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At least 19 recordsLinked to original sources
PubMed1992

Hybridization fingerprinting of high-density cDNA-library arrays with cDNA pools derived from whole tissues.

As part of an integrated mapping and sequencing analysis of genomes, we have developed an approach allowing the characterization of large numbers of cDNA library clones with a minimal number of experiments. Three basic elements used in the analysis of cDNA libraries are responsible for the high efficiency of this new approach: (1) high-density library arrays allowing thousands of clones to be screened simultaneously; (2) hybridization fingerprinting techniques to identify clones abundantly expressed in specific tissues (by hybridizations with labeled tissue cDNA pools) and to avoid the repeated selection of identical clones and of clones containing noncoding inserts; and (3) a computerized system for the evaluation of hybridization data. To demonstrate the feasibility of this approach, we hybridized high-density cDNA library arrays of human fetal brain and embryonal Drosophila with radiolabeled cDNA pools derived from whole mouse tissues. Fingerprints of the library arrays were generated, localizing clones containing cDNA sequences from mRNAs expressed at middle to high abundance (> 0.1-0.15%) in the respective tissue. Partial sequencing data from a number of clones abundantly expressed in several tissues were generated to demonstrate the value of the approach, especially for the selection of cDNA clones for the analyses of genomes based on expressed sequence tagged sites. Data obtained by the technique described will ultimately be correlated with additional transcriptional and sequence information for the same library clones and with genomic mapping information in a relational database.

Animals↗
PubMed1992

cDNA cloning of a novel heterogeneous nuclear ribonucleoprotein gene homologue in Caenorhabditis elegans using hamster prion protein cDNA as a hybridization probe.

The mammalian prion protein (PrPc) is a cellular protein of unknown function, an altered isoform of which (PrPsc) is a component of the infectious particle (prion) thought to be responsible for spongiform encephalopathies in humans and animals. The evolutionary conservation of the PrP gene has been reported in the genomes of many vertebrates as well as certain invertebrates. In the genome of nematode Caenorhabditis elegans, the sequence capable of hybridizing with the mammalian PrP cDNA probe has been demonstrated, predicting the presence of the PrP gene homologue in C.elegans. In this study, Southern analysis with the hamster PrP cDNA (HaPrP) probe confirmed the previous observation. Moreover, Northern analysis revealed that the sequence is actively transcribed in adult worms. Thus, we screened C.elegans cDNA libraries with the HaPrP probe and isolated a cDNA that hybridizes to the same sequence in C.elegans that hybridized with the HaPrP probe in the Southern and Northern analyses. The deduced amino acid sequence of this cDNA, however, is substantially homologous with heterogeneous nuclear ribonucleoprotein (hnRNP) core proteins rather than mammalian PrPc. The hnRNPs contain the glycine-rich domain in the C-terminal half of the molecule, which also seemed to be in PrPc at the N-terminal half of the molecule. Both of the glycine-rich domains are composed of tracts with high G + C content, indicating that these tracts may due to the hybridizing signals. These results suggest that this cDNA clone is derived from a novel hnRNP gene homologue in C.elegans but not from a predicted PrP gene homologue.

Amino Acid Sequence↗
PubMed1992

cDNA clones for mouse parotid proline-rich proteins. mRNA regulation by isoprenaline and the nucleotide sequence of proline-rich protein cDNA MP5.

cDNA clones for mRNA sequences regulated by isoprenaline in mouse parotid glands were identified by differential colony hybridisation and all hybridised to a diagnostic proline-rich protein (PRP) oligonucleotide. They were divided into two cross-hybridisation groups, A and B, which were shown by hybrid-selected translations to encode acidic PRP and basic PRP, respectively. The A-type subgroup consisted of sequences homologous to the previously identified mouse PRP genes MP2 and MP3. The B-type subgroup comprised clones for the previously identified cDNA pUMP125 (MP4) as well as other PRP sequences. Six of the B-type clones contained a novel PRP cDNA (MP5) and these were sequenced. The composite MP5 cDNA was 897 nucleotides long and contained an open reading frame capable of encoding a 260-residue-long salivary PRP precursor (30% Pro, 19% Gln and 18% Gly), containing nine variant repeat units of consensus PGNQQGPPPQGGPQQ(GPP)R(PPQ). MP5 was 80% identical to the sequence of MP4 and had a high degree of similarity (60%) at its 3'-untranslated region to rat salivary glutamate/glutamine-rich protein (GRP) cDNA. Two MP5 clones contained a 273-bp intron-like insertion in the 3' untranslated region, being derived, therefore, from incompletely spliced MP5 transcripts. Northern blotting showed that, although PRP mRNA species were induced by isoprenaline, a B-type PRP mRNA was present in normal parotid glands. RNA dot-blots probed with PRP-gene-specific oligonucleotides established that MP3, MP4 and MP5 PRP mRNA were all induced by isoprenaline.

