Insights on Novel Effectors and Characterization of Metacaspase (RS107_6) as a Potential Cell Death-Inducing Protein in Rhizoctonia solani

Effectors play an important role in host–pathogen interactions. Though an economically significant disease in rice, knowledge regarding the infection strategy of Rhizoctonia solani is obscure. In this study, we performed a genome-wide identification of the effectors in R. solani based on the characteristics of previously reported effector proteins. A total of seven novel effectors (designated as RS107_1 to RS107_7) in the disease mechanism of R. solani were identified and were predicted to be non-classically secreted proteins with functionally conserved domains. The function, reactivity, and stability of these proteins were evaluated through physiochemical characterization. The target proteins involved in the regulation of rice defense mechanisms were identified. Furthermore, the effector genes were cloned and RS107_6 (metacaspase) was heterologously expressed in Escherichia coli to obtain a purified protein of ~36.5 kDa. The MALD-TOF characterization confirmed that the protein belonged to a metacaspase of the Peptidase_C14 protein family, 906 bp in size, and encoded a polypeptide of 301 amino acids. These findings suggest that the identified effectors can potentially serve as a virulence factor and can be targeted for the management of sheath blight in rice.

Endoilluminator-aided cataract surgery in eyes with corneal opacity - A modified surgical approach

Background

Cataract and corneal blindness continue to be leading causes of reversible blindness in India. These can co-exist in a multitude of pathologies such as trauma, healed keratitis (old herpetic scar), chronic degenerative changes such as labrador keratopathy, bullous keratopathy, corneal dystrophies etc. Phacoemulsification in such eyes is rewarding to the patient in terms of minimal intervention, less risk of complications owing to reduced open sky time (as in case of combined keratoplasty), and better predictable visual outcomes. Approach to such eyes with poor visualisation is highly challenging.

Purpose

We illustrate a modified surgical technique of chandelier illumination through pars plana for cataract surgery in eyes with corneal opacity of varying grades.

Synopsis

Five patients with dense cataract and small pupils, associated with corneal opacity (leucomatous and macular grade) are described. Closed chamber phacoemulsification with intraocular lens with or without pupil expanders was performed assisted by 23 or 25 gauge pars plana chandelier illumination introduced in the vitreous cavity through a sclerotomy wound made prior to phacoemulsification in the inferotemporal quadrant.

Highlights

Chandelier illumination aids in reducing the light scatter that occurs due to corneal opacity. Ease of visualisation of lens structures and of performing cataract surgery was noticed. One case was combined with penetrating keratoplasty with reduced open sky time. This assisted technique has advantages such as enhancing visualisation intraoperatively and allowing working in closed chamber. Its self-retaining nature aids bimanual manipulation. No complications were encountered. The video highlights the utility, advantages and practicality of chandelier retroillumination in patients with corneal opacities of varying degree undergoing phacoemulsification.

Video Link

https://youtu.be/I3z6QG-_wD8.

Survivin expression in canine spontaneous cutaneous and subcutaneous tumors and its prognostic importance

AIM

The present study was carried out to know the expression level of survivin, an inhibitor of apoptosis protein with an objective to determine its prognostic importance in cutaneous and subcutaneous tissue tumors of dogs.

MATERIALS AND METHODS

Forty cases of canine cutaneous and subcutaneous tissue tumors on histopathological examination revealed various round cell, epithelial, and mesenchymal cell tumors. Survivin gene expression was detected in all tumors tested by TaqMan real-time polymerase chain reaction assay by comparative cycle threshold method.

RESULTS

The mean survivin gene expression value of benign tumors was 0.94±0.63 folds and that of malignant tumors was 18.87±5.30 folds. Postsurgical follow up of 30 malignant tumor cases revealed death in 8, recurrence in 7, and neoplastic free alive status in 15 dogs with mean survivin fold difference values of 48.49±12.39, 14.63±6.37, and 5.034±2.27, respectively. The mean survivin gene expression value was significantly higher in malignant (30 cases, 18.87±5.30) compared to benign tumors (10 cases, 0.94±0.63), and it varied between various postsurgical follow-up groups (p<0.05). Survival analysis, using survivin gene expression median cutoff value of 3.74 in 30 malignant tumors, was performed to predict probable survival period in malignant cutaneous and subcutaneous tumors of dogs.

CONCLUSIONS

Results of the present study indicated that the expression of survivin in canine cutaneous and subcutaneous tumors has prognostic value, and survivin expression greater than median cutoff value of 3.74 has a poor prognosis.