RESUMEN
There is ample research demonstrating improved patient outcomes when using an enhanced recovery program. However, the literature reporting the impact of preoperative education alone prior to hip and knee arthroplasty is conflicting. With the number of these surgical procedures expected to increase in the next few years, the identification of strategies that positively impact outcomes is important. The aim of this study was to evaluate immediate postoperative physical therapy (PT) performance following a total hip or knee arthroplasty in patients who attended a preoperative education class compared with those who did not. This study was a retrospective chart review of 707 hip and knee arthroplasty patients, comparing outcomes based on preoperative educational session attendance. Demographics, comorbidities, length of stay (LOS), discharge disposition, and PT performance were collected from the chart review. Patients who attended the preoperative education class had significantly greater ambulation distances (p < .001), greater degrees of knee flexion (p < .001), and greater degrees of hip flexion (p = .012) on postoperative Day 1. Both hip (p < .001) and knee (p < .001) patients who attended the class had a significantly shorter LOS. The cost benefit analysis indicated a savings of $921.57 in direct costs per knee arthroplasty in those who attended a class. Patients who received preoperative education had greater mobility in the immediate postoperative period and reduced LOS for both hip and knee arthroplasties. Based on this study's results, preoperative education is effective in improving outcomes and reducing the cost of hip and knee arthroplasties.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Humanos , Tiempo de Internación , Periodo Posoperatorio , Estudios RetrospectivosRESUMEN
BACKGROUND: A widely used method for distributing continuing education to health care professionals is via electronically delivered learning modules (EDLM). The purpose of this study is to determine if RNs retain and value education provided by an EDLM. METHOD: This is a one-group pretest-posttest and longitudinal study employing survey methodology. RNs completed an electronically delivered sepsis educational module, an immediate posttest, and then a posttest 4 weeks later. Additionally, the researchers measured participants' feelings and practices regarding EDLMs. RESULTS: The mean value for total knowledge scores increased immediately postintervention then decreased to near baseline after 1 month. Additionally, participants reported that EDLMs did not increase their knowledge, nor did they value EDLMs. CONCLUSION: Our findings suggest that didactic information received via EDLMs may have minimal sustained impact on nurses' knowledge. Participants' lack of knowledge retention may be affected by module and evaluation design. [J Contin Educ Nurs. 2019;50(7):331-336.].
Asunto(s)
Competencia Clínica/normas , Instrucción por Computador/métodos , Educación Continua en Enfermería/métodos , Evaluación Educacional/métodos , Enfermeras y Enfermeros/psicología , Personal de Enfermería en Hospital/educación , Personal de Enfermería en Hospital/psicología , Adulto , Competencia Clínica/estadística & datos numéricos , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Enfermeras y Enfermeros/estadística & datos numéricosRESUMEN
Current literature supports outpatient parenteral antimicrobial therapy (OPAT). This article presents results from a research study that evaluated an OPAT program that treated community-acquired pneumonia. If patients had the opportunity to receive outpatient intravenous antibiotics for community-acquired pneumonia, would this prevent future hospitalization? Was there a decrease in hospital admissions? An informal cost-benefit analysis comparing OPAT with inpatient hospital admissions for the same disease was also reviewed to provide evidence whether there was a change. What was the overall health care cost savings? The medical charts of 50 patients with confirmed pneumonia who had received OPAT in a 3-month period were reviewed. A retrospective medical record review was performed. All patients were evaluated by the in-house OPAT team. The resulting analysis provided evidence that an estimated savings of approximately $2100 per day would be achieved by decreasing hospital readmissions for patient who had been treated with OPAT. The conclusion of this study provides evidence that the implement of an OPAT program was, and is, essential for patient care and evidence-based best practice adherence.
Asunto(s)
Atención Ambulatoria , Antiinfecciosos/uso terapéutico , Hospitales Rurales , Infusiones Parenterales/métodos , Análisis Costo-Beneficio/economía , Humanos , Infusiones Intravenosas , Readmisión del Paciente , Estudios RetrospectivosRESUMEN
According to the American Cancer Society, more than 1.6 million new cases of cancer were diagnosed in 2015. Anxiety levels in individuals diagnosed with cancer are high, with the highest levels occurring at the time of diagnosis. A cancer diagnosis and the associated chemotherapy are life-altering events for patients and their families. In addition to managing the devastating news about the disease, patients are tasked with learning to manage the impact of chemotherapy and its impact on their bodies and sense of well-being. These authors report the development of an education video aimed at addressing typical questions and concerns about treatment regimens. Results of their studies to determine the effectiveness of their video indicate significant value for the patient, especially anxiety reduction and enhanced ability to absorb new information and instructions from their caregiving team.