Amino Acid Sequence↗
PubMed1992

Nucleotide sequence of cDNA clones encoding the beta subunit of mitochondrial ATP synthase from the green alga Chlamydomonas reinhardtii: the precursor protein encoded by the cDNA contains both an N-terminal presequence and a C-terminal extension.

cDNA and genomic clones encoding the beta subunit of mitochondrial ATP synthase from Chlamydomonas reinhardtii have been isolated using heterologous DNA probes from the photosynthetic bacterium Rhodospirillum rubrum. The protein encoded by the cDNA is 79-83% identical to corresponding proteins from higher-plant and mammalian mitochondria, and 75% identical to the R. rubrum protein. It contains both an N-terminal presequence and a unique C-terminal extension. The presequence, which is the first mitochondrial presequence determined in C. reinhardtii, is similar in structure to mitochondrial presequences from other organisms. As chloroplast presequences from C. reinhardtii also share features with mitochondrial presequences from other organisms (L.-G. Franzén et al., FEBS Lett 260 (1990) 165-168), this raises interesting questions about protein targeting to chloroplasts and mitochondria in C. reinhardtii. The possibility that the C-terminal extension is involved in targeting the protein to the mitochondrion is discussed. Southern blot analysis indicates that the protein is encoded by a single-copy gene.

Amino Acid Sequence↗
PubMed1992

A novel endothelial tyrosine kinase cDNA homologous to platelet-derived growth factor receptor cDNA.

Degenerate oligonucleotide primers complementary to the highly conserved subdomains III and VIII of subclass III tyrosine kinase receptors (TKr-III) were utilized to amplify rat aortic cDNA by polymerase chain reaction. Most of the cloned DNA products were rat platelet-derived growth factor receptor beta and macrophage-colony stimulating growth factor receptor cDNAs. Screening of the clones with probes coding for the receptor-specific kinase insert domain allowed the identification of a novel putative TKr-III cDNA, which hybridized with a approximately 6.1 kb mRNA with a distinctive tissue distribution. In situ hybridization on rat tissues and Northern analysis of cultured cells indicate that endothelial cells express a novel putative TKr-III mRNA.

Amino Acid Sequence↗
PubMed1992

Isolation of cDNA sequences around the chromosomal breakpoint in a female with Lowe syndrome by direct screening of cDNA libraries with yeast artificial chromosomes.

The Lowe oculocerebrorenal syndrome (OCRL; McKusick 309000) is an X-linked disorder characterized by congenital cataracts, muscular hypotonia, mental retardation, and Fanconi syndrome of the renal tubules. A pair of yeast artificial chromosomes (YACs) that span the Xq25-q26 translocation breakpoint in a female with OCRL were used as probes to screen cDNA libraries made from bovine lens and human kidney. The methods used to prepare the YACs as probes and to screen the libraries are presented in detail. Two different transcripts were found that map to the region around the Xq25-q26 breakpoint. These transcripts are now being studied to determine whether one or the other is a candidate gene for OCRL.

Blotting, Southern↗
PubMed1992

Molecular evolution of phosphoenolpyruvate carboxylase for C4 photosynthesis in maize: comparison of its cDNA sequence with a newly isolated cDNA encoding an isozyme involved in the anaplerotic function.

