A Study on Clinico-Pathological Presentation and Management Prospective of Venolymphatic Malformation.

To evaluate the clinical perspective of Veno lymphatic malformation and definitive management in respect to outcome. (1) To discuss clinical presentation, symptomatology of Veno lymphatic malformation. (2) Demonstration of radiological features, diagnosis and management of Veno lymphatic malformation with its complication. This prospective study was conducted on four patients attending ENT-OPD of R.G.Kar Medical College, Kolkata, India who had presented with suspected vascular malformation. The study was conducted from March 2021 to March 2023 for a period of 2 years. The patients were subjected to detailed history and examination. The diagnosis of the Veno lymphatic malformation was based on the results of Doppler ultrasonography, computed tomography and magnetic resonance imaging. In our study there was male predominance. Most of the patients belonged to the 2nd and 3rd decade of life. The main sites of involvement were lateral neck followed by parotid region. The lesion size ranged in between 3.5 × 3.5 cm and 7 × 5 cm. The patient with parotid lesion was found to have phlebolith. Since most of the lesions were small with well-defined margins, we were able to excise the lesions completely without leaving any residue. Out of four cases one patient developed temporary paresis of spinal accessory nerve which resolved eventually. Veno lymphatic malformations are rare and there is no definitive protocol for management and to be individualized. Our study will be helpful for furthering the existing knowledge regarding the management of Veno lymphatic lesion emphasizing the need of multimodality approach in surgical decision making.

One-Step Synthesis and Operando Electrochemical Impedance Spectroscopic Characterization of Heterostructured MoP-Mo2N Electrocatalysts for Stable Hydrogen Evolution Reaction.

This study presents a novel synthesis of self-standing MoP and Mo2N heterostructured electrocatalysts with enhanced stability and catalytic performance. Facilitated by the controlled phase and interfacial microstructure, the seamless structures of these catalysts minimize internal resistivity and prevent local corrosion, contributing to increased stability. The chemical synthesis proceeds with an etching step to activate the surface, followed by phosphor-nitriding in a chemical vapor deposition chamber to produce MoP-Mo2N@Mo heterostructured electrocatalysts. X-ray diffraction analyses confirmed the presence of MoP, Mo2N, and Mo phases in the electrocatalyst. Morphology studies using scanning electron microscopy characterize the hierarchical growth of structures, indicating successful formation of the heterostructure. X-ray photoelectron spectroscopy (XPS) analyses of the as-synthesized and postcatalytic activity samples reveal the chemical shift in terms of the binding energy (BE) of the Mo 3d XPS peak, especially after catalytic activity. The XPS BE shifts are attributed to changes in the oxidation state, electron transfer, and surface reconstruction during catalysis. Electrochemical evaluation of the catalysts indicates the superior performance of the MoP-Mo2N@Mo heterostructured catalyst in hydrogen evolution reactions (HER), with lower overpotentials and enhanced Tafel slopes. The stability tests reveal changes in double layer capacitance over time, suggesting surface reconstruction and an increased active surface area during catalysis. Operando electrochemical impedance spectroscopy (EIS) further elucidates the dynamic changes in resistance and charge transfer during HER. Overall, a comprehensive understanding of the synthesis, characterization, and electrochemical behavior of the developed MoP-Mo2N@Mo heterostructured electrocatalyst, as presented in this work, highlights its potential utilization in sustainable energy applications.

XoRehab: IoT Enabled Wheelchair based Lower Limb Rehabilitation System.

