🔬 Egg-Laying Mystery Solved: The Gene That Makes Platypuses & Echidnas Unique! 🦆🐾

For decades, scientists knew Australia’s egg-laying mammals—platypuses & echidnas—defy mammalian norms in sex determination. Now, we’ve cracked their genetic secret!

🧬 The Breakthrough:
A new study in Genome Biology reveals that a single gene (AMHY)—more like those in fish & amphibians—controls sex in monotremes, not the usual SRY gene found in other mammals.

🐣 Why It’s Wild:

• Monotremes split from other mammals 175 million years ago, evolving a reptile-like sex chromosome system (multiple X/Y pairs).

• AMHY, a hormone gene on their Y chromosome, triggers male development—a first for mammals!

🔎 How We Found It:

• Decoding platypus & echidna genomes revealed AMHY’s role in testis formation.

• Unlike typical sex genes (which act on DNA), AMHY works like a hormone, signaling cells directly—similar to some fish!

🌍 What’s Next?
Researchers are now studying how AMHX & AMHY evolved differently in monotremes vs. other mammals. Could this rewrite how we understand sex determination?

📖 Read the full study: [ University of Adelaide, the University of Melbourne, the University of Queensland, Monash University and Currumbin Wildlife Sanctuary]
#Evolution #Genetics #Platypus #Echidna #ScienceNews #WildlifeBiology #Australia