Comments on the Natural Expression and Artificial Extraction of Venom Gland Components from Spiders

Abstract

Milking or gland extraction can be used to harvest mRNA, toxins, and other materials from spiders that are suitable for a wide variety of studies, but the milked venom and extracts should not be assumed to be equivalent to naturally expressed venoms injected into insects. A much better understanding of the diverse anatomies, physiologies, and dispersion mechanisms is required for this understanding.

Venom regeneration in the centipede Scolopendra polymorpha: evidence for asynchronous venom component synthesis

“…Third, electrical milking may damage the venom glands or venom gland musculature, as proposed by other investigators. Among spiders, Argiope bruennichi failed to yield venom after a single milking (Friedel and Nentwig, 1989), and volume yield declined with additional milkings of Agelenopsis aperta (Kristensen, 2005). Sissom et al (1990) suggested that scorpions can only be milked, on average, four times before the muscles of the gland stop responding to electrical stimulation.…”

“…Thus, further testing would be necessary to better understand how toxicity changes during venom regeneration. Even so, protein content of venom can vary with extraction method (Mackessy, 2002;Brochetto-Braga et al, 2006;Oukkache et al, 2013), and venom elicited by electrical milking cannot be assumed to be identical in composition to that used during natural prey capture or defense (Kristensen, 2005).…”