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Isolation and characterization of the mouse P450 17 alpha-hydroxylase/C17-20-lyase gene (Cyp17): transcriptional regulation of the gene by cyclic adenosine 3',5'-monophosphate in MA-10 Leydig cells.

The biosynthesis in Leydig cells of the C19 steroid testosterone from the C21 precursor progesterone requires the activities of the enzyme cytochrome P450 17 alpha-hydroxylase/C17-20 lyase (P450(17 alpha)). Previous studies from this laboratory demonstrated that the de novo synthesis of the P450(17 alpha) protein and the accumulation of P450(17 alpha) mRNA in mouse Leydig cell cultures is absolutely dependent on cAMP stimulation. To investigate further the cAMP regulation of P450(17 alpha) expression in Leydig cells, the structural gene encoding P450(17 alpha) (Cyp17) was isolated from a mouse genomic library using a full-length mouse P450(17 alpha) cDNA. Two overlapping genomic clones were isolated and characterized by restriction mapping and partial sequencing. The two clones together contain the entire coding region and approximately 10 kilobases of 5'-flanking sequences of Cyp17. To identify regions necessary for cAMP-induced transcription, 5'-flanking regions of Cyp17 were fused with the chloramphenicol acetyltransferase (CAT) reporter gene and transiently transfected into MA-10 tumor Leydig cells. Studies localized the cAMP-responsive region of the gene to a region between -346 and -245 basepairs relative to the transcription initiation site. Transient transfections of MA-10 cells with a construct consisting of the -346/-245 sequences fused to a heterologous promoter, thymidine kinase, and the CAT reporter gene demonstrated a marked increase in cAMP stimulation of CAT expression, providing additional evidence that the -346/-245 sequences of the Cyp17 5'-flanking region confer cAMP-induced expression of Cyp17. This cAMP-responsive region of mouse Cyp17 bears no apparent homology to the cAMP-responsive regions identified in the human and bovine Cyp17 genes.

Aldehyde-Lyases↗

Isolation and partial characterization of a transformation-associated sequence from human nasopharyngeal carcinoma.

A transforming activity associated with Chinese nasopharyngeal carcinoma (NPC) cell line CNE2 DNA has been identified by transfer into nontransformed promotion-sensitive mouse JB6(P+) C141 cells. To clone this transformation-associated sequence, we carried out three cycles of transfection, followed by cloning of anchorage-independent transformants in soft agar. A tertiary CNE/JB6 clonal transfectant cell line 625 whose DNA showed transforming activity, as indicated in both soft-agar assay and nude-mice implantation, was used to make a genomic library in the vector lambda dash. Using the human repeated sequence Blur 8 to screen the library, we obtained 10 human Alu-positive clones. A cloned Alu-positive insert of 16 kbp, CNE 323, was characterized in detail. CNE 323 transferred moderate transforming activity when introduced into JB6 P+ cells and showed no homology to Ha-, Ki-, or N-ras genes; human promotion sensitivity genes; src, myb, jun, myc, fos, raf, or int-2 oncogenes; or epidermal growth factor receptor. The isolated CNE 323 DNA sequence appeared to preserve the genomic structure of the original sequence found in CNE2 cells and in nude mouse tumors induced by CNE2 cells or by CNE/JB6 transfectant cells, indicating that the cloned NPC sequence was activated during NPC carcinogenesis and not during transfection or construction of the library, and that the cloned sequence or a larger sequence of which it was part played a role in tumor formation. Finally, we identified a 1.3-kb mRNA that hybridizes to a subclone of the 16-kb NPC sequence in CNE2 cell poly (A)+ RNA.

Animals↗

Molecular cloning and characterization of mouse caspase-8.

Fas (APO-1/CD95) is a transmembrane receptor protein which induces apoptosis upon activation. In apoptosis triggered by Fas, a subset of cysteine proteases designated caspases is activated, playing a central role as effector molecules. Among these caspases, human caspase-8 (FLICE/MACH/Mch5) has been isolated and shown to be indispensable for Fas-mediated apoptotic signaling. In this study, we isolated the mouse homologue to human caspase-8 from a BaF3 cell cDNA library. This molecule conserved the death effector domain (DED) and protease domain as detected in human caspase-8, and was capable of inducing apoptosis in KB and Rat-1 cells when overexpressed. Expression of caspase-8 was detected in the various tissues of adult mouse and in embryos at 9.5 days and 17.5 days of development by Northern-blot analysis. Further, we isolated a chromosomal gene for caspase-8 from a mouse genomic library and analyzed the genomic structure of the isolated gene. This gene consisted of eight exons and seven introns spanning about 26 kb in the coding region.

