QLS Seminar *CHANGE OF TIME* - Friday, 15 May at 13h30 "Model of Sperm–Oocyte Penetration Mechanisms" by Andjelka Hedrih MISASA, Belgrade, Serbia

[Quantitative Life Sciences]

Dear All,

On Friday, 15 May at 13:30 CET,  Andjelka Hedrih (Mathematical Institute 
of the Serbian Academy of Sciences and Arts, Belgrade, Serbia) will give 
a seminar titled:

*"Model of Sperm–Oocyte Penetration Mechanisms"
_
_ *_Abstract:_

Existing theories of sperm–oocyte penetration can be classified into 
three main categories: biochemical receptor–mediated mechanisms, maximum 
normal stress–based penetration, and oscillatory relaxation mechanisms. 
Previous mechanical probing studies of zona pellucida (ZP) demonstrate 
increased structural resistance under higher perpendicular loading, 
implying that penetration is favored along directions of reduced 
mechanical resistance. Experimental observations indicate that sperm 
penetration of the ZP follows an oblique trajectory. Motivated by these 
findings, a modified mechanical model of ZP deformation is proposed to 
quantify normal and shear stresses generated during plastic sperm–oocyte 
collision. Numerical simulations were conducted for three distinct sperm 
distribution scenarios over the ZP surface. The results show 
time-dependent oscillations of both normal and shear stresses, with 
normal stress consistently exceeding shear stress across all scenarios. 
The observed stress fluctuations may contribute to oscillatory states of 
the ZP and could play a significant role in the mechanical mechanism of 
sperm penetration. The theory of phase transition of ZP as a potential 
mechanism of sperm penetration will be discussed.

Indico: https://indico.ictp.it/event/11352/

The seminar will take place in the Common Area, 2nd floor, old SISSA 
building (Via Beirut, 2).

You are all most welcome to attend!

Best regards,

Erica

Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-22404623 (NEW PHONE NUMBER)
www.ictp.it/research/qls.aspx
e-mail:qls at ictp.it