Profile

Mitochondria are a bit like little batteries in the cell and make the energy the cell needs to survive. This energy is called ATP and is used by the cell to do all the normal things like grow and divide. The cells I study are called oocytes. These are the egg cells made in the ovary of the female and they are fertilised by sperm from the male to make a baby.

Mitochondria are especially important in these cells because from the time when the oocyte is fully grown until several days after fertilisation when the newly formed embryo has already divided into many cells, no new mitochondria are created. This means that the mitochondria in the oocyte must be able to make all the energy that the embryo needs for the first few days of its life, until more mitochondria can be made. This makes the oocyte mitochondria very important for determining what makes a “good egg” as only those eggs with good mitochondria that can make enough ATP will be successfully fertilised and make it through those first few days.

I am studying mitochondria in the last part of the growth and preparation of these egg cells for fertilisation and we call this process oocyte maturation. To look at what mitochondria are doing during oocyte maturation, I inject something into the oocytes which makes the mitochondria fluorescent so that we can follow what they are doing on a microscope. Lots of our experiments involve injecting things into oocytes. We call this microinjection because the oocyte is very small and we have to do the injection by looking down a microscope. Here’s me at the microscope doing some microinjection, and a picture of what you see when you look down the microscope. The round thing in the middle is the oocyte, on the right is the holding pipette which we use to position the oocyte ready for injection, and on the left is the injection pipette containing the stuff to make the mitochondria fluorescent:

Once the mitochondria are fluorescent we can look at them in the oocyte using another microscope. This one is attached to a computer which controls how often a picture gets taken. Here’s what it looks like:

Once you put all the pictures together you have a movie which allows you to see what the mitochondria are doing. I then analyse these images. This involves sitting in front of the computer and looking at a lot of data!

Here  you can see that the mitochondria (the green things) are moving from a symmetrical distribution (a nice ring shape) to an asymmetrical distribution (it looks a bit like a horseshoe). By analysing this movement we get a spreadsheet with lots of numbers which we can turn into a graph:

This graph tells us something about how and when the mitochondria are moving and we think that where the mitochondria are in the cell and how they move around during oocyte maturation might be important for making a good egg.

No two days are exactly the same, which is one of the things I like best about science, but I start the day by walking or cycling to work. The lab is at UCL, a university in central London.

This is the door to the lab:

A lot of my time is spent doing experiments in the lab and the first thing I usually do is to get things set up and prepared for whatever experiment I will do that day. There are often gaps in the experiment while I wait for things to happen and during this time I go to my office and spend some time in front of the computer. I share my office with 4 other girls and several plants! Here’s a picture of the office and one of my office buddies hard at work:

In the office I might look at what the results of previous experiments were to try to understand what is happening, and think about what experiments I might do next. I also read about experiments that other people have done to see how this might fit in with what I am doing, or give me ideas about what other things I can try. I might also attend a seminar to hear about work that people are doing in other labs. Among all this hard work though we also manage to make time to have some coffee and eat some cake, and maybe go for a drink at the end of the day: