Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2016 May 25;4(2):19.
doi: 10.3390/jdb4020019.

Regulation of Silk Genes by Hox and Homeodomain Proteins in the Terminal Differentiated Silk Gland of the Silkworm Bombyx mori

Shigeharu Takiya  1   2 , Takuya Tsubota  3 , Mai Kimoto  4
Affiliations
Review

Regulation of Silk Genes by Hox and Homeodomain Proteins in the Terminal Differentiated Silk Gland of the Silkworm Bombyx mori

Shigeharu Takiya et al. J Dev Biol. .

Abstract

The silk gland of the silkworm Bombyx mori is a long tubular organ that is divided into several subparts along its anteroposterior (AP) axis. As a trait of terminal differentiation of the silk gland, several silk protein genes are expressed with unique regional specificities. Most of the Hox and some of the homeobox genes are also expressed in the differentiated silk gland with regional specificities. The expression patterns of Hox genes in the silk gland roughly correspond to those in embryogenesis showing "colinearity". The central Hox class protein Antennapedia (Antp) directly regulates the expression of several middle silk gland-specific silk genes, whereas the Lin-1/Isl-1/Mec3 (LIM)-homeodomain transcriptional factor Arrowhead (Awh) regulates the expression of posterior silk gland-specific genes for silk fiber proteins. We summarize our results and discuss the usefulness of the silk gland of Bombyx mori for analyzing the function of Hox genes. Further analyses of the regulatory mechanisms underlying the region-specific expression of silk genes will provide novel insights into the molecular bases for target-gene selection and regulation by Hox and homeodomain proteins.

Keywords: Antp; Bombyx mori; Hox genes; fibroin; homeodomain; promoter element; sericin; silk gland; silkworm.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Schematic of the silk gland of Bombyx mori. ASG; anterior silk gland, MSG; middle silk gland, MSG-A; anterior portion of the MSG, MSG-M; middle portion of the MSG, MSG-P; posterior portion of the MSG, PSG; posterior silk gland, PSG-A; anterior half of the PSG; PSG-P; posterior half of the PSG. In order to avoid contamination of the neighbor regions, each portion was prepared as shown in this figure. The structural border is not observed in the PSG, and so the long tubular tissue was divided simply into the anterior and posterior halves.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Tazima Y. The Genetics of the Silkworm. Logos Press; London, UK: Academic Press; London, UK: 1964.
    1. Suzuki Y. Genes that are involved in Bombyx body plan and silk gene regulation. Int. J. Dev. Biol. 1994;38:231–235. - PubMed
    1. Ueno K., Nagata T., Suzuki Y. Roles of homeotic genes in the Bombyx body plan. In: Goldsmith M.R., Wilkins A.S., editors. Molecular Model Systems in the Lepidoptera. Cambridge University Press; New York, NY, USA: 1995. pp. 165–180.
    1. Chai C.-L., Zhang Z., Huang F.-F., Wang X.-Y., Yu Q.-Y., Liu B.-B., Tian T., Xia Q.-Y., Lu C., Xiang Z.-H. A genomewide survey of homeobox genes and identification of novel structure of the Hox cluster in the silkworm Bombyx mori. Insect Biochem. Mol. Biol. 2008;38:1111–1120. doi: 10.1016/j.ibmb.2008.06.008. - DOI - PubMed
    1. Masumoto M., Yaginuma T., Niimi T. Functional analysis of Ultrabithorax in the silkworm, Bombyx mori using RNAi. Dev. Genes Evol. 2009;219:437–444. doi: 10.1007/s00427-009-0305-9. - DOI - PubMed

LinkOut - more resources