Abstract:
:EcoRI restriction of the B. nigra rDNA recombinants, isolated from a lambda genomic library, showed that the 3.9-kb fragment corresponded to the Intergenic Spacer (IGS), which was sequenced and found to be 3,928 bp in size. Sequence and dot-matrix analyses showed that the organization of the B. nigra rDNA IGS was typical of most rDNA spacers, consisting of a central repetitive region and flanking unique sequences on either side. The repetitive region was composed of two repeat families-RF 'A' and RF 'B.' The B. nigra RF 'A' consisted of a tandem array of three full-length copies of a 106-bp sequence element. RF 'B' was composed of 66 tandemly repeated elements. Each 'B' element was only 21-bp in size and this is the smallest repeat unit identified in plant rDNA to date. The putative transcription initiation site (TIS) was identified as nucleotide position 3,110. Based on the sequence analysis it was suggested that the present organization of the repeat families was generated by successive cycles of deletions and amplifications and was being maintained by homogenization processes such as gene conversion and crossing-over.A detailed comparison of the rDNA IGS sequences of the three diploid Brassica species-namely, B. nigra, B. campestris, and B. oleracea-was carried out. First, comparisons revealed that B. campestris and B. oleracea were close to each other as the repeat families in both showed high sequence homology between each other. Second, the repeat elements in both the species were organized in an interspersed manner. Third, a 52-bp sequence, present just downstream of the repeats in B. campestris, was found to be identical to the B. oleracea repeats, thereby suggesting a common progenitor. On the other hand, in B. nigra no interspersion pattern of organization of repeats was observed. Further, the B. nigra RF 'A' was identified as distinct from the repeat families of B. campestris and B. oleracea. Based on this analysis, it was suggested that during speciation B. campestris and B. oleracea evolved in one lineage whereas B. nigra diverged into a separate lineage. The comparative analysis of the IGS helped in identifying not only conserved ancestral sequence motifs of possible functional significance such as promoters and enhancers, but also sequences which showed variation between the three diploid species and were therefore identified as species-specific sequences.
journal_name
J Mol Evoljournal_title
Journal of molecular evolutionauthors
Bhatia S,Singh Negi M,Lakshmikumaran Mdoi
10.1007/BF02337518subject
Has Abstractpub_date
1996-11-01 00:00:00pages
460-8issue
5eissn
0022-2844issn
1432-1432journal_volume
43pub_type
杂志文章abstract::The mitochondrial genetic variability in European rabbit (Oryctolagus cuniculus) populations present in Europe and North Africa from 11,000 years ago to the present day has been analyzed using ancient DNA techniques. DNA was extracted from 90 rabbit bones found in 22 archaeological sites dated between the Mesolithic a...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF00163228
更新日期:1995-03-01 00:00:00
abstract::Group selection is a matter of acute controversy among evolutionary biologists. The most well-publicized debate in this regard is that between Edward O. Wilson and Richard Dawkins. As is widely known, Edward O. Wilson is very excited about the idea of social selection and eusociality; by contrast Richard Dawkins favor...
journal_title:Journal of molecular evolution
pub_type: 社论
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journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02101791
更新日期:1990-07-01 00:00:00
abstract::tRNA with a terminal UCCA-3' forms a structure in which the 3'-sequence folds back. The adenine of glycyl-AMP can base-pair with the uridine of the UCCA-3' region, which places the glycine residue in close proximity to the 3'-terminal adenosine of tRNA, possibly enabling the transfer of glycine from glycyl-AMP to tRNA...
