Researchers at the National Institute of Animal Biotechnology (NIAB) have made a significant discovery that could pave the way for new strategies to extend female fertility. Led by Prasad Rao from NIAB’s Laboratory of Molecular Reproduction and Aging, the team has uncovered a molecular clue that appears to slow down reproductive aging.
The scientific team, using both live mouse models and cultured goat ovaries, found that reducing the activity of a cellular protein called ‘Cathepsin B’ (Cat B) helps preserve the ovarian reserve. This ovarian reserve is the finite pool of egg cells (oocytes) that female mammals are born with. Unlike sperm, these crucial egg cells cannot be regenerated.
The findings are important since, unlike sperm, oocytes cannot be regenerated. “Over time, the quantity and quality of these eggs naturally decline due to factors like oxidative stress, inflammation and general cellular wear. This process accelerates with age. ‘Cat B,’ a protein-degrading enzyme, seems to be a key driver of this decline. By lowering its levels, we may be able to delay egg loss, effectively extending fertility naturally,” said Mr.Rao.
The scientist team, which includes Aradhana Mohanty, Anjali Kumari, Lava Kumar S., Ajith Kumar, Pravin Birajdar, Rohit Beniwal, Mohd Athar and Kiran Kumar P., pointed out that the implications go far beyond the laboratory. It is because across India’s rural heartlands and urban hospitals, fertility is quietly becoming a shared crisis. As both livestock and women age, their ability to reproduce declines, with significant biological and economic consequences, said researchers.
In humans, fertility begins to decline in the early 30s, with a sharper drop in the 40s, reducing chances of conception and increasing the risk of miscarriage or chromosomal disorders. While assisted reproductive technologies like IVF provide options, they are often costly, invasive and less effective in older women. A safe, biological method to slow ovarian ageing could revolutionise fertility preservation for millions.
For farmers, a simple intervention to extend reproductive lifespan of livestock could improve herd productivity, reduce stray cattle populations, and support the incomes of smallholder farmers who form the backbone of Indian agriculture.
This is a rare moment where science serves both the farm and the family. From barns to birthing rooms, this discovery bridges animal science and human medicine, promising a future where age is no longer a barrier to reproduction, said researchers.
For a country navigating the twin challenges of rural sustainability and reproductive health, the implications are profound and hopeful, said NIAB director G. Taru Sharma. The research results were published in the latest issue of ‘Aging Cell’.
Published – June 11, 2025 12:46 am IST
