A molecular cytogenetic survey of Cucumis sativus L. revealed a chromosomal polymorphism among 2 European pickling cultivars of ‘Borszczagowski’ and ‘Monastyrski’, and one Japanese cultivar of ‘Zibai’ by fluorescent banding method with chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI), and fluorescence in situ hybridization (FISH) with the probes of 5S, 45S rDNA and telomere repeat sequences. Heterochromatic banding polymorphism was found in some chromosomes with CMA and DAPI staining, whereas no chromosomal polymorphism was found in FISH. Thus, the FISH allowed us to identify all of homologous chromosomes in each cucumber cultivars, while CMA and DAPI banding showed an easy detection of the polymorphism in cucumber chromosomes, even in close related cultivars between European pickling cultivars.
We analyzed a gene in the ethylene responsive factor (ERF) family, which plays an important role in allowing plants to respond to various environmental cues, isolated from suspension cultured cells of Populus nigra subjected to cold stress. A comparison of gene homology with transcription factors of the AP2/ERF family revealed a well conserved AP2/ERF domain in the predicted amino acid sequence of PncERF1. However, it has no consensus sequences around the AP2/ERF domain, which is a characteristic sequence of the CBF/DREB subfamily belonging to the ERF family. PncERF1 likely belongs to the ERF subfamily, which is the other ERF subfamily. Expression analysis showed no expression of PncERF1 at room temperature, at which cells grew normally, although it was expressed following cold treatment for 24 h. Therefore, PncERF1 was predicted to play a role in poplar cell survival in cold environments.
We previously reported that cholesteryl glucoside (CG), a member of membrane glycolipid, is rapidly induced by exposure to some forms of stress in animal tissues and human cultured cells. As CG is induced by heat shock before the activation of heat shock transcription factor 1 (HSF1) and the production of heat shock protein 70 (HSP70), and CG added exogenously induces HSF1 activation and HSP70 production in animal tissue and human fibroblasts, it is suggested that CG functions as a crucial lipid mediator in cellular responses against heat stress. In this report, we showed the localization of CG synthetase, sterol glucosyltransferase, at lipid raft in the human cell membrane. Because the lipid raft is considered to be a scaffold of heat shock response leading to HSP induction, we propose that CG formation by sterol glucosyltransferase in lipid raft might act as a potential factor in the thermal sensing reaction. Additionally, using the artificial liposomes modeling on the states of membranes before and after CG production, we clarified that the transfer of the glucose moiety from glucose donor, glucosylceramide, to cholesterol changed membrane physical properties and formed thermostable solid-ordered domains. We suggest that the alteration of membrane physical state caused by heat stress might be linked to activate sterol glucosyltransferase to form CG in the animal.
Karyotypes of 3 wild Corchorus spp. of Tiliaceae, namely C. tridens, C. fascicularis and C. pseudo-capsularis, were investigated after differential staining with orcein, CMA and DAPI. In addition, the activities of 3 isozymes, esterase, acid phosphatase and peroxidase in these 3 species were compared. These 3 spp. were found to possess 2n=14 metacentric chromosomes. The CMA and DAPI bands were found in either the terminal or interstitial region of the respective chromosomes of 3 species. This indicated a tendency for the accumulation of GC- and AT-rich repeats at terminal or interstitial region of the chromosomes. The number and distribution of CMA- and DAPI-bands were unique for each species. A comparison of CMA- and DAPI-banding pattern indicated the presence of paracentric inversion in the concerned areas of the respective chromosomes. Different types of heteromorphicity regarding CMA- and DAPI-banding revealed the probable occurrence of deletion and tandem duplication. In acid phosphatase, 2 common bands were found in C. fascicularis and C. pseudo-capsularis. A dark, thick peroxidase band was found in C. fascicularis whereas a light, thick band occurred in C. pseudo-capsularis. These light and dark thick bands could be used as markers for these 2 spp. Moreover, a big upper esterase band makes C. tridens unique.
Cytological studies on 4 Sterigmostemum species of St. ramosissim, um, St. incanum, St. sulphureum and St. acanthocarpum showed the presence of 2n=2x=14, out of which the chromosome number of St. ramosissimum is new. The chromosomes were mainly metacentric or sub-metacentric ranging in size from 2.62 μm in St. ramosissimum to 5.50 μm in St. sulphureum and St. acanthocarpum. The species studied formed mainly ring and rod bivalents as well as univalents in metaphase of meiosis I, but a low value of quadrivalents were formed in the Firoozkooh population of St. sulphoreum and the Tehran population of St. acanthocarpum possibly due to the occurrence of heterozygote translocations. Clustering and parsimony analysis of cytological data showed close affinity between St. incanum and St. sulphureum, supporting morphometric and seed protein studies results.
