Page URL:

Cell 'arms' reach out and pull early embryo into shape

2 December 2013
Appeared in BioNews 733

Time-lapse imaging has been used to track the way that cells organise themselves to form an early mouse embryo.

'Our findings reveal a completely unanticipated mechanism regulating the earliest stages of embryo development', said Dr Nicolas Plachta, lead researcher for the study, which was carried out at Monash University's Australian Regenerative Medicine Institute.

After an egg is fertilised, it undergoes a series of divisions to produce relatively round cells. At the eight-cell stage, cells become elongated and flatten their membranes against each other, before regaining some slight roundness and continuing to divide.

Embryos that do not undergo this compaction often do not survive, and the timing of this elongation has been linked to implantation success. The study, published in Nature Cell Biology, demonstrates how the process of compaction actually takes place.

'Our images reveal arm-like structures called filopodia appearing on the outer membrane of some cells during the eight-cell stage, and it is these filopodia that are responsible for contorting cell shape, and forming the embryo's first tissue-like layers', said Dr Juan Carlos Fierro-González, who conducted the research. 'We then saw the filopodia retract as they released their grip on neighbouring cells, allowing them to return to a somewhat rounded shape before they continued on their journey of cell division'.

'For the first time, we have been able to watch as filopodia reach out and grab neighbouring cells, pulling them closer and elongating the cell membranes. We think that this enables the cells to effectively compact, as their new non-rounded shape makes the most of the available space', Dr Fierro-González said.

The research was carried out in mice, but the team hopes the results will aid embryo selection for IVF in humans.

'Now that we know what controls early development, we are designing non-invasive imaging approaches to see if human embryos used in IVF form normal filopodia and undergo normal compaction. This could help us choose which embryos should or shouldn't be implanted back in the uterus', Dr Plachta said.

Aussie scientists discover embryo secrets
The Australian |  25 November 2013
Cadherin-dependent filopodia control preimplantation embryo compaction
Nature Cell Biology |  24 November 2013
Your first hug: How the early embryo changes shape
EurekAlert! (press release) |  24 November 2013
25 April 2016 - by Dr Ashley Cartwright 
Chinese scientists have successfully grown mouse embryos in space, the first reported development of mammalian embryos in space history...
28 April 2014 - by Dr Rachel Montgomery 
A protein that allows eggs and sperm to fuse together has been identified by scientists at the Wellcome Trust Sanger Institute, Cambridge...
17 February 2014 - by Dr Shanya Sivakumaran 
An 'entrance exam' set by the cells that line the womb can determine whether or not human embryos are able to implant into the womb's lining, according to researchers...
6 January 2014 - by Dr Gabrielle Samuel 
Researchers in China have developed a new non-invasive method for detecting genetic defects in IVF embryos that could improve the chances of successful IVF for some patients...
5 December 2011 - by Dr Rebecca Robey 
Progress Educational Trust (PET)'s annual conference, 2011, 'The Best Possible Start in Life: The Robust and Responsive Embryo', started with two fantastic sessions chaired by Dr Virginia Bolton, consultant embryologist at the assisted conception unit at Guy's Hospital, London, UK....
22 June 2009 - by Dr Will Fletcher 
The genetic material in sperm has far greater influence over the development of a fertilised egg than was previously imagined. A new joint study from the Huntsman Cancer Institute (HCI) and the IVF and andrology lab at the University of Utah, US, has revealed that the father's sperm passes along a previously unrecognised set of instructions that probably tell the developing embryo which specific genes should be turned on and off. The findings, which could lead to new diagnostic tests to help ...
19 May 2008 - by Dr Charlotte Maden 
A group of Australian scientists has used a new genetic analysis technique to assess IVF embryos, to identify those most likely to develop in the womb. The findings were published in the journal Human Reproduction last week. Around one per cent of all births in the UK...
20 August 2007 - by MacKenna Roberts 
A study has found that exposure to the 'harsh' cool-white fluorescent lighting commonly used in fertility clinics, research labs and most office environments could be particularly damaging to an embryo's healthy development. A joint team of researchers in Hawaii and Japan conducted the study on mouse embryos...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.