Male Sea Lampreys, Petromyzon marinus L., Excrete a Sex Pheromone from Gill Epithelia1

Abstract

During the period when they are producing sperm, male sea lampreys (Petromyzon marinus L.) release a sex pheromone 7␣, 12␣, 24-trihydroxy-5␣-cholan-3-one-24-sulfate (3 keto-petromyzonol sulfate, 3ketoPZS) that induces search and preference behaviors in ovulating females. In this study, we conducted a series of experiments to demonstrate that release of this pheromone into water takes place exclusively through the gills. In a behavioral maze, water conditioned with the anterior region of spermiating males induced an increase of search and preference behaviors in ovulating females. Similar behavior was not elicited by water conditioned by the posterior region. The anterior region washings and whole-body washings from spermiating males also elicited large and virtually identical electro-olfactogram responses from female sea lampreys, while the posterior washings produced negligible responses. Further, mass spectrometry and immunoassay confirmed that virtually all the 3ketoPZS released into water was through the gills. Immunocytochemistry revealed some gill epithelial cells and hepatocytes from spermiating males contained dense immunoreactive 3ketoPZS, but not those from prespermiating males. These results demonstrate that 3ketoPZS is released through the gill epithelia and suggest that this pheromone or its precursor may be produced in the liver.environment, male sexual function, pheromones, spermatogenesis

Intestinal synthesis and secretion of bile salts as an adaptation to developmental biliary atresia in the sea lamprey

“…S3B). This increase in spermiating males may facilitate the synthesis of a bile acid pheromone with secretion rate about 0.5 mg/h (35). Interestingly, lipolysis and fatty acid synthesis in liver and intestine vary significantly among life stages (36).…”

“…Parasites were injected with 25 μCi of [H 3 ]TCA in 400 μL PBS via caudal vein and placed in a bisected aquarium (35) filled with aerated water. About 12 h after the injection, animals were anesthetized with 0.02% MS-222 for blood drawing, and then killed with 0.1% MS-222.…”

Tilapia male urinary pheromone stimulates female reproductive axis

“…The fish gill is considered to be the main route for release of free steroids at a rate that reflects largely their plasma concentrations. Indeed, several studies suggest that free steroids are preferentially released via the gills and are found at much lower concentrations in the urine or faeces compared to conjugated metabolites (Ellis et al, 2005;Miguel-Queralt and Hammond, 2008;Scott et al, 2008;Siefkes et al, 2003;Vermeirssen and Scott, 1996). Therefore, changes of steroid concentration in water samples can parallel those in blood, taking into account the dilution effect, and estimation of sex steroids in the water is a reliable indicator of fish endocrine status (Scott and Sorensen, 1994;Scott et al, 2008;Sebire et al, 2009).…”

Odorant organization in the olfactory bulb of the sea lamprey

“…The ex vivo preparation described in the 'Tissue preparation' section (above) was utilized. Amino acids, a bile acid (taurocholic acid) and bile acid steroid pheromones previously shown to be stimulatory to the main olfactory epithelium (Li et al, 1995(Li et al, , 2002Bjerselius et al, 2000;Siefkes et al, 2003;Siefkes and Li, 2004;Sorensen et al, 2005;Johnson et al, 2005Johnson et al, , 2009 were tested. The pheromone test solution included the migratory pheromones petromyzonol sulphate (PZS), and two disulphated aminosterol derivatives known as petromyzonamine disulphate (PADS) and petromyzonolsterol disulphate (PSDS) (Li et al, 1995;Bjerselius et al, 2000;Sorensen et al, 2005), as well as the reproductive pheromones 3-keto petromyzonol sulphate (3KPZS) and 3-keto allocholic acid (3KACA).…”

“…During spawning migration, sea lampreys encounter a mixture of bile acid steroids released from larval sea lamprey in the streambed, and these larval odours have an important role in identifying a suitable river for spawning and larval rearing (Li et al, 1995;Sorensen and Vrieze, 2003). Once a spawning location is found, spermiated male sea lampreys release steroid pheromones, which induce movement/searching and spawning behaviours in ovulated female sea lamprey (Li et al, 2002;Siefkes et al, 2003;Siefkes and Li, 2004;Johnson et al, 2005Johnson et al, , 2009. Physiological studies have also investigated olfactory function in the sea lamprey.…”