There is high interest in the natural products properties due to their use in popular medicine. Agaricus blazei Murrill ss. Heinem. (Ab) is native to Brazil and has been widely disseminated because its medicinal properties. In the present study, the genotoxic and antigenotoxic potential of Ab extracts were investigated using the comet assay. The cells utilized were the non drug-metabolizing line CHO-k1 (Chinese hamster ovary) and the drug-metabolizing line HTC (rat hepatoma). Cells were treated for 3 h in the absence of fetal bovain serum (FBS) with methanolic, hexanic and n-butanolic extracts at 50 μg/ml and 0.75% aqueous extract to test for genotoxicity. Antigenotoxic effects of extracts were determined in cells exposed to the DNA damage inducing agent ethyl methanesulfonate under simultaneous or simultaneous with 1 h pre-incubation conditions. The extracts did not show genotoxicity in HTC, while they were genotoxic in CHO-k1. No antigenotoxic effect was observed with any extract under any condition. These results demonstrate that the metabolism in presence or in absence has a direct influence on the genotoxicity of these extracts.
The genotoxic effects of cobalt chloride (CoCl2) were studied in mice using different mutagenic end points in vivo. The possible protection provided by the antioxidant selenium and vitamins (ACE) against CoCl2 genotoxicity was also assessed. The results indicate that CoCl2 has genotoxic effects on mice somatic and germ cells. It induced a significant increase in the frequency of chromosomal aberrations in mouse bone-marrow and spermatocytes after single and repeated oral treatments. The induction of morphological sperm abnormalities was also confirmed in the present study. The supplemental selenium and vitamins (ACE) to reduce the genotoxic effect of CoCl2 was proved.
The structural polymorphism in the karyotype of the acridid, Gastrimargus africanus orientalis is presented and the C-banding pattern of this species is compared with Acrida turrita and Aiolopus sp. 2 along with the percentage of heterochromatin in each species.
In vitro regeneration protocol was developed in Trifolium resupinatum, an important fodder legume in Northwestern India. Out of 6 explants (leaf, petiole, hypocotyl, cotyledon, collar and root) tried for callus induction in 2 different media, good response was observed from hypocotyl and root explants in ‘A’ medium. Successful regeneration was obtained from callus induced from hypocotyl, cotyledon and root in ‘A’ followed with subculture in ‘E’ medium. One of the regenerated plantlet was characterized and compared with mother plant for isozyme-banding pattern. Wide variation for isozyme banding pattern for SOD, Peroxidase and GOT enzyme indicates the regenerant to be a somaclonal variant. Thus, in vitro regeneration will help in widening the genetic base of the species.
The Perciformes are characterized by a remarkable chromosomal homogeneity, with a small percentage of its representatives bearing diploid numbers higher or lower than their putative basal number (2n=48). Due to the wide diversity of this group, several families from this order lack cytogenetic reports, such as Gerreidae and Priacanthidae. Chromosomal analyses were carried out in the species Diapterus olithostomus (Gerreidae) and Priacanthus arenatus (Priacanthidae), from Brazilian coast. The karyotype of D. olithostomus is composed by 2n=48 (NF=48), while P. arenatus presented 2n=52 (4st+48a; FN=56). C-banding analysis revealed heterochromatic blocks on centromeric and/or interstitial regions in the 2 species. In D. olithostomus, GC-rich blocks were identified at interstitial position and on ribosomal sites. This species shows the typical karyotype pattern of Perciformes, but the presence of GC-rich interstitial heterochromatin, as well as the presence of 2n>48 in P. arenatus, represents possible autopomorphies. The results report both structural and numerical rearrangements within this order.
The morphological similarity, relatively small size of the chromosomes and low metaphasic indexes obtained in root meristems have hindered karyotypic characterization and the application of banding techniques in Coffea. We have developed a method based on the use of cell suspension aggregates treated with amiprophos-methyl (APM) and macerated in enzymatic solution. This method generated cytogenetic preparations in which the chromosomes showed well-defined primary and secondary constrictions, facilitating the pairing of homologues and assembly of the karyogram, as well as the identification of active NOR and heterochromatin associated with the secondary constriction. This alternative technique could help on the analysis of other species with similar karyotypic characterization problems.
Silver stained-NOR patterns as well as routine Giemsa stained karyotypes of 3 Tanakia species/subspecies from East Asia, T. himantegus himantegus, T. h. chii, and T. somjinensis, were described. This is the first description of karyotypes for T. h. himantegus and T. somjinensis. Tanakia h. himantegus (2n=48: 8M+20SM+18ST+2A) and T. h. chii (2n=48: 8M+20SM+18ST+2A) had distinct acrocentric chromosomes. In T. somjinensis (2n=48: 8M+20SM+20ST), acrocentric chromosomes were not found and Ag-NORs on the terminal region of the long arm were more prevalent than those on the terminal region of the short arm, being a characteristic that is unusual in bitterlings.