IoT in healthcare brought a technological revolution in rehabilitation, enabling the patients to get rehabilitation in the comfort of their home, while being supervised remotely by the professionals. IoT enabled rehabilitation ensures a best possible way towards recovery, without inflicting further injuries. It also allows customization of rehabilitation plan based on the patient profile and progress, while helping in defining their personalised milestones. The main contribution of this paper is a novel wheelchair based IoT enabled 'XoRehab", exoskeleton for rehabilitation; a device for lower limb, with a backrest mechanism. This involves development of a well-trained robot based on electromechanical actuation with micro-controller and feedback system, which can replace the physical trainer or physiotherapist. This autonomous device will control speed of flexion and extension on patient's limbs to improve efficiency of the treatment. It also provides repetitive motion of flexion and extension. The edge system design to upload local rehabilitation data and logs to the cloud server is presented. We propose an opensource Elasticsearch Logstash Kibana (ELK) stack for providing the cloud services, which is a scalable solution. The design of the developed prototype has been discussed in detail along with the functional test results.Clinical Relevance- The introduction of well-trained exoskeleton in the rehabilitation process, gives a high level of performance in patient recovery, and it contributes to expeditious restoration of their joints and improvement in muscle and nerve system.

Organophotocatalyzed Mono- and Bis-Alkyl/Difluoroalkylative Thio/Selenocyanation of Alkenes.

Organophotocatalyzed three-component 1,2-difluoroacetyl/alkyl/perfluoroalkylative thio/selenocyanation of styrene derivatives under stoichiometric, transition metal-, oxidant-, and additive-free, and mild redox-neutral conditions is reported. Organophotocatalyst 4CzIPN operates the overall radical-polar-crossover mechanistic cycle via initial oxidative luminescence quenching, and the key intermediates were experimentally detected. Selective mono-alkylative thiocyanation of alkenes using dibromoalkanes is also demonstrated. This one-pot synthetic methodology is suitable for primary, secondary, and tertiary alkyl halides and also extended for double alkylative thiocyanation of the dibromoalkanes with excellent yields.

An organo-photocatalyzed visible-light-driven multi-component approach for carbothioaryl/alkylation of activated alkenes via C(sp3)-H bond functionalization.

A visible-light-driven organophotocatalyzed multi-component approach for carbothiolation of activated alkenes is demonstrated under environmentally benign and redox-neutral conditions, involving direct C(sp3)-H functionalization followed by electrophilic alkyl/arylthiolation. The three-component difunctionalization reaction is a complete transition-metal and peroxide-free process conducted under milder conditions. In this composite reaction, by employing bench-stable reagents, the formation of two new C(sp3)-C(sp3) and C(sp3)-S bonds is achieved for a wide variety of substrates, showcasing the excellent functional group tolerance and chemoselectivity of the methodology. Furthermore, the scalability and utilization of natural sunlight instead of artificial blue LEDs, along with the use of an inexpensive and easy-to-prepare pyrylium salt as an organo-photocatalyst, make this protocol greener and more energy efficient.

Isotopic Signatures and Outputs of Lead from Coal Fly Ash Disposal in China, India, and the United States.

Despite extensive research and technology to reduce the atmospheric emission of Pb from burning coal for power generation, minimal attention has been paid to Pb associated with coal ash disposal in the environment. This study investigates the isotopic signatures and output rates of Pb in fly ash disposal in China, India, and the United States. Pairwise comparison between feed coal and fly ash samples collected from coal-fired power plants from each country shows that the Pb isotope composition of fly ash largely resembles that of feed coal, and its isotopic distinction allows for tracing the release of Pb from coal fly ash into the environment. Between 2000 and 2020, approx. 236, 56, and 46 Gg Pb from fly ash have been disposed in China, India, and the U.S., respectively, posing a significant environmental burden. A Bayesian Pb isotope mixing model shows that during the past 40 to 70 years, coal fly ash has contributed significantly higher Pb (∼26%) than leaded gasoline (∼7%) to Pb accumulation in the sediments of five freshwater lakes in North Carolina, U.S.A. This implies that the release of disposed coal fly ash Pb at local and regional scales can outweigh that of other anthropogenic Pb sources.

Metal-Free Photoredox Four-Component Strategy to 1,3-Functionalized BCP Derivatives.

