Recombinant bagworm silk

Patent metadata

Field	Value
Publication number	US-11220529-B2
Application number	US-201716342837-A
Country	US
Kind code	B2
Filing date	Oct 16, 2017
Priority date	Oct 18, 2016
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A method of producing a transgenic silkworm that spins bagworm silks and producing a large quantity of bagworm silks by transgenic technology is developed and provided. A gene encoding a modified bagworm Fib H and a transgenic silkworm in which the gene is introduced, wherein the gene is obtained by cloning a gene fragment encoding a bagworm Fib H-like polypeptide comprising a partial amino acid sequence of bagworm Fib H, and fusing the gene fragment to a gene fragment encoding silkworm-derived Fib H, are provided.

First claim

The invention claimed is:

1. A gene encoding a modified bagworm fibroin H chain, wherein the modified bagworm fibroin H chain is a chimeric fibroin H chain comprising a bagworm fibroin H chain fused to a portion of a silkworm fibroin H chain, wherein the modified bagworm fibroin H chain comprises (a) or (b):
(a) an amino acid sequence comprising positions 1 to 153 of SEQ ID NO: 9,
one or a plurality of the amino acid sequences set forth in SEQ ID NOs: 5 and/or 7, and
an amino acid sequence comprising positions 466 to 524 of SEQ ID NO: 9,
(b) an amino acid sequence comprising positions 1 to 153 of SEQ ID NO: 9,
one or a plurality of an amino acid sequence having an amino acid identity of 90% or more to full length SEQ ID NOs: 5 and/or 7, and
an amino acid sequence comprising positions 466 to 524 of SEQ ID NO: 9.

2. An expression vector of a modified bagworm fibroin H chain gene, the vector comprising a promoter for expression in the posterior silk gland derived from a silk spinning insect, and the modified bagworm fibroin H chain gene according to claim 1 , wherein the promoter is operably linked to said gene.

3. The expression vector of a modified bagworm fibroin H chain gene according to claim 2 ,
wherein the expression vector comprises:
a first expression unit comprising a promoter for expression in the posterior silk gland derived from a silk spinning insect operably linked to a gene encoding a transcriptional regulator; and
a second expression unit comprising a promoter operably linked to the modified bagworm fibroin H chain gene, wherein the promoter operably linked to the modified bagworm fibroin H chain gene is targeted by the transcriptional regulator.

4. The expression vector of a modified bagworm fibroin H chain gene according to claim 3 , wherein the gene encoding the transcriptional regulator is a GAL4 gene and the promoter targeted by the transcriptional regulator is a UAS promoter.

5. The expression vector of a modified bagworm fibroin H chain gene according to claim 2 , wherein the promoter for expression in the posterior silkgland is a posterior silk gland-specific promoter.

6. The expression vector of a modified bagworm fibroin H chain gene according to claim 5 , wherein the posterior silk gland-specific promoter is a promoter of any of fibroin H chain, fibroin L chain, or p25.

7. The expression vector of a modified bagworm fibroin H chain gene according to claim 2 , wherein the silk spinning insect is a silkworm.

8. A transgenic silkworm comprising the expression vector of a modified bagworm fibroin H chain gene according to claim 2 , wherein the transgenic silkworm expresses the modified bagworm fibroin H chain.

9. A method of producing a transgenic silkworm that spins a modified bagworm silk, comprising:
introducing the expression vector of a modified bagworm fibroin H chain gene according to claim 6 into a host silkworm; and
selecting a transgenic silkworm comprising the expression vector, wherein the transgenic silkworm expresses the modified bagworm fibroin H chain.

10. A method of producing a transgenic silkworm that spins a modified bagworm silk, comprising:
crossing a transgenic silkworm having a first expression unit comprising a promoter for expression in the posterior silk gland derived from a silk spinning insect and a gene encoding a transcriptional regulator placed under the downstream control of the promoter and a transgenic silkworm having a second expression unit comprising a promoter targeted by the transcriptional regulator and the modified bagworm fibroin H chain gene placed under the downstream control of the targeted promoter; and
selecting a transgenic silkworm having the first and second expression units from progenies after the cross.

Assignees

• Nat Agriculture & Food Res Org

Inventors

• YONEMURA Naoyuki
• Iizuka Tetsuya
• Nakajima Kenichi
• Tsubota Takuya
• Suzuki Takao
• Sezutsu Hideki
• Kameda Tsunenori
• Yoshioka Taiyo

Classifications

• D01B7/06

  Obtaining silk from cocoons or portions thereof not suitable for reeling (de-gumming silk D01C3/02) · CPC title

• C12N15/09

  Recombinant DNA-technology · CPC title

• A01K2227/70

  Invertebrates · CPC title

• C12N2830/008

  cell type or tissue specific enhancer/promoter combination · CPC title

• A01B7/00

  Disc-like soil-working implements usable either as ploughs or as harrows, or the like · CPC title