In this work, 2 species of the Pimelodidae family, Luciopimelodus pati and Pinirampus pirinampu, were cytogenetically analyzed. Specimens collected from the Paraná River, near Corrientes city, Argentina, were assessed using conventional Giemsa, C-banding, and AgNOR staining. L. pati and P. pirinampu showed 2n=50 chromosomes. The cytogenetic characteristics of the 2 species could be considered as derivate features with respect to the other Pimelodinae fishes. Chromosome fusions and chromatin loss are proposed as the hypothetical origin of the described karyotypes.
The objective of this study is to investigate the utility of comet assay and chromosome aberrations analysis for detecting the possible antimutagenic activity of vitamin C to reduce the genotoxic effect of Trimethyltin (TMT). TMT is one of the organotin compounds which is widely used as polyvinyl chloride heat stabilizers and marine biocides. In this study, male Swiss mice were treated interapretoneally (i.p.) with 3 tested doses 0.25, 0.50 and 1.0 mg TMT/kg b.wt. for 1, 2 and 3 d. Alkaline comet assay in nucleated bone-marrow cells and chromosome analysis in spermatocytes were performed 24 h after the last treatment. The amount of DNA damage in cells was estimated from comet tail length as the extent of migration of the genetic material. A significant increase in comet tail length indicating DNA damage was observed at all concentrations compared with control (p<0.05). The mean comet tail length showed a concentration-related and time-dependent increase. Also, the percentage of chromosome aberrations in spermatocytes was statistically significant (p<0.05) and showed dose and time dependent manner. Concurrent administration of vitamin C (VC) orally at 20 mg/kg b.wt. with the highest dose of TMT for 1, 2 and 3 d reduced DNA damage in somatic and germ cells to a significant extent. In conclusion, our results indicated that vitamin C ameliorated DNA damage and genotoxicity induced by trimethyltin in mice somatic and germ cells in vivo.
Study on chromosomes of fish has become a priority area of research in recent years. Chromosome analysis can be useful for addressing a variety of evolutionary and genetic questions about fishes. The global fish fauna consists of about 28,900 species of fishes of which 2,200 species are cytogenetically studied. India's contribution so far was around 220 species. Fish chromosome studies of freshwater fishes are further sporadic in Orissa. Therefore, the present study is proposed for a systematic cytogenetic investigation of some freshwater fishes of Orissa. Karyotypic study of 5 species namely Labeo fimbriatus (Fam. Cyprinidae), Puntius sophore (Fam. Cyprinidae), Osteobrama cotio cotio (Fam. Cyprinidae), Chanda nama (Fam. Chandidae), and, Xenentodon cancila (Fam. Benonidae) from rural ponds of Bhubaneswar, India, was carried out. The diploid chromosome number in Labeo fimbriatus was 50 with a chromosomal formula of 10m+10sm+30T (FN=70), Puntius sophore 2n=48, 2m+46T (FN=50), Osteobrama cotio cotio 2n=54, 10m+8sm+8st+28T (FN=72), Chanda nama 2n=50, 8m+6sm+10st+26T (FN=64) and Xenentodon cancila, 2n=48 with chromosomal formula of 22m+10sm+6st+10T (FN=80). The evolutionary significance of these karyotypes of 5 species has been discussed.
Preparation of oocytes is one of the critical factors that determine the developmental competence of embryos produced by in vitro fertilization (IVF). The present study was conducted to evaluate the effect of different maturation media on the nuclear and cytoplasmic maturation of buffalo oocytes. Also, to investigate if the addition of ginseng and fenugreek to the maturation media during in vitro maturation (IVM) would influence on IVM, and developmental competence of buffalo oocytes as well as intracellular GSH level. Three experiments were conducted to achieve the goals of present study. In the first experiment, the buffalo oocytes were cultured in different media without any supplementations to detect the most suitable effective medium for IVM. The second experiment compared between different culture media for IVM of oocytes through measurement of intracellular glutathione level. The third experiment examined the effect of ginseng and fenugreek additives during the IVM of Egyptian buffalo oocytes. The results of this study proved that the TCM-199 medium significantly increased the percentage of cumulus expansion, nuclear maturation and intracellular GSH concentration after IVM of buffalo oocytes, while CR1aa was the least effective medium. Treatment with ginseng and fenugreek extracts during IVM culture efficiently improves the development competence of buffalo oocytes, and this improvement is correlated with increase of intracellular GSH concentration. In conclusion, TCM-199 was the most effective medium and is desirable for in vitro maturation of Egyptian buffalo oocytes. Ginseng and fenugreek additives enhanced the quality of less effective medium (CR1aa), as well as optimized the effect of TCM-199 medium.
