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Aim: The albumin-indocyanine green evaluation (ALICE) score is a useful predictor of post-hepatectomy liver failure (PHLF); however, its usefulness in combination with future liver remnant (FLR), measured by 3-D volumetry, has not been investigated. This study aimed to investigate the relationship between the ALICE of the FLR (ALICE-FLR) score and severe PHLF. Methods: The clinical data of 215 patients who underwent anatomical hepatectomy for hepatocellular carcinoma without portal vein embolization at two institutes between January 2010 and December 2021 were analyzed retrospectively. PHLF occurrence and severity were determined according to the International Study Group of Liver Surgery's definition. Grades B and C PHLF were defined as severe PHLF. The ALICE-FLR, ALICE scores, and indocyanine green clearance of FLR (ICGK-FLR) were evaluated for severe PHLF prediction. Results: Severe PHLF was observed in 40 patients (18.6%). The areas under the curve (AUCs) for the ALICE-FLR, ALICE scores, ICGK-FLR, and FLR were 0.76, 0.64, 0.73, and 0.69, respectively. The AUC of the ALICE-FLR score was significantly higher than that of the ALICE score. The ALICE-FLR score was identified as an independent predictor of severe PHLF (the odds ratio for every 0.01 increment in the ALICE-FLR score was 1.24; 95% confidence interval, 1.070-1.453; p = 0.004). Among patients with severe PHLF, the ALICE-FLR score was significantly higher in the grade C than in the grade B PHLF group. Conclusion: The combination of liver function models, including indocyanine green, albumin, and FLR is considered compatible for predicting severe PHLF.
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The acquisition of wings was a key event in insect evolution. As hemimetabolous insects were the first group to acquire functional wings, establishing the mechanisms of wing formation in this group could provide useful insights into their evolution. In this study, we aimed to elucidate the expression and function of the gene scalloped (sd), which is involved in wing formation in Drosophila melanogaster, and in Gryllus bimaculatus mainly during postembryonic development. Expression analysis showed that sd is expressed in the tergal edge, legs, antennae, labrum, and cerci during embryogenesis and in the distal margin of the wing pads from at least the sixth instar in the mid to late stages. Because sd knockout caused early lethality, nymphal RNA interference experiments were performed. Malformations were observed in the wings, ovipositor, and antennae. By analyzing the effects on wing morphology, it was revealed that sd is mainly involved in the formation of the margin, possibly through the regulation of cell proliferation. In conclusion, sd might regulate the local growth of wing pads and influence wing margin morphology in Gryllus.
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Desarrollo Embrionario , Gryllidae , Proteínas de Insectos , Factores de Transcripción , Alas de Animales , Animales , Ciclo Celular , Proliferación Celular , Desarrollo Embrionario/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Alas de Animales/embriología , Alas de Animales/metabolismo , Gryllidae/embriología , Gryllidae/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Oxacillinase (OXA)-48-like ß-lactamases are the most common carbapenemases in Enterobacterales in certain regions of the world and are being introduced on a regular basis into regions of non-endemicity. Japan has been characterized by low rates of carbapenemase-producing Enterobacterales, and among them, OXA-48-like carbapenemase-producing isolates are extremely rare. Here we describe a Japanese medical worker, without a history of travel abroad, who was diagnosed as having a community-acquired urinary tract infection, and whose urine sample was found to be positive for OXA-48-like carbapenemase-producing Escherichia coli. None of her close contacts had a history of foreign travel, and the same drug-resistant organism was not observed in other patients who had been hospitalized and undergone environmental culture tests in the same medical institution. This isolate was resistant to penicillins, narrow-spectrum cephalosporins, fluoroquinolones, and cefmetazole, but was susceptible to broad-spectrum cephalosporins, piperacillin/tazobactam, and meropenem and displayed reduced susceptibility to imipenem. The modified carbapenem inactivation test supported carbapenemase production, but inhibitor-based synergistic tests yielded negative results of carbapenemase production. Multiplex polymerase chain reaction revealed the presence of the carbapenemase gene (blaOXA-48) blaTEM and AmpC ß-lactamase gene (blaDHA). Singleplex polymerase chain reaction targeting the blaOXA-48 region amplified a product sequencing to nearly the full length (722 bp) and matching 100% with OXA-48. The present case highlights a new concern regarding OXA-48-like carbapenemase-producing Enterobacterales, which remain challenging to detect for clinical laboratories in regions of non-endemicity, and may already be latent in Japan.