Asunto(s)
Ansiedad/prevención & control , Neoplasias/tratamiento farmacológico , Educación del Paciente como Asunto , Grabación de Cinta de Video/métodos , Ansiedad/psicología , Protocolos Clínicos , Femenino , Humanos , MasculinoRESUMEN
The intensive care unit (ICU) can be a place of stress, anxiety, and emotional instability for both patients and families. Medical and nursing care during this acute time is patient focused, and family members are often left in the dark. Unintentional exclusion from information results in high levels of stress, anxiety, and uncertainty for families. Due to the acuity of illness, family members of cardiac surgery patients experience the highest levels of stress. Spouses may experience intense psychosomatic symptoms such as depression, anxiety, and fear for several months after the surgery. The purpose of this study was aimed at decreasing those feelings of anxiety in family members with postcardiac surgery through the use of a cardiac surgery tool kit. The study was a quality improvement project utilizing a convenience sample of 83 participants 18 years and older. Participants were asked to use the State Trait Anxiety Inventory (STAI) Form Y-1 (state anxiety) to rate their anxiety level preintervention and then again postintervention. Data were collected over a 6-month period. Descriptive data including age, education level, ethnicity, relationship, experience in the ICU, and active diagnoses of mental disorders did not affect the changes in the pre- and posttest data. A paired t test was conducted on the sample to assess changes in state anxiety, using the STAI Form Y-1. The results were statistically significant (t = 11.97, df = 81, P < .001). Respondents' scores decreased significantly from pre intervention (mean = 53.01, standard deviation = 12.19) to postintervention (mean = 37.38, standard deviation = 10.94). The data suggest that the use of a postcardiac surgery tool kit is a low-risk measure that can decrease the anxiety in family members of postcardiac surgery patients.
Asunto(s)
Ansiedad , Procedimientos Quirúrgicos Cardíacos , Familia/psicología , Estrés Psicológico/prevención & control , Encuestas y Cuestionarios , Adulto , Anciano , Anciano de 80 o más Años , Ansiedad/prevención & control , Ansiedad/psicología , Depresión/prevención & control , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Estrés Psicológico/psicologíaRESUMEN
Coronary artery disease (CAD) is the leading cause of death in the United States. The World Bank and the World Health Organization predict that depression and coronary heart disease will be the largest causes of global health burden and disability by the year 2020. Studies have demonstrated that patients with CAD experience depression at a higher rate than the general population. Because of this connection, it is critical to recognize depression and manage depression effectively for people with CAD. Studies have also provided evidence that identifying and treating depression in patients early after a myocardial infarction improve clinical outcomes. In addition, a number of studies have discussed the negative effects that can occur from untreated depression in these patients. The cited negative effects include mortality, recurrent myocardial events, and a worse quality of life. This article discusses the results of a research that was completed at a cardiology office using a retroactive medical record review that focused on outpatients with cardiac diseases. The primary aim of the study was to collect data using the Patient Health Questionnaire-9 (PHQ-9), a public domain screening tool. This research was intended to provide evidence that would support using the PHQ-9 as a standard depression screening tool for patients post-myocardial infarction. By recognizing the symptoms of depression, the patient would then be treated accordingly.
Asunto(s)
Enfermedad de la Arteria Coronaria/mortalidad , Depresión/epidemiología , Infarto del Miocardio/terapia , Enfermedad de la Arteria Coronaria/terapia , Depresión/terapia , Humanos , Prevalencia , Calidad de Vida , Factores de Riesgo , Encuestas y Cuestionarios , Estados Unidos/epidemiologíaRESUMEN
Heart failure (HF) is a serious medical problem in the United States and is placing a financial strain on the health care system. It is the leading cause of mortality and as the overall incidence continues to increase, so does the economic impact on the health care system. Innovative treatment options, in the form of disease management programs and implantable cardiac devices, such as the CorVue capable implantable cardioverter defibrillator (ICD) pacemaker, offer the promise of an enhanced quality of life and reduced mortality. Even with these advances, HF continues to be a challenge. Studies reviewing HF management programs have shown promising results. However, more studies are needed to determine which combination of HF management interventions has the greatest financial impact and yields the best patient outcomes. The objective of the research study was to compare 30-day readmission rates of patients implanted with the CorVue capable ICD pacemaker with patients with congestive heart failure (CHF) with no implanted device. The aim of the research focused on the usefulness of intrathoracic impedance monitoring alerts in guiding empirical treatment of patients with CHF to prevent HF readmissions. Methodology included a retrospective medical chart review, comparing 30-day readmission events among patients with class III CHF who received home health intervention with similar patients implanted with the CorVue ICD.
