Chromosome numbers were documented for 11 taxa representing 5 genera of Gentianaceae from China. Gentianopsis lutea, G. paludosa var. paludosa and var. ovato-deltoidea were diploid with 2n=26; G. grandis was tetraploid with 2n=52 (n=26); while both diploid (2n=26, n=13) and tetraploid (2n=52) cytotypes were found for G. barbata. The tetraploid number was found for the first time for the genus. The present results confirmed the basic number x=13 for the genus and revealed that the mountainous regions of western and southwestern China and the adjacent Himalayan area probably represent the most important origin and primary diversification centre of the genus, with regard to the distribution pattern of cytotypes. The chromosome number of Comastoma polycladum was 2n=16 with two satellited chromosomes is reported here for the first time. The chromosome number of C. pulmonarium was 2n=18, without any visible satellite which differed from previous reports. Lomatogonium rotatum and L. macranthum all had 2n=16 chromosomes. It is the first report of chromosome number for the second species. Swertia diluta was found to have 2n=20 chromosomes, again mentioned for the first time. The chromosome number 2n=22 was confirmed for Halenia elliptica.
The karyotypes of two bivalve molluscs, the giant scallop Placopecten magellanicus and the surf clam Spisula solidissima, were examined in unfertilized eggs and embryos. In both bivalves, a haploid number of 19 and a diploid number of 38 were determined in well-spread metaphase chromosomes of meiotic and mitotic cells respectively. Moreover, karyological analysis of induced triploid embryos in Placopecten magellanicus indicates a chromosome number of 57 and thus corroborates the haploid and diploid counts. The chromosomes of Spisula solidissima are shorter than those of Placopecten magellanicus. Their sizes vary from 1.5 to 4.4μm in surf clam while those in giant scallop range from 3.3 to 8.5μm. Both bivalve species have submetacentric, subtelocentric and telocentric chromosomes but only Spisula solidissima has metacentric chromosomes.
Karyomorphology of four varieties of Clitoria ternatea and one of C. biflora revealed the chromosome numbers as 2n=16 for C. ternatea and 2n=14 for C. biflora. Karyotypes were mostly symmetrical with majority of chromosomes being sutmedian. Only in C. ternatea var. Faint blue and C. biflora there was one pair of subterminal chromosomes. One pair of median chromosomes was noted in all the types except C. ternatea Blue. There was one pair of SAT chromosomes in all the five taxa, its position being V in C. ternatea and IV in C. biflora. Intraspecific variations were not so conspicuous. However, C. ternatea Faint blue appeared to be relatively more advanced among the types studied.
The objective of the current investigation was to study the effects of cocaine on midgestational fetuses and newborn pups of NIH Swiss mice. 24 adult female mice were divided into four groups. Two groups were used as experimental and two as control. Each experimental animal was injected with 30mg/kg cocaine HCI dissolved in 0.2ml saline, while each control animal was injected with 0.2ml vehicle only. The midgestational fetuses showed significant reduction in weights and soft tissue development. However, no reduction in weight was observed in newborn pups. No significant difference in placental weight and size was noted. No apparent skeletal or soft tissue abnormality indicating any congenital anomaly was noted. No significant difference in maternal weight gain between the control versus experimental groups was observed.
The first case of polyploidy in pulmonate snalis was found in the planorbid species Gyraulus (Torquis) circumstriatus (n=36, 2n=72). We now report the chromosome numbers of the other two members of the subgenus in North America, G. (T.) parvus and G. (T.) huronensis. The latter two species have the same chromosome number, i.e., they are also tetraploid. The basic chromosome number for the family Planorbidae is x=18. The tetraploid condition found in the three polyploid species was probably originally the result of one single event. Once the tetraploid condition was reached, the stability of this number has been maintained in each of the three species.
Somatic chromosomes of Medicago noëana Boiss (2n=16), a wild annual species belonging to the section Rotatae of the subgenus Spirocarpos, were analyzed to confirm the chromosome number as 2n=16 and to characterize each chromosome pair on the basis of its length and arm ratio value. The karyotype of this species was symmetric and consisted of four median chromosomes and three submedian chromosomes. The C-banded metaphases included a considerable amount of heterochromatin which is localized at the centromeric region of each chromosome. The results allow us to make some considerations on the genus Medicago and to demonstrate that cytogenetic studies can provide useful information for breeding programs.