journal_title:Journal of molecular evolution
pub_type: 信件
doi:10.1007/s00239-015-9694-8
更新日期:2015-10-01 00:00:00
abstract::Energised by the protonmotive force and with the intervention of inorganic catalysts, at base Life reacts hydrogen from a variety of sources with atmospheric carbon dioxide. It seems inescapable that life emerged to fulfil the same role (i.e., to hydrogenate CO(2)) on the early Earth, thus outcompeting the slow geoche...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-009-9289-3
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abstract::We have analyzed the gene that encodes receptor tyrosine kinase (RTK) from the marine sponge Geodia cydonium, which belongs to the most ancient and simple metazoan groups, the Porifera. RTKs are enzymes found only in metazoa. The sponge gene contains two introns in the extracellular part of the protein. However, the r...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006141
更新日期:1997-03-01 00:00:00
abstract::We describe the complete mitochondrial genome of the house centipede Scutigera coleoptrata. Its gene order is unique among characterized arthropod mitochondrial genomes. Comparison to the gene order in the horseshoe crab mtDNA implies 10 or more translocations. By extending comparisons to 30 arthropod mitochondrial ge...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-003-2563-x
更新日期:2004-04-01 00:00:00
abstract::We report the nucleotide sequence of the single muscle actin gene of the sea urchin Strongylocentrotus purpuratus. Comparison of the protein-coding sequence of this muscle actin gene (pSpG28) with that of two linked sea urchin cytoskeletal actin genes (pSpG17 and CyIIa) reveals a region of exceptional sequence conserv...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02100039
更新日期:1987-01-01 00:00:00
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journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF01796136
更新日期:1977-09-20 00:00:00
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journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006552
更新日期:1999-09-01 00:00:00
abstract::The mammalian olfactory system utilizes three large receptor families: the olfactory receptors (ORs) of the main nose and the vomeronasal type-1 and type-2 receptor genes (V1Rs and V2Rs) of the vomeronasal organ. We find that these loci are among the most long interspersed nuclear element (LINE)-dense regions of mamma...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-008-9195-0
更新日期:2009-02-01 00:00:00
abstract::Short interspersed DNA elements (SINEs) amplify by retroposition either by (i) successive waves of amplification from one or a few evolving master genes or by (ii) the generation of new master genes that coexist with their progenitors. Individual, highly conserved, elements of the B1 SINE family were identified from t...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s002390010087
更新日期:2000-09-01 00:00:00
abstract::This paper constructs a temporal scale for bacterial evolution by tying ecological events that took place at known times in the geological past to specific branch points in the genealogical tree relating the 16S ribosomal RNAs of eubacteria, mitochondria, and chloroplasts. One thus obtains a relationship between time ...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02111283
更新日期:1987-01-01 00:00:00
abstract::It has been suggested that inorganic membranes were forerunners of organic membranes at the origin of life. Such membranes, interposed between alkaline fluid in submarine vents and the more acidic Hadean ocean, were thought to house inorganic molecular machines. H+ flowed down the pH gradient (ΔpH) from ocean to vent ...
journal_title:Journal of molecular evolution
pub_type: 信件,评审
doi:10.1007/s00239-017-9805-9
更新日期:2017-08-01 00:00:00
abstract::The human S100 gene family encodes the EF-hand superfamily of calcium-binding proteins, with at least 14 family members clustered relatively closely together on chromosome 1q21. We have analyzed the most recently available genomic sequence of the human S100 gene cluster for evidence of tandem gene duplications during ...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-002-2410-5
更新日期:2003-04-01 00:00:00
abstract::We outline a method for estimating quantitatively the influence of point mutations and selection on the frequencies of codons and amino acids. We show how the mutation rate, i.e., the rate of amino acid replacement due to point mutation, can be affected by the codon usage as well as by the rates of the involved base e...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02102357
更新日期:1984-01-01 00:00:00
abstract::Comparisons of the sequence divergence of three species of Hawaiian Drosophila have been made by hybridization of single-copy tracer DNA of each of the species with driver DNA from each species, and measurement of the average melting temperature (Tma) in a chaotropic solvent (2.4 M tetraethylammonium chloride) which m...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF01734358
更新日期:1981-01-01 00:00:00
abstract::This study dealt with the ability of non-denaturing gel electrophoresis to separate iso-1-cytochrome c with single amino acid replacements isolated from revertants of various cyc1 nonsense mutants of the yeast Saccharomyces cerevisiae. A total of 28 different iso-1-cytochromes c with single amino acid substitutions of...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02102869
更新日期:1991-10-01 00:00:00
abstract::Bacterial family C DNA polymerases (DNA pol IIIs), the major chromosomal replicative enzymes, have been provisionally classified based on primary sequences and domain structures into three classes: class I (Escherichia coli DNA pol C-type), class II (Bacillus subtilis DNA pol C-type), and class III (cyanobacterial DNA...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006520
更新日期:1999-06-01 00:00:00
abstract::Evaporation of a solution of thymidine plus either the exo or the endo diastereomer of uridine cyclic 2',3'-O, O-phosphorothioate (U greater than p(S) in 1,2-diaminoethane hydrochloride buffer gave the 2',5' and 3',5' isomers of (P-thio) uridylylthymidine (Up(S)dT) in a ratio of 1:2 with a combined yield of about 20%....