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Antibacterianos , Enterobacteriaceae Resistentes a los Carbapenémicos , Humanos , Femenino , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pueblos del Este de Asia , Proteínas Bacterianas/genética , beta-Lactamasas/genética , Escherichia coli/genética , Combinación Piperacilina y Tazobactam , Cefalosporinas , Pruebas de Sensibilidad MicrobianaRESUMEN
The blastoderm is a broadly conserved stage of early animal development, wherein cells form a layer at the embryo's periphery. The cellular behaviors underlying blastoderm formation are varied and poorly understood. In most insects, the pre-blastoderm embryo is a syncytium: nuclei divide and move throughout the shared cytoplasm, ultimately reaching the cortex. In Drosophila melanogaster, some early nuclear movements result from pulsed cytoplasmic flows that are coupled to synchronous divisions. Here, we show that the cricket Gryllus bimaculatus has a different solution to the problem of creating a blastoderm. We quantified nuclear dynamics during blastoderm formation in G. bimaculatus embryos, finding that: (1) cytoplasmic flows are unimportant for nuclear movement, and (2) division cycles, nuclear speeds, and the directions of nuclear movement are not synchronized, instead being heterogeneous in space and time. Moreover, nuclear divisions and movements co-vary with local nuclear density. We show that several previously proposed models for nuclear movements in D. melanogaster cannot explain the dynamics of G. bimaculatus nuclei. We introduce a geometric model based on asymmetric pulling forces on nuclei, which recapitulates the patterns of nuclear speeds and orientations of both unperturbed G. bimaculatus embryos, and of embryos physically manipulated to have atypical nuclear densities.
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Blastodermo , Gryllidae , Animales , Núcleo Celular , Drosophila melanogasterRESUMEN
Many researchers are using crickets to conduct research on various topics related to development and regeneration in addition to brain function, behavior, and biological clocks, using advanced functional and perturbational technologies such as genome editing. Recently, crickets have also been attracting attention as a food source for the next generation of humans. In addition, crickets are increasingly being used as disease models and biological factories for pharmaceuticals. Cricket research has thus evolved over the last century from use primarily in highly important basic research, to use in a variety of applications and practical uses. These insects are now a state-of-the-art model animal that can be obtained and maintained in large quantities at low cost. We therefore suggest that crickets are useful as a third domesticated insect for scientific research, after honeybees and silkworms, contributing to the achievement of global sustainable development goals.
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Gryllidae , Animales , Abejas , Gryllidae/genética , InsectosRESUMEN
Objective: To follow up patients with spinal cord injuries with subdermal low-echoic lesions in the ischial region for abnormalities after 1 year. Design: A retrospective cohort study. Setting: A Japanese rehabilitation center. Participants: We included patients with chronic spinal cord injuries and subdermal low-echoic lesions who underwent routine inspection and palpation examinations (n = 7). Interventions: Education on pressure injury and instruction on pressure relief and seating was provided and the patients were followed up for abnormalities after 1 year. Self-reports were obtained on wheelchair sitting time, and interface pressure was recorded while the patients were seated on the wheelchair. Interface pressure measurements at the bilateral ischial regions were recorded with a force-sensitive application pressure mapping system. Outcome Measures: The primary outcome was the presence of subdermal low-echoic lesions in the bilateral ischial regions on ultrasonography at the 1-year follow-up examination. Secondary outcomes included wheelchair sitting time and interface pressure in the bilateral ischial regions. Results: Of the 10 areas that showed subdermal low-echoic lesions on ultrasonography, nine had improved after 1 year. One area that did not improve was an open wound. At the follow-up examination, the pressure duration was reduced in all patients, and the interface pressure could be reduced in 5/7 patients. Conclusions: This is the first study to follow up with patients having spinal cord injuries and subdermal low-echoic lesions in the ischial region using ultrasonography. The low-echoic lesions improved within 1 year by reducing the pressure duration and interface pressure. Pressure injury prevention in patients with spinal cord injuries relies on the early detection of skin abnormalities, and education and instruction to change self-management behaviors are recommended.
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Most tools available for manipulating gene function in insects have been developed for holometabolous species. In contrast, functional genetics tools for the Hemimetabola are highly underdeveloped. This is a barrier both to understanding ancestral insect biology, and to optimizing contemporary study and manipulation of particular large hemimetabolous orders of crucial economic and agricultural importance like the Orthoptera. For orthopteran insects, including crickets, the rapid spread of next-generation sequencing technology has made transcriptome data available for a wide variety of species over the past decade. Furthermore, whole genome sequences of orthopteran insects with relatively large genome sizes are now available. With these new genome assemblies and the development of genome editing technologies such as the CRISPR-Cas9 system, it has become possible to create gene knock-out and knock-in strains in orthopteran insects. As a result, orthopteran species should become increasingly feasible for laboratory study not only in research fields that have traditionally used insects, but also in agricultural fields that use them as food and feed. In this review, we summarize these recent advances and their relevance to such applications.