Asunto(s)
Insuficiencia Cardíaca/terapia , Evaluación de Resultado en la Atención de Salud , Readmisión del Paciente , Desfibriladores Implantables/estadística & datos numéricos , Insuficiencia Cardíaca/clasificación , Insuficiencia Cardíaca/economía , Humanos , Marcapaso Artificial/estadística & datos numéricos , Calidad de Vida , Estudios Retrospectivos , Estados UnidosRESUMEN
According to the latest statistics from the American Association of Suicidology, there were approximately 41,000 suicides in the United States, accounting for 112 suicides per day or one every 12.8minutes (Drapeau & McIntosh, 2015). Survivors bereaved by suicide often experience complicated grief and feelings of social isolation. The study was a secondary data analysis from a study which involved 44 participants over the age of 18 from Southwestern Pennsylvania. Symptoms of depression and loneliness were assessed in relation to reported social support available to participants. The findings support the notion that increased availability of support can decrease symptoms of depression.
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Aflicción , Depresión/psicología , Soledad/psicología , Apoyo Social , Suicidio , Sobrevivientes/psicología , Adulto , Femenino , Humanos , Masculino , Pennsylvania , Escalas de Valoración Psiquiátrica , Suicidio/estadística & datos numéricosRESUMEN
Family presence during resuscitation (FPDR) has been an ongoing topic of discussion in many hospital emergency departments throughout the United States. With the current emphasis promoting patient- and family-centered care, families are now exercising their right to be present at the bedside during resuscitation. With or without a policy, there is continued resistance to allow families to remain with their loved ones during resuscitation. The purpose of this study was to evaluate if an evidence-based educational intervention would increase physicians' and nurses' knowledge, attitudes, and compliance with allowing FPDR. This quasi-experimental study evaluated 30 attending physicians' and 65 registered nurses' knowledge of an existing family presence policy and their attitudes toward family presence post-educational intervention in an emergency department setting. Compliance of family presence was observed for 2 months pre- and post-educational intervention. Results show that most physicians and nurses either were not sure or were not aware that there was an existing written policy. The study demonstrated that nurses agree more than physicians that the option of FPDR is a patient/family right. The results also showed that the educational intervention had no effect on the physicians and nurses attitudes for FPDR, but it did change behaviors. Of the events involving professionals who were exposed to the educational intervention, family members were present 87.5% of the time. In contrast, only 23% of the events involving professionals who did not receive the educational intervention had families present. Ongoing staff education will heighten awareness to FPDR, make the staff more comfortable with families being present, and will presumably continue to increase invitations for FPDR.
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Servicio de Urgencia en Hospital , Familia , Conocimientos, Actitudes y Práctica en Salud , Personal de Enfermería en Hospital/psicología , Médicos/psicología , Resucitación , Actitud del Personal de Salud , Femenino , Humanos , Capacitación en Servicio , Masculino , Personal de Enfermería en Hospital/educación , Relaciones Profesional-Familia , Encuestas y Cuestionarios , Visitas a PacientesRESUMEN
This was a non-experimental, descriptive, correlational study designed to assess the feasibility and efficacy of an evidence-based online pelvic floor treatment program targeting stress urinary incontinence in adult women. The majority of the participants reported some level of improvement in their incontinence symptoms and overwhelmingly supported the web-based physical therapy program.
