Over the past 20 years, we have been interested in the genetics of the iconic platypus and echidna. We strive to use our discoveries to help species conservation, and to better understand our own genetic history and human diseases.
Current Research
The comparison of genes, genomes and epigenetic mechanisms in different species has provided many fundamental insights into how genes function in humans, how they evolved, and how they contribute to diseases. Our group studies gene evolution in mammalian species distantly related to humans – monotremes in particular.
Monotremes have an extraordinary sex chromosome system that can reveal novel genes and pathways involved in sex determination and differentiation in all mammals, including humans. They also provide valuable insight into the beginnings of placentation and lactation in mammals. Monotremes have undergone radical changes to their stomach anatomy and physiology. Studying monotremes provides the opportunity to identify the role of key genes involved in stomach function and metabolism in humans, and may even lead to the identification of new therapeutic targets for metabolic diseases such as diabetes.
Monotremes have an extraordinary sex chromosome system that can reveal novel genes and pathways involved in sex determination and differentiation in all mammals, including humans. They also provide valuable insight into the beginnings of placentation and lactation in mammals. Monotremes have undergone radical changes to their stomach anatomy and physiology. Studying monotremes provides the opportunity to identify the role of key genes involved in stomach function and metabolism in humans, and may even lead to the identification of new therapeutic targets for metabolic diseases such as diabetes.
Our projects:
Identification and characterisation of monotreme sex determining genes
The generation of males and females in any animal population is crucial to success in species survival. Many different pathways of sex determination have evolved but certain genes/gene families have conserved functions in this process. The conserved mammalian sex determination gene, SRY is absent in egg-laying mammals (monotremes), the oldest living lineage of mammals. We are working to identify and characterise candidate sex determination genes in monotremes to shed light on the evolution of this process in mammals.
Contact Linda Shearwin for more information
Contact Linda Shearwin for more information
Evolution of platypus sex chromosomes
Monotremes have a unique sex chromosome system consisting of multiple XY sex chromosomes compared to the single XY sex chromosomes in other mammals. We are studying this unique system during meiosis in platypus spermatogenesis looking for sex-biased chromosome segregation.
Contact Linda Shearwin for more information
Contact Linda Shearwin for more information
ECHIDNACSI
Echidnas are an iconic Australian species and are the most widespread native mammal in Australia. However, there are still major knowledge gaps in terms of the distribution, biology and ecology of these fascinating animals. We have created a citizen science project, the Echidna Conservation Science Initiative – EchidnaCSI – using an innovative approach of combining public engagement with molecular biology to better understand wild echidna populations and to help their conservation. Through a specially designed app, the public take photos of echidnas in the wild to record their sightings for us to establish the first Australia-wide distribution map. The public also collect and send us echidna scats, allowing us to investigate the DNA and hormones within these scats. DNA helps us to understand the echidnas diet, population genetics and microbiome while hormones can show whether echidnas are stressed in particular environments and help us to better understand their reproduction. EchidnaCSI has now been running for over five years and we have more than 10000 users with 13000+ echidna sightings recorded and 800+ scats sent in from across Australia.
Visit the EchidnaCSI website for more information
Visit the EchidnaCSI website for more information
Monotreme microbiomes
Although the microbiome is increasingly being recognised for its importance to health and development, very little is known about monotreme microbiomes. We have been using citizen science and zoos to collect echidna scats from across Australia to perform the largest gut microbiome study on any native Australian animal. From this, we have found significant differences between zoo held and wild echidnas, as well as managed animals on different diets, revealing that diet is important in shaping the gut microbiomes in echidnas (click here to read the paper).
We are continuing to investigate monotreme microbiomes by sequencing the bacteria within the echidna pouch microbiome during different reproductive stages. We are also developing novel strategies to introduce microbiome research into undergraduate teaching at the University of Adelaide.
We are continuing to investigate monotreme microbiomes by sequencing the bacteria within the echidna pouch microbiome during different reproductive stages. We are also developing novel strategies to introduce microbiome research into undergraduate teaching at the University of Adelaide.
