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PubMed1978

Recharacterization of fungal dinucleoside polyphosphate (HS3).

Three polyphosphorylated dinucleosides given the pseudonyms of HS3, HS2, and HS1 that were erroneously described as diguanosine polyphosphates (LéJohn, H. B., Cameron, L. E., McNaughton, D. R. & Klassen, G. R. (1975) Biochem, Biophys, Res, Commun. 66, 460-467) have been repurified and partially recharacterized. They have proved to be extremely complex molecules; chemical (HCl and KOH hydrolysis), physical (ultraviolet-light spectral analysis and ion-exchange chromatography), and enzymic (nucleotide pyrophosphatase and bacterial alkaline phosphatase hydrolysis) studies showed that (i) all three HS compounds are uracil rich and (ii) only HS3 contains a purine nucleoside and glutamate. The partial structure of HS3 was deciphered as a moiety of ADP--sugar X--glutamate (the mode of attachment of glutamate is obscure) that is covalently linked to another moiety composed of UDP, mannitol, and four phosphates. Sugar X had chromatographic characteristics of ribitol, but the chromatographic isolate also contained a ninhydrin-sensitive entity presumed to be an amino group. Sugar X, THEREFore, may be an amino sugar polyol. Only the general chemical compositions of HS2 and HS1 were determined. Each contained two uridines and HS2 had 10 phosphates whereas HS1 had 12.

Adenosine Diphosphate↗
PubMed2006

Development of a 9600-clone procedure for oligonucleotide fingerprinting of rRNA genes: utilization to identify soil bacterial rRNA genes that correlate in abundance with the development of avocado root rot.

Oligonucleotide fingerprinting of rRNA genes (OFRG) is an array-based method that generates microbial community profiles through analysis of rRNA gene clone libraries. The original OFRG method allowed 1536 clones to be analyzed per experiment. This report describes a procedure for analyzing 9600 clones per experiment, including a new probe set for bacterial analysis, and improved data processing and statistical analysis tools. The software tools are available at the OFRG website (). Use of the 9600-clone procedure was demonstrated by examining the bacterial rRNA gene compositions of soils subjected to various temperature treatments. These treatments produced a series of soils with a range of abilities to suppress avocado root rot, enabling the identification of bacterial rRNA genes that correlate in abundance with root rot suppressiveness. OFRG analysis of these soils produced 8876 bacterial rRNA gene fingerprints grouped into 5123 clusters, or operational taxonomic units (OTUs). Eleven OTUs exhibited a positive correlation between the number of clones and the percentage of healthy roots. An in silico analysis was performed to examine the relationship between the number of rRNA genes analyzed and the number of correlates (rRNA gene-avocado root rot symptoms) identified. As the number of clones decreased, fewer correlates were identified. To further increase the throughput of the OFRG method, use of a glass slide-fluorescent probe microarray format was also explored.

DNA Fingerprinting↗
PubMed2004

Aptasensor development: elucidation of critical parameters for optimal aptamer performance.

Aptamers are synthetic oligonucleotides specifically selected to bind a certain target. Thanks to their high affinity and sensitivity, aptamers appear as alternative candidates to antibodies for analytical devices and several assays have been reported. However, and contrary to what happens with DNA probes, the aptamers' ability to bind their targets depends on folding and 3-D structure, which may be affected by the incubation conditions and buffer composition. In this report, a systematic evaluation of the parameters with potential effect on the ELAA (Enzyme Linked Aptamer Assay) performance has been carried out. Additionally, diverse ELAA and mixed ELISA/ELAA formats exploiting the thrombin-binding aptamer have been optimized and their efficiencies compared. ELAA results have been confirmed using nuclear magnetic resonance, electrophoresis, and surface plasmon resonance. Our results indicate that parameters such as immobilization strategy, incubation time/temperature, and buffer composition should be optimized for each aptamer as they affect folding and, thus, binding efficiency. Among the studied assays, the mixed ELISA/ELAA sandwich formats showed the lowest limit of detection observed (<1 nM thrombin), while a competition ELAA appeared as the best assay in terms of high sensitivity (1.8 nM) and short assay time (1 h, 30 min). The elucidation of optimal parameters for assay performance reported here clearly indicates that aptamers are unique structures. Formation of the 3-D structures required for target binding is influenced by variable parameters, and unlike DNA/antibody based assays, there are no general recommendations, with each assay requiring individual optimization of parameters.