Asunto(s)
Terapia por Ejercicio/métodos , Internet , Trastornos del Suelo Pélvico/terapia , Autocuidado , Incontinencia Urinaria de Esfuerzo/terapia , Adulto , Medicina Basada en la Evidencia , Estudios de Factibilidad , Femenino , Humanos , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
The switch gene Sex-lethal (Sxl) was thought to elicit all aspects of Drosophila female somatic differentiation other than size dimorphism by controlling only the switch gene transformer (tra). Here we show instead that Sxl controls an aspect of female sexual behavior by acting on a target other than or in addition to tra. We inferred the existence of this unknown Sxl target from the observation that a constitutively feminizing tra transgene that restores fertility to tra(-) females failed to restore fertility to Sxl-mutant females that were adult viable but functionally tra(-). The sterility of these mutant females was caused by an ovulation failure. Because tra expression is not sufficient to render these Sxl-mutant females fertile, we refer to this pathway as the tra-insufficient feminization (TIF) branch of the sex-determination regulatory pathway. Using a transgene that conditionally expresses two Sxl feminizing isoforms, we find that the TIF branch is required developmentally for neurons that also sex-specifically express fruitless, a tra gene target controlling sexual behavior. Thus, in a subset of fruitless neurons, targets of the TIF and tra pathways appear to collaborate to control ovulation. In most insects, Sxl has no sex-specific functions, and tra, rather than Sxl, is both the target of the primary sex signal and the gene that maintains the female developmental commitment via positive autoregulation. The TIF pathway may represent an ancestral female-specific function acquired by Sxl in an early evolutionary step toward its becoming the regulator of tra in Drosophila.
Asunto(s)
Proteínas de Drosophila/genética , Drosophila/genética , Genes de Cambio/genética , Neuronas/metabolismo , Ovulación/genética , Proteínas de Unión al ARN/genética , Procesos de Determinación del Sexo/genética , Transducción de Señal/genética , Animales , Femenino , Mutagénesis , Proteínas Nucleares/genética , Ovulación/metabolismo , TransgenesRESUMEN
In Drosophila melanogaster, the gene Sex-lethal (Sxl) controls all aspects of female development. Since melanogaster males lacking Sxl appear wild type, Sxl would seem to be functionally female specific. Nevertheless, in insects as diverse as honeybees and houseflies, Sxl seems not to determine sex or to be functionally female specific. Here we describe three lines of work that address the questions of how, when, and even whether the ancestor of melanogaster Sxl ever shed its non-female-specific functions. First, to test the hypothesis that the birth of Sxl's closest paralog allowed Sxl to lose essential ancestral non-female-specific functions, we determined the CG3056 null phenotype. That phenotype failed to support this hypothesis. Second, to define when Sxl might have lost ancestral non-female-specific functions, we isolated and characterized Sxl mutations in D. virilis, a species distant from melanogaster and notable for the large amount of Sxl protein expression in males. We found no change in Sxl regulation or functioning in the 40+ MY since these two species diverged. Finally, we discovered conserved non-sex-specific Sxl mRNAs containing a previously unknown, potentially translation-initiating exon, and we identified a conserved open reading frame starting in Sxl male-specific exon 3. We conclude that Drosophila Sxl may appear functionally female specific not because it lost non-female-specific functions, but because those functions are nonessential in the laboratory. The potential evolutionary relevance of these nonessential functions is discussed.
Asunto(s)
Evolución Biológica , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Genes de Cambio , Proteínas de Unión al ARN/genética , Animales , Drosophila melanogaster/fisiología , Femenino , Masculino , Datos de Secuencia Molecular , Mutación , ARN Mensajero/análisis , Procesos de Determinación del Sexo , Factores Sexuales , Especificidad de la EspecieRESUMEN
