In the beginning: egg-microbe interactions and consequences for animal hosts.

Area of Science:

• Microbiology
• Evolutionary Biology
• Developmental Biology

Background:

• Microorganisms associate with animal eggs, influencing host biology.
• Eggs are vulnerable to pathogens and biofouling, especially in aquatic environments.
• Egg microbiomes can facilitate vertical symbiont transmission or act as parasites.

Purpose of the Study:

• To review the diverse functions of egg-associated microbiomes.
• To explore how these microbial associations impact animal host biology and evolution.
• To highlight the mechanisms underlying beneficial egg microbiome functions.

Main Methods:

• Literature review of existing research on egg microbiomes.
• Synthesis of findings on microbial roles in egg protection and development.
• Analysis of evolutionary implications of host-microbe interactions at the egg stage.

Main Results:

• Egg microbiomes provide essential functions, including pathogen inhibition and nutrient acquisition.
• Beneficial associations enhance host fitness and are critical for successful development.
• Mechanisms driving these positive outcomes often require further investigation.

Conclusions:

• Egg microbiomes play a significant role in animal reproduction and evolution.
• Understanding these associations is key to comprehending host-microbe co-evolution.
• Further research is needed to elucidate the precise mechanisms of microbiome-mediated benefits.