LAB NEWS

2021 marked the end of the first full year for the EvoGenomics lab at Macquarie, and what a year it was. We had some notable new additions, including:

 

  • Dr Jessica Dudley who started as a postdoc trying to understand the maternal-fetal interface in marsupials. Jess brings an incredible understanding of marsupial reproduction and some amazing microscopy and molecular skills.

 

  • Raani Kumeran started as a short term research assistant over summer and ended up seeing us through the whole year. The end of 2021 brought her some good news too, when she was offered a place at Usyd to study to become a vet.

 

  • Jinglin Wen was offered a place as a PhD student and joined the lab in early 2022.

 

We had some exciting papers published, which involved some awesome collaborators, both in Australia and overseas. Furthermore, we were successful in obtaining funding to begin some new research projects that we hope to report on soon.

 

We also began to establish some important research programs for the lab. This started with the founding of a Macquarie fat-tailed dunnart colony. These animals were sourced from Prof. Fritz Geiser and Assoc. Prof. Bronwyn McAllen. Once the animals had settled in they began to breed in captivity, and our humble colony has now exploded with new young.

 

Another exciting opportunity came through support from the Australia Amphibian and Reptile Genomics (AusARG) initiative. We sequenced the genomes of 3 skinks (the delicate skink, Southern grass skink, and the three toed skink) as well as the green and gold bell frog. These resources will provide us with new opportunities to answer cutting edge questions in animal evolution and conservation.

 

Thanks to everyone who has supported the lab in 2021 and we are excited to continue the fun in 2022 and beyond.

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New work published in the Proceedings of the Royal Society B, where we discovered that maternal recognition of pregnancy is widespread in marsupials, and may be ancestral to live bearing mammals. Checkout a summary of the finding and its implications in The Conversation.

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New paper published in PLoS Biology, lead by collaborators Eric Erkenbrack & Günter Wagner. By comparing endometrial cells of eutherian and marsupial mammals we show that a new cell type evolved in eutherians by re-wiring the gene-regulatory network of a cellular stress response. This exciting discovery provides a new mechanism that can explain the evolution and origin of new cell types.

Our research on the inflammatory nature of implantation was recently featured in Nature and Science. These articles were based on the recent paper in PNAS and the new discoveries by Yale graduate student Arun Chavan

In a series of letters published in PNAS, Ji-Long Liu of South China Agricultural University, my colleagues, and I discuss why inflammation and implantation are linked. Specifically, Dr. Liu argues that inflammation is used by the trophoblast to support invasion, and evolved through mimicry of the leukocyte–endothelium interaction. Whereas my colleagues and I argue that inflammation had a role in pregnancy prior to the origin of invasive placentation and that inflammation at implantation is a consequence of the maternal fetal interactions which occurred following the evolution of pregnancy. This inflammatory maternal-fetal interaction is something we observed in opossum earlier this year

Next stop Melbourne 

I am excited to announce that in 2018 I will be taking up a Discovery Early Career Research Award at the University of Melbourne.  Funded by the Australian Research Council, I will be investigating the role of maternal fetal signalling in the evolution of vertebrate pregnancy. This research will bring together my interests in herpetology, my experience as a member of Yale's Systems Biology Institute, and my passion to understand the evolution of pregnancy in vertebrates.

In my latest publication, colleagues at Yale University, collaborators at the NICHD and I study opossums to understand the reproductive biology of the first live bearing mammals. This research, published in the Proceedings of the National Academy of Sciences, demonstrated that embryo implantation, in humans, evolved from an inflammatory reaction which is still present in the opossum. The research provides a new paradigm for understanding implantation, and the role of inflammation in implantation success.

Read my public interest summary of our recent discoveries on the evolution of embryo implantation.

Read my public science article which explains how research into the evolution of the placenta is helping us understand how complex organs evolve in animals. 

Check out my latest paper with colleague Günter Wagner in Nature Ecology and Evolution. In this paper we argue that the placenta is an outstanding model to understand the origin and evolution of organs in vertebrates. We discuss the current molecular and genomic understanding of placenta evolution in fish, reptiles, and mammals and identify that the mere act of apposing maternal and fetal tissues results in new placental signalling networks. In this paper we argue that this mechanism for the evolution of new tissue signalling networks might be a key process that supports the evolution of new organs more broadly in animals. 

The latest paper on the evolution of pregnancy in reptiles has come out in Genome Biology and Evolution! In this paper we show that the evolution of pregnancy in reptiles occured following substantial changes to gene expression, and the evolution of a new pregnancy specific transcriptional state. 

My images of Southern grass skink embryos were featured on the cover of the Journal of Experimental Zoology Part B. This issue of the journal was dedicated to understanding viviparity 

Pregnancy although beautiful is not always cooperative. Some of my recent research was highlighted in an article I wrote for the conversation, where I discuss how the placenta is the product of an ongoing battle between mother and child.

New paper published in General and Comparative Endocrinology. We show that many hormone genes are expressed in the chorioallantoic membrane of egg laying reptiles, and this hormonal expression has been retained during the evolution of viviparity in amniotes. 

New paper published in Development Genes and Evolution. We show that mammalian imprinted genes are not imprinted in a placental reptile, suggesting fundamental differences between reptile and mammalian pregnancy.

Southern grass skink giving birth. A video I filmed showing a skink giving birth to a live baby. Shortly after delivery you can see the mother eat the placental tissues. Nature doesn't let a good meal go to waste. 

Seahorse pregnancy manuscript featured in Science as editor's choice. 

Have you ever wondered why we give birth to live young rather than lay eggs? Scientists have pondered this for a long time and answers have come from an unlikely source: some of Australia’s lizards and snakes!

Reproduction in seahorses is unusual because pregnancy takes place in males, and in a unique pouch like structure at the fish's abdomen. Recent genetic studies performed as a collaboartion with Dr Camilla Whittington have shown that the genetics of pregnancy in seahorses is similar to that of reptiles and mammals. This story has got a lot of media attention, but is best summarised By Dr Whittington's article in the conversation linked below.

Ever wondered what evolutionary biologists do? In my first blog post I discuss why the study of evolutionary biology is necessary for society.