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Edición Génica , Gryllidae , Animales , Tecnología de Alimentos , Edición Génica/métodos , Genómica , Gryllidae/genética , Insectos/genéticaRESUMEN
Mindfulness is a process of focusing one's attention on the present moment. Applying this concept to eating (i.e., mindful eating (ME)) is associated with regulated eating behaviors, particularly in people with obesity and who are overweight. Sustaining healthy eating habits requires both healthy eating literacy (HEL) and proficiency in ME. However, ME proficiency in Japanese people has not been sufficiently investigated. In this paper, we conduct a survey of mothers with 4- to 5-year-old children in Aomori City, Japan, to investigate their ME proficiency and HEL level and eating behavior and self-reported body mass index in both mothers and their children from August to September 2019. This study is the first to describe ME proficiency in Japanese mothers. The study sample includes 128 participants from 18 nursery schools. ME proficiency in mothers was positively correlated with both their own and their children's eating behaviors, thereby suggesting a potential relationship, while strong relationships were not observed between the HEL level and eating behaviors of mothers and children. Improving ME skills, rather than HEL, may be an effective way to sustain healthier eating behaviors in mothers and their children. The level of evidence was Level V: Opinions of respected authorities based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.
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Conducta Infantil , Dieta Saludable/psicología , Conducta Alimentaria , Alfabetización en Salud , Atención Plena , Madres/psicología , Obesidad/psicología , Sobrepeso/psicología , Adulto , Pueblo Asiatico , Preescolar , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
The authors would like to make the following corrections to this paper [...].
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Two cases of laparoscopic remnant cholecystectomy using near-infrared fluorescence cholangiography (NIFC) for remnant gallbladder calculi following subtotal-cholecystectomy are reported. Case 1: a 36-year-old woman was referred to our hospital with acute abdomen. Computed tomography showed remnant gallbladder calculi, with detected no other findings as the cause of the abdominal pain. For intraoperative exploration of the biliary anatomy, 0.25 mg/kg of indocyanine green (ICG) was administered intravenously the day before the operation. NIFC clearly showed the common bile duct and enabled safe laparoscopic remnant cholecystectomy. She was free from symptoms after the operation. Case 2: a 40-year-old woman was referred to our hospital with epigastralgia due to remnant gallbladder calculi after open cholecystectomy. ICG was administered intravenously the day before the operation. Severe adhesions were observed in the upper abdominal cavity and there was tight adherence of the duodenum to the remnant gallbladder. NIFC showed a clear margin that appeared to be the margin between the duodenum and remnant gallbladder. However, dissection of the margin observed by NIFC caused perforation of the duodenum. The clear margin seen with NIFC was likely due to visualization of the gallbladder through the duodenum. Although NIFC is a useful modality for confirming the intraoperative biliary anatomy, it is important not to rely too heavily on NIFC alone, which may lead to misinterpretation of the anatomy.
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Most of our knowledge of insect genomes comes from Holometabolous species, which undergo complete metamorphosis and have genomes typically under 2 Gb with little signs of DNA methylation. In contrast, Hemimetabolous insects undergo the presumed ancestral process of incomplete metamorphosis, and have larger genomes with high levels of DNA methylation. Hemimetabolous species from the Orthopteran order (grasshoppers and crickets) have some of the largest known insect genomes. What drives the evolution of these unusual insect genome sizes, remains unknown. Here we report the sequencing, assembly and annotation of the 1.66-Gb genome of the Mediterranean field cricket Gryllus bimaculatus, and the annotation of the 1.60-Gb genome of the Hawaiian cricket Laupala kohalensis. We compare these two cricket genomes with those of 14 additional insects and find evidence that hemimetabolous genomes expanded due to transposable element activity. Based on the ratio of observed to expected CpG sites, we find higher conservation and stronger purifying selection of methylated genes than non-methylated genes. Finally, our analysis suggests an expansion of the pickpocket class V gene family in crickets, which we speculate might play a role in the evolution of cricket courtship, including their characteristic chirping.
