Nucleotide sequence of phospholipase A2 gene expressed in snake pancreas reveals the molecular evolution of toxic phospholipase A2 genes

Snake fangs from the Lower Miocene of Germany: evolutionary stability of perfect weapons

“…This comprises also a specialized venom gland producing a complex mixture of toxic and enzymatically active proteins, which is perfectly suited to subdue, kill, and help digest prey, and which is also used for defense. These snake venom components had been recruited from multiple protein families like phospholipases A 2 and proteases or had been modified from existing salivary proteins (Fry 2005;Fujimi et al 2002;Kochva 1987, Kochva et al 1983. They became toxic proteins like neurotoxins, cytotoxins, inhibitors, hemorrhagins, or clotting enzymes and may have coevolved with a refined venom-delivery system, particularly with the development of the injection device, the fangs.…”

Structural Characteristics and Evolution of theProtobothrops elegansPancreatic Phospholipase A2Gene in Contrast with Those ofProtobothropsGenus Venom Phospholipase A2Genes

“…1) similarly to the L. semifaciata group IB pancreatic PLA 2 gene 30) and the group IA venom PLA 2 gene. 31) In Fig.…”

“…A 9,846-nt sequence encoding the L. semifasciata group IB pancreatic PLA 2 gene, designated LsPLA2GL16-1, was obtained by combining its gene sequence 30) and its promoter sequence. 33) A 8,279-nt sequence encoding the L. semifasciata group IA venom PLA 2 gene, designated LsPLA2GL1-1, was obtained by combining its gene sequence 31) and its promoter sequence.…”

“…RT-PCR for first-strand cDNA from the P. elegans pancreas with primers PPP20 and PPP21, which gave a 512-nt product, was conducted under the conditions described above, but with three different cycle, 25 (i), 30 (ii), and 35 cycles (iii). Relative signal intensities were assessed by Image J and were normalized relative to that of -actin mRNA (iv).…”

“…In addition, pancreatic PLA 2 s from Homo sapiens, 27) Mus muscurus, 28) Canis familiaris 29) are perhaps present as singlecopy genes. cDNA and gene encoding group IB pancreatic PLA 2 have been cloned from Laticauda semifasciata (Elapinae), 30) together with those of group IA venom PLA 2 . 31) On the other hand, the pancreatic PLA 2 s of Crotalinae snakes, which contain group II PLA 2 s in the venom, have not been investigated to date.…”