Latest Articles

Discovery of a new approach to fertility preservation in women undergoing treatment for cancer

Survival rates for many common cancers now exceed 80%, and there are an estimated 14 million female cancer survivors world-wide. Unfortunately, one of the major side effects of cancer treatment in women is infertility and premature menopause. This is because cancer treatments cause DNA damage in cells other than just the cancerous cells. Oocytes (eggs) are extremely sensitive to DNA damage and kill themselves via a process known as apoptosis, presumably to prevent genetic mutations to be passed onto the next generation.

Researchers in Dr Karla Hutt’s Ovarian Biology lab at the Monash Biomedicine Discovery Institute have found that when the oocytes are prevented from killing themselves they are able to accurately repair the damaged DNA. These animals can be treated with radiation yet produce healthy offspring without any genetic mutations or health issues. This study provides a fundamental step towards developing a truly effective fertility preservation strategy for female cancer patients and has important implications for prolonging women’s fertile lifespan.

Read more here.

Identification of a new mechanism that could underly disorders of foetal testis development

It is well known that perturbations to testis development in foetal life can underpin certain reproductive disorders in males, such as infertility, hypospadias, cryptorchidism and testicular cancer.

New research from the Hudson Institute of Medical Research has discovered a new mechanism in foetal testis development that could be vulnerable to environmental disturbances and could, in turn, have long lasting impacts on male health and fertility.

Previous research has shown that the protein activin A is required for the normal development of the seminiferous cords, the structures in the foetal testis that will eventually become the site of sperm production in the adult. Alterations in activin A can disturb the balance between the gonocytes (the foetal germ cells that will ultimately differentiate into sperm) and the somatic cells that support sperm production, leading to infertility.

Research by Kate Loveland’s group at the Centre for Reproductive Health has now revealed that alterations in activin A impact on the production of androgen within the testis and that this could be a key reason why the testis develops abnormally. Androgens are essential for male development, yet alterations in activin A caused important changes in the amount and type of androgens produced in the foetal testis.

This is important because circulating activin A can be altered by various conditions in pregnant women, including preeclampsia, infection or exposure to certain medications. This work suggests exposure to certain conditions during pregnancy could alter activin A at a key stage of testis development, and this could result in androgen imbalance and disorders of reproduction.  

See the article here

An extraordinary lizard that lays eggs and gives birth – watching evolution in action

The transition from egg-laying (oviparity) to live-bearing (viviparity) represents a key evolutionary innovation that has arisen multiple times across a range of animal groups. The evolution of viviparity is significant because it has enabled several vertebrate groups to become highly successful in exploiting novel environmental conditions. Understanding how viviparity evolves is a question that is linked to the evolution of biological diversity itself and, not surprisingly, has been the focus of considerable research interest.  A new study has now shed light on the possible genetic mechanisms underpinning the evolution of viviparity.

New work by a team of researchers from the University of Sydney has capitalised on the extraordinary reproductive biology of the three-toed skink, a small native lizard that exhibits geographic variation in reproductive mode.

While some skink populations are viviparous, others are oviparous. However, oviparity in three toed skinks is atypical and may represent an intermediate form between ‘true’ oviparity and viviparity. This is because, in contrast to the more conventional oviparity seen in other lizards, oviparous three toed skinks have a long egg retention stage, such that most of the embryonic development has already occurred inside the mother before the eggs are laid.

Using a transcriptomics approach, the researchers found functional similarities between differentially expressed genes between viviparous and oviparous three toed skinks. Intriguingly, genes expressed in oviparous three toed skinks over the reproductive cycle differed from more typical oviparous lizards.

These results suggest that the oviparous mode of reproduction seen in populations of three toed skinks may, indeed, represent an intermediate form between the ancestral egg laying state and live birth.  Importantly, they offer important insights into the genetic changes that may have given rise to viviparity.      

The paper was published in Molecular Ecology.

New strategies to improve reproductive success in Australian livestock

Australia is the World’s largest exporter of sheep meat and the third largest exporter of beef, with the red meat industry contributing billions of dollars to the national economy. The international market for both products is growing despite serious challenges within the Australian livestock industry, including drought and feed restriction, and now flood and bushfires.

These factors all combine to create an acute need for strategies to rapidly increase herd/flock size. Assisted reproduction technologies (ART) have the potential to do this and, when combined with genetic selection strategies, improvements in the quality of the herd and its ability to withstand external challenges can be achieved at the same time.

A recent review by Australian researchers provides a timely reminder of why, and how, knowledge of animal reproduction is being harnessed to optimise calving/lambing rates.

Much research has gone into improving the ART technologies themselves, leading to increased efficiency and decreased costs. However, the transfer of an ART-generated embryo to a recipient cow or ewe is another major determinant of the effectiveness of ART. The ability of a recipient to establish and maintain a pregnancy is a key factor in breeding success, and the major cause of reproductive loss is failure to maintain a pregnancy. The authors highlight that improvements in the selection and management of recipient animals could play a major role in increasing productivity in Australian livestock industries.