Aptamers, Nucleotide↗
PubMed1998

Structure and expression of the mouse AhR nuclear translocator (mArnt) gene.

Aryl hydrocarbon receptor (AhR) nuclear translocator (Arnt) gene has been isolated and characterized from a mouse genomic DNA library. The gene is about 60 kilobases long and split into 22 exons. An unusual exon/intron junctional sequence was found in the 11th intron of the gene that begins with GC at its 5'-end. The exon/intron arrangement of mArnt gene differs greatly from those of the other members of the same basic-helix-loop-helix/PAS family. The gene is TATA-less and has several transcription start sites. The promoter region of the mArnt gene is GC-rich and contains a number of putative regulatory DNA sequences such as two GC-boxes, a cAMP-responsive element, E-box, AP-1 site, and CAAT-box. Deletion experiments revealed that all these DNA elements made substantial contributions to a high level of expression of the gene, except for the cAMP-responsive element. Of all, two GC-boxes displayed the most dominant enhancing effects. It was demonstrated that there exist specific factors binding to these DNA elements in the nuclear extracts of HeLa cells. Among them, Sp1 and Sp3, and CAAT-box binding factor-A were identified to bind the GC-boxes and CAAT-box, respectively. Expression of MyoD in HeLa cells stimulated the Arnt promoter activity by binding to the E-box.

Amino Acid Sequence↗
PubMed1999

The marine cyanobacterium Synechococcus sp. WH7805 requires urease (urea amidohydrolase, EC 3.5.1.5) to utilize urea as a nitrogen source: molecular-genetic and biochemical analysis of the enzyme.

Cyanobacteria assigned to the genus Synechococcus are an important component of oligotrophic marine ecosystems, where their growth may be constrained by low availability of fixed nitrogen. Urea appears to be a major nitrogen resource in the sea, but little molecular information exists about its utilization by marine organisms, including Synechococcus. Oligonucleotide primers were used to amplify a conserved fragment of the urease (urea amidohydrolase, EC 3.5.1.5) coding region from cyanobacteria. A 5.7 kbp region of the genome of the unicellular marine cyanobacterium Synechococcus sp. strain WH7805 was then cloned, and genes encoding three urease structural subunits and four urease accessory proteins were sequenced and identified by homology. The WH7805 urease had a predicted subunit composition typical of bacterial ureases, but the organization of the WH7805 urease genes was unique. Biochemical characteristics of the WH7805 urease enzyme were consistent with the predictions of the sequence data. Physiological data and sequence analysis both suggested that the urease operon may be nitrogen-regulated by the ntcA system in WH7805. Inactivation of the large subunit of urease, ureC, prevented WH7805 and Synechococcus WH8102 from growing on urea, demonstrating that the urease genes cloned are essential to the ability of these cyanobacteria to utilize urea as a nitrogen source.

Amino Acid Sequence↗
PubMed1990

Unorthodox expression of an enzyme: evidence for an untranslated region within carA from Pseudomonas aeruginosa.

The genes encoding carbamoylphosphate synthetase from Pseudomonas aeruginosa PAO1 were cloned in Escherichia coli. Deletion and transposition analysis determined the locations of carA, encoding the small subunit, and carB, encoding the large subunit, on the chromosomal insert. The nucleotide sequence of carA and the flanking regions was determined. The derived amino acid sequence for the small subunit of carbamoylphosphate synthetase from P. aeruginosa exhibited 68% homology with its counterparts in E. coli and Salmonella typhimurium. The derived sequences in the three organisms were essentially identical in the three polypeptide segments that are conserved in glutamine amidotransferases but showed low homology at the amino- and carboxy-terminal regions. The amino-terminal amino acid sequences were determined for the large and small subunits. The first 15 amino acids of the large subunit were identical to those derived from the carB sequence. However, comparison of the derived sequence for carA with the amino-terminal amino acid sequence for the small subunit suggested that codons 5 to 8 are not translated. The DNA sequence for the region encompassing these four codons was confirmed by direct sequencing of chromosomal DNA after amplification by the polymerase chain reaction. The mRNA sequence was also deduced by in vitro synthesis of cDNA, enzymatic amplification, and sequencing, confirming that 12 nucleotides in the 5' terminal of carA are transcribed but are not translated.