Cirsium species grow in various regions of Iran but their cytological study is very limited. Therefore, meiotic analysis of 21 populations in 17 Cirsium species was performed, showing the occurrence of synezetic knots and post pachyten diffuse stages possibly due to adaptation to different environmental conditions. The occurrence of 0–2 B-chromosomes was observed in most of the species, which significantly affected chiasma frequency and distribution as well as chromosome pairing. Such effects may change genetic recombination in the next generation, to be used in the adaptation of these species. Meiotic abnormalities including chromosome stickiness, multipolar cell formation and cytomixis were observed in some of the species, which may result in some degree of pollen sterility in Cirsium.
We previously found an inverse correlation between the number of bacteria and the number of fungi collected throughout the year from tatami mats in judo halls. Antibacterial substances produced by the fungi are presumably responsible for the decline in bacterial populations. Culture extracts from fungi isolated from the tatami mats were prepared and their antibacterial activity against Micrococcus luteus, Staphylococcus warneri, and Bacillus subtilis isolated from the mats was determined by the paper disc method. For all 3 bacteria, clear inhibitory zones were obtained indicative of the presence of a growth inhibitory compound in the fungal culture extract. A sampling method was developed for the scanning electron microscopic observation of bacteria around the inhibitory zones produced by the fungal culture extract. Using this method, changes in the surface microstructures of bacteria existing inside the inhibitory zone and growth region were successfully compared by scanning electron microscopy.
A male sterile-female fertile mutant of Uraria picta (Jacq.) DC. (Family-Leguminosae, Papillionoidae), possessing dwarf habit, normal chromosome behaviour at meiosis and 100.0% sterile pollen grains (1.00% EMS, 6 h; 0.16% over the M2 mutant population), was identified and it segregated into 4 normal and 3 mutant plants at M3 (70 seeds sown, 11 plants germinated, but 7 survived till maturity). Out of 3 mutants, 1 plant showed abnormal meiosis, 100.0% sterile pollen grains with size variations and in some cases pollen grain agglutination, and the other 2 plants instead showed normal meiosis and 100.0% sterile pollen grains; these were designated as MS1 and MS2 respectively. Meiotic chromosome analysis and studies of pollen grains (pollen viability tests: Lugol's Iodine, Aniline blue, x-gal, Amido black, TTC, Neutral red and Methylene blue; DAPI staining for pollen nuclei; SEM analysis) in relation to untreated control revealed possible differential gene behaviour in MS1 (evident in microsporogenesis as well as microgametogenesis) and MS2 (microsporogenesis only). Male sterility is a non-structural nuclear type (monogenic recessive–ms1 ms1) and is being reported for first time in the species.
Dipcadi goaense A. Prabhugaonkar, U. S. Yadav & Janarth. is so far known from type locality with a single population spread over about 1 sq. km. in south Goa. It is allied to D. concanense (Dalz.) Baker but differs in its small flowers and funnel-shaped perianth tube. The present paper describes the distribution, ornamental potential and karyotype analysis and reports on meiotic count in the species. The haploid chromosome number n=6, somatic chromosome number 2n=12 and karyotypic analysis is reported for the first time for the species. The bimodal asymmetrical karyotype represents an advanced nature of the taxon. It has glistening white fragrant flowers of considerable ornamental potential. The species can be best conserved through its utilization as an ornamental bulbous plant by introduction in gardens.
Present investigations were carried out to study the microsporogenesis in populations of Croton bonplandianum Baill. from 5 cities of north India. The chromosome count of n=10 was uniform in all the populations. Among the analysed populations 32.50–40.96% of PMCs were recorded to be interconnected through cytoplasmic connections, with many of them showing actual transfer of genetic material between the cells. Cytomixis was observed to involve 2–8 cells at a time. Presence of laggards and resultant micronuclei has been observed in all the populations. As a result of cytomixis and its associated abnormalities heterogeneous pollen size and variation in pollen fertility were also recorded.
