A comparative study of hemocytes from six different snails: morphology and functional aspects

Area of Science:

• * Invertebrate immunology
• * Gastropod biology
• * Cellular defense mechanisms

Background:

• * Hemocytes are crucial for invertebrate immune responses.
• * Understanding snail hemocyte function is vital for disease vector control and ecological studies.
• * Previous research on snail hemocytes has been species-specific.

Purpose of the Study:

• * To comparatively analyze hemocyte morphology and function across six gastropod snail species.
• * To assess peroxidase activity and reactive oxygen intermediate generation in different snail hemocytes.
• * To investigate phagocytic stimulation responses, including superoxide generation and chemiluminescence.

Main Methods:

• * Hemocytes were isolated from six gastropod species: Achatina achatina, A. fulica, Biomphalaria glabrata, Bulinus natalensis, Helix aspersa, and Lymnaea stagnalis.
• * Morphological analysis, peroxidase activity assays, and reactive oxygen intermediate generation (using nitroblue tetrazolium reduction) were performed.
• * Luminol-dependent chemiluminescence was measured to assess phagocytic activity.

Main Results:

• * Significant variations in hemocyte numbers and microscopic morphology were observed among the species.
• * Peroxidase activity was present in most species' hemocytes, but absent in Biomphalaria glabrata and Achatina fulica.
• * All tested hemocytes generated superoxide upon stimulation with zymosan; Achatina achatina and A. fulica hemocytes exhibited luminol-dependent chemiluminescence.

Conclusions:

• * Gastropod hemocytes display diverse characteristics and functional capabilities.
• * Superoxide generation is a conserved response, but peroxidase activity and chemiluminescence vary across species.
• * These findings provide a comparative basis for understanding snail hemocyte immunity and potential differences in disease resistance.