A study cooperated with Kiwi and Chinese scientists to use earthworms as a model organism to investigate the impact heavy metals and pesticides could have on human genes is in progress, Massey University of New Zealand said in a statement Tuesday.

Michelle Thunders, Director of Teaching and Learning for the College of Health in Massey University has recently returned from a trip to China, where she is working with researchers from the Shanghai Jiaotong University (SJTU) to explore how heavy metal toxins, initially cadmium, can interfere with gene expression in adult and juvenile earthworms.

Cadmium is a heavy metal found in soil and previous research has described it as an 'environmental estrogen'. Environmental estrogens are potentially dangerous as they mimic the function of endogenous, or the body's own, estrogen and therefore may interfere with puberty or the reproductive system.

The research project plans to make use of rapid advances in next-generation sequencing and Bio-information analysis to look at the impact of such environmental toxins on gene expression.

The work contributes to a field of science known as ecotoxicogenomics, which aims to understand the link between the internal genome and the external environment. It will provide vital groundwork for future studies on how toxins affect both detoxification and reproductive functions.

Thunders said the studies could ultimately be carried out on humans in a bid to unlock the puzzle of the increasing incidence of human sub-fertility.

Earthworms sensitive to toxic chemicals present in the soil and so are useful as bio-indicator organisms. Researchers said that selecting a model organism such as the earthworm to understand environmental regulators of fertility is pertinent for many reasons, including their short reproductive cycle, the fact they are hermaphrodite but breed sexually, they are easy to manipulate and an increasing body of genomic data is becoming available on this species.

Thunders said the successful relationship between Massey University and the SJTU School of Agriculture and Biology is vital for a project like this one.

"We can share expertise and different approaches to the question. They also have an amazing lab and field facilities, and I was fortunate enough to see the experiments they are carrying out," Thunders said.

Shanghai Jiaotong University is ranked in the top four of more than 2550 universities in China and sits in the top 150 in world rankings. (Xinhua)