This study conducted karyological analysis and detection of nucleolar organizer regions (NORs) in the Asiatic jackal (Canis aureus Linnaeus, 1758) from Khao Suan Kwang Zoo, Khon Kaen Province, Thailand. Blood samples were taken from two male and two female jackals. After standard whole blood lymphocytes had been cultured at 37°C for 72 h in the presence of colchicine, metaphase spreads were performed on microscopic slides and air-dried. Giemsa's staining, GTG-banding, high-resolution banding and Ag-NOR banding techniques were used to stain chromosomes. The results showed that the diploid chromosome number of C. aureus was 2n=78 and the fundamental numbers (NF) of both sexes were 80. The types of autosomes were 18 large telocentric, 18 medium telocentric and 40 small telocentric chromosomes. The X chromosome was the largest metacentric chromosome and the Y chromosome was the smallest acrocentric chromosome. In addition, the long arm near the centromere of chromosome pair 7 and the long arm near the telomere of chromosome pairs 10 and 28 contained NORs. From the GTG-banding and high-resolution banding techniques, the numbers of bands were 205 and 269, respectively, and each chromosome pair could be clearly differentiated. The karyotype formula for C. aureus is: 2n (diploid) 78=L18t+M18t+S40t+sex chromosomes.
Karyological analysis of the Indo-Chinese water dragon (Physignathus cocincinus) from Northeast Thailand was studied. Dragon lizard chromosome preparations were conducted by a squash technique from bone marrow and testis. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosome with Giemsa's solution. The results showed that the number of diploid chromosome was 2n=26, while the fundamental number (NF) were 48 in both males and females. The types of chromosome were five metacentric pairs and one submetacentric pair of macrochromosomes, and 12 pairs of apparent microchromosomes. No irregularly sized chromosomes related to sex were observed. Nucleolar organizer regions (NORs) are located at the secondary constriction of the long arm near telomere in macrochromosome pair 2. We found that during metaphase I the homologous chromosomes showed synapsis, which can be defined as 18 bivalents and 18 haploid chromosomes at metaphase II as in diploid species. The karyotype formula is as follows: 2n (36)=L4m+L2sm+M4m+S2m+24 microchromosomes.
Trichomycteridae is a family of small catfish which is widely distributed throughout Southern Central America and South America. Specimens of Trichomycterus brasiliensis collected in the upper São Francisco River Basin in Brasil were studied cytogenetically. All individuals presented 2n=54 chromosomes, including 34 metacentric, 18 submetacentric and 2 subtelocentric chromosomes. A secondary constriction was observed in the interstitial region of the short arm of the chromosome pair number 20, coinciding with the NOR and 18S rDNA. The first metacentric pair is considerably larger than the second metacentric pair and the NORs occur in the pericentromeric position of the short arm of a large submetacentric pair, allowing to place this species in one of the cis-Andean groups already identified of Trichomycterus.
This article reveals the micro-morphology and karyomorphological characters of three mulberry varieties, namely, Thysong, S41 and Morus multicaulis. Stomatal frequency, somatic chromosome number, ploidy level and karyotype analysis were studied for these varieties. Thysong is diploid with 2n=28, S41 is triploid with 2n=42 and Morus multicaulis is uneuploid with 2n=30 regarding somatic chromosomes numbers. The somatic chromosome length ranges from 1.26 to 2.83 μm, whereas the arm ratio ranges from 0.48 to 1.00 μm. Stomatal frequency is smaller in triploid varieties when compared to diploid and uneuploid mulberry varieties. In all the three varieties three to four types of chromosomes have been observed. Chromosomes are small sized with a narrow range of variation in length.
Pennisetum orientale is an important perennial species having high ecological and forage value. It is largely tetraploid (2n=4x=36) and obligate apomictic in mode of reproduction. A new hexaploid (2n=6x=54) derivate of P. orientale is reported here, recovered in a population derived from self-pollination of a tetraploid genotype. The origin of the 6x cytotype from a 4x cytotype is demonstrated through fertilization of an unreduced egg cell with a reduced male gamete (BIII hybridization), yielding experimental evidence of uncoupling of apomixis components in P. orientale. This 6x cytotype was compared for its morphological, cytological and reproductive traits vis-à-vis parental 4x cytotype, and also for potential of gene transfer in otherwise apomictic P. orientale.
