1. synapses{ M A K I N G C O N N E C T I O N S }
AUGUST 2012
István Ábráham Up close and personal… with oestrogen and
brain cells – by Jill Leichter
Neil Gemmell Genetics and the Platypus – by SueVoice
Jon Waters Unrecognised treasure trove – by Sophia McKay
Daphne Lee A question of preservation – by Sandra Copeland
Registrations for Hands-On Science are open
from 1 August to 19October. Don’t forget!
http://handsonscience.otago.ac.nz
Heinz Wattie Scholarships for Food Science
– applications close 31 October
www.otago.ac.nz/foodscience/scholarships/
undergradscholarships/wattie.html
Up close and personal...with
oestrogen and brain cells
A powerful microscope can tell you a lot about biology,but what if you could
see living molecules interacting with each other in real time?That is precisely
what Dr István Ábrahám is looking at in the Department of Physiology.
Two years ago,
with help of
Olympus, Dr
Ábrahám’s
research group
acquired a
custom-made
microscope
system that uses
electromagnetic
waves instead
of light to
observe living molecules, molecules that would die under a traditional
light. Then Dr Ábrahám spent six months at Kyoto University in
Japan working with Professor Akihiro Kusumi, the Director of the
Center for Meso-Bio Single-Molecule Imaging (CeMI). Professor
Kusumi helped Dr Ábrahám establish special imaging techniques so
he could look at up to three independently coloured molecules as they
interacted over time. Using a time lapse super-resolution imaging
technique, Dr Ábrahám can make a 100-µsec mini film to see how his
molecules change over time.
His molecules of interest are oestrogen and cholinergic neurons,
neurons in the brain affected by Alzheimer’s disease. Specifically,
he is investigating oestrogen-induced neuro-protective effects on
living cholinergic neurons, concentrating on changes in the plasma
membrane.
Unfortunately, taking oestrogen has serious side effects for people,
so in a collaboration with Professor Warren Tate (Department
of Biochemistry), Dr Ábrahám, will also be testing synthetic
oestrogens without harmful side effects to determine whether they
help cholinergic brain cells recover from injury. Dr Ábrahám hopes
this research will lead to new treatments for people suffering from
Alzheimer’s disease.
Professor Warren Tate and Dr Ábrahám are members of the Brain
Health Research Centre (BHRC) at the University of Otago.
Genetics and the Platypus
A natural aptitude for genetics and an inquisitive mind led Professor Neil
Gemmell on a quest to understand the inheritance and evolution of genetic
material. Especially, genes linked to regions of XY-chromosomes that
determine sex.
The quest began with a serendipitous moment in a hut in Tasmania,
where waiting for the rain to clear, Neil read an advert in the local
paper: research assistant wanted to investigate sex determination in
marsupials and monotremes (mammals who lay eggs; platypus and
echidnas). Later that year Neil started a PhD with Professor Jenny
Graves at La Trobe University.
In humans and most other mammals, sex is determined by the presence
of a Y chromosome, which carries the Sex-determining Region Y (SRY)
gene that triggers the development of the testis and thus maleness. At the
time of Neil’s PhD this gene had just been found in humans and work
in the Graves’ lab sought to determine whether sex in marsupials and
monotremes was controlled by the same gene.
They discovered that SRY is the sex-determining gene in marsupials,
but that monotremes were more complex. Unlike other mammals,
which have a single pair of sex chromosomes, monotremes have
multiple Xs and Ys. Platypuses have ten, 5X5Y for males and 10X for
females. However, the SRY gene was not found suggesting that sex is
determined through another gene in monotremes.
We still don’t know how sex is determined in monotremes.
While the initial question of the PhD was not
answered, Neil used the genetic
data he collected to ascertain
the relationships within
and among platypus
populations, and
the evolution of
the modern
mammals. This
work contributed to the future completion of the platypus genome in
which his laboratory played a role.
Neil has continued to explore the inheritance and evolution of genetic
material. His ongoing work spans pure research through to the applied,
the latter of which includes application in conservation science,
biosecurity, agriculture and aquaculture.
Neil says people who ask questions, seek answers and can put together
connections make good geneticists.