Amino Acid Sequence↗
PubMed1989

In vitro studies of interactions between frequent and unique mRNAs and cytoplasmic factors from brain tissue of several species of wild timber voles of northern Eurasia, Clethrionomys glareolus, Clethrionomys frater and Clethrionomys gapperi: a new criticism to a modern molecular-genetic concept of biological evolution.

As a result of the complex comparative neurochemical study of the translation machinery functioning in the brain cells of three conventionally "phylogenetically related" species of wild timber voles (Clethrionomys glareolus, Clethrionomys frater and Clethrionomys gapperi), it has been found that the cytoplasm of brain cells of the latter contain an oligonucleotide (oligoribonucleotide) factor(s) with mol. weight below 1.0 KD which is able completely and highly selectively to inhibit the translation directed by mRNA which are species-specific templates and which were isolated from analogical tissue (brain) of "closely related" organisms. This phenomenon was found for the first time using special Cell-Free Translation Systems (CFTS) of very different variants of their composition consisting of the following main components: Post-Mitochondrial Supernatant (PMS), total cytoplasmic poly(A)+ mRNA or a species-specific poly(A)+ mRNA isolated form the PMS by affinity chromatography on the columns with the anti-mRNA1-FAB-(CNBr)-Sepharose, or purified 9S or 11S globin or histone specific mRNAs, respectively, and, finally a few samples of the CFTS used contain the additions of high or low molecular weight cytosolic compounds isolated from S150 fraction by ultrafiltration on Diaflo UM2 membrane with an exclusion limit of 1.0 KD. All CFTs components listed were isolated separately from the brain tissue of each organism studied. A new complex way for construction and using of the CFTS leads to an adequately documented conclusion which suggested the existence of special, so far uncharacterized in detail, cytoplasmic oligoribonucleotide factor(s) for efficient blocking for the cytoplasmic expression of "evolutionally renovated part" of genome; i.e., these factors seem to be sufficiently powerful suppressors of the translation of every mRNA template if the latter is not usual for the cell type containing the cytoplasmic suppressors mentioned in the case of a "so-called" newly found (perhaps, due to spontaneous but nonlethal mutagenesis) genes expression at the level of mRNA functioning in the cytoplasm. All findings and ideas of the paper are under discussion.

Animals↗
PubMed1993

Structure, organization, and expression of the lct gene for lacticin 481, a novel lantibiotic produced by Lactococcus lactis.

The structural gene for the lactococcal lantibiotic lacticin 481 (lct) has been identified and cloned using a degenerated 20-mer DNA oligonucleotide based on the amino-terminal 7 amino acid residues of the purified protein. The transcription of the lct gene was analyzed, and its promoter was mapped. DNA sequence analysis of the lct gene revealed an open reading frame encoding a peptide of 51 amino acids. Comparison of its deduced amino acid sequence with the amino-terminal sequence and the amino acid composition of lacticin 481 indicates that the 51-residue peptide is prelacticin 481, containing a 27-residue carboxyl-terminal propeptide and a 24-residue amino-terminal leader peptide which lacks the properties of a typical signal sequence and which is significantly different from the leaders of other lantibiotics. The predicted amino acid sequence of prolacticin 481 contains 3 cysteines, 2 serines, and 2 threonines which were not detectable in amino acid analyses of mature lacticin 481. Based on these results and on characterization by two-dimensional NMR techniques, a structural model is proposed in which 2 cysteine residues are involved in lanthionine and one in beta-methyllanthionine formation, and a 4th threonine residue is dehydrated. This model predicts a molecular mass for lacticin 481 of 2,901, which is in excellent agreement with that obtained from mass spectrometry.

Amino Acid Sequence↗
PubMed1997

Relationships between genomic G+C content, RNA secondary structures, and optimal growth temperature in prokaryotes.