The starch content (dry weight basis) from Curcuma amada Roxb., C. aromatica Salisb., C. caesia Roxb., and C. xanthorrhiza Roxb. was 45.24–48.48% (w/w), and the four species differed significantly in terms of ash content and the swelling power, solubility, and water-holding capacity of starch. Curcuma amada recorded the maximum swelling power, solubility, and water-holding capacity, whereas C. caesia recorded the lowest values for these parameters. Scanning electron micrographs revealed variation in the shape and size of starch granules as follows. Curcuma amada: oval to elliptical with a smooth surface, 16–48 μm long and 11–26 μm wide; C. aromatica: oval to elliptical, flat with concentric rings on the surface, 9–60 μm long and 6–24 μm wide; C. caesia: round to oval with a smooth surface, 10–39 μm long and 9–23 μm wide; C. xanthorrhiza: elongated, 9–47 μm long and 8–23 μm wide.
In this study, the possible cytotoxic effects of diniconazol fungicides on root tip cells of Allium cepa L. were investigated. Germination percentage, root length, weight gain, frequency of micronuclei (MN), chromosomal aberrations (CAs) and anatomical changes were used as toxicity markers (indicators). Seeds were divided four groups as one control group treated with tap water, and three treatment groups treated with 25, 50 and 100 ppm doses of diniconazole for 72 h. As a result, germination percentage, root length and weight gain decreased, and MN level and chromosomal aberrations increased in the treatment groups compared to the control group. As a result of microscopic examination, stimulation of the chromosomal damages such as C-mitosis, fragment, chromosome bridge, binucleus cell, abnormal polarization, sticky chromosomes or unequal chromatin distribution by diniconazole treatment were observed. Also, in the root tip cells, diniconazole application caused anatomical damages such as cell deformation, nonspecific vascular tissue, flattening cell nucleus and necrosis.
The Egyptian clover or berseem (Trifolium alexandrinum L.) is widely cultivated as a winter season forage crop in about two million hectare of land in India. It is widely accepted because of its multicut nature, high yield and nutritional value. A plausible approach for increasing yield could be through increasing photosynthetically active leaf area and consequently the biomass. The present investigation deals with induction of polyploidy and evaluation of tetraploids vis-à-vis diploids lines of Egyptian clover for multifoliate leaf formation. Immersing of pre-hydrated seeds, from diploid multifoliate plants, in colchicine followed with seedlings immersed in 0.1 and 0.2% colchicine solution for 24 and 48 h, respectively, was effective in inducing tetraploidy. Distinct characteristic features observed among induced pentafoliate tetraploid plants were presence of serrate leaflet margin, prominent rachis and bold seeds. Leaves were thick, succulent, and hairy with apical notch characterized by presence of pigmentation on the outer margin. The autotetraploids had better expression of pentafoliate trait than in diploid plants.
Tabernaemontana coronaria of Apocynaceae is an economically important medicinal plant, distributed throughout the tropics of the world. The different alkaloids produced by this species are effective against various disorders like abdominal tumors, asthma, diarrhoea, epilepsy, eye infections and fever. Morphological characters including internode length, petiole length, leaf area and leaf index varied between these varieties. Cytological analysis revealed three diploid varieties with 2n=22 chromosomes (Wild type T. coronaria, T. coronaria var. Variegata, T. coronaria var. Dwarf) and a triploid variety with 3n=33 chromosomes (T. coronaria var. Flore-pleno). A variation was recorded in total chromosome length and volume among the diploid varieties of T. coronaria. Most of the centromeric chromosomes were either median or median region. The present study indicated that cryptic structural changes of chromosomes might be responsible in the evolution of different varieties of T. coronaria except the Flore-pleno variety. Moreover, differential condensation of chromosomes attributing to variable chromosome length and volume has been suggested.
Soil stabilization is a serious exercise, which involves establishing and implanting resistive measures against soil erosion. Growing grasses is one of the most efficient and cost effective methods of stabilizing banks of slopes and newly created slopes from landslides, etc. Selection of suitable candidate species for this job is an important question. Male meiotic studies have been carried out on two soil stabilizing grass species, Eremopoa persica and Pennisetum lanatum, of family Poaceae from district Kinnaur, Himachal Pradesh, a cold desert region of the Northwestern Himalayas, India. Meiotic analysis of three populations of Eremopoa persica revealed that all populations exist at a haploid chromosome number of n=21, a new hexaploid cytotype recorded for the species at world level. The present count of n=9+1–3 B in Pennisetum lanatum is the first report of B-chromosomes. The meiotic course varies from normal to abnormal in various populations, thus reducing the pollen fertility in the analyzed populations.
Presently, cytomorphological investigations have been carried out in five populations of Aster thomsonii from different altitudinal areas of district Sirmaur (H.P.). The investigations revealed three cytomorphotypes: diploid (2n=18), tetraploid (2n=36) and hexaploid (2n=54). The chromosome count of 2n=54 (hexaploid cytotype) has been reported for the first time at world level. All the populations have anomalous meiotic course and reduced reproductive potential of 72, 81 and 59% for diploid, tetraploid and hexaploid, respectively.
