共查询到20条相似文献,搜索用时 343 毫秒
1.
2.
3.
Nucleotide sequence of the gene for the gamma chain of human fibrinogen 总被引:15,自引:0,他引:15
4.
5.
6.
7.
8.
9.
Cross-hybridization of the grey seal myoglobin gene to human DNA detected a single human myoglobin gene plus an extensive family of sequences apparently related to the central exon of this gene. The functional human gene is 10.4 kb long and has a haemoglobin-like three exon/two intron structure with long non-coding regions similar to its seal homologue. At least 300 bp of 5'-flanking region are closely homologous between the two genes, with the exception of a divergent purine-rich region 68-114 bp upstream of the cap site. A diverged tandem repetitive sequence based on (GGAT)165 is located 1100-1750 bp upstream from the gene; internal homology units within this sequence suggest sequence homogenization by gene microconversions. A second 33-bp tandem repeat element in the first intron is flanked by a 9-bp direct repeat, shares homology with other tandem repetitive elements in the human genome and may represent a novel form of transposable element. 相似文献
10.
The nucleotide sequences of the 5'-flanking regions of the duplicated Amy
genes in eight sibling species belonging to the melanogaster species
subgroup are analyzed. In Drosophila melanogaster, a region of about 450 bp
immediately upstream of the translation initiation site of the two
paralogous genes (the proximal and distal genes) has sequence similarities.
However, we could not detect any significant sequence similarity in the
region more upstream than -450. This result indicates that the coding
regions of the ancestral Amy gene were duplicated together with 450 bp of
the 5'-flanking region as one unit. Multiple alignment of these 450-bp
sequences in the proximal and distal genes of all eight species revealed a
mosaic pattern of highly conserved and divergent regions. The conserved
regions included almost all the putative regulatory elements identified in
previous analyses of the sequences. A phylogenetic analysis of the aligned
sequences shows that these 450-bp sequences are clustered into the proximal
and the distal groups. As a whole, the divergence between groups in this
region is very large in contrast to that in the coding regions. Based on
the divergence between groups, the 450-bp region is divided into two
subregions. We found that the ratios of the divergence between groups to
that within groups differ in the two subregions. From these observations,
we discuss a possibility of positive selection acting on the subregion
immediately upstream of the Amy coding region to cause divergence of
regulatory elements of the paralogous genes.
相似文献
11.
12.
13.
Structure of the rat L-type pyruvate kinase gene 总被引:10,自引:0,他引:10
14.
15.
16.
17.
18.
19.
Using iodinated single-stranded M13 probes to facilitate rapid DNA sequence analysis--nucleotide sequence of a mouse lysine tRNA gene. 总被引:4,自引:3,他引:1
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
From a recombinant lambda phage, we have determined a 387 bp sequence containing a mouse lysine tRNA gene. The putative lys tRNA (anticodon UUU) differs from rabbit liver lys tRNA at five positions. The flanking regions of the mouse gene are not generally homologous to published human and Drosophila lys tRNA genes. However, the mouse gene contains a 14 bp region comprising 13 A-T base pairs, 30-44 bp from the 5' end of the coding region. Cognate A-T rich regions are present in human and Drosophila genes. The coding region is flanked by two 11 bp direct repeats, similar to those associated with alu family sequences. The sequence was determined by a "walking" protocol that employs, as a novel feature, iodinated single-stranded M13 probes to identify M13 subclones which contain sequences partially overlapping and contiguous to an initially determined sequence. The probes can also be used to screen lambda phage and in Southern and dot blot experiments. 相似文献
20.
Conserved structural features are found upstream from the three co-ordinately regulated discoidin I genes of Dictyostelium discoideum 总被引:7,自引:0,他引:7
The discoidin I genes of Dictyostelium form a small, co-ordinately regulated multigene family. We have sequenced and compared the upstream regions of the DiscI-alpha, -beta and -gamma genes. For the most part the upstream regions of the three genes are non-homologous. The upstream sequences of the beta and gamma genes are exceedingly A + T-rich, while those of the alpha gene are less so. All three genes have a relatively G + C-rich region 20 to 40 base-pairs in length, found approximately 200 base-pairs 5' to the messenger RNA start site. This G + C-rich region 5' to the beta and gamma genes is flanked by short inverted repeats. Within this region, there is an 11 base-pair exact homology between the alpha and gamma genes, and a less perfect homology between these genes and the beta gene. The homology is flanked at a short distance by interspersed G and T residues. The gamma gene is greater than 90% A + T for greater than 800 base-pairs upstream. Further upstream there is a G + C-rich region that is also found inverted approximately 3.5 X 10(3) base-pairs away. The gamma and beta genes are tandemly linked, and the entire approximately 500 base-pair intergene region between the 3' end of the gamma gene and the 5' end of the beta gene is A + T-rich (approximately 90%) with the exception of the homology region 5' to the gamma gene. We demonstrate also the presence of a discoidin I pseudogene fragment having only 139 base-pairs of discoidin homology with greater than 8% mismatch. It is flanked upstream by five 39 base-pair G + C-rich repeats, and downstream by sequences that are extremely A + T-rich. We discuss the possible significance of the conserved G + C-rich structures on discoidin I gene expression. 相似文献