Trifluoromethyl bicyclo[1.1.1]pentanes (BCPs) have attracted significant attention from the scientific community and pharmaceutical industries due to their advantageous physicochemical properties as arene bioisosteres. Initial photoredox perfluoroalkylation of [1.1.1]propellane triggers the tandem reaction to the perfluoroalkyl BCP radical followed by Giese addition to an in situ generated electron-deficient alkene by Knoevenagel condensation in a four-component fashion to form 1,3-functionalized BCPs. This strategy provides easy access to various 1,3-functionalized perfluoroalkyl BCP derivatives with the added advantage of nitrile group as a functional handle to diversified transformations. This methodology offers scalability and late-stage derivatization of drug molecules with high chemoselectivity.

Raman Spectroscopic Characterization of Chemical Bonding and Phase Segregation in Tin (Sn)-Incorporated Ga2O3.

Using detailed Raman scattering analyses, the effect of tin (Sn) incorporation on the crystal structure, chemical bonding/inhomogeneity, and single-phase versus multiphase formation of gallium oxide (Ga2O3) compounds is reported. The Raman characterization of the Sn-mixed Ga2O3 polycrystalline compounds (0.00 ≤ x ≤ 0.30), which were produced by the high-temperature solid-state synthesis method, indicated that the Sn-induced changes in the chemical bonding and phase segregation were significant. Furthermore, the evolution of Sn-O bonds with increasing Sn concentration (x) was confirmed. While the monoclinic ß-Ga2O3 was unperturbed for lower x values, Raman spectra revealed the nucleation of a composite with a distinct SnO2 secondary phase. A higher Sn content led to the formation of a Ga-Sn-O + SnO2 mixed phase compound, which was reflected in shifts in the high-frequency stretching and bending of the GaO4 tetrahedra that structurally formed the ß-Ga2O3 phase. Thus, a chemical composition/phase/chemical bonding correlation was established for the Sn-incorporated Ga2O3 compounds.

Complications of Thyroidectomy and Learning Curve for Thyroid Surgeons: An Institutional Experience.

To study the complications of thyroidectomy and the various methods to be followed in the intra and post-operative period to prevent complications. It is a prospective study of 5 years and 9 months duration from 1/1/2015 to 31/9/2020 done in a tertiary care hospital. A total of 268 patients were included in this study. Adequate measures were taken intraoperatively to prevent any complications and the patients were observed post-operatively for development and management of any complications. The patients were followed up regularly. Out of the 268 thyroidectomies performed in our study following which 5 patients had hemorrhage, 19 patients had temporary recurrent laryngeal nerve dysfunction, 3 patients developed respiratory obstruction, 12 patients developed transient parathyroid insufficiency, 62 patients developed thyroid insufficiency,1 patient had permanent parathyroid insufficiency, permanent recurrent laryngeal nerve dysfunction was seen in 7 patients, 3 patients developed seroma formation, 7 patients developed post-operative hypertrophic scar and 3 developed keloid. Sound anatomical knowledge, meticulous surgical technique and effective protocol for the management of complication can reduce the postoperative morbidity of the patient.

Nature-Inspired Design of Nano-Architecture-Aligned Ni5P4-Ni2P/NiS Arrays for Enhanced Electrocatalytic Activity of Hydrogen Evolution Reaction (HER).

