Latest news with #ShantanuShukla
Time of India
11 hours ago
- Science
- Time of India
Fungus, not insect, is true source of prized lac pigment: Indian Institute of Science studeyt
Bengaluru: The red lac pigment, long thought to be made by insects, may actually originate from a yeast-like fungus living symbiotically inside them, researchers at Indian Institute of Science (IISc) have found. By sequencing the lac insect's microbial community, the team from department of developmental biology and genetics discovered that only the fungus, not the insect or its bacteria, carried genes needed to produce laccaic acid, the key compound in the pigment. Their findings were published in Proceedings of the National Academy of Sciences. "For thousands of years, India has been a key producer of lac pigment," Shantanu Shukla, assistant professor and corresponding author of the study, said. The pigment, derived from resin secreted by the insect, is widely used in textiles, food colouring, handicrafts, and traditional art. Lac insects, which feed on the sugary sap of host trees such as "Butea monosperma" (commonly known as Flame of the Forest), secrete shellac and laccaic acid. However, the pathway through which the pigment is synthesised has remained unclear for decades. Repeated efforts to locate the required genes in the insect's own genome had been unsuccessful. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Giao dịch vàng CFDs với sàn môi giới tin cậy IC Markets Tìm hiểu thêm Undo The new study suggests the insect lacks the capability to produce tyrosine, an amino acid essential for laccaic acid synthesis, and relies instead on microbial partners. "Such missing nutrients are often supplied by symbiotic bacteria or fungi in insects," said Shukla. By sequencing the bacterial and fungal communities associated with the insect, researchers narrowed down their search to two candidates: a "Wolbachia" bacterium and a yeast-like fungus. The fungus, previously hinted at, but not fully characterised in earlier studies, turned out to possess the entire genetic toolkit for pigment synthesis. This included genes for enzymes that catalyse the formation of aromatic molecules, which form the structural basis of laccaic acid. According to Vaishally, a PhD student and first author of the paper, isolating the role of the fungus was not straightforward. "The fungus is uncultivable, and the insects cannot survive outside their host plants. All our work had to be done using plant-reared insects, which made it challenging," she said. One striking feature of the fungus is its location and mode of inheritance. It is present not just in the insect's haemolymph — comparable to blood — but also inside its egg cells. "The fungus enters the oocyte as it matures and is passed on to the next generation. This kind of vertical transmission is rare and noteworthy," Shukla said. Researchers also observed treating the insects with a fungicide led to reduced pigment production and stunted growth. This indicates the insect likely depends on the fungus for more than just pigment synthesis, possibly for other nutrients it cannot obtain from its sap-based diet. "The yeast-like organism is central to the story. Fungal symbionts are still poorly understood in insects, and this study adds to our understanding of their evolutionary role," Shukla said. The findings suggest a more complex biological relationship behind the production of lac pigment than previously known, and may open up avenues for studying fungal symbiosis in other pigment-producing insects.