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Evolución Molecular , Genoma de los Insectos/genética , Gryllidae/genética , Insectos/genética , Animales , Metilación de ADN , Elementos Transponibles de ADN/genética , Femenino , Genes de Insecto/genética , Masculino , Filogenia , Secuencias Repetitivas de Ácidos Nucleicos/genética , Análisis de Secuencia de ADNRESUMEN
Objective: To determine the relationship between physical findings, wheelchair sitting time, and interface pressure on ischial region in subjects with spinal cord injury (SCI).Design: Cross-sectional study.Setting: Rehabilitation center in Japan.Participants: Manual wheelchair users with chronic SCI (n = 45).Interventions: Pressure ulcers (PU) were diagnosed by inspection, palpation, and ultrasonography. Self-reports were obtained on wheelchair sitting time and pressure mapping was recorded while the subject was seated on the wheelchair.Outcome measures: Subjects were divided into those with ultrasonographically low-echoic lesions (PU-positive group, n = 11) and no such lesions (PU-negative group, n = 34). Outcome measures included wheelchair sitting time and interface pressure at bilateral ischial regions.Results: Using ultrasonography, 13 low-echoic lesions were identified in 11 subjects of the PU-positive group. The pressure duration was longer and interface pressure was significantly higher in subjects of the PU-positive group compared with those of the PU-negative group (P < 0.05 and P < 0.001, respectively).Conclusions: This is the first study to evaluate the interrelationship between physical findings, sitting time, and ultrasonographically measured interface pressure on ischial region area in subjects with spinal cord injury. To prevent pressure ulcers, we recommend avoidance of prolonged wheelchair sitting and measures that can reduce the interface pressure. These variables should be carefully tailored to the needs of the individual subjects with SCI.
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Úlcera por Presión , Traumatismos de la Médula Espinal , Silla de Ruedas , Estudios Transversales , Humanos , Úlcera por Presión/diagnóstico por imagen , Úlcera por Presión/etiología , Úlcera por Presión/prevención & control , Sedestación , Traumatismos de la Médula Espinal/diagnóstico por imagen , Traumatismos de la Médula Espinal/rehabilitaciónRESUMEN
The spore of the fission yeast Schizosaccharomyces pombe is a dormant cell that is resistant to a variety of environmental stresses. The S. pombe spore is coated by a proteinaceous surface layer, termed the Isp3 layer because it comprises mainly Isp3 protein. Although thin-section electron microscopy and scanning electron microscopy have revealed the fundamental structure of the spore, its architecture remains unclear. Here we visualized S. pombe spores by using a quick-freeze replica electron microscopy (QFDE-EM) at nanometer resolution, which revealed novel characteristic structures. QFDE-EM revealed that the Isp3 layer exists as an interwoven fibrillar layer. On the spore cell membrane, many deep invaginations, which are longer than those on the vegetative cell membrane, are aligned in parallel. We also observed that during spore germination, the cell surface changes from a smooth to a dendritic filamentous structure, the latter being characteristic of vegetative cells. These findings provide significant insight into not only the structural composition of the spore, but also the mechanism underlying the stress response of the cell.
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In Schizosaccharomyces pombe, the spore wall confers strong resistance against external stress. During meiosis II, the double-layered intracellular forespore membrane (FSM) forms de novo and encapsulates the nucleus. Eventually, the inner FSM layer becomes the plasma membrane of the spore, while the outer layer breaks down. However, the molecular mechanism and biological significance of this membrane breakdown remain unknown. Here, by genetic investigation of an S. pombe mutant (E22) with normal prespore formation but abnormal spores, we showed that Meu5, an RNA-binding protein known to bind to and stabilize more than 80 transcripts, is involved in this process. We confirmed that the E22 mutant does not produce Meu5 protein, while overexpression of meu5+ in E22 restores the sporulation defect. Furthermore, electron microscopy revealed that the outer membrane of the FSM persisted in meu5∆ spores. Investigation of the target genes of meu5+ showed that a mutant of cyc1+ encoding cytochrome c also showed a severe defect in outer FSM breakdown. Lastly, we determined that outer FSM breakdown occurs coincident with or after formation of the outermost Isp3 layer of the spore wall. Collectively, our data provide novel insights into the molecular mechanism of spore formation.