The projection of developing sustainable and cost-efficient electrocatalysts for hydrogen production is booming. However, the full potential of electrocatalysts fabricated from earth-abundant metals has yet to be exploited to replace Pt-group metals due to inadequate efficiency and insufficient design strategies to meet the ever-increasing demands for renewable energies. To improve the electrocatalytic performance, the primary challenge is to optimize the structure and electronic properties by enhancing the intrinsic catalytic activity and expanding the active catalytic surface area. Herein, we report synthesizing a 3D nanoarchitecture of aligned Ni5P4-Ni2P/NiS (plate/nanosheets) using a phospho-sulfidation process. The durability and unique design of prickly pear cactus in desert environments by adsorbing moisture through its extensive surface and ability to bear fruits at the edges of leaves inspire this study to adopt a similar 3D architecture and utilize it to design an efficient heterostructure catalyst for HER activity. The catalyst comprises two compartments of the vertically aligned Ni5P4-Ni2P plates and the NiS nanosheets, resembling the role of leaves and fruits in the prickly pear cactus. The Ni5P4-Ni2P plates deliver charges to the interface areas, and the NiS nanosheets significantly influence Had and transfer electrons for the HER activity. Indeed, the synergistic presence of heterointerfaces and the epitaxial NiS nanosheets can substantially improve the catalytic activity compared to nickel phosphide catalysts. Notably, the onset overpotential of the best-modified ternary catalysts exhibits (35 mV) half the potential required for nickel phosphide catalysts. This promising catalyst demonstrates 70 and 115 mV overpotentials to attain current densities of 10 and 100 mA cm-2, respectively. The obtained Tafel slope is 50 mV dec-1, and the measured double-layer capacitance from cyclic voltammetry (CV) for the best ternary electrocatalyst is 13.12 mF cm-2, 3 times more than the nickel phosphide electrocatalyst. Further, electrochemical impedance spectroscopy (EIS) at the cathodic potentials reveals that the lowest charge transfer resistance is linked to the best ternary electrocatalyst, ranging from 430 to 1.75 Ω cm-2. This improvement can be attributed to the acceleration of the electron exchangeability at the interfaces. Our findings demonstrate that the epitaxial NiS nanosheets expand the active catalytic surface area and simultaneously elevate the intrinsic catalytic activity by introducing heterointerfaces, which leads to accommodating more Had at the interfaces.

Effect of High-Anisotropic Co2+ Substitution for Ni2+ on the Structural, Magnetic, and Magnetostrictive Properties of NiFe2O4: Implications for Sensor Applications.

This work reports on the effect of substituting a low-anisotropic and low-magnetic cation (Ni2+, 2µB) by a high-anisotropic and high-magnetic cation (Co2+, 3µB) on the crystal structure, phase, microstructure, magnetic properties, and magnetostrictive properties of NiFe2O4 (NFO). Co-substituted NFO (Ni1-xCoxFe2O4, NCFO, 0 ≤ x ≤ 1) nanomaterials were synthesized using glycine-nitrate autocombustion followed by postsynthesis annealing at 1200 °C. The X-ray diffraction measurements coupled with Rietveld refinement analyses indicate the significant effect of Co-substitution for Ni, where the lattice constant (a) exhibits a functional dependence on composition (x). The a-value increases from 8.3268 to 8.3751 Å (±0.0002 Å) with increasing the "x" value from 0 to 1 in NCFO. The a-x functional dependence is derived from the ionic-size difference between Co2+ and Ni2+, which also induces grain agglomeration, as evidenced in electron microscopy imaging. The chemical bonding of NCFO, as probed by Raman spectroscopy, reveals that Co(x)-substitution induced a red shift of the T2g(2) and A1g(1) modes, and it is attributed to the changes in the metal-oxygen bond length in the octahedral and tetrahedral sites in NCFO. X-ray photoelectron spectroscopy confirms the presence of Co2+, Ni2+, and Fe3+ chemical states in addition to the cation distribution upon Co-substitution in NFO. Chemical homogeneity and uniform distribution of Co, Ni, Fe, and O are confirmed by EDS. The magnetic parameters, saturation magnetization (MS), remnant magnetization (Mr), coercivity (HC), and anisotropy constant (K1) increased with increasing Co-content "x" in NCFO. The magnetostriction (λ) also follows a similar behavior and almost linearly varies from -33 ppm (x = 0) to -227 ppm (x = 1), which is primarily due to the high magnetocrystalline anisotropy contribution from Co2+ ions at the octahedral sites. The magnetic and magnetostriction measurements and analyses indicate the potential of NCFO for torque sensor applications. Efforts to optimize materials for sensor applications indicate that, among all of the NCFO materials, Co-substitution with x = 0.5 demonstrates high strain sensitivity (-2.3 × 10-9 m/A), which is nearly 2.5 times higher than that obtained for their intrinsic counterparts, namely, NiFe2O4 (x = 0) and CoFe2O4 (x = 1).