Molecular events associated with the evolution of an enzyme for C4 photosynthesis were investigated. In maize, at least three isozymes of phosphoenolpyruvate carboxylase [EC 4.1.1.31] are known: the C4-form, the C2-form and the root-form, being named according to their physiological roles and pattern of tissue distribution [Ting, I.P. & Osmond, C.B. (1973) Plant Physiol. 51, 448-453]. A cDNA clone which presumably encodes the C3-form isozyme was newly isolated and analyzed. Comparison of the sequences of the C3-form and C4-form isozymes revealed that (i) the homologies in the nucleotide and deduced amino acid sequences were 71 and 77%, respectively, and (ii) the gene for the C4-form isozyme evolved under strong G/C pressure. The genes for these isozymes were found to be located apart on different chromosomes. A phylogenetic tree was constructed using 8 amino acid sequences of phosphoenolpyruvate carboxylases from various sources. The topology of the tree indicated that, at least in monocots such as maize and sorghum, the genes for the C4-form and C3-form isozymes diverged from their common ancestral gene earlier than the monocot-dicot divergence (about 2 x 10(8) yr ago), though the divergence of maize (C4 plant) from wheat (C3 plant) is supposed to have occurred much later (6 x 10(7) yr ago).

Amino Acid Sequence↗
PubMed1992

A region of antisense RNA from human p120 cDNA with high homology to mouse p120 cDNA inhibits NIH 3T3 proliferation.

The human nucleolar p120 protein is a proliferation-associated antigen which is expressed in G1 and peaks during the early S phase of the cell cycle. Overexpression of the human p120 protein caused the transformation of NIH 3T3 cells and expression of an antisense p120 construct inhibited the growth of NIH 3T3 cells (Perlaky et al., Cancer Res., 52:428-436, 1992). The middle region of the antisense p120 RNA was found to be almost as inhibitory as the full length antisense construct but the 5' and 3' antisense portions did not affect NIH 3T3 cell proliferation. After the mouse p120 complementary DNA was cloned and sequenced, comparison with the human p120 complementary DNA showed a striking conservation of 85% of the nucleotide sequence and 96% of the amino acid sequence. The two ends of the p120 molecule had less homology in their nucleotide and amino acid sequences. Based on this homology, the observed inhibitory effects of the middle portion of antisense human p120 RNA may be related to suppression of mouse p120 expression by RNA:RNA duplex formation. The high evolutionary conservation of the middle region suggests it has a critical role for the function of this protein.

3T3 Cells↗
PubMed1977

Purification of biologically active globin mRNA using cDNA-cellulose affinity chromatography.

A complementary DNA (cDNA) copy of mouse globin mRNA was synthesized using the RNA-dependent DNA polymerase from avian myeloblastosis virus and the oligo(dT) covalently attached to cellulose as primer. All four deoxyribonucleotide triphosphates, NaCl, the globin mRNA template, and an oligo(dT) primer were required for optimal synthesis of cDNA. By saturating the primer sites using a 3-fold excess of mRNA, sufficient concentrations of immobilized cDNA could be synthesized to allow the hybridization reactions to be performed using an excess of globin cDNA. Conditions which permitted the annealing of globin mRNA to cDNA-cellulose were selected and the sequence specificity for hybridization to cDNA-cellulose was determined using 28 S ribosomal RNA, polyadenylic acid, and mouse L-cell RNA. Both analytical and preparative applications of this chromatographic medium were explored. When radioactively labeled poly(A)-containing 9 S RNA isolated from nucleated erythroid cells was analyzed by affinity chromatography on globin cDNA-cellulose, 46 per cent of the applied radioactivity hybridized to the cDNA-cellulose column. Only 1 per cent of the labeled RNA was retained by the column during reapplication of the unbound fraction, while 96 per cent of the bound RNA reannealed to cDNA-cellulose. Hybridizations utilizing unfractionated RNA extracts from either mouse reticulocytes or nucleated erythroid cells provided a one-step purification method for globin mRNA sequences. The relative purity of the RNA isolated by cDNA-cellulose affinity chromatography was determined by hybridization kinetic analysis. The cDNA-bound fraction obtained from the unfractionated RNA of either cell type was shown to have a Crt1/2 of 2.7 x 10-3. This represents a 60-fold purification of the globin sequences present in reticulocyte polysomal RNA and a 280-fold enrichment of the globin mRNA in nucleated erythroid cells. Hybridization to cDNA-cellulose did not result in any change in the sedimentation rate of globin mRNA. Furthermore, experiments were performed which demonstrated that the globin mRNA isolated by hybridization to cDNA-cellulose retained its biological activity when assayed in a wheat germ cell-free lysate.

Animals↗
PubMed1990

The isolation and identification of cDNA genes by their heterologous expression and function.