METABOLIC GENES OF MONOTREMES AND DIABETES
Diabetes has become a major health burden, not only for Australia but worldwide. One of the major targets for treatment is the hormone glucagon-like peptide 1 (GLP-1), which helps the release of insulin to the blood stream and assists in glucose control. One problem with GLP-1 is that it is broken down within minutes of its release by and enzyme called DPP-4. In platypus and echidna this hormone has gained a mutation which has made it resistant to break down by DPP-4. This was recently shown in vivo along with the ability for platypus and echidna GLP-1 to assist with insulin secretion.
Our group is assessing the effects of platypus and echidna GLP-1 in a mouse model. We are analysing the impact of monotreme GLP-1 in obese and insulin-resistant mice, including their glucose tolerance, weight, and other metabolic outcomes as a result of treatment. Alongside this, we are using bioinformatics approaches to investigate a group of metabolic genes and their evolution in monotremes. Previous research has found that many genes involved in stomach function are missing or altered in the platypus, and it is likely that there are many other changes in monotreme metabolic genes that are yet to be investigated.
Contact Frank Grutzner for more information.
Our group is assessing the effects of platypus and echidna GLP-1 in a mouse model. We are analysing the impact of monotreme GLP-1 in obese and insulin-resistant mice, including their glucose tolerance, weight, and other metabolic outcomes as a result of treatment. Alongside this, we are using bioinformatics approaches to investigate a group of metabolic genes and their evolution in monotremes. Previous research has found that many genes involved in stomach function are missing or altered in the platypus, and it is likely that there are many other changes in monotreme metabolic genes that are yet to be investigated.
Contact Frank Grutzner for more information.
EVOLUTION OF THE PLACENTA AND LACTATION IN MAMMALS
Monotremes represent an intermediary between egg-laying and live-bearing animals. Unlike other mammals, most of their development occurs after hatching and is provided through lactation rather than through the placenta. They have acquired some but not all placentation genes and have lost some but not all egg yolk genes, and with their lack of nipples, they are the closest living representation of the ancestral form of lactation. By better understanding the genetic basis of monotreme lactation and placentation, we can understand how and when mammals came to possess their reproductive qualities. We are currently researching the evolution, expression, and function of a range of placenta and mammary gland genes in the platypus and echidna using a combination of bioinformatics and wet-lab techniques.
THE ROLE OF PIRNA PATHWAY GENES IN OVARIAN AND PROSTATE CANCER
piRNA, a relatively recently discovered group of small non-coding RNA, has caught the eye of researchers worldwide as a potential cancer biomarker. Research to uncover its functions and the genes involved in its biogenesis is ongoing. We aim to unveil the effects of piRNA pathway genes on key molecular characteristics and metastatic potential of cancer.
Ovarian cancer is the most lethal gynaecological malignancy while prostate cancer ranks one of the most commonly diagnosed cancer in men. Together, they affect the lives of millions of people worldwide. While the effects of the piRNA pathway genes have been more broadly covered in many cancers, there are limited studies on their effects in ovarian and prostate cancer.
Ovarian cancer is the most lethal gynaecological malignancy while prostate cancer ranks one of the most commonly diagnosed cancer in men. Together, they affect the lives of millions of people worldwide. While the effects of the piRNA pathway genes have been more broadly covered in many cancers, there are limited studies on their effects in ovarian and prostate cancer.
THE ROLE AND EVOLUTION OF LONG NON-CODING RNAS IN MONOTREMES
Long non-coding RNAs (lncRNAs) are highly expressed in mammalian testis and they are likely to be involved in spermatogenesis. To understand the roles of lncRNAs in mammalian reproduction, it is important to study their expressions in the most basal clade of living mammals, monotremes. Monotremes have a fascinating reproductive system and studies show that there is a global transcriptional repression during spermatogenesis in monotremes. We are working to identify monotreme testis-specific lncRNAs by utilizing the monotreme genome assemblies and a comprehensive transcriptome dataset using bioinformatics approaches. Additionally, we are investigating the functions of lncRNAs in gene regulation during spermatogenesis in monotremes.
