Systematic analysis of head-to-head gene organization: evolutionary conservation and potential biological relevance.

Several "head-to-head" (or "bidirectional") gene pairs have been studied in individual experiments, but genome-wide analysis of this gene organization, especially in terms of transcriptional correlation and functional association, is still insufficient. We conducted a systematic investigation of head-to-head gene organization focusing on structural features, evolutionary conservation, expression correlation and functional association. Of the present 1,262, 1,071, and 491 head-to-head pairs identified in human, mouse, and rat genomes, respectively, pairs with 1- to 400-base pair distance between transcription start sites form the majority (62.

In vivo analysis of fibroin heavy chain signal peptide of silkworm Bombyx mori using recombinant baculovirus as vector.

In order to investigate the functional signal peptide of silkworm fibroin heavy chain (FibH) and the effect of N- and C-terminal parts of FibH on the secretion of FibH in vivo, N- and C-terminal segments of fibh gene were fused with enhanced green fluorescent protein (EGFP) gene. The fused gene was then introduced into silkworm larvae and expressed in silk gland using recombinant AcMNPV (Autographa californica multiple nuclear polyhedrosis virus) as vector. The fluorescence of EGFP was observed with fluorescence microscope.

Loss of posterior silk gland transcription specificity of fibroin light chain promoter due to absence of 41 bp sequence containing possible inhibitor binding sites.

The gene encoding fibroin light chain protein (FibL) is specifically expressed in the posterior silk gland of silkworm and repressed in other tissues. The binding sites of several transcription factors involved in the silk gland transcription specificity of fibl promoter have been recognized, including SGFB, PSGF and BMFA. Here we report the leak expression of the enhanced green fluorescent protein (EGFP) reporter gene in tissues other than the posterior silk gland in vivo when under the control of a shortened fibl promoter with deletion of the 5' terminal 41 bp sequence, which is located at -650 nt to -610 nt upstream of the fibl transcription starting site.

Introduction of foreign genes into silkworm eggs by electroporation and its application in transgenic vector test.

Electroporation as a methodology to introduce foreign genes into silkworm eggs was systematically analyzed. The foreign gene in both the newly hatched and 3rd instar larva DNA can be detected by PCR. The amount of foreign gene in 3rd instar larva DNA was about 1/1000 of that in newly hatched larva DNA.

[Production and application of rabbit anti-imitative spider dragline silk protein polyclonal antibody].

A synthetic spider dragline gene s600 was cloned into fusion protein expression vector pGEX-KG and expressed in Escherichia coli. Protein S600 was purified and rabbit antiserum was prepared. Amino acid composition analysis confirmed the right expression of S600.