Researchers have created a lab-based human germ cell development model to shed light on how an egg and a sperm pass genetic traits from one generation to the next, an advance that may lead to a molecular-level understanding of conditions such as infertility.
The underlying mechanisms of early germ cell development in humans have remained unclear because of a lack of robust experimental methods, as well as inherent difficulties with studying human embryos.
In a promising breakthrough, recently published in the journal Cell Stem Cell, the research team from Kyoto University in Japan has recreated human germ cell development in the laboratory, showing specific key elements and events that occur at the beginning of human life.
For the study, five laboratories at the university’s Centre for iPS Cell Research and Application (CiRA) collaborated.
To date, most such research has been restricted to mice. While this work provides useful information that is generally applicable to mammals, there has still been a lack of information specific to humans.
Lead researcher Mitinori Saitou’s team recreated the developmental process of human germ cells, which gives rise to reproductive sperm and eggs.
In addition to illustrating key transcription interactions and signalling events, the scientists gained insight into how epigenetic marks – traits that are inherited without changes to the DNA sequence – are “erased” at the beginning of germ cell development.
“We demonstrated the early events in human germ cell development. Our work should provide a basis to gain a better understanding of how certain disorders such as infertility and growth impairment come about,” said co-first author Kotaro Sasaki.
The team’s model, still in its early stages, is hoped to form a foundation for continuing studies on germ cell lineage.
“By further reconstituting human germ cell development in vitro, we may be able to discover the mechanisms throughout the entire developmental process from embryo to adult,” said Saitou.