G:C pairs are more stable than A:T pairs because they have an additional hydrogen bond. This has led to many studies on the correlation between the guanine+cytosine (G+C) content of nucleic acids and temperature over the last 20 years. We collected the optimal growth temperatures (Topt) and the G+C contents of genomic DNA; 23S, 16S, and 5S ribosomal RNAs; and transfer RNAs for 764 prokaryotic species. No correlation was found between genomic G+C content and Topt, but there were striking correlations between the G+C content of ribosomal and transfer RNA stems and Topt. Two explanations have been proposed-neutral evolution and selection pressure-for the approximate equalities of G and C (respectively, A and T) contents within each strand of DNA molecules. Our results do not support the notion that selection pressure induces complementary oligonucleotides in close proximity and therefore numerous secondary structures in prokaryotic DNA, as the genomic G+C content does not behave in the same way as that of folded RNA with respect to optimal growth temperature.

Bacteria↗
PubMed1996

PCR-based development of DNA substrates containing modified bases: an efficient system for investigating the role of the exocyclic groups in chemical and structural recognition by minor groove binding drugs and proteins.

DNA molecules containing inosine in place of guanosine and/or 2,6-diaminopurine in place of adenine have been synthesized and tested as substrates for binding of sequence-selective ligands, both small and large. Footprinting patterns reveal that the binding sites for AT- or GC-specific antibiotics (distamycin or mithramycin, respectively) are completely changed in the modified DNAs, as expected for direct sequence readout involving contact with the purine 2-amino group. However, we also find large changes in the binding of HMG-D, a member of the HMG-1 family of chromosomal proteins, pointing to an indirect influence of the exocyclic amino group on ligand binding via an effect on the deformability of the double helix. This interpretation is confirmed by the finding that deoxyuridine-containing poly- and oligonucleotides, which lack the exocyclic methyl group of thymidine in the major groove, interact 5-10 times more strongly with HMG-D than do their counterparts containing natural nucleotides.

2-Aminopurine↗
PubMed2004

Sigma54 enhancer binding proteins and Myxococcus xanthus fruiting body development.

A search of the M1genome sequence, which includes 97% of the Myxococcus xanthus genes, identified 53 sequence homologs of sigma54-dependent enhancer binding proteins (EBPs). A DNA microarray was constructed from the M1genome that includes those homologs and 318 other M. xanthus genes for comparison. To screen the developmental program with this array, an RNA extract from growing cells was compared with one prepared from developing cells at 12 h. Previous reporter studies had shown that M. xanthus has initiated development and has begun to express many developmentally regulated genes by 12 h. The comparison revealed substantial increases in the expression levels of 11 transcription factors that may respond to environmental stimuli. Six of the 53 EBP homologs were expressed at significantly higher levels at 12 h of development than during growth. Three were previously unknown genes, and they were inactivated to look for effects on fruiting body development. One knockout mutant produced fruiting bodies of abnormal shape that depended on the composition of the medium.

Amino Acid Sequence↗
PubMed1982

Oligoadenylate is present in the mitochondrial RNA of Saccharomyces cerevisiae.

We examined Saccharomyces cerevisiae mitochondrial RNA for polyadenylate. Using hybridization to [3H]polyuridylate as the assay for adenylate sequences, we found adenylate-rich oligonucleotides approximately 8 residues long. Longer polyadenylate was not detected. Most of the adenylate-rich sequence is associated with the large mitochondrial rRNA. The remainder is associated with the 10-12S group of transcripts.

Base Composition↗
PubMed2001

Gene expression profile of the aging process in rat liver: normalizing effects of growth hormone replacement.

The mechanisms that control life span and age-related phenotypes are not well understood. It has been suggested that aging or at least some of its symptoms are related to a physiological decline in GH levels with age. To test this hypothesis, and to improve our understanding of the cellular and molecular mechanisms behind the aging process, we have analyzed age-induced changes in gene expression patterns through the application of DNA chip technology. In the present study, the aging process was analyzed in rat liver in the presence or absence of GH replacement. Out of 3,000 genes printed on the microarrays, approximately 1,000 were detected in the rat liver. Among these, 47 unique transcripts were affected by the aging process in male rat livers. The largest groups of age-regulated transcripts encoded proteins involved in intermediary metabolism, mitochondrial respiration, and drug metabolism. Approximately 40% of the differentially expressed gene products were normalized after GH treatment. The majority of those transcripts have previously not been shown to be under GH control. The list of gene products that showed normalized expression levels in GH-treated old rats may shed further insight on the action and mechanism behind the positive effects of GH on, for example, fuel metabolism and body composition observed in different animal and human studies.

Aging↗
PubMedDate not supplied

Polyion complex micelles with protein-modified corona for receptor-mediated delivery of oligonucleotides into cells.

