Biotech Updates

Effect of BBX-B8 Overexpression on Development, Silk Protein Synthesis and Egg Diapause of Silkworms

March 9, 2016

Bombyxin (BBX) is an insulin-like peptide that exists in silkworm (Bombyx mori). Previous studies on the effects of inhibiting BBX-B8 expression found that BBX-B8 is important for organ development, reproduction and trehalose metabolism in silkworms. Soochow University researchers, led by Xiaojian Zheng, investigated the effect of BBX-B8 overexpression on the development, body weight, silk protein synthesis and egg diapause of silkworm to further understand BBX-B8 functions.

BBX-B8 gene expression was detected throughout the silkworm's body, but was mainly expressed in the brain. Analysis showed that the change in BBX-B8 expression was not obvious in the brain of 1- to 4-day-old larvae of fifth instar silkworms. However, expression increased substantially at 5- to 6-day-old larvae of fifth instar silkworms.

Transgenic silkworms overexpressing BBX-B8 were then generated. Development duration of the transgenic silkworms was delayed by 2.5–3.5 days. The cocoon shell weight as well as the pupal weight of transgenic silkworms were also reduced compared to non-transgenic silkworms. The overexpression of BBX-B8 also led to transgenic moths laying non-diapausing eggs, or those that do not temporarily pause their development due to adverse environmental conditions.

All results indicated that BBX-B8 plays an important role in the development, silk protein synthesis and egg diapause of silkworm.

For more information, read the article on Transgenic Research.