Ashutosh Singh

The elytra of ladybird beetles serve not only as protective structures but also as key surfaces for chemical communication during reproduction. In this study, we investigated the role of elytral surface chemicals in mating behaviour of Cheilomenes sexmaculata (Fabricius) (Coleoptera: Coccinellidae) by experimentally manipulating chemical cues. Treatments included removal of surface chemicals, exchange of cuticular extracts, and coating of elytra with ink-based solvents that varied in persistence. Mating behaviour was assessed using two parameters: time to commence mating (TCM) and copulation duration (CD). Our results showed that persistent coatings caused the longest delays in mating initiation and the shortest copulation durations, suggesting strong interference with natural chemical signals. Temporary coatings also disrupted mating, though less severely, while solvent-washed and exchanged treatments produced moderate effects. Control groups, including handling and solvent-only treatments, did not differ significantly, confirming that the observed effects were due to chemical manipulations. Importantly, no treatment completely inhibited reproduction, highlighting the robustness of C. sexmaculata and the likely use of multiple sensory pathways in mate recognition. This work demonstrates that sexual recognition compounds on elytra plays a crucial role in mating communication but also reveals the adaptive resilience of C. sexmaculata when cues are disrupted. By showing that reproduction persists despite experimental interference, our study provides insight into the flexibility of insect communication systems and strengthens the case for C. sexmaculata as a reliable biological control agent under variable ecological and chemical conditions.

Iron is a critical determinant in the development of drug tolerance in Candida albicans . Several genes essential for iron acquisition, transport, and regulation have been studied. Previous studies have shown that growth in an iron‐limited medium alters the lipid compositions of C. albicans cells. In the present study, we performed a mass spectrometry‐based lipid analysis of two major iron acquisition pathway proteins: an iron transporter, Ftr1 (ferrous permease), and a closely linked copper transporter, Ccc2. Deletions of FTR1 or CCC2 lead to significant changes in the lipid profile of C. albicans , especially the phospholipid and sphingolipid metabolism. For example, both Δ ftr1 and Δ ccc2 mutants showed depleted sphingolipid and steryl ester contents, but not much change in their DAG and TAG contents. The phospholipid profile of Δ ccc2 cells was quite unique with a much elevated PG content. The overall phospholipid profile of Δ ftr1 was not much different from the wild type. Both Δ ftr1 and Δ ccc2 cells showed significant differences in their molecular lipid species compositions. These lipid perturbations correlated with the susceptible response towards the drugs targeting lipid biogenesis and iron acquisition in Δ ftr1 and Δ ccc2 mutants. Taken together, this study shows that iron pathway proteins such as Ftr1 and Ccc2 are closely linked to lipid metabolism and iron acquisition in C. albicans . Understanding the mechanism of this lipid‐iron association should be useful in exploring the two pathways for understanding the mechanism of iron uptake and designing the combinatorial drug therapies.

Dermatophytosis is a superficial fungal infection caused by a group of keratinophilic fungi, which can sometimes be invasive. Factors like its contagious nature, widespread impact, resistance to treatment, and the fact that it is recurrent and highly impacts the quality of life make it more serious. This review will delve into the intricacies of infection caused by Trichophyton rubrum. T. rubrum is the most common and potent infectious agent among all the dermatophytes. Reported worldwide, it causes chronic infections in humans. These infections are difficult to manage due to frequently encountered cross-resistance to known antifungals. Independent studies have implicated the roles of several proteins in virulence and pathogenesis mechanisms. In this review, we have discussed research advances in the field of host-pathogen interaction, virulence factors, drug development, drug resistance mechanism and other technological progress concerning T. rubrum mediated dermatophytosis.

Purification and characterization of milk oligosaccharides is a challenging process due to the complexity of the constituent oligosaccharides, which behave differently under various chemical treatment procedures and often lose their structural properties in the process. Rathi cow’s milk is widely used in the Rajasthan region of India for its nutritional and medicinal benefits. Here, we aim to present an optimized method for the purification and analysis of oligosaccharides present in Rathi cow milk. Contrary to the freeze transport methods used earlier, we treated the collected milk with ethanol for preservation, followed by microfiltration, lyophilization, and fractionation on silica gel (60–120 mesh size) column chromatography (CC) coupled with chloroform/methanol-mediated gradient elution. Fractions 31–45 (1.78 g), 71–80 (470 mg), and 106–120 (498 mg) from CC-1 and fractions 26–49 (1.14 g) from CC-2 were analysed for sugar content via the phenol–sulfuric acid method. Fraction homogeneity was confirmed using high-performance liquid chromatography. Isolated analytes were treated with acetic anhydride/pyridine (1:1, v/v) to form less polar oligosaccharide derivatives, which could then be easily visualized and semi-quantitated using partition chromatography (thin later and paper) with chloroform/methanol. Structural identities of the purified oligosaccharides were determined using a combination of mass spectrometry and NMR (¹H, ¹³C, HSQC, TOCSY, COSY, HMBC) techniques. Our results clearly demonstrate that the ethanol-based preservation, transport, and purification of oligosaccharides is a simple and robust method for the analysis of Rathi cow’s milk oligosaccharides. Furthermore, using the acetylation, purified oligosaccharides allow for rapid analysis on thin-layer chromatography, which is quite cost effective compared with other analytical methods.

The intrinsic resistance of Candidozyma auris (C. auris) to antifungal drugs poses a major therapeutic challenge, with conventional resistance mechanisms providing only partial explanations. Sphingolipids (SLs), known for their interclade heterogeneity, play a crucial role in antifungal resistance. This study examined the SL landscape in two drug-susceptible clade II isolates, C-line and P-line, from distinct geographical origins, which were experimentally evolved to develop stable fluconazole (FLC) resistance. The progenitors displayed distinct SL profiles, P1 had higher PhytoCer and αOHPhytoCer, indicating a more active acidic SL biosynthesis branch, whereas C1 exhibited elevated αOHGlcCer, αOHCer, and LCBs, reflecting a greater role of the neutral biosynthesis branch. The principal component analysis also confirmed distinct segregation of the two progenitors. Upon evolution, P1.1 and C1.1 adaptors showed significant SL alterations. P1.1 exhibited PhytoCer enrichment, while C1.1 showed reduced αOHGlcCer alongside increased PhytoCer, dhCer, and αOHPhytoCer levels. Notably, αOHGlcCer remained unchanged in P1.1, whereas LCBs and αOHPhytoCer decreased compared to P1. Despite these lineage-specific differences between the progenitors, both evolved replicates exhibited increased PhytoCer as a common denominator like what is also observed in clinical FLC-resistant isolates. These findings highlight intraclade SL variability and suggest that specific SLs contribute to FLC resistance in C. auris.