Graft-copolymers, containing poly(ethylene glycol) (PEG) and polyethyleneimine (PEI) chains have been proposed as carriers for delivery of phosphorothioate oligonucleotides (SODNs). Complexes of such copolymers with SODN self-assemble into particles having a core of neutralized PEI and SODN and a corona of PEG. Transferrin molecules are attached to the PEG corona using avidin/biotin construct. For this purpose, biotin moieties are covalently linked to the free ends of the PEG chains in the PEG-g-PEI copolymer. SODNs are reacted with mixtures of biotinylated and biotin-free PEG-g-PEI copolymers of various compositions to adjust the number of the biotin moieties in the complex. Resulting complexes have small size (ca. 40 nm) and do not aggregate in aqueous solutions for at least several days. To attach transferrin, they are supplemented first with avidin and then with biotin-transferrin conjugate. This increases the effective diameter of the particles to ca. 75-103 nm, depending on the composition of the complex. Cellular accumulation and fluorescence microscopy studies characterize the effects of these modifications on interaction of fluorescently labeled SODNs with KBv cell monolayers. The data suggest significant enhancement of SODN association with cells resulting from modification of the complex with transferrin. SODN complimentary to the site 546-565 of human mdr 1-mRNA was used to inhibit expression of the drug efflux transporter, P-glycoprotein (P-gp), in multiple drug resistant (MDR) cancer cells (KBv, MCF-7 ADR). Accumulation of a P-gp specific probe, rhodamine 123, in the cell monolayers is used to characterize the effects on P-gp efflux system following the treatment of the cells with antisense SODN or its complexes. This study suggests that antisense SODN incorporated in the complexes retain the ability to inhibit P-gp efflux system, while complexes of the randomized control SODN are inactive. Therefore, the antisense SODN is released from the complex and interacts with its intracellular target upon interaction of the complexes with the cells. Furthermore, modification of the complexes with transferrin leads to a significant increase of the effects of the antisense SODN on the P-gp efflux system in the cells. Overall, this study suggests that polyion complex micelles with protein-modified corona are promising tools for the delivery of antisense SODN.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Elevated p21 mRNA level in skeletal muscle of DMD patients and mdx mice indicates either an exhausted satellite cell pool or a higher p21 expression in dystrophin-deficient cells per se.

Abnormalities in proliferation and differentiation of the dystrophin-deficient muscle are a controversial aspect of the pathogenesis of Duchenne muscular dystrophy (DMD). Analyses of molecules involved in cell cycle modulation do not exist in this context. Cells withdrawn from the cell cycle permanently express p21. The fact that p2 1, in contrast to other cell cycle proteins, is not diminished when myotubes are reexposed to growth media, allocates this cyclin-dependent kinase inhibitor a special function. Here we report for the first time statistically increased p21 mRNA levels in dystrophin-deficient muscle tissue. Only 42% of conventional RT-PCRs from six muscle samples of human controls yielded positive results but almost all skeletal muscle biopsy samples (87%) from DMD patients (n=5). For p21 mRNA quantification in murine muscle samples we were able to use the exact real-time TaqMan PCR method due to generally higher p21 mRNA levels than in human muscles. In addition, contamination with fibroblasts can be excluded for the murine samples because they do not demonstrate fibrosis at the age of 350 days but start to lose their regenerative capacity. In accord with the results in humans, we observed p21 mRNA levels in mdx mice that were approx. four times as high as those in control mice. Elevated p21 mRNA level may indicate a shift in cell composition towards differentiated p21 expressing cells as a result of an exhausted pool of undifferentiated, non-p21-expressing satellite cells due to previous cycles of de- and regeneration. Alternatively, dystrophin-deficient cells per se may express higher p21 levels for unknown reasons. Although we cannot distinguish between these possibilities, the eventual transfec tion of a patient's own satellite cells with p21 antisense oligonucleotides may enable the dystrophic process to be influenced.

Actins↗
PubMed2005

SMAD proteins are involved in apoptosis induction in ventricular cardiomyocytes.

