Nanopore Technology Unveils the Secrets of the Human Placenta

The placenta is a remarkable, temporary organ responsible for coordinating every aspect of pregnancy between mother and foetus. Despite its critical role, it possesses a distinct and somewhat chaotic genetic landscape compared to normal body tissues, featuring higher mutation rates and lower levels of methylation—chemical tags that regulate gene activity.

In a recent study, scientists applied nanopore sequencing technology to gain a comprehensive view of this organ's biology. By sequencing the genomes of eight 'trios' (mother, father, and child), the team achieved robust phasing. This technique allows researchers to distinguish between the two copies of chromosomes inherited from each parent, offering an unprecedented look at parent-of-origin effects on gene expression.

This detailed genomic investigation highlighted the placenta's unique methylome. Methylation acts like a dimmer switch for genes, and the study identified many Differentially Methylated Regions (DMRs) that vary between individuals. Most notably, the high-fidelity sequencing revealed previously unreported 'imprinted' genes, such as ILDR2 and RASA1. Imprinted genes are unique because only the copy inherited from a specific parent is active, while the other is silenced. Identifying these genes is a significant step forward, as they are potentially crucial for ensuring healthy placental function and foetal development.