A highly differentiated region of wheat chromosome 7AL encodes a Pm1a immune receptor that recognizes its corresponding AvrPm1a effector from Blumeria graminis.

Pm1a, the first powdery mildew resistance gene described in wheat, is part of a complex resistance (R) gene cluster located in a distal region of chromosome 7AL that has suppressed genetic recombination. A nucleotide-binding, leucine-rich repeat (NLR) immune receptor gene was isolated using mutagenesis and R gene enrichment sequencing (MutRenSeq). Stable transformation confirmed Pm1a identity which induced a strong resistance phenotype in transgenic plants upon challenge with avirulent Blumeria graminis (wheat powdery mildew) pathogens. A high-density genetic map of a B. graminis family segregating for Pm1a avirulence combined with pathogen genome resequencing and RNA sequencing (RNAseq) identified AvrPm1a effector gene candidates. In planta expression identified an effector, with an N terminal Y/FxC motif, that induced a strong hypersensitive response when co-expressed with Pm1a in Nicotiana benthamiana. Single chromosome enrichment sequencing (ChromSeq) and assembly of chromosome 7A suggested that suppressed recombination around the Pm1a region was due to a rearrangement involving chromosomes 7A, 7B and 7D. The cloning of Pm1a and its identification in a highly rearranged region of chromosome 7A provides insight into the role of chromosomal rearrangements in the evolution of this complex resistance cluster.

Infected congenital lumbosacral dermal sinus tract with conus epidermoid abscess: a rare entity.

PURPOSE: Dermal sinus is more commonly associated with intradural dermoid than an epidermoid cyst. Conus epidermoid cyst with dermal sinus is a rare entity. We are presenting a rare case of infected conus epidermoid cyst along with the dermal sinus in an 18-month-old girl presented with flaccid paraparesis with sphincter dysfunction and timely intervention leads to complete recovery. We had searched PubMed for previously reported similar cases and did a case-based review of the literature. CASE REPORT: This 18-month-old girl with discharging lumbosacral sinus with fever since 3 days presented with flaccid paraparesis with sphincter dysfunction. Preoperative magnetic resonance imaging (MRI) showed a large enhancing lesion from L1-S1 along with the dermal sinus tract. Complete excision of the cyst along with the sinus tract, followed by long-term antibiotic therapy. The excision of the infected cyst was done through myelotomy under neuromonitoring, while some part of the capsule densely adherent to the neural tissue was left behind. The patient gradually improved following surgery and motor power of the lower limbs were [Formula: see text] while going home. Histopathology revealed epidermoid cyst with secondary inflammatory tissue. Follow-up MRI of the spine showed excision of the dermal sinus tract and cyst with postoperative changes. At 1-year follow-up, the patient was asymptomatic without any focal deficits. CONCLUSION: Early surgical intervention followed by long-term antibiotic therapy is a must for good functional recovery in patients of an infected dermal sinus tract with associated cyst. While excising cyst through myelotomy, some part of the capsule densely adherent to neural tissue may be left behind. Regular follow-up in the first year of surgery is essential to look for the recurrence of the lesion.

Manual Instruments as an Alternative to Drilling for Bony Exposure in Skull Base Surgery: Concept and Technique.

Background Drilling in neurosurgery is an integral part of surgical exposure, especially in skull base approaches and craniovertebral junction (CVJ) surgeries. Most of such drillings are done in close proximity to the neurovascular structures in skull base surgeries and cervical-medullary junction or facet/pedicle in CVJ surgeries. Reluctance to drilling among young neurosurgeons is due to less hands-on experience during training and also, in the early part of the career, due to fear of injury to neurovascular structures. Methods Five commonest bone removals for skull base region and CVJ surgeries that can be safely done using manual instruments were identified based on experiences of senior authors. The authors highlight key technical nuances to widen surgical corridors using manual instruments safely for skull base surgical approaches. Results Basic neuroanatomical concepts and basic physics help in using manual instruments safely for bone removals in various skull base surgical approaches. Conclusions Manual instruments may be used for bone removals in selected skull base surgical approaches, which help young neurosurgeons to perform these surgeries in limited-resource settings.

Modified expression of an auxin-responsive rice CC-type glutaredoxin gene affects multiple abiotic stress responses.

