Combined with the known IGF-1 sequence and bioinformaticanalysis, we concluded that: In CCS1,074, <1~1,580 base was the 5′ end ofIGF-1; exon 1 and intron 1 localized in 1,581~1,966 base and 1,967~>2,087base separately; the amino residues at 1,903~1,966 base were characterizedsignal peptide.
1. The Cloned BmandLSP and BmLSP 5'FR and Functional analysis of BmLSP promoterThe Cloned BmandLSP and BmLSP 5'FR, consisting of the first intron, the first exon, the core promoter region and 5'-upstream region, harbor the classic TATA box, sequences commonly found in insect genes that were specifically transcribed in fat body and the deduced ERE.
It was predicted that CYP305B1V1 gene structure of Bombyx mandarina was possessed of at least 7 introns and all the introns obey the GT-AG rule by searching silkworm genome database in NCBI.
The BmUCE2I gene contains 4 exons and 3 introns and the putative promoter was between-219 bp~-268 bp of 5′upstream sequence relative to translation start site. The BmUCE2I promoter contains no TATA box,but potential binding sites for the transcription factors were detected in both forward and reverse orientation : CF2-Ⅱ、FTZ、DFD、BRCZ2、DL、STAT、PRD-HD.
We presume that CYP305B1V1 of wild silkworm contains at least 6 introns and they all obey the GT-AG rule by searching and aligning the silkworm genome database on NCBI.
The result of analysing the sequence using the Gene Finder software showed there are 3 introns at the position of 1717th~3078th site, 3341st~3442nd site, and 3678th~3760th site, respectively;
is obtained. The alignments and structure analysis result shows that this gene . which is consist of 6 exons and 5 introns, encodes DH, PBAN, a - SGNP, P - SGNP and Y-SGNP .
1. The Cloned BmandLSP and BmLSP 5'FR and Functional analysis of BmLSP promoterThe Cloned BmandLSP and BmLSP 5'FR, consisting of the first intron, the first exon, the core promoter region and 5'-upstream region, harbor the classic TATA box, sequences commonly found in insect genes that were specifically transcribed in fat body and the deduced ERE.
The 5'-upstream region contains the homologous sequence with the first intron of Fib-L (S) and the inactive mariner like element (MLE). Using PCR and restriction endonuclease methods, a series of luciferase reporter plasmids, driven by different length of BmLSP promoters, are constructed.
The 5′ flanking fragment of fibroin gene of Chinese Oak Silkworm(Antheraea pernyi) was amplified through PCR. It consists of CAAT box, TATA box(Hogness box), prim transcript, start code ATG, part of structural gene and first intron.
Furthermore, characteristics of EID, such as intron phase, distribution of different splice sites, and the relationship between genome size and intron proportion or intron density, have been studied.
The exon-intron structure of these genes has been analyzed in zebrafish Danio rerio, loach Misgurnus fossilis, fugu Takifugu rubripes, and Nile puffer Tetraodon fahaka.
This is supported by high sequence similarity between mlc1 and mlc3 as well as by the exon-intron structure of these genes and their localization on different chromosomes.
The result indicated that the sequence was 1,813 bp (BamHI and SacI were introduced at the 5' and 3' end) including 7 extrons and 6 introns, coding 238 amino acids.
Studies on the statistical characteristics of EID show that there were 103, 848 genes, 478,484 introns, and 582,332 exons, with an average of 4.61 introns and 5.61 exons per gene.
Results of the statistical analysis on the data from nine model species showed that in eukaryotes, higher species do not necessarily have more introns or exons in a gene than lower species.
As shown by nitrocellulose filtration assays with RNA fragments transcribed from various regions of the human ribosomal protein (rp) S26 gene, proteins of the 40S ribosome subunit bind to the first intron of the rpS26 pre-mRNA.
Small-subunit proteins did not affect the efficiency of in vitro splicing of a pre-mRNA fragment corresponding to the first intron, second exon, second intron, and a part of the third exon of the rpS26 gene.
Immunoassays with specific antibodies showed that rpS26 contained in the nuclear extract of HeLa cells binds to the first intron of its pre-mRNA and, less efficiently, to its mRNA.
We have investigated the frequency distribution, across a broad range of geographically dispersed populations, of alleles of the polymorphicAlu insertion that occurs within the 8th intron of the tissue plasminogen activator gene (PLAT).
No nucleotide mutation in two important regions of the presumptive promoter for tr-kit mRNA was detected within the 16th intron of the mouse strains examined.