| two dispersed highly repeated dna families of triturus vulgaris meridionalis (amphibia, urodela) are widely conserved among salamandridae. | two bamhi families of repeated sequences were characterized from the genome of the italian smooth newt, triturus vulgaris meridionalis (amphibia, urodela). the first family, which is divided into subfamilies, consists of tandemly arranged arrays whose basic repeat is around 398 bp long; these arrays are dispersed throughout the entire chromosome sets of the various species of triturus tested. moreover the family is widely conserved among salamandridae, being detected by genomic dna blotting of n ... | 1991 | 2009819 |
| extra-ribosomal spacer sequences in triturus. | we show that, in triturus vulgaris meridionalis, sequences homologous to the rdna "non-transcribed" spacer (nts) are clustered at chromosomal loci where they are not associated with 18 s or 28 s rdna genes: these sequences are referred to as the extra-ribosomal spacer sequences. genomic clones containing such extra-ribosomal spacer sequences have been isolated. as shown by restriction mapping, these clones appear to consist mostly of repetitive bamhi fragments that are, in turn, internally repet ... | 1988 | 3065517 |
| unraveling climate influences on the distribution of the parapatric newts lissotriton vulgaris meridionalis and l. italicus. | climate is often considered as a key ecological factor limiting the capability of expansion of most species and the extent of suitable habitats. in this contribution, we implement species distribution models (sdms) to study two parapatric amphibians, lissotriton vulgaris meridionalis and l. italicus, investigating if and how climate has influenced their present and past (last glacial maximum and holocene) distributions. a database of 901 gps presence records was generated for the two newts. sdms ... | 2017 | 29255477 |
| expression of fgf2 in the limb blastema of two salamandridae correlates with their regenerative capability. | limb regenerative potential in urodeles seems to vary among different species. we observed that triturus vulgaris meridionalis regenerate their limbs significantly faster than t. carnifex, where a long gap between the time of amputation and blastema formation occurs, and tried to identify cellular and molecular events that may underlie these differences in regenerative capability. whereas wound healing is comparable in the two species, formation of an apical epidermal cap (aec), which is require ... | 2003 | 14613605 |
| molecular structure of the rdna intergenic spacer (igs) in triturus: implications for the hypervariability of rdna loci. | ribosomal dna (rdna) variation in the species triturus vulgaris meridionalis (amphibia, urodela) is remarkable because of unusually high intraspecific variability in the number and distribution of ribosomal loci in the karyotype; in addition, portions of the intergenic spacer (igs) are clustered at chromosomal loci where they are not associated with ribosomal 18s and 28s rna genes. these clusters are referred to as extraribosomal, and they appear to consist mostly of repetitive bamhi elements. i ... | 1997 | 9297510 |
| a newt ribozyme: a catalytic activity in search of a function. | we analyzed the cleavage properties and the transcription regulation of the newt (triturus vulgaris meridionalis) self-cleaving rna. in vitro self-cleavage of model oligoribonucleotides occurs within a double hammerhead structure. in addition, an entire ribozyme molecule, as well as its catalytic domain, "trans-cleaves" in vitro appropriate oligoribonucleotide substrates. signals encoded within the ribozyme dna sequences regulate the ribozyme transcription, which is rna polymerase ii dependent. ... | 1992 | 1542657 |
| heterochromatic dna in triturus (amphibia, urodela) ii. a centromeric satellite dna. | the mspi family of highly repeated sequences is a centromeric satellite dna representing about 1% of the genome of the italian smooth newt, triturus vulgaris meridionalis. we have studied the structure, genomic organization, chromosomal localization and conservation across species of this family. mspi sequences are around 197 bp long, as shown by sequencing of three cloned units. the family is organized in large clusters of tandemly arrayed units, present at almost all the centromeres of t.v. me ... | 1988 | 3219917 |
| heterochromatic dna in triturus (amphibia, urodela). i. a satellite dna component of the pericentric c-bands. | we have studied the structure, genome organization, chromosomal location, conservation across species and transcription on lampbrush chromosomes, of an at-rich satellite dna component of the newt, triturus vulgaris meridionalis. the satellite (sat g), originally isolated by gradient centrifugation, represents about 2% of the vulgaris genome and comprises a highly repetitive sequence family (hindiii family), whose monomers have been cloned. the repeat units are about 330 bp long, as measured on g ... | 1986 | 3013516 |
| molecular organization of ribosomal rna genes clustered at variable chromosomal sites in triturus vulgaris meridionalis (amphibia, urodela). | the ribosomal rna genes of triturus vulgaris meridionalis (amphibia, urodela) show the peculiar feature of being clustered not only at the nucleolar organizer, present in the species at a definite chromosome location, but also at "additional ribosomal sites" which are highly variable in number and chromosomal distribution among individuals. the additional ribosomal sites are most often found at specific chromosome regions, such as telomeres, c-bands and centromeres, in virtually all the chromoso ... | 1985 | 3003361 |
| chromosome location of the ribosomal rna genes in triturus vulgaris meridionalis (amphibia, urodela). | the mitotic chromosomes of six specimens from triturus vulgaris meridionalis have been examined by both in situ hybridization with 3h 18s + 28s rrna and as-sat staining method. the results of these two sets of experiments can be summarized as follows: 1) in each specimen the nors and the additional ribosomal sites, which react positively to in situ hybridization with 3h 18s + 28s rrna, are also stained by silver; 2) other chromosomal regions, which do not hybridize in situ with 3h 18s + 28s rrna ... | 1978 | 83935 |
| chromosome location of the ribosomal genes in triturus vulgaris meridionalis (amphibia urodela). iii. inheritance of the chromosomal sites for 18s + 28s ribosomal rna. | in triturus vulgaris meridionalis, the 18s + 28s rdna sequences have been shown to be located in a number of additional chromosomal sites besides the nucleolus organizing region. the additional ribosomal sites have been found to vary as to their number and chromosomal location in different individuals of the species.--the data presented in this study concern the chromosomal distribution of the ribosomal sequences as analyzed by in situ hybridization technique in two individuals as well as in the ... | 1978 | 630997 |
| chromosome location of the ribosomal rna genes in triturus vulgaris meridionalis (amphibia, urodela). ii. intraspecific variability in number and position of the chromosome loci for 18s + 28s ribosomal rna. | ribosomal genes have been localized on mitotic and lampbrush chromosomes of 20 specimens of triturus vulgaris meridionalis by in situ hybridization with 3h 18s + 28s rrna. the results may be summarized as follows: 1) each individual shows positive in situ hybridization at the nucleolus organizing region (nor) on chromosome xi; 2) in addition, many specimens exhibit a positive reaction in chromosomal sites other than the nor (additional ribosomal sites); 3) the chromosomal distribution of the add ... | 1977 | 598264 |
| the maps of the lampbrush chromosomes of triturus (amphibia urodela). iv. triturus vulgaris meridionalis. | | 1970 | 5489360 |
| spontaneous aberrations in lampbrush chromosome xi from a specimen of triturus vulgaris meridionalis (amphibia, urodela). | | 1970 | 5474809 |