14.4% of them reported they were suffering from LBP at the moment of answering the questionnaire. Physiotherapy students reported a higher prevalence of LBP when compared with the medical students in all measures. In the logistic regression model, physiotherapy students (A-OR 2.51; 95% CI 1.35-4.67; p = 0.003), and being exposed to the undergraduate study for more than four semesters (A-OR 2.55; 95% CI 1.43-4.55; p = 0.001) were independently associated with LBP. There were no differences between the courses concerning pain intensity and disability. As it was a crosssectional study, we were not able to observe accurately if there is an increasing incidence of LBP during the course. Also, we did not intend to identify which activities in the course were associated with the development of LBP. This study clearly demonstrated an association between undergraduate physiotherapy study and LBP. The length of course exposure is also associated with LBP.

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Object Deep wound infections are one of the most common and serious complications of spinal surgery. The impact of such infections on long-term outcomes is not well understood. The purpose of this study was to evaluate the functional status and satisfaction in patients who suffered a deep wound infection after undergoing lumbar arthrodesis for symptomatic degenerative disc disease. Methods The authors conducted a prospective study in 13 patients with a clinical and radiological diagnosis of symptomatic degenerative lumbar stenosis and instability; after undergoing decompression and instrumentation-augmented arthrodesis, the patients suffered a deep wound infection (infection group). A 3:1 (39-patient) matched cohort was selected for comparison (control group). All surgeries were performed during the same period and by a single surgeon. The postoperative infections were all treated in a similar manner and the instrumentation was not removed. Both groups were followed up and assessed with validated outcome instruments: Numerical Rating Scale of pain, Oswestry Disability Index, 36-Item Short Form Health Survey, Beck Depression Inventory, and Hospital Anxiety and Depression Scale. Patient satisfaction was also determined. Results The median follow-up duration was 22 months (range 6–108 months). The mean patient age was 62 ± 10 years, and 59.6% of the patients were female. There was no significant difference between the groups in pain, functional disability, quality of life, or depression and anxiety. However, 53.8% of the patients with infection were not satisfied with the procedure at the final evaluation, compared with 15.4% of the patients without a deep wound infection (p = 0.003). Conclusions Patients with successfully treated postoperative deep wound infections do not have a difference in functional outcome compared with patients who underwent an identical operation but did not suffer a complicating infection. Patients who suffered an infection were more likely to be unsatisfied with the procedure than patients who did not.