Photo:ODT

2. synapses{ M A K I N G C O N N E C T I O N S }
Division of Sciences
www.otago.ac.nz/sciences
CONTACT:
Rose Newburn
Marketing – Communications
Division of Sciences
University of Otago
PO Box 56
Dunedin 9054
Email rose.newburn@otago.ac.nz
www.sciences.otago.ac.nz
A question of preservation
Travel about 80 km inland from Dunedin and about 23 million years
back in time and watch as extremely hot magma wells up through
a crack in the Earth’s crust and contacts groundwater.The resulting
explosive eruption forms a crater about 2 km across and maybe 150 m
deep. Rain falls and the crater slowly fills with water.
The water lies still and deep within the crater, no outflow disturbs
it. Microscopic diatoms live in the water, with freshwater sponges
feeding on them. Very occasionally over the centuries there may be
a short-lived stream flowing into the lake, bringing tiny fish who
survive for a time in the surface waters. Trees surrounding the lake
lose their leaves, pollen, occasional flowers and insects are blown into
the waters. Sinking into the depths is like sinking into a pickling jar;
acidic and anoxic, no oxygen to breathe, nothing to decompose the
remains; whatever falls to the bottom is compressed and mummified.
Fast forward 20 million years to the present. The lake is gone – filled
up and dried out, but the layers of diatomite containing the preserved
material are still there. Enter a team of scientists led by Daphne Lee
of the Department of Geology. A serendipitous find on a scoping
expedition for a field trip led to a return trip with a chainsaw, and
eventually a Marsden-funded drilling exploration. Fossil leaves that
have been carefully prepared have been examined and photographed
– even microscopic cellular detail is preserved and can be seen using
electron microscopy. Pollen grains, insects, flowers and fish are being
found, photographed, named, compared and catalogued.
The fossils indicate the climate in Otago was seasonally dry, warmer,
temperate to subtropical; probably similar to that of Queensland.
The plants and animals were different from those we know now;
many plants, like proteas, are extinct in New Zealand’s native flora,
but once flourished in Otago. Among the significant finds are the
earliest known southern hemisphere orchids.
Ironically, once the specimens are removed and prepared they
are extremely fragile and can hardly be handled for fear of their
disintegration. They are kept untouched, hidden away from light
and movement, but they will not last.
Daphne is a passionate time-traveller. Her team has much material to
work on, and many more remarkable discoveries lie still preserved in
the core samples. Daphne’s cry is that “there is so much to be done!”
Unrecognised treasure trove
We have little trouble accepting the evolutionary consequences of‘natural’
upheaval, but what about the evolutionary effects of human-mediated
change?
As an example, it has been discovered that Yellow-eyed penguins
arrived in New Zealand only in the past 500 years, replacing a
prehistoric penguin species, the Waitaha penguin, that was wiped
out shortly after human settlement.
Professor Jon Waters and his research team from the Department
of Zoology are investigating how animals such as penguins and
sea-lions responded to the impact of humans and how many of New
Zealand’s coastal species were actually new arrivals from overseas.
One of Waters’ former Otago PhD students, Dr Sanne Boessenkool,
undertook research several years ago and discovered remains of the
extinct Waitaha penguin.
“This highlights the fact that we still have a great deal to learn about
New Zealand’s natural history, and especially about the impact of
human arrival here.
“We tend to think that things that are here now are things that have
been here for a long time, yet many people would be surprised to
know that the yellow-eyed penguin may not have been living in
Otago as long as previously believed,” says Professor Waters.
Supported by an $878,000 grant from the Marsden Fund, Waters
and his team will use carbon dating and state-of-the-art DNA
analysis of prehistoric bones to shed further light on the country’s
“dramatic biological history”, and to conduct a biological audit of
prehistoric New Zealand.
“The ancient DNA approach used in this penguin study is enormously
powerful as it provides a direct means of characterising historical
biodiversity. When coupled with more traditional techniques, this
method has potential to revolutionise our understanding of the past.
“More broadly, this study indicates that we inhabit a highly dynamic
part of the world - an idea that contrasts with the more traditional view
of an ancient and relatively unchanging New Zealand biota inherited
from Gondwana. It is now becoming clear that species respond rapidly
to human-mediated impacts such as climate change and extinction.”
As Professor Waters says,“Who knows what other fascinating stories
might have been overlooked?”