Glutaredoxins (GRXs) are the ubiquitous oxidoreductase enzymes, which play an important role in defense against various stresses. Here, we report the role of a CC-type GRX gene from rice, OsGRX8, in abiotic stress tolerance. OsGRX8 protein was found to be localized in nucleus and cytosol and its gene expression is induced by various stress conditions and plant hormone auxin. The over-expression of OsGRX8 in Arabidopsis plants conferred reduced sensitivity to auxin and stress hormone, abscisic acid. In addition, the transgenic Arabidopsis plants exhibited enhanced tolerance to various abiotic stresses, including salinity, osmotic and oxidative stress. Further, the transgenic RNAi rice plants exhibited increased susceptibility to various abiotic stresses, which further confirmed the role of OsGRX8 in abiotic stress responses. The microarray data analysis revealed that expression of a large number of auxin-responsive, known stress-associated and transcription factor encoding genes was altered in GRX transgenic Arabidopsis plants in response to exogenous auxin and stress conditions as compared to wild-type plants. Altogether, these findings suggest the role of OsGRX8 in regulating abiotic stress response and may be used to engineer stress tolerance in crop plants.

Surgical Outcome of Large Solid Posterior Fossa Hemangioblastoma without Preoperative Embolization.

BACKGROUND: Large solid hemangioblastoma in the posterior fossa has an abundant blood supply as an arteriovenous malformation. The presence of adjacent vital neurovascular structures makes them vulnerable and difficult to operate. Complete surgical resection is always a challenge to the neurosurgeon. MATERIAL AND METHOD: We share the surgical difficulties and outcome in this case series of large solid hemangioblastomas without preoperative embolization as an adjunct. This study included five patients (three men and two women, with a mean age of 42.2 years). Preoperative embolization was attempted in one patient but was unsuccessful. All the patients have headache (100%) and ataxia (100%) as an initial symptom. A ventriculoperitoneal shunt was inserted in one case before definite surgery due to obstructive hydrocephalus. The surgical outcome was measured using the Karnofsky Performance Status (KPS) score. RESULT: The tumor was excised completely in all the cases. No intra- and postoperative morbidity occurred in four patients; one patient developed transient lower cranial nerve palsy. Mean blood loss was 235 mL, and no intraoperative blood transfusion was needed in any case. The mean follow-up period was 14.2 months. The mean KPS score at last follow-up was 80.One patient had a KPS score of 60. CONCLUSION: Our treatment strategy is of circumferential dissection followed by en bloc excision, which is the optimal treatment of large solid hemangioblastoma. The use of adjuncts as color duplex sonography and indocyanine green video angiography may help complete tumor excision with a lesser risk of complication. Preoperative embolization may not be needed to resect large solid posterior fossa hemangioblastoma, including those at the cerebellopontine angle location.

A Giant Nondural-Based Lumbosacral Clear Cell Meningioma Mimicking Schwannoma: A Case Report and Review of the Literature.

Spinal clear cell meningiomas (CCMs) are rare and dural-based lesion usually affecting the younger population. We report the rare case of giant nondural-based spinal CCM mimicking schwannoma and review the literature. A literature search was performed at PubMed and Embase until January 1, 2020. A total of 19 cases of nondural-based spinal CCM was reported. The following relevant data were extracted: authors, publication year, patient and tumor characteristics, treatment, and outcome. The mean age of the presentation was 20.58 years. Twelve (63.16%) were female and seven patients (36.84%) were male. The most common location was lumbosacral region 15 (79%). Fifteen (79%) tumors had cranio-caudal dimension ≤2 vertebral level, and only four (21%) tumors had dimension ≥2 vertebral level. Gross total resection (GTR) was performed in 18 (95%) patients and subtotal resection (STR) in 1 patient. Recurrences were reported in five (26.14%) patients. Four of them showed recurrences within 6 months; earliest at 2.3 months in the patient had undergone STR. Our patient is 19-year-old male diagnosed with a lumbosacral intradural lesion. Craniocaudal dimension is ≥2 vertebral level shows the foraminal extension and vertebral scalloping. GTR is performed. Intraoperatively, the tumor has foraminal extension and shows attachment with right S1S2 nerve root. No dural attachment is found. Six-month follow-up magnetic resonance image shows no evidence of disease. Nondural-based spinal CCMs are extremely rare and should be kept as a differential diagnosis in young patients with giant intradural tumor, and whose radiological features suggesting of schwannoma. It affects young patients and usually involves more than one vertebral level. The chances of recurrences and metastasis are always high even after GTR; hence, close follow-up of the entire neuraxis is warranted.

