EchidnaCSI is a citizen science project that combines field ecology and molecular biology for echidna conservation.
The project aims to:
establish the first Australia wide detailed echidna distribution map. Integration of historic data and in-depth analysis in specific areas (e.g. revegetated, agricultural and urbanised) will provide valuable information about variation in echidna numbers and how they are affected by our changing environment.
utilise the collection and molecular analysis of echidna scat samples from captive and wild populations to provide novel insight into fundamental aspects of echidna biology (e.g. diet, stress, breeding) and their role in natural or cultivated environments.
use EchidnaCSI as an outreach and engagement platform via traditional (media, seminars, flyers, videos) and social (e.g. phone app, Facebook, Twitter, email) media to educate and enthuse the community about biodiversity, environmental awareness and the value of interdisciplinary research for application in conservation and animal biology, and to foster change in behaviour to help protect and preserve biodiversity.
The project has now been running for a year and we have more than 5000 users with over 2800 sightings recorded and 200 scats sent in. This provides interested students to do projects on the data and molecular analysis of these unique samples.
The platypus genome was published in 2008 and provided fundamental new information about monotreme biology and mammalian evolution. The echidna genome has been sequenced and we are part of a small international team helping with the assembly and carrying out analysis on the genome for the Echidna genome publication (which will also feature a much improved Platypus genome). This is a great opportunity for students to take part in an international collaboration, which will provide the first echidna genome assembly and carries out analysis of the echidna genome to better understand the fascinating biology of these animals.
Sex determination is one of the most puzzling aspects of monotreme biology. They have an extraordinary complex sex chromosomes system that consists of ten sex chromosomes in platypus and nine in echidna. In contrast to sex chromosomes in other mammals, platypus sex chromosomes show extensive homology to bird sex chromosomes.
In addition the mammalian sex determining gene SRY is missing in platypus. We are investigating candidate sex determining genes (know mammalian sex determination genes) and we are identifying and characterising new genes on the Y specific parts of the five Y chromosomes in platypus to get insight into how sex is determined in these animals. This will also potentially identify new sex determination and spermatogenesis genes in other mammals including humans.
Monotremes feature an extraordinarily complex sex chromosome system that consists of 5X and 5Y chromosomes in platypus and 5X and 4Y chromosomes in echidna. At the first meiotic division the ten sex chromosomes in male platypus (nine in echidna) assemble into a sex chromosomes chain. Over the past five years we have been able to identify these sex chromosomes and show how they are arranged in the chain. We have also shown how they commence pairing in prophase I, how they segregate at anaphase I, and where they reside in mature sperm. Our current work investigates the composition of the synaptonemal complex (formed by proteins that hold chromosomes together at meiosis I). We also investigate if the monotreme sex chromosome complex undergoes sex chromosome inactivation as in other mammals. In addition, we investigate the pattern of meiotic recombination on monotreme sex chromosomes.
In mammals a sex chromosome system has evolved where males have one X chromosome and a very gene poor Y chromosome and females have two copies of the X chromosome. This means females have two copies of many X-linked genes while males have only one copy. In order to compensate for the difference in gene dosage in females one X chromosome is inactivated in all somatic cells. This inactivation is initiated through expression of the Xist gene from the inactive X. In addition, epigenetic modifications such as DNA methylation, histone deacetylation and histone variants like macroH2A play an important role in the transcriptional silencing of one of the X chromosomes.
It has recently been shown that the Xist gene has evolved only recently in the eutherian lineage. So far nothing is known about dosage compensation and X inactivation in monotremes but it is particularly interesting to investigate this in monotremes as they feature five pairs of X chromosomes in females and in males one copy of each of these X chromosomes and five Y chromosomes in platypus and four Y chromosomes in echidna. We investigate if X inactivation occurs by combination of immunostaining with antibodies and fluorescence in situ hybridisation with X-specific DNA probes on fibroblast cell lines and western blotting to detect epigenetic changes on the X chromosomes in females. This will reveal whether or not dosage compensation and X inactivation occurs in female monotremes.