Maternally contributed mRNAs and proteins control the initial stages of development following fertilization. During this time, most of the zygotic genome remains transcriptionally silent. The initiation of widespread zygotic transcription is coordinated with the degradation of maternally provided mRNAs at the maternal-to-zygotic transition (MZT). While most of the genome is silenced prior to the MZT, a small subset of zygotic genes essential for the future development of the organism is transcribed. Previous work in our laboratory and others identified the TAGteam element, a set of related heptameric DNA-sequences in the promoters of many early-expressed Drosophila genes required to drive their unusually early transcription. To understand how this unique subset of genes is regulated, we identified a TAGteam-binding factor Grainyhead (Grh). We demonstrated that Grh and the previously characterized transcriptional activator Zelda (Zld) bind to different TAGteam sequences with varying affinities, and that Grh competes with Zld for TAGteam occupancy. Moreover, overexpression of Grh in the early embryo causes defects in cell division, phenocopying Zld depletion. Our findings indicate that during early embryonic development the precise timing of gene expression is regulated by both the sequence of the TAGteam elements in the promoter and the relative levels of the transcription factors Grh and Zld.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/genética , Regulación del Desarrollo de la Expresión Génica , Regiones Promotoras Genéticas , Factores de Transcripción/metabolismo , Animales , Proteínas de Unión al ADN/genética , Drosophila/embriología , Drosophila/metabolismo , Proteínas de Drosophila/genética , Embrión no Mamífero/metabolismo , Femenino , Proteínas Nucleares , Factores de Transcripción/genéticaRESUMEN
Wolbachia is a ubiquitous intracellular endosymbiont of invertebrates. Surprisingly, infection of Drosophila melanogaster by this maternally inherited bacterium restores fertility to females carrying ovarian tumor (cystocyte overproliferation) mutant alleles of the Drosophila master sex-determination gene, Sex-lethal (Sxl). We scanned the Drosophila genome for effects of infection on transcript levels in wild-type previtellogenic ovaries that might be relevant to this suppression of female-sterile Sxl mutants by Wolbachia. Yolk protein gene transcript levels were most affected, being reduced by infection, but no genes showed significantly more than a twofold difference. The yolk gene effect likely signals a small, infection-induced delay in egg chamber maturation unrelated to suppression. In a genetic study of the Wolbachia-Sxl interaction, we established that germline Sxl controls meiotic recombination as well as cystocyte proliferation, but Wolbachia only influences the cystocyte function. In contrast, we found that mutations in ovarian tumor (otu) interfere with both Sxl germline functions. We were led to otu through characterization of a spontaneous dominant suppressor of the Wolbachia-Sxl interaction, which proved to be an otu mutation. Clearly Sxl and otu work together in the female germline. These studies of meiosis in Sxl mutant females revealed that X chromosome recombination is considerably more sensitive than autosomal recombination to reduced Sxl activity.
Asunto(s)
Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiología , Drosophila melanogaster/genética , Células Germinativas/metabolismo , Proteínas de Unión al ARN/fisiología , Infecciones por Rickettsiaceae/genética , Wolbachia , Animales , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiología , Epistasis Genética/fisiología , Femenino , Dosificación de Gen , Regulación del Desarrollo de la Expresión Génica , Células Germinativas/fisiología , Mutación/fisiología , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Recombinación Genética , Infecciones por Rickettsiaceae/fisiopatología , Infecciones por Rickettsiaceae/veterinaria , Vitelogénesis/genética , Vitelogeninas/genética , Vitelogeninas/metabolismo , Wolbachia/fisiología , Cromosoma X/genéticaRESUMEN
We describe a surprising new regulatory relationship between two key genes of the Drosophila sex-determination gene hierarchy, Sex-lethal (Sxl) and transformer (tra). A positive autoregulatory feedback loop for Sxl was known to maintain somatic cell female identity by producing SXL-F protein to continually instruct the target gene transformer (tra) to make its feminizing product, TRA-F. We discovered the reciprocal regulatory effect by studying genetically sensitized females: TRA-F from either maternal or zygotic tra expression stimulates Sxl-positive autoregulation. We found female-specific tra mRNA in eggs as predicted by this tra maternal effect, but not predicted by the prevailing view that tra has no germline function. TRA-F stimulation of Sxl seems to be direct at some point, since Sxl harbors highly conserved predicted TRA-F binding sites. Nevertheless, TRA-F stimulation of Sxl autoregulation in the gonadal soma also appears to have a cell-nonautonomous aspect, unprecedented for somatic Sxl regulation. This tra-Sxl retrograde regulatory circuit has evolutionary implications. In some Diptera, tra occupies Sxl's position as the gene that epigenetically maintains female identity through direct positive feedback on pre-mRNA splicing. The tra-mediated Sxl feedback in Drosophila may be a vestige of regulatory redundancy that facilitated the evolutionary transition from tra to Sxl as the master sex switch.