Functional cDNA genes for cell surface proteins, receptors, growth factors and nuclear and cytoplasmic proteins can be isolated by a heterologous expression-function gene isolation strategy. The method of this strategy is dependent on highly efficient mammalian expression vectors, the properties of COS cells as hosts for SV40-origin-containing mammalian expression vectors, the well-established technology of constructing highly complex plasmid cDNA libraries and on the sensitivity of biological assays. These technologies are combined to identify a specific gene sequence by its biological phenotype. In theory this can be accomplished by individually testing each single gene of the cDNA library by expression in COS cells. In practice complex cDNA libraries are formed so that multiple cDNA genes can be tested and analyzed simultaneously. When the biological assay can discriminate phenotypic changes at the single cell level as typified by cellular morphology, cell membrane proteins or receptors or intracellular enzymes, then a reiterative expression screening method can be used. This was demonstrated by the isolation of cDNA genes encoding cell membrane proteins (7-10, 12). For the isolation of cDNA genes for growth factors and cytoplasmic enzymes by the expression-function cDNA gene isolation strategy, an alternative method is followed. The cDNA library is partitioned into sets of cDNA clones for transfection and analysis. The number of clones in a set is dependent on the efficiency of the expression vector used and on the sensitivity of the biological assay. For secreted cytokines and growth factors which can be simply detected by factor dependent cell lines, about 1,000 cDNA clones can be tested as a single set. By this strategy the genes for numerous hematopoietic growth factors, cytokines and interleukins have been isolated. With such numerous successes we can expect that the heterologous expression-function cDNA gene isolation strategy will become an important molecular biology method.

Animals↗
PubMed1992

Efficiency and limitations of the hn-cDNA library approach for the isolation of human transcribed genes from hybrid cells.

The use of splice donor site consensus sequences as primers in cDNA synthesis (to make a cDNA library from heterogeneous RNA or unprocessed transcript--an hn-cDNA library) and the screening of such an hn-cDNA library with human repeat DNA probe in order to isolate human genes from somatic cell hybrids have been demonstrated. Here, we optimize and evaluate the efficiency and limitations of the approach. Computer analysis of genomic sequences of 22 randomly selected human genes indicated that hexamers CTTACC, CTCACC, and CCTACC were most efficient at beginning first-strand cDNA synthesis at donor splice sites of hnRNA and suggested that the procedure is efficient for priming cDNA synthesis of at least one exon from most every gene. Primer extension experiments established conditions in which the primers would initiate synthesis of cDNA starting from a perfectly matched position on the RNA template at more than 60-fold higher yield than any other product. By isolation of a clone containing exon III of the human DNA repair gene ERCC1, we indicate that the approach is capable of cloning exons from weakly expressed genes. Sequencing of clones revealed a structure of hn-cDNA clones consistent with the expectations of the cloning strategy and indicated the potential of the clones in detecting polymorphisms. Finally, we demonstrate that the expression of these hn-cDNA sequences in cells can be detected efficiently at the hnRNA level by reverse transcriptase-polymerase chain reaction (RT/PCR).

Animals↗
PubMed1992

Characterization of a fusion cDNA (RARA/myl) transcribed from the t(15;17) translocation breakpoint in acute promyelocytic leukemia.

A nonrandom chromosomal translocation breakpoint, t(15;17)(q22;q21), is found in almost all patients with acute promyelocytic leukemia (APL). Most of these breakpoints occur within the second intron of the retinoic acid receptor-alpha (RARA) gene. We screened a cDNA library of APL and have identified and sequenced a cDNA transcribed from the t(15;17) translocation breakpoint. The 5' end of cDNA p1715 consists of 503 bp of the RARA exon II sequence. A 1.76-kb cDNA without homology to any known gene available in GenBank was found truncated downstream. This cDNA sequence was assigned to chromosome 15 by dot blot hybridization of the flow cytometry-sorted chromosomes. We designate this fusion cDNA RARA/myl, which is different from myl/RARA reported by de The et al. (H. de The, C. Chomienne, M. Lanotte, L. Degos, and A. Dejean, Nature (London) 347:558-561, 1990). This result demonstrates that the two different types of hybrid mRNA can be transcribed from this breakpoint. We screened a non-APL cDNA library and identified a 2.8-kb myl cDNA. This cDNA is able to encode a polypeptide with a molecular weight of 78,450. Alternative splicing of the myl gene which resulted in myl proteins with different C terminals was found. Southern blot analysis of the genomic DNA isolated from 17 APL patients by using the myl DNA probe demonstrated that the myl gene in 12 samples was rearranged. Northern (RNA) blot analysis of RARA gene expression in two APL RNA samples showed abnormal mRNA species of 4.2 and 3.2 kb in one patient and of 4.8 and 3.8 kb in another patient; these were in addition to the normal mRNA species of 3.7 and 2.7-kb. The myl DNA probe detected a 2.6-kb abnormal mRNA in addition to the normal mRNA species of 3.2, 4.2, and 5.5 kb. Using the polymerase chain reaction, we demonstrated that both RARA/myl and myl/RARA were coexpressed in samples from three different APL patients. From this study, we conclude that the t(15;17) translocation breakpoint results in the transcription of two different fusion transcripts which are expected to be translated into fusion proteins.