Australian researchers investigate whether supplements can improve egg quality and fertility in women

Oocyte (egg) quality has a major influence on female fertility and pregnancy outcomes, and scientists are trying to find ways to improve or preserve oocyte quality in women. Two recent papers from Australian researchers have addressed whether a particular supplement, nicotinamide mononucleotide, or NMN, can improve egg quality in women.

One study focussed on testing whether NMN could prevent the loss of eggs by women undergoing treatment for cancer. Cancer treatments, such as radiation and chemotherapy, cause the loss of the ovarian follicles (primordial follicles) that contain the oocytes, leading to ovarian insufficiency and premature menopause. The authors hypothesized that treatment of young mice with NMN, a precursor of the well-known cofactor NAD+, would protect their eggs from the cancer therapies. Unfortunately, intraperitoneal administration of NMN could not protect oocytes from either radiation or a chemotherapy agent under the experimental conditions used. It is likely that one action of cancer therapies is to inflict DNA damage in the eggs, so unless the damage is repaired quickly, the egg will die. The authors suggest that further research should investigate whether different NMN formulations could protect against DNA damage in oocytes during cancer treatment.

Another study addressed the problem of declining egg quality with ageing, an important problem as many women wish to fall pregnant later in life when their oocyte number and quality is rapidly declining. The authors showed that treating old mice with NMN in the drinking water could restore egg quality and subsequent fertility, and that this was recapitulated by treating eggs recovered from old mice in vitro. This exciting finding suggests that NMN supplementation could be a promising approach to preserve fertility in older women, but independent verification will be required. The authors caution against the immediate use of NMN supplements by patients until further research establishes how this treatment actually works.  

Could chlamydia be a silent cause of infertility in men?

Chlamydia is the most common sexually transmitted infection in Australia, however many people who have been exposed to the virus will have no symptoms and will be unaware of their infection. Chlamydia infection in women is linked to infertility, but whether chlamydia causes infertility in men is unknown.

Researchers in Australia have now found active chlamydia infection shows a surprisingly high prevalence in testis biopsies from infertile men. Although this research cannot reveal a causal link between chlamydia infection and human male infertility, studies in mice suggest that chlamydia infection in the testis can directly impair sperm production.

More research is urgently needed to establish whether chlamydia is a potentially preventable cause of human male infertility.

How contraception could improve human welfare, the environment and the climate

A commentary from US scientists entitled Climate Change and Contraception is a timely reminder of how research in reproduction could have wide-ranging implications for our planet and for our ability to tackle climate change.

The article, published in BMJ Sexual & Reproductive Health, highlights the urgent need for other approaches to reduce greenhouse gas emissions – and one approach that has been “largely overlooked by the international climate community” is contraception.

Because population growth is a key driver of climate change, the authors argue that improving universal access to contraception in both men and women would reduce millions of unintended pregnancies and births, increase the ability of couples to plan their families and slow population growth. And slower population growth in the future could lead to significant reductions in global emissions.

To achieve this, the authors argue that there needs to be more investment in family planning programmes in developing countries, wider distribution of contraceptives already on the market, and more research and development of improved and/or novel contraceptives in both men and women.

The authors conclude that improved access to contraception worldwide “would have a profound positive impact on human welfare, the climate and the environment”.

Read the commentary here

Australian researchers develop evidence-based online tool to support breastfeeding

Lactation is the final phase of the reproductive cycle. While 96% of Australian women initiate breastfeeding, most are unable to sustain it for the minimum recommended duration.

Women often receive conflicting advice that can have a negative impact on their ability to initiate and sustain breastfeeding. Therefore, an important strategy to improve lactation rates is the education of health professionals so that they can better support women during breastfeeding.

Australian scientists have now developed the online tool LactaMap to deliver evidence-based support to doctors and other healthcare professionals. This enables breastfeeding women to have access to consistent and high-quality advice during an important period in their baby’s development.  

Medical practitioners utilise LactaMap’s clinical practice guidelines to develop a personal care plan for their patient. LactaMap can be accessed for free by medical practitioners as well as the general public.

Read more here

How reproductive technologies are being harnessed to produce “ethical eggs”

Every year, approximately 7 billion male chickens are slaughtered when they are a day old. Apart from obviously not being able to produce eggs, male chickens grow too slowly to be used for meat production. After they hatch, males are manually identified and destined for slaughter.

But now new reproductive technologies are focussing on identifying male-bearing eggs soon after fertilisation. Different technologies being developed around the world, including Australia, can detect male-bearing eggs well before they hatch. Instead of hatching, these eggs can be frozen before a mature chick develops and can then be sold for use in other industries.

This is an amazing example of how reproductive technology can be harnessed for ethical agriculture practice and to improve economic outcomes. Read more here.

Could a supplement improve IVF success rates in older women?

As women age, the number and quality of their eggs (oocytes) rapidly declines. Poorer oocyte quality is a major factor in lower IVF success rates in older women. However, Australian scientists have discovered that a dietary supplement improves oocyte quality, embryo development and fertility outcomes in ageing female mice.

This research has been published online  and, although it has not yet been published in a peer-reviewed journal, it is generating a lot of interest amongst reproductive scientists.

Stay tuned for updates…