Leucine-rich fibroin gene of the Japanese wild silkmoth, Rhodinia fugax (Lepidoptera: Saturniidae)

Abstract

Abstract. We cloned and characterized a partial fibroin gene of Rhodinia fugax (Saturniidae). The gene encodes a fibroin consisting mainly of orderly arranged repeats, each of which is divided into a polyalanine and a nonpolyalanine block, similar to the fibroins of Antheraea pernyi and A. yamamai. Three repeat types differ in the sequence of the nonpolyalanine block. In contrast to the Antheraea fibroins, the fibroin of R. fugax is rich in glutamate and leucine residues (about 3% and 5%, respectively) and contains less alanine.

Characterization of Partial Coding Region Fibroin Gene on Wild Silkmoth Cricula trifenestrata Helfer (Lepidoptera: Saturniidae)

“…The composition of amino acids after polyalanin a repetition consists of the amino acid glycine (G) and serine (S). The amino acid arrangement like that, was similar with amino acid sequence of second exon fi broin of Saturniidae family (Da a et al, 2001b;Sezutsu et al, 2010 ). There are four type of polyalanine sequence motif in second exon fibroin A. pernyi (Sezutsu & Yukuhiro, 2000;Sezutsu, et al, 2009), while repetitive GAGASG pa ern was founded in B. mori (Zhou et al, 2000).…”

“…acid alanine has the highest frequency among 3 triplet codons for amino acid alanine, i.e (GCA, GCT, GCG, GCC, with a frequency of consecutive 49, 17, 16, 1 times respectively). This result indicated that the composition of the nucleotide was similar, but their size was heterogeneous, such as the second exon of other Lepidoptera (Craigh & Riekel, 2002;Sezutsu et al, 2010) Many Repetitif Alanine Amino Acid with…”

“…Note that two cysteine residues were conserved in this region in all four Saturniidae fi broins and B. mori also ( Table 2). The high conserved nucleotide (amino acid) of fi broin gene was founded in most Saturniidae (Hwang et al, 2001;Kobayashi et al, 2009;Sezutsu & Yukuhiro, 2000;Sezutsu et al, 2009;Sezutsu et al, 2010).…”

“…Interestingly, the fi broin L chain and fi brohexamarine/P25 are not founded in A. yamamai and A. myli a fi broin (Tanaka & Mizuno, 2001;Da a et al, 2001b). Most of Saturniidae fi broin protein consists of heavy chain dimer, which are formed by disulfi de bound of two cysteine amino acid residues (Sezutsu & Yukuhiro, 2000;Sezutsu et al, 2010).…”

“…To date, all silk and fi broin gene studies of Lepidoptera have focused on B. mory (Bombycidae) (Zhou et al, 2000;Katsuhiko et al, 2007;Lefevre et al, 2007), Antheraea spesies and Samia cynthia ricini (Saturniidae) (Da a et al, 2001a, b;Sezutsu et al, 2009;Sezutsu & Yukuhiro, 2000;Sezutsu et al, 2010), Araneus diadematus, and Nephila edulis (Araneoidae), Galleria mellonella, and Hepialus californicus (Hepialidae) (Zurovec & Sehnal, 2002;Yonemura & Sehnal, 2006;Chen et al, 2006;Saravanan et al, 2006;Collin et al, 2010). No date for C. trifenestrata.…”