Amino Acid Sequence↗
PubMed1992

Rapid isolation of desired sequences from lone linker PCR amplified cDNA mixtures: application to identification and recovery of expressed sequences in cloned genomic DNA.

A simple and efficient method for the rapid isolation of specific sequences from PCR-amplified cDNA mixtures has been developed. cDNA mixtures obtained using lone linker PCR (Ko et al. 1990) appeared to be highly representative even though the starting material, 100 ng-2 micrograms of total RNA, is much less than is required for making an ordinary cDNA library. With this method, cDNA mixtures were obtained from limited materials, including early mouse embryos and primordial germ cells. For selective enrichment of desired cDNAs, biotinylated probe was hybridized with the lone linker-linked cDNA in solution and the resulting probe-cDNA hybrid was captured by Streptavidin-coated magnetic beads. After appropriate washing, cDNA was released from the beads and subjected to amplification followed by cloning into a vector. Using genomic fragments isolated during chromosomal walking in the T/t complex of mouse Chromosome (Chr) 17, cDNAs encoding novel germ cell specific genes have been readily isolated by the above procedures. The method, termed random access retrieval of genetic information through PCR (RARGIP), will streamline the entire process from RNA to cDNA greatly. Its application potentials in various areas of molecular genetics will be discussed.

Animals↗
PubMed1992

Mechanism of interferon action: cDNA structure, expression, and regulation of the interferon-induced, RNA-dependent P1/eIF-2 alpha protein kinase from human cells.

A molecular cDNA clone (P1 KIN) was isolated that encodes the human RNA-dependent P1/eIF-2 alpha protein kinase. The complete cDNA sequence of the P1 KIN cDNA was determined; the longest open reading frame (ORF) encoded a 551 amino acid protein with a deduced molecular weight of 62055 Da. Transcripts prepared from the P1 KIN cDNA by transcription in vitro with T7 RNA polymerase programmed the cell-free synthesis of a protein indistinguishable by immunoprecipitation and immunoblot gel analyses from the authentic 67-kDa P1 protein synthesized in human U cells treated with interferon (IFN). Furthermore, by use of a sensitive primer extension assay with T7 DNA polymerase, the major site of translation initiation within the deduced ORF of the P1 KIN cDNA was directly identified. Northern RNA gel-blot analysis revealed that the P1 KIN cDNA strongly hybridized to two IFN-induced mRNAs present in both human amnion U cells and HeLa cells; their sizes were 2.5 and 6 kb. Both transcripts were efficiently induced by IFN-alpha, but poorly by IFN-gamma. Polyclonal antibody was prepared against the product of the P1 KIN cDNA expressed in Escherichia coli. In Western blot analysis the antibody recognized a 67-kDa protein induced in human cells by IFN-alpha and, in addition, a 90-kDa protein whose level was not greatly altered by IFN treatment. The IFN-induced 67-kDa protein was found associated with the ribosomal salt-wash fraction of IFN-treated human cells, whereas the 90-kDa protein was predominantly in the S100 soluble fraction. The time course for the induction by IFN-alpha of RNA-dependent protein P1 kinase activity measured by immunoprecipitation was comparable to the time course for protein P1 induction measured by Western immunoblot analysis. The amino acid sequence of P1/eIF-2 alpha protein kinase deduced from the cDNA was 62% identical with the 518-residue murine TIK kinase and contained, within the carboxy-terminal half of the protein, the motifs commonly conserved among protein-serine/threonine kinases. The amino-terminal half of the P1 protein did not possess conserved kinase motifs, but did show extensive homology with vaccinia virus-predicted protein E3L.