Amino Acid Sequence↗

Structure and genomic organization of the ipiB and ipiO gene clusters of Phytophthora infestans.

Two in planta-induced (ipi) genes, designated ipiB and ipiO, of the potato late blight fungus, Phytophthora infestans (Mont.) de Bary, were isolated from a genomic library by a differential hybridization procedure [Pieterse et al., Physiol. Mol. Plant Pathol. (1993a) in press]. Both genes are expressed at high levels in the early phases of the pathogenic interaction of P. infestans with its host plant potato, suggesting that their gene products have a function in the early stages of the infection process. Here, we describe the nucleotide (nt) sequence and genomic organization of ipiB and ipiO. The ipiB gene belongs to a small gene family consisting of at least three genes, designated ipiB1, ipiB2 and ipiB3, which are clustered in a head-to-tail arrangement. The three ipiB genes are highly homologous throughout the coding regions and 5' and 3' flanking regions. The P. infestans genome contains two very similar ipiO genes, ipiO1 and ipiO2, which are closely linked and arranged in an inverted orientation. The ipiB genes encode three novel, highly similar Gly-rich proteins of 301, 343 and 347 amino acids (aa), respectively. The Gly-rich domains of the IPI-B proteins are predominantly composed of two repeats with the core sequences, A/V-G-A-G-L-Y-G-R and G-A-G-Y/V-G-G. The ipiO genes code for two almost identical 152-aa proteins which do not have any homology with sequences present in data libraries. IPI-B, as well as IPI-O, contains putative signal peptides of 20 and 21 aa, respectively, suggesting that they are transported out of the cytoplasm. In the promoter regions of ipiB and ipiO, a 16-nt sequence motif, matching the core sequence, GCTCATTYYNCAWTTT (where N = A or C or G or T; W = A or T; Y = C or T), was found. This sequence motif appears to be present around the transcription start point (tsp) of seven out of eight oomycetous genes for which the tsp have been determined, suggesting that oomycetes have a sequence preference for transcription initiation.

Amino Acid Sequence↗

Isolation of the Arabidopsis GA4 locus.

Progeny from a transgenic Arabidopsis plant generated by the Agrobacterium root transformation procedure were found to segregate for a gibberellin (GA)-responsive semidwarf phenotype. Complementation analysis with genetically characterized GA-responsive mutants revealed that the transgenic plant has an insertional mutation (ga4-2) that is an allele of the ga4 locus. The semidwarf phenotype of ga4-2 is inherited as a recessive mutation that cosegregates with both the T-DNA insert and the kanamycin resistance trait. DNA gel blot analysis indicated that the insertion site contains a complex T-DNA unit. A genomic library was constructed with DNA from the tagged ga4 mutant; a DNA clone was isolated from the library that flanks the T-DNA insert. The plant sequence isolated from this clone was used to isolate the corresponding full-length genomic and cDNA clones from wild-type libraries. DNA sequence comparison of the clones to the existing data bases suggests that they encode a hydroxylase. This conclusion is in agreement with a biochemical study that indicated that the ga4 mutant is deficient in 3 beta-hydroxylase in the GA biosynthetic pathway of Arabidopsis. RNA gel blot analysis showed that the message is ubiquitously expressed in different tissues of Arabidopsis but most abundantly in the silique. Unexpectedly, a higher level of transcription was detected in the ethyl methanesulfonate-induced ga4 mutant, and this overexpression was repressed by treatment with exogenous GA.

Alleles↗

The Schizosaccharomyces pombe cwg2+ gene codes for the beta subunit of a geranylgeranyltransferase type I required for beta-glucan synthesis.

