Sexual reproduction: the mysteries of meiosis


Dr Corentin Claeys Bouuaert has received an ERC starting grant. This prestigious European funding will help him continue his research on the DNA biochemistry of sexual reproduction.

There are two modes of cell division in nature: mitosis and meiosis. Mitosis is the classic division that cells use to build our body: a mother cell divides into two identical daughter cells. Meiosis is different: the cell divides twice in succession to give birth to reproductive cells (gametes). In humans, gametes have one set of 23 chromosme – versus the 23 pairs, or 46 chromosomes, in other human cells. So a male gamete and a female gamete must meet for sexual reproduction to take place and to restore the number of chromosomes to 46.

All animals, including humans, reproduce sexually. ‘For reproduction to be successful, there are a number of things that must go well during meiosis’, says Dr Corentin Claeys Bouuaert, a biochemistry researcher. ‘The maternal and paternal chromosomes will first fragment and then, by rebuilding themselves, each chromosome will find its partner. The chromosomes will thus progressively mate along their entire length, like a zipper, and will exchange fragments and recombine before separating again. My research focuses on these two fundamental processes: DNA breakage and recombination. I'm studying the proteins that are responsible for them.’

Becoming a biochemist…without biochemistry training

Dr Claeys Bouuaert’s interest in DNA was born during secondary school. ‘I found it fascinating how DNA encodes the information needed for life! That's what made me want to be a biochemist. The problem was such training didn’t exist as such. It was necessary to choose between the two courses. I chose chemistry but took the maximum of optional courses in biology.’

After an Erasmus programme in Spain, where he took a liking to the expat life, he settled on a thesis topic at the University of Nottingham. ‘The four years I spent in the UK made me a real scientist. That’s where I started to really read the scientific literature, which I didn’t really do sufficiently during my studies at UCLouvain. I also learned the biochemist's basic techniques: how to purify DNA and proteins, how to study the action of a particular protein on DNA, and so on.’

From in vitro research to in vivo work

After defending his thesis, Dr Claeys Bouuaert achieved his first goal: he became a biochemist. He brought his expertise to Dr Scott Keeney’s molecular biology laboratory, in New York. ‘The lab works on in vivo meiosis, in yeasts and mice. I didn’t want to work with mice, the yeast cells already seemed big enough! So I moved to a new scale, from molecules to cells. That said, I stayed in the DNA field, focusing on what happens during meiosis. During this postdoc in New York, I combined the biochemistry techniques I learned in Nottingham with the in vivo techniques used by molecular biologists and geneticists.’(1)

His own research laboratory

The subtleties of meiosis are not yet fully understood. To study it from a biochemical point of view is an original approach. This is undoubtedly why the European Research Council (ERC) awarded Dr Claeys Bouuaert a Starting Grant.2 The funding will enable him to acquire equipment and recruit one or more PhD students – in short, set up his own laboratory, which he has always wanted to do.
‘My work is fundamental research’, he says. ‘Indirectly, it could potentially be of interest in two health fields: cancer and fertility. Indeed, cancer can be seen as a disease of DNA, caused by the accumulation of mutations that come from, among other things, "breaks" in DNA and poor recombinations. Regarding human fertility, many miscarriages are caused by chromosomal problems in the foetus. By better understanding how the processes of meiosis (mal)function, we may find solutions to such problems, or learn how to avoid them altogether.’ 

Candice Leblanc

(1)    An example of a technique used by molecular biologists is fluorescence microscopy, which locates cell proteins dyeing them with a fluorinating agent. An example of genetic engineering is introducing a mutation into DNA in order to observe the consequences for the cell or the organism. 
(2)    D’un montant de 1,5 million d’euros, les « ERC starting grants » sont destinés aux jeunes chercheurs européens. 


A glance at Corentin Claeys Bouuaert's bio

2006: Master’s Degree in Chemistry, UCLouvain 
2007: DEA in Biochemistry, UCLouvain, and Erasmus programme, University of Salamanca (Spain)
2011: PhD in Biomedicine, University of Nottingham (UK)
Depuis 2012: Researcher, Memorial Sloan Kettering Cancer Center, and Howard Hughes Medical Institute (New York, USA)

Published on October 11, 2018