Amino Acid Sequence↗
PubMed1992

Molecular cloning of a cDNA for rat diabetes-inducible cytochrome P450RLM6: hormonal regulation and similarity to the cytochrome P4502E1 gene.

1. A polyclonal, monospecific antibody to a constitutive, diabetes-inducible and insulin-reversible cytochrome P-450 isozyme (RLM6) was used to screen a male rat liver cDNA library in lambda gt 11. Six clones harbouring the RLM6 cDNA insert were isolated initially from the expression library and three of these were further plaque-purified and sub-cloned. A 1.1 Kb cDNA insert, representing approximately 65% of the expected full length cDNA was characterized by restriction endonuclease mapping and sequenced by the dideoxy chain-termination method. Comparison of the nucleotide sequence of RLM6 cDNA to that of ethanol-inducible P4502E1 rat cDNA showed the two cDNAs to be identical, the RLM6 cDNA corresponding to nucleotides 310-1402 of the P4502E1 sequence. 2. RLM6 cDNA probe was used in Northern blot and RNA dot blot hybridization analysis to demonstrate that both streptozotocin-induced diabetes and fasting significantly elevated the steady-state level of RLM6 mRNA in male rat liver. Increased RLM6 mRNA level in the diabetic rat resulted in increased RLM6 apoprotein synthesis when polysomal RNA was used in a cell-free, protein-synthesizing system, indicating that the elevated RLM6 level observed in diabetic rats was correlated directly with the increased RLM6 mRNA concentration. 3. Daily insulin treatment of diabetic rats reversed the diabetes-dependent increase in RLM6 mRNA in a time-dependent manner, returning to control values after approximately 2 weeks of continuous insulin treatment. This insulin-dependent decrease of the RLM6 mRNA level was paralleled by a similar time-dependent decrease in serum acetone concentration. 4. Treatment of the male diabetic rat with testosterone also resulted in a decrease in both RLM6 mRNA and in vitro translated apoprotein. 5. Modulation of RLM6 mRNA level in the diabetic rat by insulin and testosterone, and the nucleotide sequence similarity with that of P4502E1 confirms that diabetes-inducible P450RLM6 and ethanol-inducible P4502E1 are coded for by the same gene.

Amino Acid Sequence↗
PubMed1978

Cloning of a double-stranded cDNA that codes for a portion of chicken preproalbumin. A general method for isolating a specific DNA sequence from partially purified mRNA.

A scheme is presented for cloning a double-stranded cDNA molecule that codes for a portion of chicken preproalbumin. This method, which does not require pure mRNA or cDNA, has widespread applicability. Chicken preproalbumin was identified as a Mr = 72,000 polypeptide by immunoprecipitation of proteins synehesized in a wheat germ cell-free translation system from total, guanidine.HCl-extracted, rooster liver RNA. After removal of the bulk of the ribosomal RNA by poly(U)-Sephadex G-10 chromatography, albumin mRNA was enriched approximately 2-fold by centrifugation through low salt, isokinetic sucrose gradients, until it represented about 30% of the mRNA sequences present. Double-stranded cDNA prepared from this mRNA was then inserted into the Pst 1 site of the plasmid PBR322 by the "G-C tailing" technique and the recombinant DNA was used to transform Echerichia coli stran X1776. Transformants containing putative albumin DNA sequences were identified by colony hybridization with a cDNA probe that was highly enriched for albumin cDNA sequences. This probe was isolated by hybridizing the partially purified RNA preparation to its cDNA, under conditions of RNA excess, to a R0t value such that only the most abundant cDNA sequences had hybridized. Unhybridized, less abundant, sequences were destroyed by subsequent S1 nuclease digestion. The identity of clones that hybridized to this abundant class cDNA was established by DNA-mRNA hybrid-arrested cell-free translation. Hybridization of nick-translated, albumin-containing, plasmid DNA to total liver poly(A)+ RNA, that had been separated on methyl mercury agarose gels and transferred to diazobenzyloxymethyl paper, established that avian albumin mRNA has a molecular weight of 850,000. This molecular weight corresponds to approximately 2,600 nucleotides, or 600 nucleotides longer than the size required to code for the preproalbumin polypeptide.

Animals↗