OSADHI - An online structural and analytics based database for herbs of India.

The current study aims to develop a PAN India database of medicinal plants along with their phytochemicals and geographical availability. The database consists of 6959 unique medicinal plants belonging to 348 families which are available across 28 states and 8 union territories of India. The database sources the information on four different sections - traditional knowledge, geographical indications, phytochemicals, and chemoinformatics. The traditional knowledge reports the plant taxonomy with their vernacular names. A total of 27,440 unique phytochemicals associated with these plants were curated from various sources in this study. However, due to the non-availability of general information like IUPAC names, InChI key, etc. from reliable sources, only 22,314 phytochemicals have been currently reported in the database. Various analyses have been performed for the phytochemicals which include analysis of physicochemical and ADMET properties calculated from open-source web servers using in-house python scripts. The phytochemical data set has also been classified based on the class, superclass, and pathways respectively using NPClassifier, a deep learning framework. Additionally, the antiviral potency of the phytochemicals was also predicted using two machine learning models - Random Forest and XGBoost. The database aims to provide accurate and exhaustive data of the traditional practice of medicinal plants in India in a single platform integrating and analyzing the rich customary practices and facilitating the development and identification of plant-based therapeutics for a variety of diseases. The database can be accessed at https://neist.res.in/osadhi/.

Pretreatment of cyanobacterial biomass for the production of biofuel in microbial fuel cells.

The present study delves into phototrophic cyanobacterial biomass production by concomitant CO2 sequestration, selecting an effective pretreatment condition followed by using this as feedstock for green fuel or bioelectricity production by Microbial Fuel Cells (MFC). The performance of the various photobioreactors were put up against Anabaena sp. PCC 7120 biomass production. Maximum microalgal biomass of 1.15 gL-1 was attained in an airlift bioreactor for 9 days under a light intensity of 100 µEm-2s-1. Pretreatment methods like sonication, HCl acid, and H2O2 treatment (2 % vv-1) were applied to digest harvested biomass. Higher power output (6.76 Wm-3) was attained, and 73.5 % COD was eliminated using 2 % (vv-1) acid pre-treated biomass. Better results were obtained using acid pre-treated biomass because the conductivity of the anolyte increased with the neutralization of acid-pre-treated biomass. The results demonstrate that cyanobacterial biomass could be employed successfully as a renewable resource for green fuel generation in MFCs.

Utilization of dark fermentation effluent for algal cultivation in a modified airlift photobioreactor for biomass and biocrude production.

Developing an efficient photobioreactor (PBR) and reducing freshwater dependence are among the significant challenges for generating 3rd generation biomass feedstock. Addressing these, the present study focused on developing a modified airlift (MoAL) PBR. Its performance was further evaluated and compared with the traditional airlift PBR by cultivating microalgae in dark fermentation spent wash. Lower mixing time and higher interfacial mass transfer coefficient was observed in the MoAL PBR having a perforated draft tube. Experimentally, the MoAL exhibited the maximum biomass concentration of 3.18 g L-1, which was 30% higher than that of the conventional airlift PBR. The semi-continuous operation of the MoAL (with water recycling) achieved the maximum biomass productivity of 0.83 g L-1 d-1, two folds superior to that of batch culture. The comprehensive biomass characterization (proximate, ultimate, and thermochemical) further confirmed its potential for bioenergy application. Considering that, hydrothermal liquefaction of the biomass resulted in a maximum biocrude yield of 31% w/w with a higher heating value (HHV) of 36.6 MJ kg-1. In addition, the biocrude comprised 66.6% w/w lighter fraction (<343 °C), including 21.5% w/w of heavy naphtha, 20.5% w/w of kerosene, and 24.6% w/w of diesel. The results can help develop sustainable technology for simultaneous wastewater remediation and biocrude production.