OBJECTIVE: The transcription factor AP-1 is a mediator of hypertrophic growth and apoptosis in cardiomyocytes. This puts AP-1 in the center of two important processes found in the failing heart and implies that variations (i) in the AP-1 composition itself or (ii) in additional, interacting transcription factors are responsible for the diverse actions of AP-1. To test this hypothesis, we performed studies on isolated ventricular cardiomyocytes of rat under hypertrophy- or apoptosis-inducing conditions. METHODS AND RESULTS: The NO donor SNAP (100 microM), which is a pro-apoptotic stimulus in cardiomyocytes, activated AP-1 within 2 h. c-Jun, JunB and FosB are identified as the main components of this AP-1 complex. This complex formation is identical to the composition of AP-1 found under hypertrophic growth stimulation by phenylephrine (PE, 10 muM). Analysis of other transcription factors able to interact with AP-1 revealed activation of SMAD activity only during stimulation with SNAP to 131+/-9.6% (p < 0.05 vs. control, n = 9). The SMAD complex is formed from SMAD4 and 3. Intracellular scavenging of SMAD proteins by transformation of cardiomyocytes with SMAD decoy oligonucleotides or inhibition of SMAD4 synthesis using SMAD4 antisense oligonucleotides reduced the number of apoptotic cells under stimulation with SNAP from 13.3 +/- 1.2% to control levels (8 +/- 1%, p < 0.05, n = 6). TGFbeta, which is a known stimulator of SMAD proteins, is also shown to stimulate apoptosis in cardiomyocytes. Again, simultaneous activation of AP-1 and SMAD is needed for this apoptosis induction. CONCLUSIONS: In conclusion, AP-1/SMAD signaling has been identified as a common pathway in cardiomyocyte apoptosis. In contrast, SMAD proteins are dispensable for AP-1-mediated hypertrophic growth. This finding characterizes SMAD proteins as potential candidates for proteins that shift AP-1 signaling from hypertrophy to apoptosis.

Adrenergic alpha-Agonists↗
PubMed2000

Community structure, cellular rRNA content, and activity of sulfate-reducing bacteria in marine arctic sediments.

The community structure of sulfate-reducing bacteria (SRB) of a marine Arctic sediment (Smeerenburgfjorden, Svalbard) was characterized by both fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization by using group- and genus-specific 16S rRNA-targeted oligonucleotide probes. The SRB community was dominated by members of the Desulfosarcina-Desulfococcus group. This group accounted for up to 73% of the SRB detected and up to 70% of the SRB rRNA detected. The predominance was shown to be a common feature for different stations along the coast of Svalbard. In a top-to-bottom approach we aimed to further resolve the composition of this large group of SRB by using probes for cultivated genera. While this approach failed, directed cloning of probe-targeted genes encoding 16S rRNA was successful and resulted in sequences which were all affiliated with the Desulfosarcina-Desulfococcus group. A group of clone sequences (group SVAL1) most closely related to Desulfosarcina variabilis (91.2% sequence similarity) was dominant and was shown to be most abundant in situ, accounting for up to 54. 8% of the total SRB detected. A comparison of the two methods used for quantification showed that FISH and rRNA slot blot hybridization gave comparable results. Furthermore, a combination of the two methods allowed us to calculate specific cellular rRNA contents with respect to localization in the sediment profile. The rRNA contents of Desulfosarcina-Desulfococcus cells were highest in the first 5 mm of the sediment (0.9 and 1.4 fg, respectively) and decreased steeply with depth, indicating that maximal metabolic activity occurred close to the surface. Based on SRB cell numbers, cellular sulfate reduction rates were calculated. The rates were highest in the surface layer (0.14 fmol cell(-1) day(-1)), decreased by a factor of 3 within the first 2 cm, and were relatively constant in deeper layers.

Arctic Regions↗
PubMed1999

Chromosomal localization of zebrafish AluI repeats by primed in situ (PRINS) labeling.

Two zebrafish AluI repeats were localized in metaphase chromosomes by means of the primed in situ (PRINS) labeling technique, using oligonucleotide primers based on published sequences. An AT-rich, tandemly repeated, long AluI restriction fragment (RFAL1) labeled the (peri)centromeric regions of all chromosomes. The GC-rich short fragment (RFAS) was found to be localized in the paracentromeric regions of 17 chromosome pairs, which were mostly subtelocentric. The RFAS labeling pattern generally fits the previously described chromomycin A3 (CMA3) staining pattern. The differential composition of heterochromatin in zebrafish chromosomes is discussed.

Alu Elements↗