In this study, we examined the chromosomal number for Glechoma hederacea subsp. grandis in a total of 1,030 specimens collected from different distribution areas in Japan. We found that G. hederacea subsp. grandis could be categorized into 3 cytotypes with 2n=36 (tetraploid), 2n=45 (pentaploid) and 2n=54 (hexaploid) chromosomes. Tetraploid plants were found throughout different areas in Japan; however, hexaploid plants were mainly distributed in central Honshu, Shikoku and Kyushu. Likewise, pentaploid plant distribution was found to overlap with hexaploid plant distribution areas. The pentaploid plant group appeared only in regions common to both tetraploid and hexaploid plants. All 3 cytotypes were found to have karyotypes which could be represented by the following equations: A) 6M+4m+18sm+8st for tetraploids, B) 6M+15m+19sm+5st for pentaploids, and C) 6M+26m+20sm+2st for hexaploids. Pentaploid specimen karyotypes had half the tetraploid and half the hexaploid chromosomal set, indicating that this specimen was a hybrid between tetraploid and hexaploid plants.
The genus Chlorophytum Ker-Gawl, with about 216 species, is distributed mainly in the Old World tropics especially in Africa and India. In India 17 species represent the genus. This genus has attracted the interest of scientific community owing to the presence of pharmacologically important saponins. Recently described species, C. kolhapurense Sardesai, S. P. Gaikwad & S. R. Yadav was studied cytologically, the chromosome number was 2n=16 and n=8 and the karyotype was symmetrical.
Degradation of the extracellular matrix by proteases secreted by invading tumor cells is thought to be essential for metastasis. Using an in vitro transcellular migration assay model, we examined the requirement of matrix metalloproteinases (MMP) in the invasion of MM1 rat hepatoma cells through normal mesothelial cell monolayers. Here we show that MM1 cells transmigrate using MMPs not expressed in the tumor cells but secreted by host mesothelial cells. Additionally, the amount of MMP secreted by mesothelial cells was increased by co-culture with hepatoma cells. Our results point to the role of normal host cells in the tumor microenvironment as a source of invasion factors necessary for the metastatic process.
The present study revealed the varied frequencies of natural chromosomal abnormalities in 4 populations of Artemisia absinthium Linn. collected from different altitudes of Kashmir Himalaya. All the populations are diploid showing n=9 with abnormal meiotic behaviour like quadrivalent formation at diakinesis, cytomixis at early prophase-I and laggards at telophases, resulting into reduced pollen fertility. Besides the heterogeneous sized pollen grains, occasionally inter pollen channels were also observed.
Karyotype analyses have been useful for clarifying phylogenetic and evolutionary relationships among related species and sub-specific taxa. Within the 22 wild species in the genus Fragaria (Rosaceae), karyotype analyses had been restricted to diploid species. The objectives of this research were to determine the chromosomal morphology and analyze the karyotypes of wild octoploid and decaploid species within this genus. Somatic chromosome images of 16 wild genotypes of F. chiloensis, F. virginiana and F. iturupensis were taken at the metaphase stage of mitosis under a light microscope. To evaluate phylogenetic relationships among 12 accessions, karyotypic similarity was examined by cluster analysis. Chromosome numbers of F. chiloensis and F. virginiana genotypes were octoploid (2n=8x=56), except for PI 551462 (2n=8x−2=54), an aneuploid F. chiloensis subsp. pacifica, and PI 551527, a decaploid genotype of F. virginiana subsp. platypetala. Chromosome morphology in F. virginiana subspecies varied more than that in F. chiloensis subspecies. Results of the cluster analyses separated the F. chiloensis and F. virginiana subspecies, except for F. virginiana subsp. grayana PI 616699. The decaploid, F. iturupensis, clustered within the octoploid F. virginiana clade, and was particularly close to F. virginiana subsp. glauca.