Pachytene chromosome analysis was studied in three species with different basic chromosome numbers (x) in the genus Pennisetum viz. P. ramosum (2n=2x=10), P. glaucum (2n=2x=14) and P. hohenackeri (2n=2x=18). The studies pointed out chromosome differentiating characteristics in between different species as well as within the same species. It was concluded that the length of the chromosomal complement remains almost same irrespective of differences of basic chromosome number. Appearance of longer chromosomes was observed with decrease of chromosome numbers in three species.
The mutagenic potential of the prokaryotic blue-green bacterium, Plectonema boryanum in mice treated with its culture against parallel control assayed by chromosome aberration and micronucleus test in bone marrow cells and sperm head abnormalities in epididymes yielded positive results showing time-dependent effect in all the tests and the dose-dependent effect assayed for chromosome aberration only. Further, the treatment of 1 ml dose each of culture (T1), culture filtrate (T2), isolated filaments in phosphate buffer (T3), heat-killed sample (T4) and cell homogenate-filament DNA (T5) of P. borayanum to different sets of mice against controls yielded net increase in chromosome aberration frequencies at 48 hr of 9.00% in T1, 5.00% in T5 3.25% in T3, 1.50% in T2 and 0.75% in T4 in decreasing order, suggesting that the genotoxic active principle was largely associated with filament and it was heat labile. The results of positive genotoxic potential of P. boryanum in experimental mice filled up the lacuna of ‘Microbes as Living Mutagens’ advocated by Manna.
NTP-binding proteins were detected in the plasma membrane purified from elongating third internodes of etiolated pea (Pisum sativum Alaska) seedlings. After [α-32P] ATP and [α-32P] GTP bound to proteins in the plasma membrane, the reaction mixtureas were UV crosslinked, then analyzed by SDS-polyacrylamide gel electrophoresis (PAGE). Pretreatment of the membrane fraction by a Ras-specific antibody efficiently blocked the binding of [α-32P] ATP and [α-32P] GTP. Several proteins in the plasma membrane were [32P] ADP-ribosylated by endogenous ADP-ribosyl transferase, and by cholera and pertussis toxins. The [32P] ADP-ribosylation of these proteins by endogenous ADP-ribosyl transferase was partly reduced by pretreating the plasma membrane with a Ras-specific antibody. Most of the [α-32P]ATP binding to several NTP-binding proteins was inhibited efficiently by 10-3 M ATP. The binding of [α-32P] GTP was inhibited more efficiently, however, by 10-3 M ATP or UTP than by 10-3 M GTP or CTP. Red light irradiation of the third internodes stimulated the binding of [α-32P] ATP and [α-32P] GTP to 16, 21, 32, 34, 37, 71 and 92 kDa proteins, as analyzed by UV-induced crosslinking followed by SDS-PAGE, and the results were supported by using Triton X-100-PAGE without UV-induced crosslinking. Among these, the amount of a 37 kDa protein exhibiting cross-reactivity with α subunit of transducin-sepcific antibody, was rapidly reduced in the plasma membrane after red light irradiation of the third internodes. A 30 kDa protein showing cross reactivity with β, γ subunit-specific antibody, however, stayed relatively unchanged.
The F1 intergeneric hybrids of Psathyrostachys huashanica Keng with Roegneria ciliaris (Trin.) Nevski was made and cytologically studied. Chromatin transfer through conjugation tube or conjugation opening before, during and after meiosis was observed in these hybrids. Consequently, unusual nuclear behaviors frequently observed include coenocytism, cell size variation and abnomal chromosome or nuclei number, non-synchronous or multipolar division, and delayed chromatin condensation. In addition, cytomixis was observed in early stages of micro-sporogenesis. These events could lead to spontaneous chromosome number doubling and, in turn, the origin of alloautoploid species.