Management of Tracheo-Bronchial Foreign Bodies in Children: Our Experience.

(1) To study the epidemiological profile of the patients. (2) To study the various modalities of investigations to arrive at confirmatory diagnosis. (3) To study the post-operative complications. It was a hospital based prospective study. A total of 36 paediatric patients were included in the study over a duration of 2 years (August 2017 to July 2019). Written informed consent was taken from the parent of each patient before performing bronchoscopy. All the patients were subjected to careful clinical examination and investigations required followed by emergency bronchoscopic removal of foreign body. The patients were followed up at 1 and 3 months after bronchoscopic removal. Amongst the 36 cases, 12 cases presented with airway emergency which addressed by bronchoscopic removal immediately. 10 cases presented with suggestive history of foreign body aspiration were subjected to clinical and radiological studies followed by bronchoscopic removal. 14 cases were referred from paediatric in-patient department who were being treated for unresolved LRTI. Early intervention is life saving if timely done. Unresolved LRTIs should be looked carefully to address missed foreign bodies. HRCT Thorax with 3-D reconstruction (Virtual Bronchoscopy) helps in exact localization of the foreign body. Experienced team of surgeons and anesthetist along with a ICU support is needed for efficient management.

Structural, Magnetic, and Magnetostriction Properties of Flexible, Nanocrystalline CoFe2O4 Films Made by Chemical Processing.

We report on the simple, single-step, and cost-effective fabrication, characterization, and performance evaluation of cobalt ferrite (CoFe2O4; CFO) nanocrystalline (NC) thin films on a flexible mica substrate. The chemical solution-based drop-casting method employed to fabricate crystalline CFO films and their characterization was performed by studying the phase formation, surface morphology, and magnetic parameters, while sensor applicability was evaluated using combined magnetic and magnetostrictive properties. X-ray diffraction (XRD) indicates the single-phase and nanocrystalline nature of CFO films, where the crystallite size is ∼60 nm. The optimum conditions employed resulted in CFO NC films with surface particles exhibiting a spherical shape morphology with a homogeneous size distribution, as revealed by scanning electron microscopy analyses. Raman spectroscopic characterization of the chemical bonding indicates all of the active bands that are characteristic of the ferrite phase confirm the spinel structure, which is in agreement with XRD studies. The saturation magnetization (M S) and coercivity (H C), which are extracted from the field-dependent magnetization data, of CFO NC films were found to be 15.8 emu/g and 1.6 kOe, respectively, while the first-order magnetocrystalline anisotropy constant K 1 was ∼1.07 × 106 erg/cm3. The magnetostriction strain curve indicates that the CFO NC films exhibit a strain value of ∼86 ppm at an applied magnetic field of 8 kOe, indicating their suitability for flexible sensor devices.

North East India medicinal plants database (NEI-MPDB).

The rich biodiversity of North East India is one of the recognized biodiversity hotspots of the world. This region comprises of eight states (Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, and Tripura) with diverse ethnic communities having invaluable traditional knowledge/practices, passed through genesis. The medicinal plants in this region are rich in natural products/phytochemicals and have been used extensively by pharmaceutical industries. The present study is an attempt to develop a comprehensive resource of the medicinal plants with a quantitative analysis of the phytochemicals which can enhance knowledge on therapeutic indications and contribute in drug discovery and development. The database is a collection of 561 unique plants comprising of 9225 phytochemicals. The physiochemical properties of the phytochemicals were analyzed using indigenous python scripts whereas for the ADMET properties, open access servers were used. The data available in NEI-MPDB will help to connect the cutting-edge approach of various research groups and will help to translate the information into economic wealth by the pharmaceutical industries. The database is openly accessible at https://neist.res.in/neimpdb/.

