Geula Hanin

🤱 🧬 Some discoveries really do take a long gestation....

🙏 Huge thank you
This work was only possible thanks to an incredible team! thank you to all my co-authors for their insight, persistence, and patience over the many years this project took to come to life. @geneticscam.bsky.social @koulman.bsky.social @pdncambridge.bsky.social

🧬 Our work challenges the idea that mother-offspring co-adaptation is driven purely by shared environment. Instead, we provide evidence for a genetically driven co-adaptation, with ZFP57 coordinating nutritional provisioning prenatally via imprinting and postnatally via lactation.

➡️ Out take-home message:

1️⃣ Milk from the biological mother is optimally matched to the specific requirements of her offspring.
2️⃣ Early-life nutritional programming is shaped by both prenatal and postnatal epigenetic mechanisms and mismatching these environments can have lasting consequences.

🧩 A surprising twist

Milk from ZFP57-deficient mothers can partially protect these offspring from excessive adult weight gain. When the same pups are instead raised by healthy mothers, this protection is lost.

👶 But the story goes deeper

The prenatal environment also shapes outcomes.
Offspring that develop in a ZFP57-deficient pregnancy show long-lasting changes in suckling, postnatal growth trajectories and adult metabolic health.
These offspring are more prone to obesity and diabetes later in life.

🥛 Milk composition is altered

Dams lacking ZFP57 show:
• delayed lactation onset
• abnormal milk composition
• increased oxidised triglycerides
• reduced phosphatidylcholines

This altered milk attenuates offspring growth during lactation.

This points to a previously unrecognised, imprinting-independent function for ZFP57 in the postnatal period.

🔬 What we discovered

Loss of ZFP57:
• alters mammary ductal branching and epithelial cell balance
• disrupts gene expression programs linked to alveologenesis and lactation
• does not cause widespread loss of imprinting in the mammary gland

💡 The starting idea

ZFP57 controls imprinting.
Imprinting operates in the adult mammary gland (as we showed in our 2025 NAR paper).
So we asked: Could disrupting ZFP57 and therefore multiple imprinted pathways, alter postnatal resource allocation?

❓Why this matters

Lactation is central to maternal nutritional support, yet the genetic and epigenetic control of lactation and postnatal growth remains surprisingly poorly understood. Our study fills an important gap by identifying a specific epigenetic regulator linking these processes.

✨ What did we find?

Zinc finger protein 57 (ZFP57), best known as a master regulator of genomic imprinting in early development, also regulates postnatal nutritional provisioning to the offspring by shaping:
• mammary gland development
• milk composition
• offspring growth and lifelong health

🎉 After a very long one (appropriately…), I’m excited to share work revealing an unexpected role for the epigenetic regulator ZFP57 - linking development, lactation, milk composition and lifelong health.

Check it out: www.nature.com/articles/s41...
#MammaryGlandBiology #DOHaD

Designing nanomedicine to overcome therapeutic challenges in pregnancy - Nature Reviews Bioengineering Illness during pregnancy presents a therapeutic dilemma: treatment must protect the mother without compromising fetal health. Yet, most drugs remain insufficiently studied in pregnancy. Understanding pregnancy stage-specific drug pharmacokinetics and placental drug transport can guide the design of nanomedicine to optimize treatments during pregnancy.

A Comment article in Nature Reviews Bioengineering discusses how understanding pregnancy stage-specific drug pharmacokinetics and placental drug transport can guide the design of nanomedicine to optimize treatments during pregnancy. 🔒

Oestrogen changes at menopause: insights into obesity-associated breast risk and outcomes Nature Reviews Endocrinology, Published online: 02 December 2025; doi:10.1038/s41574-025-01208-7Oestrogen levels change after menopause and with weight gain above the normal BMI category, both of which can affect breast cancer risk and outcomes. This Review explores the current understanding of these associations.