Pertussis toxin is composed of the A protomer with a molecular mass of 28 kDa and the B oligomer which consists of subunits with those of 9.3, 11.7, 22 and 23 kDa. The 11.7, 22 and 23 kDa subunits of the B oligomer showed a binding capacity for [α-32P] ATP, [α-32P] GTP, [α-32P] CTP and [α-32P] UTP, at a concentration of 1.6×10-7 M. The binding of [α-32P] NTP to these subunits was greatly affected by the presence of either of the 4 NTP at a concentration of 10-4-10-3 M. The binding of [α-32P] ATP or [α-32P] GTP to these proteins was greatly affected by NAD at a concentration of 10-4-10-3 M. These three subunits were auto-[32P] ADP-ribosylated from [32P] NAD but the presence of 10-4 M NTP prevented the reaction. Blue light (460 nm) irradiation (100 sec, 6μmoles/m2/sec) of a microsomal fraction prepared from the third internode of etiolated pea seedlings in the presense of pertussis toxin stimulated the binding of [α-32P]ATP and [α-32P] GTP to the 11.7, 22 and 23 kDa subunits of the toxin and to the 52, 92 and 120 kDa proteins in the fraction at 0°C for 5 min.
The success of sorghum tissue culture depends upon reliable callus induction and efficient plant regeneration systems. The objective of this study was to identify callus-inducible genotypes and evaluate media for effectiveness in plant regeneration. Seven sorghum inbred lines and eight wild sorghum species were evaluated for their abilities to undergo callus induction and plant regeneration. In our research, genotype and medium effects, as well as the interaction between genotype and medium, significantly affected callus induction and plant regeneration. MA and MZ media were significantly more effective in callus induction than MN medium. MA medium was the best for plant regeneration of cultivar Xinling 1, Jinliang 5, Xin White, KS 21 R, C-401 and Pl-2, while MZ medium was the best for plant regeneration of S. versicolor, a 10 chromosome wild sorghum. The rooting medium containing NAA was the most effective in developing a strong root system. Plants regenerated from both inbred lines and wild sorghums exhibited a high degree of stability in morphology, chromosome number, and chromosome structure.
By the trypsin treatment method, clear G-banding structures were demonstrated on the chromosomes of cultured fin cells of Chinese crucian carp, Carassius auratus auratus with 2n=100. More precise karyotyping was done on the basis of the G-banding patterns. Problems of phylogeny and chromosome structure of the crucian carp were discussed based on the results of this study.
Rubus×tawadanus (2n=21) has been reported to be a hybrid between R. parvifolius (2n=14) and R. sieboldii (2n=28) (Migo 1970, Hatusima 1971). In this study, karyotypic comparisons among R.×tawadanus, R. parvifolius and R. sieboldii indicated that the 3x chromosome complement of R.×tawadanus was composed of one basic set of R. parvifolius and two from R. sieboldii. Hence the taxonomic treatment of R.×tawadanus was supported by the study. The lack of chromosome pairing in PMCs of R.×tawadanus showed that this hybrid has 3 non-homologous chromosome sets. This indicates that there is no genomic homology among either the chromosomes of R. parvifolius and the two genomes of R. sieboldii nor between the 2 basic sets within R. sieboldii. For this reason, R. sieboldii is thought to be allotetraploid.
Heterogeneity in the external spacers of the ribosomal DNA (rDNA) from eight species of terrestrial carnivores (Canidae, Mustelidae) was analyzed using twelve different restriction enzymes and cloned mouse rDNA probes. We constructed species-specific maps of restriction sites on rDNA. Based on differences in the arrangements of the restriction sites, sequence divergence among the repeating units of rDNA was estimated in order to construct a molecular-phylogenetic tree and to estimate the timing of the divergence of species. The divergence between Nyctereutes procyonoides viverrinus and Vulpes vulpes japonica was 8.4%. The sequence divergence between Mustela putorius furo versus Mustela sibirica itatsi, Mustela nivalis nivalis and Martes melampus melampus was 0.65%, 1.59% and 7.27%, respectively.