Cynops pyrrhogaster

One well-analysed chemosignal system is that of the Red-bellied Newt (Cynops pyrrhogaster). Males of this species produce from the abdominal gland a semiochemical protein (sodefrin) with marked VNO activity as a female attractant (Kikuyama et al., 1997). Courtship displays of newts often contain tail-waving bouts, which direct cloacal or other secretions from the male toward female recipients (Fig. 3.1). A large stable molecule like sodefrin, alone or as part of a VNPr complex, is presumably suitable for such local transference. 

Jones F., Pfeiffer C. and Asashima M. (1994). Ultrastructure of the olfactory organ of the newt, Cynops pyrrhogaster. Ann Anat 176, 269-275. 

Toyoda F. and Kikuyama S. (2000). Hormonal influence on the olfactory response to a female-attracting pheromone, sodefrin, in the newt, Cynops pyrrhogaste. Comp Biochem Physiol [B] 126, 239-245. 

Red-bellied newt Cynops pyrrhogaster Male Abdominal gland (cloaca) Attracts female Sodefrin (decapeptide) Kikuyama etal, 1995... 

Male red-bellied newts, Cynops pyrrhogaster (Salamandridae), attract females with a pheromone that is released into the water from epithelial cells of the abdominal gland of the cloaca. A decapeptide called sodefrin (Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys) is the first amphibian pheromone with female-attracting properties ever chemically identified (Kikuyama etal., 1995). Silefrin in the related sword-tailed newt, Cynops ensicauda, is a similar decapeptide and differs from sodefrin in only two amino acid residues (Yamamoto et al, 2000) (Table 7.3). 

F. Toyoda Y. Hayakawa M. Ichikawa S. Kikuyama, Olfactory Responses to a Female Attracting Pheromone in the Newt, Cynops pyrrhogaster. In Advances in Chemical Signals in Vertebrates R. E. Johnston, D. Muller-Schwarze, P. W. Sorensen, Eds. Kluwer Press, Plenum New York, 1999 pp 607-615. 

Sodefrins, peptide pheromones from the red-bellied newt. The 10-peptide H-Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys -OH was first isolated from the abdominal gland of the male newt Cynops pyrrhogaster, while [Leu, Gln ]sodefrin occurs in C. ensicauda. The sodefrins are potent conspecific female-attracting pheromones, and act primarily on the lateral nasal sinus cells [S. Kikuyama et al.. Science 1995, 267,1643 T. Nakada et al.. Front. Neuroendicrinol. 2006, 27,149]. 

Tsuruda, K., Arakawa, O., and Noguchi, T. 2001. Toxicity and toxin properties of the newt Cynops pyrrhogaster collected from the western Japan. J. Nat. Toxins 10, 79-89. 

Amphibian pheromones have been previously isolated fh>m newt and salamander species, however, this peptide, which we have named splendipherin, is the first pheromone isolated fiom any anuran species. The delivery method of those previously isolated amphibian species are very clear. Sodefiin, the ten-residue peptide pheromone of Cynops pyrrhogaster and silefiin, the ten residue peptide pheromone of Cynops ensicauda are both sent through the water by the male newts by a vigorous shaking movement of the tail (Kikuyama et al., 1995 Yamamoto et al., 2000). The 20 kDa proteinaceous male courtship pheromone of Plethodon jordani is applied to the female s sldn by direct contact (Rollman et al., 1999). 

Toyoda, F., Hayakawa, Y., Ichikawa, M., and Kikuyama, S., 1999, Olfactory responses to a female-attracting pheromone in the newt, Cynops pyrrhogaster, in R. E. Johnston, D. Mflller-Schwarze, and P. W. Sorensen, eds., Advances in Chemical Signals in Vertebrates, Kluwer Academic / Plenum, New York, pp. 607-615. 

Kikuyama, S., Toyoda, F., Ohmiya, Y, Tanaka, S., Matsuda, K. Hayashi, H. 1995b. A sex-attractant in the cloacal gland of the newt, Cynops pyrrhogaster. Neth. J. Zool, 45, 169-162. 

Recently we have found a novel female-attracting peptide pheromone, sodefrin, in the abdominal glands of Cynops pyrrhogaster males (Kikuyama, Toyoda, Ohmiya, Mat-suda, Tanaka Hayashi, 1995). In this article, we review the isolation, characterization, and localization of this pheromone, as well as the hormonal control of its secretion and the possible existence of a precursor pheromone. A variant type of pheromone in a congeneric species (C ensicaudd) will also be a topic in this article. 

The presence of a chemical attractant from the female Cynops pyrrhogaster has been suggested by the observation that many males swarm about a single sexually developed... 

Kikuyama, S., Seshimo, H., Shirama, K., Kato, T. and Noumura, T. 1986. Interaction of prolactin with sex steroid in oviduct and tail of newts, Cynops pyrrhogaster. Zool. Sci. 3, 131—138. 

Matsumoto, A., Arai, Y, Toyoda, F., Kikuyama, S. Prins, G.S. 1996. Immunohistochemical analysis of androgen receptor in the abdominal glands of the cloaca of male red-bellied newts, Cynops pyrrhogaster. Zool. Sci. 13, 429-433. 

Toyoda, F., Ito, M., Tanaka, S. Kikuyama, S. 1993. Hormonal induction of male courtship behavior in the Japanese newt, Cynops pyrrhogaster. Horm. Behav. 27, 511—522. 

OLFACTORY RESPONSES TO A FEMALE-ATTRACTING PHEROMONE IN THE NEWT, CYNOPS PYRRHOGASTER... 

Figure 1. A transverse section of nasal cavity of an adult female red-bellied newt, Cynops pyrrhogaster. The head region was fixed in Bouin s solution, cut in paraffin at 10pm and stained with Azan. (a) Main chamber of nasal cavity (NC) and lateral diverticulum (LD). Bar is 250 pm. (b) Floor of the nasal cavity lined with sensory epithelium (SE) and non-sensory epithelium (NSE). The sensory area is interspaced with non-sensory epithelial bands. Bar is 40 pm. (c) Lateral diverticulum lined with vomeronasal epithelium (VNE). Bar is 40 pm.

A newt pheromone, sodefrin, has been isolated from the abdominal gland of the male Cynops pyrrhogaster. It is a decapeptide that has a potent activity in attracting con-specific females (Kikuyama et al, 1995). Sexually undeveloped female newts do not respond to the pheromone. Treatment of these newts with prolactin (PRL) and gonadotropin makes them responsive to the pheromone. The attraction to sodefrin of hormone-treated newts was completely abolished by bilateral nostril plugging and was restored by the removal of the plugs (Toyoda, Hayashi, Ohmiya, Tanaka, Mochida, Matsuda, Kikuyama,... 

Tanaka, S. Takikawa, H. 1983. Seasonal changes in plasma testosterone and 5a-dihydrotestosterone levels in the adult male newt, Cynops pyrrhogaster pyrrhogaster. Endocrinol. Japon 30, 1—6. 

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