Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Quantum Analysis of Sericin Protein Mrna in the Middle Silkgland at Different Developmental Stages of Silkworm, Bombyx Mori L.

S. Islam
Research Officer
Bangladesh Sericulture Research and Training Institute (BSRTI), Rajshahi

E. Haque
Professor
Department of Chemistry, Rajshahi University

A.C. Barman
Director (Incharge)
Bangladesh Sericulture Research and Training Institute (BSRTI), Rajshahi.

R. Haque
Department of Zoology, Rajshahi University

Abstract/ Executive Summary:

Ribonucleic acid (RNA) is known' to play an important part in the biosynthesis of proteins. Messenger RNA in animal tissues is produced in the nucleus and served to transfer genetical information from the nuclear DNA to the site of protein synthesis in the cytoplasm (Georgiev, 1962). The silk gland of the mulberry silkworm Bombyx mori, represents an organ which is very active for synthesis of silk protein. Eggs of four silkworm races, Nistari-P (Multivoltine), BSRI-C (MultixBi breed), Ziangsu-12P and Dong-34P (bivoltine) were considered for the study. In the fifth instar observations were taken every day. Middle silkglands were dissected out and homogenized. However there was a significant day to day difference in the quantity of mRNA synthesis in all the races taken for the study. Multi x Bi (BSRI-C) breeds showed moderate ranges for all the characters in between multi and bivoltine races. It may be safely inferred that the regulation of sericin protein is positively enhanced producing more sericin protein mRNA in the developmental stages of bivoltine than in the multivoltines.

Keywords: Sericin protein, mRNA, Middle silkgland, Developmental stages, Bombyx mori L.

Location: Bangladesh Sericulture Research and Training Institute (BSRTI)

Start Date:

End Date:

Program Area: Socio-economic and Policy

Commodity: Silkworm

Objectives:

To find out the concentration of mRNA of sericin protein in the larval stages of different silkworm races.

Methodology:

Eggs of four silkworm races, Nistari-P (Multivoltine), BSRI-C (MultixBi breed), Ziangsu-12P and Dong-34P (bivoltine) were considered for the study. Twenty larvae were taken randomly from each race on 1st, 2nd and 3rd day of fourth instar and fourth moulting respectively. In the fifth instar observations were taken every day. Middle silkglands were dissected out and homogenized. Then the extraction of sericin mRNA was done following standard method of Lizard and Engelberg (1979) with slight modification. Spectrophotometric methods (Beer and Lamberts, 1977) was used to determine the concentrations of sericin mRNA. It was found that the absorbance value increased with the increase of larval age and varied greatly amongst the races. The highest absorbance value (0.532 to 1.678) was recorded in the bivoltine (Ziangsu-12P) and the lowest (0.442 to 1.275) in Nistari-P. Similarly highest concentrations (3.454 x 10-5 to 10.896x 10-5 mol/ml) were found in the bivoltine Ziangsu-12P. Multivoltine Nistari-P showed the least values for concentrations. However there was a significant day to day difference in the quantity of mRNA synthesis in all the races taken for the study. Multi x Bi (BSRI-C) breeds showed moderate ranges for all the characters in between multi and bivoltine races. Tripoulas and Samols (1986) observed that the sericin mRNA was abundantly available in the middle silkgland of final two larval instars. According to them it is present in low abundance during the 4th larval instar, undetectable during moult and high abundance during the 5th instar. Present findings partially supports above investigation for the 4h and 5th instars.

Source of Information: Bulletin of Sericulture Research. 1996 Vol.7 :99-101 published by Bangladesh Sericulture Research and Training Institute.

Article Link (Online Journal):

Funding Source:

1. Government

Budget:

Total Budget (Tk.) :

Achievement/Findings:

It was noticed that synthesis of sericin in mRNA does not stopped during the 4th moulting period, rather it continues to synthesis at a relatively higher rate than the 4th instar. Okamoto et cd. (1982) found that sericin mRNAs encoding glue proteins to silk fibre are synthesized in the middle silkgland. The sericin genes coding for major sericin mRNAs are known to transcribed specifically in the fifth instar larva (Ishikawa and Suzuki 1985). The results obtained in the present study also suggested that sericin mRNA gradually increased with the advancement of developmental stages, specifically in the fifth instar. It may be safely inferred that the regulation of sericin protein is positively enhanced producing more sericin protein mRNA in the developmental stages of bivoltine than in the multivoltines.

Knowledge Management: Journal