Asunto(s)
Proteínas de Drosophila/genética , Drosophila/genética , Evolución Molecular , Genes de Insecto , Proteínas Nucleares/genética , Proteínas de Unión al ARN/genética , Animales , Drosophila/embriología , Proteínas de Drosophila/metabolismo , Embrión no Mamífero/metabolismo , Femenino , Gónadas/metabolismo , Masculino , Mutación , Proteínas Nucleares/metabolismo , Empalme del ARN , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Procesos de Determinación del SexoRESUMEN
Female differentiation of Drosophila germ cells is induced by cell-nonautonomous signals generated in the gonadal soma that work with germ-cell-autonomous signals determined by germ-cell X chromosome dose. Generation of the nonautonomous feminizing signals was known to involve female-specific protein encoded by the master sex-determination gene Sex-lethal (Sxl) acting on its switch-gene target transformer (tra) to produce Tra(F) protein. However, it was not known whether Sxl's action on tra alone would suffice to trigger a fully feminizing nonautonomous signal. We developed a constitutively feminizing tra transgene that allowed us to answer this question. In gynanders (XX//XO mosaics) feminized by this Tra(F) transgene, functionally Sxl- haplo-X (chromosomally male) somatic cells collaborated successfully with diplo-X (chromosomally female) germ cells to make functional eggs. The fertility of such gynanders shows not only that Tra(F) is sufficient to elicit a fully feminizing nonautonomous signal, but also that haplo-X somatic cells can execute all other somatic functions required for oogenesis, despite the fact that their genome is not expected to be dosage compensated for such diplo-X-specific functions. The unexpected observation that some Tra(F)-feminized gynanders failed to lay their eggs showed there to be diplo-X cells outside the gonad for which Tra(F)-feminized haplo-X cells cannot substitute.
Asunto(s)
Drosophila melanogaster/citología , Feminización , Células Germinativas/citología , Proteínas Nucleares/metabolismo , Óvulo/citología , Animales , Cromosomas , Proteínas de Drosophila/metabolismo , Femenino , Fertilidad , Genotipo , Gónadas/citología , Haploidia , Masculino , Proteínas Nucleares/genética , Oogénesis , Proteínas de Unión al ARN/metabolismo , TransgenesRESUMEN
The Drosophila sex-determination switch gene Sex-lethal (Sxl) and the X-chromosome signal element genes (XSEs) that induce the female-specific expression of Sxl are transcribed extremely early in development when most of the genome of this organism is still silent. The DNA sequence CAGGTAG had been implicated in this pre-cellular blastoderm activation of sex-determination genes. A genome-wide computational search, reported here, suggested that CAGGTAG is not specific to early sex-determination genes, since it is over-represented upstream of most genes that are transcribed pre-cellular blastoderm, not just those involved in sex determination. The same search identified similarly over-represented, one-base-pair degenerate sequences as possible functional synonyms of CAGGTAG. We call these heptamers collectively, the TAGteam. Relevance of the TAGteam sequences to pre-cellular blastoderm transcription was established through analysis of TAGteam changes in Sxl, scute (an XSE), and the ;ventral repression element' of the pattern-formation gene zerknüllt. Decreasing the number of TAGteam sites retarded the onset of pre-blastoderm transcription, whereas increasing their number correlated with an advanced onset. Titration of repressors was thought to be the rate-limiting step determining the onset of such early transcription, but this TAGteam dose effect shows that activators must also play an important role in the timing of pre-blastoderm gene expression.
Asunto(s)
Blastodermo , ADN/química , Drosophila/embriología , Drosophila/genética , Transcripción Genética , Animales , Secuencia de Bases , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Embrión no Mamífero , Femenino , Dosificación de Gen , Genes de Insecto , Modelos Biológicos , Datos de Secuencia Molecular , Filogenia , Regiones Promotoras Genéticas , Homología de Secuencia de Ácido Nucleico , Diferenciación Sexual , Factores de Tiempo , Cromosoma XRESUMEN
Five Drosophila melanogaster genes belong to the highly conserved sir2 family, which encodes NAD(+)-dependent protein deacetylases. Of these five, dsir2(+) (CG5216) is most similar to the Saccharomyces cerevisiae SIR2 gene, which has profound effects on chromatin structure and life span. Four independent Drosophila strains were found with P-element insertions near the dsir2 transcriptional start site as well as extraneous linked recessive lethal mutations. Imprecise excision of one of these P elements (PlacW07223) from a chromosome freed of extraneous lethal mutations produced dsir2(17), a null intragenic deletion allele that generates no DSIR2 protein. Contrary to expectations from the report by Rosenberg and Parkhurst on their P-mobilization allele dSir2(ex10), homozygosity for dsir2(17) had no apparent deleterious effects on viability, developmental rate, or sex ratio, and it fully complemented sir2(ex10). Moreover, through a genetic test, we ruled out the reported effect of dSir2(ex10) on Sex-lethal expression. We did observe a modest, strictly recessive suppression of white(m4) position-effect variegation and a shortening of life span in dsir2 homozygous mutants, suggesting that dsir2 has some functions in common with yeast SIR2.