Cyclic phosphatidic acid (cPA) has a similar structure to that of lysophosphatidic acid (LPA), but possesses distinct biological functions. For example, cPA suppresses cancer cell invasion and metastasis through the inhibition of autotaxin (ATX) and transient activation of low molecular weight GTPase, RhoA. We designed and chemically synthesized several metabolically stabilized derivatives of cPA, and revealed that 2-carba-cPA was the most potent inhibitor of cancer cell invasion and metastasis. We have developed a novel method of 2ccPA enantiomeric synthesis, and here we examined the effects of natural (R)-cPA, both enantiopure 2ccPA, and (S)-3ccPA (corresponding to the configuration of (R)-2ccPA) on ATX. We also predicted the effects of (R)-cPA, (R)-2ccPA and (S)-3ccPA on ATX activity by combined quantum mechanics and molecular mechanics (QM/MM) computational methods. By these methods, we demonstrated that 2ccPA was the most potent inhibitor on ATX, and the chirality of 2ccPA was not involved in ATX inhibition. These results suggest that racemic-2ccPA may be utilized as an effective compound for cancer therapeutics.
Agrimonia eupatoria L., a medicinally important species of the family Rosaceae, has been presently worked out for the first time from the 3 geographical areas of Kashmir (Jammu and Kashmir) and the Kangra and Sirmaur districts (Himachal Pradesh) of the Western Himalayas in India. The cytotypes with n=14 and n=28 were in conformity with the previous reports of the species from different parts of the world. A new cytotype of n=42 from Kashmir was observed for the first time. In comparison, these cytotypes (n=14, 28, 42) show significant variations in relation to morphology as well as geographical distribution in the Western Himalayas. Further, intra-population variability has been observed in different accessions of hexaploid cytotype in the form of B-chromosomes, abnormal meiotic course or aberrant type of flower morphology.
Cytogenetics of banded palm civet (Hemigalus derbyanus) in Thailand was studied. Blood samples were taken from 2 males and 2 females then subjected to standard whole blood T-lymphocyte culture. The samples were harvested by colchicine-hypotonic-fixation-air-drying technique and followed by conventional staining, GTG-banding and high-resolution techniques with Giemsa's. The results showed diploid number as 2n=42, and fundamental number (NF) as 81 in both male and 82 in female. The autosomes consist of 10 large submetacentric, 12 large acrocentric, 4 medium submetacentric, 4 small metacentric, 8 small submetacentric and 2 small telocentric chromosomes. We found that nucleolar organizer regions (the representative of chromosome marker) locate on the long arms of a pair metacentric autosome 15. The X chromosome was a large acrocentric chromosome while the Y chromosome was the smallest telocentric chromosome. From GTG-banding and high-resolution techniques, the numbers of bands and locations in banded palm civet were 218 and 244, respectively. Each homologous chromosome pair appears clearly differentiated.
Robertsonian translocation, or centric fusion, which is known to be the most common mechanism in karyotype evolution of bovid species, was observed and described in captive Thai gaur (Bos gaurus readei). Blood samples were taken from 2 male and 2 female captive Thai gaur. After the standard whole blood lymphocyte culture in the presence of colchicine, the metaphase spreads were performed on microscopic slides and air-dried. Conventional staining, GTG-banding, CBG-banding and Ag-NOR banding techniques were applied to stain the chromosomes. The number of diploid chromosomes (2n) were 57 in 2 males and 56 in 2 females instead of the normal 2n=58. The fundamental number (NF) was 62 in both the 2 males and 2 females. The autosome consists of 3 submetacentric and 52 telocentric chromosomes in males, and 4 submetacentric and 50 telocentric chromosomes in females. The X chromosome was a large submetacentric chromosome and the Y chromosome was the smallest metacentric chromosome. Eight telocentric chromosomes and 2 submetacentric chromosomes (5 autosome pairs) were identified as satellite chromosomes which showed clearly observable nucleolar organizer regions (NORs). The presence of an extra submetacentric chromosome and the loss of 2 telocentric chromosomes [57,XY,rob(1;29)] were observed in both males. Also, the presence of 2 extra submetacentric chromosomes and the loss of 4 telocentric chromosomes [56,XX,rob(1;29)] were observed in both females. Results from the GTG-banding and CBG-banding techniques analyses confirmed that the 2 autosomes of male (2n=57) and 4 autosomes of female (2n=56) involved in the translocation are the chromosome pairs 1 and 29, which are common in translocation of the bovid species.