The product of the Schizosaccharomyces pombe cwg2+ gene is involved in the biosynthesis of beta-D-glucan. When grown at the non-permissive temperature, cwg2-1 mutant cells lyse in the absence of an osmotic stabilizer and display a reduced (1-3) beta-D-glucan content and (1-3) beta-D-glucan synthase activity. The cwg2+ gene was cloned by the rescue of the cwg2-1 mutant phenotype using an S. pombe genomic library and subsequently verified by integration of the appropriate insert into the S. pombe genome. Determination of the nucleotide sequence of this gene revealed a putative open reading frame of 1065 bp encoding a polypeptide of 355 amino acids with a calculated M(r) of 40,019. The cwg2+ DNA hybridizes to a main transcript, the 5' end of which maps to a position 469 bp upstream of the predicted start of translation. The sequence between the transcription and the translation start sites is unusually long and has several short open reading frames which suggest a translational control of the gene expression. Comparative analysis of the predicted amino acid sequence shows that it possesses significant similarity to three Saccharomyces cerevisiae proteins, encoded by the DPR1/RAM1, CDC43/CAL1 and ORF2/BET2 genes respectively, which are beta subunits of different prenyltransferases. When grown at 37 degrees C, cwg2-1 mutant extracts were specifically deficient in geranylgeranyltransferase type I activity, as measured in vitro. Multiple copies of the CDC43 gene can partially suppress the growth and (1-3) beta-D-glucan synthase defect of the cwg2-1 mutant at the restrictive temperature. In a similar manner, the cwg2+ gene can partially suppress the cdc43-2 growth defect. These results indicate that cwg2+ is the structural gene for the beta subunit of geranylgeranyltransferase type I in S. pombe and that this enzyme is required for (1-3) beta-D-glucan synthase activity. The functional homology of Cwg2 with Cdc43, which has been implicated in the control of cell polarity, suggests a link between two morphogenetic events such as establishment of cell polarity and cell wall biosynthesis.

Amino Acid Sequence↗

Evidence for a relationship between the Bombyx mori middle repetitive Bm1 sequence family and U1 snRNA.

Several genomic library equivalents of Bombyx mori were constructed in the EMBL-4 lambda derivative. The genomic bank was screened with purified Bombyx mori U1 RNA and twenty positive clones for the U1 gene were isolated. Three U1-related sequences were subcloned and sequenced. Two of the sequences are U1 pseudogenes while a third sequence represents a member of the Bm 1 family of repetitive elements of B.mori with significant sequence similarity to U1 small nuclear RNA. The U1-related Bm1 element exhibits 82% sequence similarity with the Bm1 consensus sequence and, under less stringent computer comparison parameters, 60% similarity with a composite B.mori/Drosophila melanogaster U1 gene. The Bm1 family consensus sequence exhibits 53% sequence similarity with the composite U1 gene. The two pseudogenes possess highly conserved sequences with the B.mori U1 gene only for the first 101 nucleotides. These findings are indicative of at least two different categories of U1-related sequences in B.mori, one with a possible evolutionary relationship to the Bm1 family of repetitive elements and the other representing characteristic processed pseudogenes with retroposon mode of dispersion and target selection for the TTTA hotspot. In addition, the U1-related Bm1 element may demonstrate for the first time that a family of retroposons is ultimately derived from a U snRNA.

Animals↗

Simple sequence repeat (SSR) analysis for assessment of genetic variability in apricot germplasm.

Thirty SSR primer combinations, developed from peach SSR-enriched genomic libraries and BAC libraries of peach [ Prunus persica (L.) Batsch.], were tested for cross amplification with 74 apricot ( Prunus armeniaca L.) germplasm accessions. Twelve primer pairs amplified 14 polymorphic SSR loci useful for discriminating most apricot cultivars, as well as for investigating patterns of variation in apricot germplasm. Levels of polymorphism were higher than the levels described using other codominant marker systems (i.e., isozymes, RFLP markers). Overall, 107 alleles were identified, and all but 11 accessions were unambiguously discriminated. Genetic differentiation of native germplasm into traditional ecogeographical groups was low, with a high level of genetic identity (> 0.75) between the groups. However, neighbor joining cluster analysis of marker distances between cultivars reflected the complex history of apricot domestication, producing groupings not evidently based on the geographical origin of the cultivars. Distant positioning of Chinese cultivars on UPGMA and neighbor joining dendrograms supports the authors' consideration of Chinese apricots as subspecies, Prunus armeniaca var. ansu Maxim., rather than a separate species.

Alleles↗

Co-amplification to tail-to-tail copies of MuRVY and IAPE retroviral genomes on the Mus musculus Y chromosome.

