Studies on newt sex-attractant

人们普遍认为，在求偶期间，雄性蝾螈利用化学线索吸引性发育的雌性。在红腹蝾螈（Cynops pyrrhogaster）中，性成熟的雌性会被性活跃的雄性蝾螈所在的水中所吸引，但不会被腹部腺体切除的雄性蝾螈所吸引，这表明吸引雌性的信息素是由腹部腺体分泌的。已经尝试从性成熟雄性蝾螈的腹部腺体中分离和表征这种信息素。近年来，人们发现雌性吸引信息素是一种氨基酸序列为Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys的十肽。该肽与已知肽序列无同源性。因此，这种新型肽被命名为sodefrin。在本研究中，为了揭示sodefrin在红腹水螈腹腺中的定位，并开发一种特异性的测量sodefrin的放射免疫测定系统，我们在兔子体内注射了sodefrin，该sodefrin在其cooh末端与Cys偶联到锁眼帽贝血青素，从而产生了一种抗sodefrin的抗血清。用免疫荧光法检测抗血清染色的腹腔腺冰冻切片显示，上皮细胞顶区对sodefrin呈阳性反应。用过量的sodefrin预吸附的抗血清染色的切片降低了免疫荧光，表明抗血清特异性识别组织中的sodefrin。用sodefrin抗血清和金颗粒标记的山羊抗兔IgG作为第二抗体对腹腔腺进行免疫电镜观察。金颗粒主要分布在分泌颗粒上，说明sodefrin是由腹腔腺上皮细胞分泌的。此外，经证实，将水置于抗sodefrin柱中，雌性吸引活性显着降低。将雄性水与正常兔IgG柱接触得到的未吸附部分显示出与未处理水相近的活性。这表明sodefrin是雄性水中主要的吸引雌性的物质。少

It has been well accepted that during courtship, male newts attract sexually developed females using chemical cues. In the red-bellied newt, Cynops pyrrhogaster, sexually mature females are attracted to water in which sexually active male newts have been kept, but not to water in which abdominal gland-ablated male newts have been kept, indicating that the female-attracting pheromone is secreted by the abdominal gland. An attempt has been made to isolate and characterize this pheromone from the abdominal glands of sexually mature male newts. Recently, female-attracting pheromone was revealed to be a decapeptide with the amino acid sequence Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys. The peptide showed no sequence homology with any known peptide. Thus the novel peptide was designated sodefrin. In this study, to reveal the localization of sodefrin in the abdominal gland of the red-bellied newt and to develop a specific radioimmunoassay system for the measurement of sodefrin, we generated an … More antiserum against sodefrin in a rabbit by injecting sodefrin that was extended on its COOH-terminus with Cys coupled to keyhole limpet hemocyanin. Frozen sections of abdominal glands stained with the antiserum to sodefrin by immunofluorescenece showed that the apical region of the epithelial cells was positive for sodefrin. Staining of sections with the antiserum preadsorbed with an excess amount of sodefrin reduced the immunofluorescenece, indicating that the antiserum specifically recognizes sodefrin in the tissue. An immunoelectron microscopic study of the abdominal gland was performed using sodefrin antiserum and goat anti-rabbit IgG labeled with gold particles as a second antibody. The gold particles were distributed mainly on the secretory granules, indicating clearly that sodefrin is secreted by the epithelial cells of the abdominal gland. Furthermore, it was confirmed that female-attracting activity was markedly reduced by subjecting the water to an anti-sodefrin column. The unadsorbed fraction obtained by subjecting the male water to a normal rabbit IgG column exhibited its activity that was close to the activity of the untreated water. This indicates that sodefrin is the major female-attracting substance in the male water. Less