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BACKGROUND: The most common sites of recurrence after liver transplantation for hepatocellular carcinoma (HCC) have been reported to be the liver, lung, bone, and adrenal glands, but there have also been many reports of cases of multiple recurrence. The prognosis after recurrence is poor, with reported median survival after recurrence of HCC ranging from 9 to 19 months. Here, we report a case of long-term survival after recurrence of pharyngeal metastasis following living-donor liver transplantation (LDLT) for HCC within the Milan criteria, by resection of the metastatic region and cervical lymph node dissection. CASE PRESENTATION: A 47-year-old man with a Model End-stage Liver Disease (MELD) score of 11 underwent LDLT for HCC within the Milan criteria for liver cirrhosis associated with hepatitis B virus infection, with his 48-year-old elder brother as the living donor. One year and 10 months after liver transplantation, he visited a nearby hospital with a chief complaint of discomfort on swallowing. A pedunculated polyp was found in the hypopharynx, and biopsy revealed HCC metastasis. We performed pharyngeal polypectomy. Two years later, cervical lymph node metastasis appeared, and neck lymph node dissection was performed. Although recurrence subsequently occurred three times in the grafted liver, the patient is still alive 12 years and 10 months after recurrence of pharyngeal metastasis. He is now a tumor-free outpatient taking sorafenib. CONCLUSION: It is necessary to recognize that the nasopharyngeal region is a potential site of HCC metastasis. Prognostic improvement can be expected with close follow-up, early detection, and multidisciplinary treatment, including radical resection.
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Carcinoma Hepatocelular/terapia , Enfermedad Hepática en Estado Terminal/cirugía , Neoplasias Hepáticas/terapia , Trasplante de Hígado/efectos adversos , Recurrencia Local de Neoplasia/diagnóstico , Neoplasias Faríngeas/secundario , Aloinjertos/diagnóstico por imagen , Aloinjertos/patología , Aloinjertos/cirugía , Biopsia , Carcinoma Hepatocelular/complicaciones , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/secundario , Ablación por Catéter , Quimioterapia Adyuvante/métodos , Combinación de Medicamentos , Enfermedad Hepática en Estado Terminal/etiología , Hepatectomía , Humanos , Hígado/diagnóstico por imagen , Hígado/patología , Hígado/cirugía , Neoplasias Hepáticas/complicaciones , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patología , Donadores Vivos , Metástasis Linfática/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/terapia , Ácido Oxónico/uso terapéutico , Neoplasias Faríngeas/diagnóstico , Neoplasias Faríngeas/terapia , Faringe/diagnóstico por imagen , Faringe/patología , Faringe/cirugía , Tomografía Computarizada por Tomografía de Emisión de Positrones , Sorafenib/uso terapéutico , Tegafur/uso terapéutico , Resultado del TratamientoRESUMEN
Fission yeast Ypt2, an orthologue of the mammalian small GTPase Rab8, is responsible for post-Golgi membrane trafficking. During meiosis, Ypt2 localizes at the spindle pole body (SPB), where it regulates de novo biogenesis of the spore plasma membrane. Recruitment of Ypt2 to the SPB is dependent on its meiosis-specific GDP/GTP exchange factor (GEF), the SPB-resident protein Spo13. Here we have examined the SPB recruitment of Ypt2 by Spo13. The GEF activity of Spo13 was required, but not essential for recruitment. Furthermore, Ypt2 recruitment was regulated in a meiosis-specific manner and partially regulated by the nuclear Dbf2-related (NDR) kinase Sid2, indicating the existence of a novel regulatory mechanism for localization of Rab GTPases during meiosis.
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Exocitosis , Meiosis , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/citología , Schizosaccharomyces/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Transporte de ProteínasRESUMEN
Liver cirrhosis can cause splenic artery aneurysms (SAA) that pose a threat to patients undergoing liver transplantation. However, liver transplantation with multiple visceral artery aneurysms including giant SAA caused by arterial fragility has never been reported. We describe a 36-year-old man with decompensated liver cirrhosis due to Wilson disease that was complicated by giant SAA and multiple aneurysms in the bilateral renal arteries caused by fibromuscular dysplasia (FMD). The maximal diameter of the triple snowball-shaped SAA was 11 cm. We planned a 2-stage strategy consisting of a splenectomy with distal pancreatectomy to treat the SAA and subsequent living donor liver transplantation (LDLT) to address the liver cirrhosis. This strategy was selected to prevent fatal postoperative infectious complications caused by the potential development of pancreatic fistula during simultaneous procedures and to histopathologically diagnose the arterial lesion before LDLT to promote safe hepatic artery reconstruction. However, a postoperative pancreatic fistula did not develop after a splenectomy with distal pancreatectomy, and the pathologic findings of the artery indicated FMD. The patient underwent ABO-identical LDLT with a right lobe graft donated by his brother. Other than postoperative rupture of the aneurysm in the left renal artery requiring emergency interventional radiology, the patient has remained free of any other arterial complications and continues to do well at 2 years after LDLT.
