Seminar: Inside Fertilization: The Track of How Fish Eggs Accept, Remodel, or Reject Sperm

Titel: Inside Fertilization: The Track of How Fish Eggs Accept, Remodel, or Reject Sperm

Kurzinhalt:
What happens in the first minutes after life begins? We usually imagine fertilization as a simple moment when sperm meets egg and a new embryo forms. But inside the egg, an unexpected and highly dynamic process begins almost immediately. Sperm DNA must be unpacked, reorganized, and tested by the egg before development can continue.

In our research, we use model zebrafish and non-model hybrid loaches from the same order (Cypriniformes) to watch fertilization in real time using high-resolution microscopy. These animals reveal a surprising fact: eggs do not always treat sperm equally. Some sperm are accepted and become part of the future embryo, while others are stopped, remodelled, or even completely rejected after entering the egg.

By tracking post-translational modifications, cellular structures, and DNA organization minute by minute, we explore how eggs control the earliest stages of life and determine the fate of the sperm genome. Remarkably, some hybrid fish can even begin development using sperm without inheriting its DNA at all, creating a biological paradox: sperm is required, but fatherhood is optional.

This work combines cell biology, developmental biology, microscopy, and evolution to uncover the hidden events occurring at the very beginning of vertebrate life, a stage that remains largely invisible despite being fundamental to every sexually reproducing organism.

 

Das Seminar findet in hybrider Form statt:

• Seminarraum „Drachenwand“ 2. Stock
• Webconference UIBK-Link: https://webconference.uibk.ac.at/rooms/qc6-5hp-jl3 “Eleonora Pustovalova”