We have isolated a clone from a C57BL/6 genomic library that contains both part of the Y Chromosome-specific 8.7 kbp MuRVY genome (Hutchinson and Eicher, J. Virol. 63, 4043, 1989) and a full-length 8.3 kbp Intracisternal A Particle genome (IAPE-Y), in a tail-to-tail organization. Although IAPs are encoded by a disperse multigene family (approximately 1000 copies per haploid genome), we present evidence that a significant proportion of the IAP-related sequences are present on the Y Chromosome (Chr) and that a >25 kbp genomic sequence, which contains the two proviral genomes, has been amplified on the Y Chr. Two discrete amplified families of MuRVY retroviral genomes distinguishable by a polymorphic restriction site were detected, suggestive that amplification occurred in incremental stages. The presence of MuRVY-related DNA sequences, but absence of IAPE-Y-related DNA sequences in Mus spretus suggests that the IAPE-Y retrotransposition event occurred after the evolutionary divergence of the lineages leading to Mus musculus and Mus spretus, and that the amplification of MuRVY occurred independently in the two lineages.

Animals↗

An arrayed library enriched in hncDNA corresponding to transcribed sequences of human chromosome 19: preparation and analysis.

A simple technique for preparation of libraries of the human chromosome specific transcribed sequences is developed. It uses hnRNA from human-rodent hybrid cell lines containing particular human chromosomes or their fragments and includes three stages: (i) reverse transcription of the hnRNA with Alu-specific primers directing the transcription beyond the Alu-repeats to flanking non-repetitive sequences of the chromosome; (ii) nested primer PCR strategy with specifically designed primers; (iii) direct selective cloning of the second-stage nested primer PCR products. An arrayed hncDNA library was prepared from a hybrid cell line containing chromosome 19 and fragments of 22 and X chromosomes. The library contains around 98% of human-specific transcribed sequences. Sequences of 52 human-specific, according to PCR analysis, clones differed from each other and had no close analogs in the EMBL Data Bank. Of 17 clones assigned to certain human chromosomes, 9 belonged to chromosome 19, 5 to chromosome 22 and 3 to chromosome X. Some of the human specific clones contained repetitive elements scattered over different human chromosomes. Clones from hncDNA libraries are useful as STSs/ESTs, as probes for detecting full-size genes in genomic libraries, for RFLP analysis and for identification of chromosome specific cDNAs.

Animals↗

Chromosome landing: a paradigm for map-based gene cloning in plants with large genomes.

The original concept behind map-based or positional cloning was to find a DNA marker linked to a gene of interest, and then to 'walk' to the gene via overlapping clones (e.g. cosmids or YACs). While chromosome walking is straightforward in organisms with small genomes, it is difficult to apply in most plant species, which typically have large, complex genomes. The strategy of chromosome walking is based on the assumption that it is difficult and time consuming to find DNA markers that are physically close to a gene of interest. Recent technological developments invalidate this assumption for many species. As a result, the mapping paradigm has now changed such that one first isolates one or more DNA marker(s) at a physical distance from the targeted gene that is less than the average insert size of the genomic library being used for clone isolation. The DNA marker is then used to screen the library and isolate (or 'land' on) the clone containing the gene, without any need for chromosome walking and its associated problems. Chromosome landing, together with the technology that has made it possible, is likely to become the main strategy by which map-based cloning is applied to isolate both major genes and genes underlying quantitative traits in plant species.

Chromosome Mapping↗

Identification and cloning of three novel human G protein-coupled receptor genes GPR52, PsiGPR53 and GPR55: GPR55 is extensively expressed in human brain.

The G protein-coupled receptor (GPCR) family share a structural motif of seven transmembrane segments with large numbers of conserved residues in those regions. Here, we report the identification and cloning of two novel human intronless GPCR genes, GPR52, GPR55 and a pseudogene PsiGPR53. GPR55 was identified from the expressed sequence tags (EST) database whereas GPR52 and pseudogene PsiGPR53 originated from the high throughput genome (HTG) database. A partial cDNA clone obtained from the IMAGE Consortium of GPR55 was used to screen a human genomic library to acquire the full length gene. GPR52 and PsiGPR53 were amplified from human genomic DNA using primers based on the HTG sequences. GPR55 and GPR52 encode receptors of 319 and 361 amino acids, respectively. GPR55 gene was mapped to chromosome 2q37, using fluorescence in situ hybridization (FISH), and its mRNA transcripts have been detected in the caudate nucleus and putamen, but not in five other brain regions. Human receptors showing the highest amino acid identity to GPR55 include P2Y5 (29%), GPR23 (30%), GPR35 (27%) and CCR4 (23%). GPR52 gene localized to chromosome 1q24 shares the highest identity with GPR21 (71%), histamine H2 (27%) and 5-HT4 (26%) human receptors. PsiGPR53 is a pseudogene mapped to chromosome 6p21 that demonstrates the highest similarity to the MRG (35%), MAS (28%) and C5a (24%) human receptor genes.