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF01731369
更新日期:1979-11-01 00:00:00
abstract::We have cloned and sequenced a protamine gene from the chum salmon (Oncorhynchus keta). This gene sequence is highly homologous to one found in the rainbow trout (Salmo gairdneri), including the conservation of two structurally different repetitive elements. One of these repeats resembles a nonviral retroposon and the...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF02099725
更新日期:1988-01-01 00:00:00
abstract::Fish protamines are highly specialized molecules which are responsible for chromatin condensation during the last stages of spermatogenesis (spermiogenesis). However, not all fish contain protamines in their sperm nuclei; rather, there seems to be a random distribution of protamines within this group. The origin of th...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/BF00160152
更新日期:1994-09-01 00:00:00
abstract::Using all currently predicted coding regions in the honeybee genome, a novel form of synonymous codon bias is presented that affects the usage of particular codons dependent on the surrounding nucleotides in the coding region. Nucleotides at the third codon site are correlated, dependent on their weak (adenine [A] or ...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-006-0198-4
更新日期:2007-06-01 00:00:00
abstract::Since the discovery of the coelacanth, Latimeria chalumnae, more than 50 years ago, paleontologists and comparative morphologists have debated whether coelacanths or lungfishes, two groups of lobe-finned fishes, are the closest living relatives of land vertebrates (Tetrapoda). Previously, Meyer and Wilson (1990) deter...
journal_title:Journal of molecular evolution
pub_type: 杂志文章,评审
doi:10.1007/BF00183221
更新日期:1992-08-01 00:00:00
abstract::The major histocompatibility complex (MHC) consists of polymorphic frozen blocks (PFBs) that are linked to form megabase haplotypes. These blocks consist of polymorphic sequences and define regions where recombination appears to be inhibited. We have been able to show, using a highly polymorphic sequence centromeric o...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006194
更新日期:1997-07-01 00:00:00
abstract::RNA has a myriad of biological roles in contemporary life. We use the RNA paradigm for genotype-phenotype mappings to study the evolution of multiple coding in dependence to mutation rates. We study three different one-to-many genotype-phenotype mappings which have the potential to encode the information for multiple ...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-014-9648-6
更新日期:2014-12-01 00:00:00
abstract::This study was designed to characterize further the nontranscribed intergenic spacers (NTSs) of the 5S rRNA genes of fish and evaluate this marker as a tool for comparative studies. Two members of the closely related North American Great Lakes cisco species complex (Coregonus artedi and C. zenithicus) were chosen for ...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006348
更新日期:1998-06-01 00:00:00
abstract::The size and diversity of bacteriophage populations require methodologies to quantitatively study the landscape of phage differences. Statistical approaches are confronted with small genome sizes forbidding significant single-phage analysis, and comparative methods analyzing full phage genomes represent an alternative...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239-008-9068-6
更新日期:2008-03-01 00:00:00
abstract::We present two new models of protein sequence evolution based on structural properties of mitochondrial proteins. We compare these models with others currently used in phylogenetic analyses, investigating their performance over both short and long evolutionary distances. We find that our models that incorporate second...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/s00239001-0052-7
更新日期:2002-04-01 00:00:00
abstract::Parsimony is commonly used to infer the direction of substitution and mutation. However, it is known that parsimony is biased when the base composition of the DNA sequence is skewed. Here I quantify this effect for several simple cases. The analysis demonstrates that parsimony can be misleading even when levels of seq...
journal_title:Journal of molecular evolution
pub_type: 杂志文章
doi:10.1007/pl00006427
更新日期:1998-12-01 00:00:00