Male meiosis and pollen fertility studies have been performed in 35 species belonging to 25 genera and 13 families of Polypetalae from the Dalhousie hills. Impatiens laxiflora (n=6) was counted chromosomally for the first time. Corydalis cornuta (n=8), Erysimum hieracifolum (n=16), Arenaria serpyllifolia (n=10), Drymaria diandra (n=13), Geranium lucidum (n=14), Nasturtium officinale (n=16), Geum roylei (n=21) and Chaerophyllum reflexum (n=11) are worked out chromosomally for the first time in India. New cytotypes are recorded for Thalictrum saniculiforme (n=14), Drymaria diandra (n=13), Geranium lucidum (n=14) and Chaerophyllum reflexum (n=11). Present chromosome counts for the rest of the species substantiate earlier reports by other researchers. Intraspecific diploid (n=12) and tetraploid (n=24) cytotypes recorded presently from Dalhousie hills in Oxalis corniculata are morphologically indistinguishable. The phenomenon of cytomixis involving inter PMC (pollen mother cell) migration of chromatin material has been observed in Ranunculus diffusus (n=16), Thalictrum foliolosum (n=7), T. saniculiforme (n=14), Gypsophila cerastioides (n=15), Oxalis corniculata (n=24), Murraya koenigii (n=9), Geum roylei (n=21), Potentilla atrisanguinea (n=21) and Pimpinella diversifolia (n=9). Cytomixis in these species results in various meiotic abnormalities and heterogeneous sized pollen grains. In the remaining species, the meiosis is normal, leading to high pollen fertility.
Failure of chromosome pairing was observed in all the presently investigated natural populations of Erigeron karvinskianus (2n=36). All 4 populations were observed with a different range of univalents besides bivalents at diakinesis and metaphase I. The presence of univalents bound with various other meiotic irregularities, such as laggards and chromatin bridges, which further lead to abnormal microsporogenesis. Pollen sterility was found to be high.
Eight macromutants (albina, xantha, chloroxantha, bushy, thick leaf, dwarf, early flowering and synchronous flowering) were induced in Poshita and Jawahar 22 (recommended varieties) of Withania somnifera (L.) Dunal; (Family: Solanaceae) at M2 following EMS treatments (0.25, 0.50, 1.00% for 2 h and 4 h durations) to dry seeds. Albina and Xantha in both varieties and chloroxantha in Poshita were non-viable. Viable mutation frequency was recorded to be 0.00% to 3.00% in Poshita and 0.00% to 2.31% in Jawahar 22; however, estimated mutation frequency over M2 population was 2.54%. Meiosis was nearly normal in mutants as control (2n=48), except chloroxantha of Jawahar 22 (22.58II+2.84I/cell at MI, 57.0% cells with 24/24 separation at AI, 39.27% pollen fertility; control: 23.69II+0.62I/cell at MI, 90.0% cells with 24/24 AI separation, 71.05% pollen fertility). The mutant trait(s) were monogenic recessive to normal. Analysis of morphological parameters (root and shoot attributes including seed yield), secondary metabolites (total alkaloid and withanolides; withaferin A and withanolide A by HPLC) and fibre content of the roots (withaferin A was analyzed also from leaf) of M3 plants revealed that bushy and thick leaf were noteworthy mutants.
Poa annua L. (family Poaceae) is a cosmopolitan, cytologically variable and apomictic species. At present, cytomorphological studies have been carried out for North-Indian materials on 29 populations from Haryana (North Indian plains), Shiwalik hills and Kangra (H.P.) covering different altitudinal ranges (216–1489 m) of relatively unexplored areas. All the 29 populations are found to be tetraploid with n=14. Morphologically, plants of all the populations looked similar without any significant variation but cytologically speaking, among these, 24 populations show normal meiotic course whereas 4 populations show abnormal meiosis in the form of bridges, laggards, etc. The phenomenon of cytomixis has also been studied in 1 population. The variable number of B-chromosomes (1–3B) has been reported in some of the populations.
Sex-linked genetic markers of Silene latifolia were mapped to the sex chromosomes with the aim of analyzing their evolutionary origins. SlAP3X/Y has been particularly uncertain for years. Its X-counterpart has not been identified, and very few Y-deletion mutants delete SlAP3Y. In this study, we verified the sex chromosome-linkage of SlAP3X and SlAP3Y through cloning, sequencing, and fluorescent in situ hybridization (FISH). SlAP3X, spanning a region of 1.6 kb, consists of 6 exons and 5 introns. SlAP3Y has 7 exons and 6 introns, the second intron being particularly large (24.4 kb). SlAP3Y spans 31 kb in total. Their Harr-plot analysis and the chromosome positions indicated by FISH using their own probes support the hypothesis that the translocation of SlAP3X/Y has occurred on either chromosome.