The karyotype of a fish species belonging to the family Scoloplacidae, Scoloplax distolothrix, is described for the first time. Cytogenetic studies showed that this species has 2n=50 chromosomes, 18 metacentrics, 18 submetacentrics, 10 subtelocentrics and 4 acrocentrics. The Ag-NORs are restricted to a single large metacentric pair in the interstitial position on the long arm.
Somatic chromosome number, karyotype and 4C DNA content was studied in 13 species of Cassia of the family Leguminosae obtained from Royal Botanic Gardens, Kew. Somatic chromosome number 2n=28 was observed in all the species except C. lindheimariana and C. versicolor with 2n=26 chromosomes. In addition, polyploid chromosomes were observed in C. atomaria and C. hirsuta (2n=56). Variations among the species were observed in their minute structural details of the karyotype. On the basis of centromeric index, 4 types (Type A, B, C and D) of chromosomes were found in different species. Significant variations in the chromosome length were observed among different species from 13.25 μm in C. wislizenii to 24.73 μm in C. polyantha. Total chromosome volume varied significantly from 6.93 μm3 in C. hirsuta to 11.10 μm3 in C. lindheimariana. Highest centromeric index percentage (43.69%) was noted in C. italica and that of lowest (34.12%) was found in C. polyantha. Significant variation in 4C nuclear DNA content was observed among the species that varied from 6.45 pg in C. italica to 15.77 pg in C. spectabilis. The correlation coefficients showed various chromosomal and nuclear parameters interdependent suggesting a interspecific relationship between structural and genetic changes of the genome architecture during evolution of speciation.
Comparative karyotypic studies on 3 species, large-spotted civet (Viverra megaspila), large Indian civet (V. zibetha) and small Indian civet (Viverricular indica) using conventional staining and G-banding patterns were investigated. Blood samples taken from Khao Khiew and Dusit Zoo were examined using lymphocyte culture techniques. The results indicate that the number of diploid chromosome of large-spotted civet, large Indian civet and small Indian civet are 38, 38, and 36, respectively. The fundamental number (NF) are 72 for female and 71 for male, 72 for female, and 70 for female and 69 for male. The type number of autosomes, metacentric, submetacentric, acrocentric and telocentric chromosomes are 10-10-12-4, 10-10-12-4 and 10-12-10-2, respectively. Chromosome pairs 15, 17 and 17 are satellite chromosomes. The X and Y chromosomes are submetacentric and telocentric for large-spotted civet and small Indian civet, whereas. The X and Y chromosome are not known for large Indian civet. In addition, G-banding techniques show that there are 143, 148 and 145 banding patterns which are able to chromosomal classify of these 3 species.
Meiotic behavior was analysed in 30 accessions of 12 wild (Capsicum flexuosum, C. parvifolium, C. buforum, C. campylopodium, C. cornutum, C. pereirae, C. friburgense, C. schottianum, C. villosum var. villosum, and 3 new species) and 2 semi-domesticated (C. baccatum L. var praetermissum and C. chinense) Brazilian Capsicum species. This is the first report on meiosis for most of these taxa. Except for C. baccatum L. var praetermissum, C. chinense, C. flexuosum and C. parvifolium, with 2n=24 chromosomes, all other taxa had 2n=26 chromosomes, a number previously considered as not common in the genus. Meiotic pairing was generally regular (12 or 13 bivalents) for most of the species analyzed. However, different irregularities such as univalents, multivalents, bridges, chromosome stickiness, unoriented chromosomes, monads, dyads and polyads, among others, were found at both meiosis I and meiosis II, leading to unbalanced final meiotic products but generally not a high pollen sterility. It was not possible to establish with certainty if these irregularities were due to genetic (meiotic mutations) or environmental (such as pests and diseases) causes.
In this study, we studied the abnormal metaphase division cells which were induced by microtubules depolymerization and photosystem II inhibiting herbicides. Experiment results revealed that metaphase synchronization division cells, multipolar division cells, metaphase chromosome-bridge, fragments and micronuclei could be induced by microtubules depolymerization herbicide amiprophose-methyl (APM) in root meristem of rye and maize. The threshold concentration is 2 mg/l (multipolar division, micronuclei, chromosome-bridge), 3 mg/l (fragment) for 16 h treatment and metaphase synchronization cells were induced at 4–5 mg/l for 5–6 h. These results further supported the idea that APM is a specific chemical that directly interrupts microtubule dynamics in plant cells. Abnormal metaphase division cells were thought to be directly related to the disturbance of spindle function.