Regulation of oocyte maturation: Role of conserved ERK signaling.

During oogenesis, oocytes arrest at meiotic prophase I to acquire competencies for resuming meiosis, fertilization, and early embryonic development. Following this arrested period, oocytes resume meiosis in response to species-specific hormones, a process known as oocyte maturation, that precedes ovulation and fertilization. Involvement of endocrine and autocrine/paracrine factors and signaling events during maintenance of prophase I arrest, and resumption of meiosis is an area of active research. Studies in vertebrate and invertebrate model organisms have delineated the molecular determinants and signaling pathways that regulate oocyte maturation. Cell cycle regulators, such as cyclin-dependent kinase (CDK1), polo-like kinase (PLK1), Wee1/Myt1 kinase, and the phosphatase CDC25 play conserved roles during meiotic resumption. Extracellular signal-regulated kinase (ERK), on the other hand, while activated during oocyte maturation in all species, regulates both species-specific, as well as conserved events among different organisms. In this review, we synthesize the general signaling mechanisms and focus on conserved and distinct functions of ERK signaling pathway during oocyte maturation in mammals, non-mammalian vertebrates, and invertebrates such as Drosophila and Caenorhabditis elegans.

Visible-Light-Driven Organophotocatalyzed Multicomponent Approach for Tandem C(sp3)-H Activation and Alkylation Followed by Trifluoromethylthiolation.

A visible-light-driven organophotocatalyzed multicomponent approach has been developed for tandem direct C(sp3)-H activation and alkylation followed by trifluoromethylthiolation in a one-pot operation. We report a completely metal-free, tandem, three-component approach for the difunctionalization of activated alkenes via the photoinduced radical pathway. This protocol allows the formation of two new C(sp3)-C(sp3) and C(sp3)-SCF3 bonds using a bench-stable, easy-to-handle trifluoromethylthiolating reagent under mild reaction conditions. The generosity of this reaction is shown with a library of C(sp3)-H donors and alkenes derivatives. The reaction conditions can tolerate a wide variety of functional groups. Gram-scale synthesis using environmentally benign and straightforward conditions highlights the synthetic advancement of the methodology. Further functionalization of the final product is also successfully demonstrated.

Phosphorylation of HORMA-domain protein HTP-3 at Serine 285 is dispensable for crossover formation.

Generation of functional gametes is accomplished through a multilayered and finely orchestrated succession of events during meiotic progression. In the Caenorhabditis elegans germline, the HORMA-domain-containing protein HTP-3 plays pivotal roles for the establishment of chromosome axes and the efficient induction of programmed DNA double-strand breaks, both of which are crucial for crossover formation. Double-strand breaks allow for accurate chromosome segregation during the first meiotic division and therefore are an essential requirement for the production of healthy gametes. Phosphorylation-dependent regulation of HORMAD protein plays important roles in controlling meiotic chromosome behavior. Here, we document a phospho-site in HTP-3 at Serine 285 that is constitutively phosphorylated during meiotic prophase I. pHTP-3S285 localization overlaps with panHTP-3 except in nuclei undergoing physiological apoptosis, in which pHTP-3 is absent. Surprisingly, we observed that phosphorylation of HTP-3 at S285 is independent of the canonical kinases that control meiotic progression in nematodes. During meiosis, the htp-3(S285A) mutant displays accelerated RAD-51 turnover, but no other meiotic abnormalities. Altogether, these data indicate that the Ser285 phosphorylation is independent of canonical meiotic protein kinases and does not regulate HTP-3-dependent meiotic processes. We propose a model wherein phosphorylation of HTP-3 occurs through noncanonical or redundant meiotic kinases and/or is likely redundant with additional phospho-sites for function in vivo.