Amino Acid Sequence↗

Characterization of the gene encoding human TAFI (thrombin-activable fibrinolysis inhibitor; plasma procarboxypeptidase B).

Thrombin-activable fibrinolysis inhibitor (TAFI) is a recently described human plasma zymogen that is related to pancreatic carboxypeptidase B. The active form of TAFI (TAFIa), which is formed by thrombin cleavage of the zymogen, likely inhibits fibrinolysis by removal from partially degraded fibrin of the carboxyl-terminal lysine residues which act to stimulate plasminogen activation. We have isolated and characterized genomic clones which encompass the entire human TAFI gene from lambda phage and bacterial artificial chromosome genomic libraries. The complete TAFI gene contains 11 exons and spans approximately 48 kb of genomic DNA. The positions of intron/exon boundaries are conserved between the TAFI gene and the rat pancreatic carboxypeptidase A1, A2, and B and the human mast cell carboxypeptidase A genes, indicating that these carboxypeptidases arose from a common ancestral gene. However, the intron lengths diverge significantly among all of these genes. The TAFI promoter lacks a consensus TATA sequence, and transcription is initiated from multiple sites. Transient transfection of reporter plasmids containing portions of the TAFI 5'-flanking region into mammalian cells allowed localization of the promoter and identified a approximately 70 bp region crucial for liver-specific transcription. Sequence analysis of cDNA clones obtained from human liver RNA indicated that the TAFI transcript is polyadenylated at three different sites. Our findings will facilitate the assessment of the regulation of TAFI expression by transcriptional and/or posttranscriptional mechanisms. Furthermore, knowledge of the genomic structure of the TAFI gene will aid in the identification of mutations that may be associated with the tendency to either bleed or thrombose.

3' Untranslated Regions↗

The STR120 satellite DNA of soybean: organization, evolution and chromosomal specificity.

A highly repeated DNA sequence family, STR120, with tandemly arranged repetitive units (monomers) of approximately 120bp, has been identified in soybean [Glycine max (L.) Merr.]. Five related clones showing tandem repeats of a 120-bp-long monomer were isolated from a soybean genomic library. Results of Southern blotting experiments using three of the clones as probes onto genomic DNA digested with different restriction enzymes were in agreement with a tandem arrangement of these sequences in the genome. A total of 12 monomers were sequenced, showing considerable sequence heterogeneity. A consensus sequence of 126 bp was obtained that exhibits an average similarity of 81% to the sequenced units. In three of the clones identified, neighbouring units are significantly more similar to each other than to units from different clones; in the remaining two clones, however, similarity between the two units observed is low (70%), while the overall similarity between the two clones is high (95%). This indicates that in these cases the repetitive unit may be the dimer rather than the monomer. Based on the presence of direct repeats within each monomer, we suggest that the 120-bp monomer may itself have evolved by duplication of an ancestral 60-bp unit. The STR120 family distribution is limited to annual soybeans and is not found, at least at high-copy number, in related perennial soybeans or other members of the tribe Phaseolae. Fluorescence in situ hybridization (FISH) to metaphase chromosomes using four of the clones as probes shows that the number of chromosomal locations differs depending on the stringency conditions and goes from two to eight when the stringency is progressively lowered. The estimated copy number for one of the clones is from 5000 to 10000, but this may just represent a lower boundary for the whole family in consideration of the high sequence divergence observed within the family. FISH and sequence analysis therefore indicate that different subfamilies as well as higher-order repeat units are present in the STR120 family, very much like those in primate alpha satellite DNA, and that some of the subfamilies seem to exhibit divergence on a chromosomal basis.