Over-Expression of OsHOX24 Confers Enhanced Susceptibility to Abiotic Stresses in Transgenic Rice via Modulating Stress-Responsive Gene Expression.

Homeobox transcription factors play critical roles in plant development and abiotic stress responses. In the present study, we raised rice transgenics over-expressing stress-responsive OsHOX24 gene (rice homeodomain-leucine zipper I sub-family member) and analyzed their response to various abiotic stresses at different stages of development. At the seed germination stage, rice transgenics over-expressing OsHOX24 exhibited enhanced sensitivity to abiotic stress conditions and abscisic acid as compared to wild-type (WT). OsHOX24 over-expression rice seedlings showed reduced root and shoot growth under salinity and desiccation stress (DS) conditions. Various physiological and phenotypic assays confirmed higher susceptibility of rice transgenics toward abiotic stresses as compared to WT at mature and reproductive stages of rice development too. Global gene expression profiling revealed differential regulation of several genes in the transgenic plants under control and DS conditions. Many of these differentially expressed genes were found to be involved in transcriptional regulatory activities, besides carbohydrate, nucleic acid and lipid metabolic processes and response to abiotic stress and hormones. Taken together, our findings highlighted the role of OsHOX24 in regulation of abiotic stress responses via modulating the expression of stress-responsive genes in rice.

Over-expression of a rice tau class glutathione s-transferase gene improves tolerance to salinity and oxidative stresses in Arabidopsis.

Glutathione S-transferases (GSTs) are multifunctional proteins encoded by large gene family in plants, which play important role in cellular detoxification of several endobiotic and xenobiotic compounds. Previously, we suggested the diverse roles of rice GST gene family members in plant development and various stress responses based on their differential expression. In this study, we report the functional characterization of a rice tau class GST gene, OsGSTU4. OsGSTU4 fusion protein was found to be localized in nucleus and cytoplasm. The over-expression of OsGSTU4 in E. coli resulted in better growth and higher GST activity under various stress conditions. Further, we raised over-expression transgenic Arabidopsis plants to reveal its in planta function. These transgenic lines showed reduced sensitivity towards plant hormones, auxin and abscisic acid. Various analyses revealed improved tolerance in transgenic Arabidopsis plants towards salinity and oxidative stresses, which may be attributed to the lower accumulation of reactive oxygen species and enhanced GST activity. In addition, microarray analysis revealed up-regulation of several genes involved in stress responses and cellular detoxification processes in the transgenic plants as compared to wild-type. These results suggest that OsGSTU4 can be used as a good candidate for the generation of stress-tolerant crop plants.

Transcriptome analysis of Catharanthus roseus for gene discovery and expression profiling.

The medicinal plant, Catharanthus roseus, accumulates wide range of terpenoid indole alkaloids, which are well documented therapeutic agents. In this study, deep transcriptome sequencing of C. roseus was carried out to identify the pathways and enzymes (genes) involved in biosynthesis of these compounds. About 343 million reads were generated from different tissues (leaf, flower and root) of C. roseus using Illumina platform. Optimization of de novo assembly involving a two-step process resulted in a total of 59,220 unique transcripts with an average length of 1284 bp. Comprehensive functional annotation and gene ontology (GO) analysis revealed the representation of many genes involved in different biological processes and molecular functions. In total, 65% of C. roseus transcripts showed homology with sequences available in various public repositories, while remaining 35% unigenes may be considered as C. roseus specific. In silico analysis revealed presence of 11,620 genic simple sequence repeats (excluding mono-nucleotide repeats) and 1820 transcription factor encoding genes in C. roseus transcriptome. Expression analysis showed roots and leaves to be actively participating in bisindole alkaloid production with clear indication that enzymes involved in pathway of vindoline and vinblastine biosynthesis are restricted to aerial tissues. Such large-scale transcriptome study provides a rich source for understanding plant-specialized metabolism, and is expected to promote research towards production of plant-derived pharmaceuticals.