The Hindu
16 hours ago
- Science
- The Hindu
IISc researchers unravel the mystery behind how lac insect produces pigment
In a new study, researchers at the Indian Institute of Science (IISc) have unravelled the mystery behind how the lac insect produces laccaic acid that is used to make lac pigment. The lac pigment is a prized commodity used in food colouring, textiles, dyes, handicrafts, and folk art. According to IISc, the lac insect grows on certain trees (like the flame of the forest), drinks its sugary sap, and secretes a sticky resin called shellac. It also makes a bright red compound called laccaic acid, which is used to make the pigment. 'How the insect produces laccaic acid has remained a source of mystery. For decades, scientists have unsuccessfully hunted for genes coding for its synthesis in the insect's genome,' IISc said. However, now the researchers have found that the colourful pigment extracted from the lac insect may actually be produced by a symbiotic yeast-like organism living inside the insect. The team also showed that the yeast-like organism exclusively harbours genes coding for key ingredients in the pigment synthesis pathway. India, a key producer 'For thousands of years, India has been a key producer of lac pigment. The pathway for the pigment production was not very clear,' said Shantanu Shukla, assistant professor in the Department of Developmental Biology and Genetics, IISc. IISc said that one of the key ingredients required for laccaic acid synthesis is an amino acid called tyrosine, which the insect cannot make on its own or source from the tree sap. Such missing ingredients are usually supplied by symbiotic bacteria or fungi that live inside insect bodies and secrete these molecules in exchange for housing. The team sequenced the entire bacterial and fungal microbiome of the insect and zeroed in on two possible candidates: a bacterium belonging to the Wolbachia genus and a yeast-like fungus. Previous studies by other researchers had hinted at the presence of the fungus but had not identified it or sequenced its genome. In the current study, the team found that neither the insect nor the bacterium carried the genes needed to make tyrosine and other components of the pigment pathway. But the yeast-like organism did — it carried the entire set of genes needed for laccaic acid production. This includes genes coding for various enzymes which catalyse the production of aromatic molecules that are the building blocks of laccaic acid. Inside egg cell Mr. Shukla said that the fungus is actually inside the insect's oocyte (egg cell). The fungus floats around in the insect's haemolymph — the equivalent of animal blood — and as soon as the oocyte matures, it latches on to it and enters the oocyte, and gets transmitted to the offspring that emerges from the oocyte.
Time of India
a day ago
- Science
- Time of India
Fungus, not insect is true source of prized lac pigment: IISc study
Scientists at IISc found that the red lac pigment, earlier thought to come from insects, may actually be made by a fungus living inside them BENGALURU: The red lac pigment , long thought to be made by insects, may actually originate from a yeast-like fungus living symbiotically inside them, researchers at IISc have found. By sequencing the lac insect's microbial community, the team from the Department of Developmental Biology and Genetics discovered that only the fungus — not the insect or its bacteria — carried genes needed to produce laccaic acid , the key compound in the pigment. Their findings were published in the Proceedings of the National Academy of Sciences. 'For thousands of years, India has been a key producer of lac pigment,' Shantanu Shukla, Assistant Professor and corresponding author of the study, said. The pigment, derived from resin secreted by the insect, is widely used in textiles, food colouring, handicrafts, and traditional art. Lac insects , which feed on the sugary sap of host trees such as 'Butea monosperma' (commonly known as Flame of the Forest), secrete shellac and laccaic acid. However, the pathway through which the pigment is synthesised has remained unclear for decades. Repeated efforts to locate the required genes in the insect's own genome had been unsuccessful. The new study suggests that the insect lacks the capability to produce tyrosine — an amino acid essential for laccaic acid synthesis — and relies instead on microbial partners. 'Such missing nutrients are often supplied by symbiotic bacteria or fungi in insects,' said Shukla. By sequencing the bacterial and fungal communities associated with the insect, researchers narrowed down their search to two candidates: a 'Wolbachia' bacterium and a yeast-like fungus. The fungus, previously hinted at but not fully characterised in earlier studies, turned out to possess the entire genetic toolkit for pigment synthesis. This included genes for enzymes that catalyse the formation of aromatic molecules, which form the structural basis of laccaic acid. According to Vaishally, a PhD student and first author of the paper, isolating the role of the fungus was not straightforward. 'The fungus is uncultivable, and the insects cannot survive outside their host plants. All our work had to be done using plant-reared insects, which made it challenging,' she said. One striking feature of the fungus is its location and mode of inheritance. It is present not just in the insect's haemolymph — comparable to blood — but also inside its egg cells. 'The fungus enters the oocyte as it matures and is passed on to the next generation. This kind of vertical transmission is rare and noteworthy,' Shukla said. Researchers also observed that treating the insects with a fungicide led to reduced pigment production and stunted growth. This indicates that the insect likely depends on the fungus for more than just pigment synthesis — possibly for other nutrients it cannot obtain from its sap-based diet. 'The yeast-like organism is central to the story. Fungal symbionts are still poorly understood in insects, and this study adds to our understanding of their evolutionary role,' Shukla said. The findings suggest a more complex biological relationship behind the production of lac pigment than previously known, and may open up avenues for studying fungal symbiosis in other pigment-producing insects.