Six populations of Bromus tomentellus were selected based on their morphological characteristics to investigate their karyotypes. Preparations were made using fresh grown root tips. Saturated α-bromonaphtaline, glacial acetic acid and ethanol, 1 N HCl and hematoxiline were used for pre-treatment, fixative, hydrolyser and chromosome staining agent, respectively. Karyotypic data were recorded on well-prepared cells at metaphase stage containing a complete set of chromosomes. The studied populations differed in their ploidy levels and karyotypic characteristics. Several statistical parameters were estimated on the data to compare the karyotypes of the populations. UPGMA method of cluster analysis was performed to classify the populations based on their karyotypic characteristics. Finally, Pearson correlation coefficient was estimated for all paired combinations of the karyotypic characteristics to investigate their inter-relationships.
Genetic studies of 5 species of macaques using G-banding patterns were investigated. Blood samples of them were examined using lymphocyte culture technique. The results indicate that they have identical data including the number of diploid chromosome is 42; the types of autosomes are metacentrics and submetacentrics viz. 6 large metacentrics, 4 medium metacentrics and 8 small metacentrics, and 8 large submetacentrics, 12 medium submetacentrics and 2 small submetacentrics; the short arm of chromosome pair 13 is a satellite chromosome. A few difference is X and Y chromosome. The X and Y chromosomes are medium submetacentrics and medium metacentrics, and small submetacentric, medium submetacentric and small telocentrics, respectively. The cytogenetic studies show that all 5 species Thai macaques have a common evolutionary relationship. For studying in depths, molecular markers were assessed using the Amplified Fragment Length Polymorphism (AFLP) method. The AFLP fingerprints from 7 primer combinations were compared. A total of 1754 bands, with 890 (50.71%) polymorphic bands, were generated. Seven monomorphic bands (0.78%) were found in all individuals of macaques. The average genetic distance (D) between species based on AFLP analysis shows 0.269 to 0.380. The developing of specific cytogenetic and AFLP fingerprints of a species is possible further benefit for humanity.
The presence of plastids has been accepted as morphologically crucial evidence for the Prototheca species being the green alga. In the present study, a clinical isolate of Prototheca wickerhamii was examined for plastid DNA and 2 chloroplast proteins by immunoelectron microscopy. Cells of P. wicherhamii contained double-membraned plastids which enclosed starch grains. Membraneous, lamella-like structures developed in plastids of cells grown under light. Deposition of anti-DNA immunogold particles showed the presence of DNA in the plastids. The chloroplast DNA-coded large subunit of the CO2-fixing enzyme, ribulose-1,5-bisphosphate carboxylase (RuBisCO), was found in plastids of cells grown under either light or darkness. The nuclear DNA-coded small subunit of RuBisCO was distributed in the cytoplasm and plastids. The nuclear-coded thylakoid protein, light-harvesting chlorophyll a/b-binding protein in photosystem II apoprotein (LHCP II), was also detected in both the cytoplasm and plastids of cells grown under light, but not in cells grown under darkness. These results show that the genus Prototheca retains the ability to synthesize some of chloroplast proteins despite defect in chlorophyll synthesis.
Pollen germination and tube growth are the necessary events for fertilization and seed formation. The objective of the present investigation was to study and compare in vitro germination characteristics of pollens from γ-ray irradiated seeds. Considerable differences in pollen viability and tube length alongwith increasing doses of gamma-ray have been observed in the study. Similarly, pollen germination percentage also decreased significantly with the increased doses of γ-ray. The study revealed that at the 400 Gy and 500 Gy doses most of the pollen grains, though viable did not germinate. The pollen morphology and pollen tubes were also found affected at higher doses viz. 300, 400 and 500 Gy, while, an enhancement of tube length has been observed at 100 Gy dose but it was statistically insignificant. It appears that at 400 Gy dose pollen grains start losing their property of tube formation. Normal seed percentage and pod formation also registered a decrease alongwith increase in dose of gamma ray. This feature can be exploited in breeding programmes for raising male-sterile lines in soybean since it is a highly self-pollinated crop and male-sterile lines can prove to be of much use in this case.
A spontaneous fasciated mutant exhibiting broad-strap like stem with weak tall, irregular leaf arrangement, fewer branches, larger leaves and flowers which appear like a whorled “chrysanthemum” was isolated in a local cultivar of Capsicum annuum L. The mutant had delayed maturity. In general, an increase in the number, size and shape of the floral organs, except the size of the anthers was discernible in the mutant compared to those in the sibs. The mutant did display irregular meiotic behaviour of varying degrees, while meiosis was normal and regular in the sibs of the same population. The seed set was low. The fasciation was found to be governed by a single recessive gene. The fasciation has been transferred to different genetic back grounds. This is the first report on fasciated stem mutation in members of the chili pepper.