Base Sequence↗

Evolution and organization of the fibrinogen locus on chromosome 4: gene duplication accompanied by transposition and inversion.

Human fibrinogen cDNA probes for the alpha-, beta-, and gamma-polypeptide chains have been used to isolate the corresponding genes from human genomic libraries. There is a single copy of each gene. Restriction endonuclease analysis of isolated genomic clones and human genomic DNA indicates that the human alpha-, beta-, and gamma-fibrinogen genes are closely linked in a 50-kilobase region of a single human chromosome: the alpha-gene in the middle flanked by the beta-gene on one side and the gamma-gene on the other. The alpha- and gamma-chain genes are oriented in tandem and transcribed toward the beta-chain gene. The beta-chain gene is transcribed from the opposite DNA strand toward the gamma- and alpha-chain genes. The three genes have been localized to the distal third of the long arm of chromosome 4, bands q23-q32, by in situ hybridization with fibrinogen cDNAs and by examination of DNA from multiple rodent-human somatic cell hybrids. Alternative explanations for the present arrangement of the three fibrinogen genes involve either a three-step mechanism with inversion of the alpha/gamma-region or a two-step mechanism involving remote transposition and inversion. The second more simple mechanism has a precedent in the origin of repeated regions of the fibrinogen and immunoglobulin genes.

Biological Evolution↗

Sequence investigation of the major gastrointestinal tumor-associated antigen gene family, GA733.

The monoclonal antibody-defined, tumor-associated antigen GA733 was purified from the SW948 human colorectal carcinoma cell line and its partial amino acid sequence was determined. By using a synthetic oligonucleotide probe, two recombinants were isolated from a total human genomic library. We prove the existence of a family of GA733 genes. One of the genomic isolates is demonstrated to be an intronless gene, which is transcribed in pancreatic carcinoma cell lines and in placenta. The GA733 proteins were observed to contain sequences homologous to a repeat unit occurring 10 times in thyroglobulin and once in the HLA-DR-associated invariant chain. A more evolutionarily distant relationship was found with the alpha chain of the interleukin 2 growth factor receptor.

Amino Acid Sequence↗

Complementation of a glucose transporter mutant of Schizosaccharomyces pombe by a novel Trypanosoma brucei gene.

The African trypanosome Trypanosoma brucei has a digenetic life cycle that involves the insect vector and the mammalian host. This is underscored by biochemical switches in its nutritional requirements. In the insect vector, the parasite relies on amino acid catabolism, but in the mammalian host, it derives its energy exclusively from blood glucose. Glucose transport is facilitated, and constitutes the rate-limiting step in ATP synthesis. Here, we report the cloning of a novel glucose transporter-related gene by heterologous screening of a lambdaEMBL4 genomic library of T. brucei EATRO 164 using a rat liver glucose transporter cDNA clone. Genomic analysis shows that the gene is present as a single copy within the parasite genome. The gene encodes a protein with an estimated molecular mass of 55.9 kDa, which shares only segmental homology with members of the glucose transporter superfamily. Several potential post-translational modification sites including phosphorylation, N-glycosylation, and cotranslational myristoylation sites also punctuate the sequence. It is distinguished from classical transporter proteins by the absence of putative hydrophobic membrane-spanning domains. However, this protein was capable of complementing Schizosaccharomyces pombe glucose transporter mutants. The rescued phenotype conferred the ability of the cells to grow on a broad range of sugars, both monosaccharides and disaccharides. The kinetics of glucose uptake reflected those in T. brucei. In addition to complementation in yeast, we also showed that the gene enhanced glucose uptake in cultured mammalian cells.

Amino Acid Sequence↗

DNA sequence determination by hybridization: a strategy for efficient large-scale sequencing.

The concept of sequencing by hybridization (SBH) makes use of an array of all possible n-nucleotide oligomers (n-mers) to identify n-mers present in an unknown DNA sequence. Computational approaches can then be used to assemble the complete sequence. As a validation of this concept, the sequences of three DNA fragments, 343 base pairs in length, were determined with octamer oligonucleotides. Possible applications of SBH include physical mapping (ordering) of overlapping DNA clones, sequence checking, DNA fingerprinting comparisons of normal and disease-causing genes, and the identification of DNA fragments with particular sequence motifs in complementary DNA and genomic libraries. The SBH techniques may accelerate the mapping and sequencing phases of the human genome project.

Animals↗