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Aneurisma/etiología , Displasia Fibromuscular/complicaciones , Degeneración Hepatolenticular/complicaciones , Trasplante de Hígado , Arteria Esplénica/patología , Adulto , Aneurisma/cirugía , Humanos , Cirrosis Hepática/etiología , Cirrosis Hepática/cirugía , Donadores Vivos , Masculino , Pancreatectomía/efectos adversos , Pancreatectomía/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Arteria Renal/patología , Esplenectomía/efectos adversos , Esplenectomía/métodos , Arteria Esplénica/cirugíaRESUMEN
Altering gene function in a developing organism is central to different kinds of experiments. While tremendously powerful genetic tools have been developed in traditional model systems, it is difficult to manipulate genes or messenger RNA (mRNA) in most other organisms. At the same time, evolutionary and comparative approaches rely on an exploration of gene function in many different species, necessitating the development and adaptation of techniques for manipulating expression outside currently genetically tractable species. This protocol describes a method for injecting reagents into cricket eggs to assay the effects of a given manipulation on embryonic or larval development. Instructions for how to collect and inject eggs with beveled needles are described. This relatively straightforward technique is flexible and potentially adaptable to other insects. One can gather and inject dozens of eggs in a single experiment, and survival rates for buffer-only injections improve with practice and can be as high as 80%. This technique will support several types of experimental approaches including injection of pharmacological agents, in vitro capped mRNA to express genes of interest, double-stranded RNA (dsRNA) to achieve RNA interference, use of clustered regularly interspaced short palindromic repeats (CRISPR) in concert with CRISPR-associated protein 9 (Cas9) reagents for genomic modification, and transposable elements to generate transient or stable transgenic lines.
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Gryllidae , Microinyecciones/instrumentación , Microinyecciones/métodos , Óvulo , Animales , Sistemas CRISPR-Cas , AgujasRESUMEN
Hox genes are conserved transcription factor-encoding genes that specify the identity of body regions in bilaterally symmetrical animals. In the cricket Gryllus bimaculatus, a member of the hemimetabolous insect group Orthoptera, the induction of a subset of mesodermal cells to form the primordial germ cells (PGCs) is restricted to the second through the fourth abdominal segments (A2 to A4). In numerous insect species, the Hox genes Sex-combs reduced (Scr), Antennapedia (Antp), Ultrabithorax (Ubx), and abdominal-A (abd-A) jointly regulate the identities of middle and posterior body segments, suggesting that these genes may restrict PGC formation to specific abdominal segments in G. bimaculatus Here we show that reducing transcript levels of some or all of these Hox genes results in supernumerary and/or ectopic PGCs, either individually or in segment-specific combinations, suggesting that the role of these Hox genes is to limit PGC development with respect to their number, segmental location, or both. These data provide evidence of a role for this ancient group of genes in PGC development.
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Células Germinativas/crecimiento & desarrollo , Gryllidae/genética , Proteínas de Homeodominio/genética , Proteínas de Insectos/genética , Secuencia de Aminoácidos/genética , Animales , Tipificación del Cuerpo/genética , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica/genética , Genes Homeobox/genética , Células Germinativas/metabolismo , Gryllidae/crecimiento & desarrollo , Insectos/genética , Insectos/crecimiento & desarrolloRESUMEN
In the fission yeast Schizosaccharomyces pombe, the mating reaction is controlled by two mating pheromones, M-factor and P-factor, secreted by M- and P-type cells, respectively. M-factor is a C-terminally farnesylated lipid peptide, whereas P-factor is a simple peptide. To examine whether this chemical asymmetry in the two pheromones is essential for conjugation, we constructed a mating system in which either pheromone can stimulate both M- and P-cells, and examined whether the resulting autocrine strains can mate. Autocrine M-cells responding to M-factor successfully mated with P-factor-lacking P-cells, indicating that P-factor is not essential for conjugation; by contrast, autocrine P-cells responding to P-factor were unable to mate with M-factor-lacking M-cells. The sterility of the autocrine P-cells was completely restored by expressing the M-factor receptor. These observations indicate that the different chemical characteristics of the two types of pheromone, a lipid and a simple peptide, are not essential; however, a lipid peptide might be required for successful mating. Our findings allow us to propose a model of the differential roles of M-factor and P-factor in conjugation of S. pombeThis article has an associated First Person interview with the first author of the paper.