New content online: Oestrogen changes at menopause: insights into obesity-associated breast risk and outcomes

Big shoutout to Boshra Alsulaiti for driving this review! @geneticscam.bsky.social

From mammary glands to nutrients: genetic insights into milk composition† This review integrates comparative perspectives on mammary gland development and lactation, highlighting genetic and epigenetic determinants that influence

🔥🤱Excited to share our new review “From Mammary Glands to Nutrients: Genetic Insights into Milk Composition”

We integrate GWAS, cross-species biology and biochemistry to reveal how maternal genetics shapes breastmilk and its essential role in mammalian life. tinyurl.com/bdevetkx

FindAPhD : PhD Opportunities in the Department of Physiology, Development and Neuroscience at University of Cambridge Apply for a PhD: PhD Opportunities in the Department of Physiology, Development and Neuroscience at University of Cambridge

If this sounds like you - send me a DM/email with your CV + transcript + a few lines on your interests. I’d be happy to discuss ideas and support a competitive application.

www.findaphd.com/phds/program...

If you’re excited by lactation biology / mammary gland development / milk composition and want to do mechanistic work in vivo, get in touch.

You’ll need:
• strong academic track record (min good 2:1 or equivalent)
• essential: hands-on molecular biology experience

Looking for a fully funded PhD in Cambridge? 🤱👩‍🔬🔬

I’m interested in hearing from strong candidates who want to apply with me to the competitive PhD funding scheme in the Department of Physiology, Development and Neuroscience @ Cambridge.

From 2006. A younger and shell-shocked looking Catherine on a balcony holding a very tiny baby with the mountains of Vancouver in the background. The baby is so new, Catherine still has the pregnant bump.

Conventional wisdom says motherhood should wait for tenure as before you land a permanent post, #academia is just not that family friendly🙁

@carersinstemm.bsky.social are calling for change and to celebrate their new report, a Saturday🧵on parenting & academia! 1/9 👩‍🔬🧪🔭⚛️

ℹ️: carersinstemm.co.uk

Looking to pursue cutting-edge research in early development, maternal-fetal interaction, or placental biology? See 👇

- Funded PhD www.trophoblast.cam.ac.uk/phd-students...
- Next Generation Fellowship www.trophoblast.cam.ac.uk/next-generat...
- MPhil www.mphil.bio.cam.ac.uk/mphil-pathwa...

A Genetic Atlas of the Mammary Gland 🧬🤱🐭

New research from @geula.bsky.social & team shows shifts in gene activity across pregnancy → lactation → weaning.

This new 'atlas' provides new avenues for studying lactation disorders and breast cancer.

academic.oup.com/nar/article/...

Dynamic allelic expression in mouse mammary glands across the adult developmental cycle Abstract. The mammary gland, which primarily develops postnatally, undergoes significant changes during pregnancy and lactation to facilitate milk producti

🔥🚨 Our new paper is finally out in @narjournal.bsky.social!
academic.oup.com/nar/article/53/17/gkaf804/8248607
We built the first comprehensive atlas of dynamic allelic expression in the mouse mammary gland across adulthood, tracking genes across virgin, #pregnancy, #lactation & #involution.
🧵

Study of breast cell changes in motherhood provides clues to breastfeeding difficulties A University of Cambridge study of adult mammary gland development has revealed new genes involved in breastfeeding, and provided insights into how genetic

Breastfeeding boosts babies' lifelong health – but 1 in 20 women struggle.

@geula.bsky.social @geneticscam.bsky.social found that 'milk squeezing' cells, rather than 'milk-producing' cells, may be to blame.

Find out how this could lead to new ways to supporting mothers 👉 bit.ly/4mTUixN

Our atlas is open & ready to explore in this link: geulahanin-mammarygland.shinyapps.io/mammary_data...
Excited to see what the community will do with it!

Big shoutout to my amazing co-authors 👏 thank you for your ideas and teamwork. A real privilege to work together on this! A special thank you to my mentor Anne Ferguson-Smith, for her guidance and support! @geneticscam.bsky.social

Why does it matter?
💡 We identify new targets for lactation failure
💡 Early risk markers for postpartum breast cancer
💡 Insight into how maternal vs paternal genes control lactation
💡 We provide a comprehensive public atlas for the community

We also find that postpartum breast cancer–associated genes are activated after weaning in a cell type often overlooked in the mammary gland, revealing early molecular signals specific to postpartum breast cancer.