Molecular Cloning and Characterization of Spiggin

Abstract

One of the most definitive examples of a vertebrate extraorganismal structural protein can be found in three-spined sticklebacks (Gasterosteus aculeatus). In the breeding male the kidney hypertrophies and synthesizes an adhesive protein called "spiggin," which is secreted into the urinary bladder from where it is employed as a structural thread for nest building. This paper describes the first molecular characterization of spiggin and demonstrates that this adhesive is a protein complex assembled from a potential of three distinct subunits (␣, ␤, and ␥). These subunits arise by alternative splicing, and 11-ketoandrogens induce their expression in stickleback kidneys. Analysis of the predicted amino acid sequence of each subunit reveals a modular organization whose structural elements display a similarity to the multimerization domains found within von Willebrand Factor-related proteins. These results implicate that spiggin utilizes a conserved multimerization mechanism for the formation of a viscous agglutinate from its constituent subunits in the urinary bladders of male sticklebacks. This novel extraorganismal structural protein is therefore ideally suited to its function as an adhesive thread.Extrorganismal proteins are common among invertebrates. Examples range from the fibroin threads forming spider webs and silkworm cocoons (1, 2) to the collagen-based matrixes of the byssus threads of Mytilus and the Drosophila sgs family (3, 4).

Developmental exposure to progestins causes male bias and precocious puberty in zebrafish (Danio rerio)

“…Furthermore, the similar effect of LNG on sex differentiation reported by Hua et al (Hua et al, 2015) was inhibited by co-exposure to the specific AR antagonist flutamide. The absence of effect of P4 on sex differentiation is in concordance with the very low affinity of P4 for both mammalian and fish AR (Bain et al, 2015;Bauer et al, 2000), and the absence of androgenic effects of P4 in fish (Jolly et al, 2006;Jones et al, 2001;Liang et al, 2015), it is therefore intriguing that P4 induced precocious puberty in males in the present study. Since P4 is virtually non-androgenic, its effect on male puberty appears to be mediated via PR activation.…”

“…Levonorgestrel (LNG) was chosen as the model androgenic progestin due to its high AR affinity (58% of that of testosterone to rat AR) (Africander et al, 2011;Philibert et al, 1999;Runnalls et al, 2013), environmental presence (Al-Odaini et al, 2010;Chang et al, 2011;Vulliet and Cren-Olivé, 2011;Vulliet et al, 2008), and known androgenic effects in fish (Runnalls et al, 2013;Svensson et al, 2013Svensson et al, , 2014. P4 was chosen as the model non-androgenic progestin due to its low AR affinity (3% of that of testosterone to rat AR) (Bain et al, 2015;Bauer et al, 2000;Philibert et al, 1999), frequent environmental detection (Ammann et al, 2014;Chang et al, 2011;Velicu and Suri, 2009;Vulliet and Cren-Olivé, 2011;Vulliet et al, 2008), and absence of androgenic effects on fish (Jolly et al, 2006;Jones et al, 2001). Zebrafish larvae were exposed to either LNG or P4 during the critical developmental period of sex differentiation and puberty.…”

Arctic Teleost Fishes with Canceled Accelerated Senescence Program Are a Potential Source of Stress Protectors and Cancer Drugs

“…Secondary epithelial cells in the kidney of spawning males release a 200 kDa sticky glycoprotein, which is, together with some other light proteins and mucoid substances, a component of glue used to build a spawning nest from algae (Jakobsson et al , 1999;Jones et al , 2001).…”

The organophosphorous pesticide, fenitrothion, acts as an anti-androgen and alters reproductive behavior of the male three-spined stickleback, Gasterosteus aculeatus

“…However, arguably the biomarker with the greatest sensitivity, specificity and resolution for detection of androgens (and anti-androgens) in the environment is spiggin production in the kidney of the threespined stickleback, Gasterosteus aculeatus both in vivo (Katsiadaki et al 2002a(Katsiadaki et al , b, 2006Sanchez et al 2008) and in vitro (Jolly et al 2006;Björkblom et al 2007). Spiggin is a glue protein that is used for building nests and is specifically under the control of androgens (Borg et al 1993;Jakobsson et al 1999;Jones et al 2001).…”