The karyotypes of Sinotaia quadrata using air-drying method collected from Hyogal-ri, Pungyang-myeon, Yecheon-gun, Gyeongbuk, Korea were investigated. The diploid number of chromosomes is 2n=16. The eight chromosome pairs were identified and classified into three groups. The diploid cell has 1 pair of metacentric, 5 pairs of submetacentric and 2 pairs of subtelocentric chromosomes. Observed chromosomes ranged from 3.10 to 4.90 μm and the total length was 34.12 μm. The karyotype of S. quadrata is described for the first time.
Orthetrum taeniolatum, collected from the Patnitop area of Jammu and Kashmir, has been cytogenetically studied. The species possesses diploid chromosome number 2n=21m with X0 type sex determining mechanism. During the course of meiosis, two autosomal bivalents are distinctly large as compared to the remaining autosomal bivalents. The X chromosome also shows the phenomenon of precocious segregation. The reduction in chromosome number from the type number (2n=25m) is due to the fusion of two autosomal pairs, which is very common in case of holokinetic chromosomes. This type of karyomorphological variations in the species has been observed for the first time.
Fetal macrosomia is one of the major clinical problems that carry health hazards for both mother and fetus. Diabetic mothers with mild hyperglycemia or gestational diabetes are at a high risk of having macrosomic babies. This study aimed to describe the cellular changes of skin and brown fat of macroscomic fetuses born to mildly diabetic rats. This experimental study used 36 adult female rats divided into control (n=12) and experimental (n=24) groups. The latter were injected intra-peritoneally with Alloxan (100 mg/kg) and animals with blood glucose (130–250) mg/mL (n=16) were designated as diabetic and were housed with known fertile males. On day 21 of gestation, pregnant females were sacrificed and fetuses were weighted and processed for histological and histochemical examination. A significant increase in body weight of macrosomic fetuses born to diabetic mothers (6.6±0.37) was recorded. Mean dermal thickness (7.9±0.2) and brown fat mass (451.8±11.2) were significantly increased (p=0.004 and p=0.04) in macrosomic fetuses. Brown fat adipocytes showed earlier transformation into white fat adiopocytes. Lipid and polysaccharide accumulation as well as significant cell proliferation were observed in both tissues of macrosomic fetuses. Increased thickness of skin and mass of fat brown fat of macrosomic fetuses of mild diabetic rats could be attributed to increased deposition of polysaccharides and lipids as well proliferation of their cells.
Standardized karyotype and idiogram of the vermiculate spinefoot, Siganus vermiculatus (Valenciennes, 1835) from Andaman Sea, Southern Thailand were established. The mitotic chromosome preparations were prepared directly from kidney cells of two male and two female fish. The chromosomes were stained by using conventional and Ag-NOR banding techniques. Its diploid chromosome number was 2n=48 and the fundamental number (NF) was 50 in both males and females. The types of chromosomes were 2 large acrocentric, 30 large telocentric, 12 medium telocentric, and 4 small telocentric chromosomes. No strange size chromosomes related to sex were observed. The region adjacent to the telomere of the short arm of chromosome pair 1 showed clearly observable nucleolar organizer regions (NORs). The karyotype formula could be inferred as: 2n (diploid) 48=L2a+L30t+M12t+S4t
Two species, E. colona and E. crus-galli, belonging to genus Echinochloa from Saudi Arabia were subjected to cytogenetic investigation in this study. These species are common grass belonging to family Poaceae, mostly distributed in wet or damp places throughout agricultural and public gardens in the Arabian Peninsula. Mitotic studies show that E. colona has 36 chromosomes as tetraploid species, whereas E. crus-galli has 54 chromosomes as hexaploid. Both species are based on x=9 as the common basic number in this genus and the majority of genera of family Poaceae. Karyotype structure and mitotic measurements of E. colona show a high degree of homogeneity in chromosome morphology and centromere position, reflecting its autotetraploid nature. Regarding E. crus-galli, the karyotype structure and mitotic measurements show significant variation between chromosome measurements and morphology, insuring the alloploid nature of the species. Meiotic chromosome associations, chiasma frequency, pollen fertility and irregularities for the two species were carried out. E. colona recorded normal association and high ratio of chiasma frequency as well as low irregularities, indicating the genetic stability of the species and giving rise to high pollen viability. In contrast, E. crus-galli shows low frequency of bivalents compared to E .colona, low chiasma frequency and high percentage of meiotic irregularities, reflecting genetic instability and alloploidy structure of the species. The genetic stability of E. colona directly affects seed production, especially at open pollination conditions, in contrast to E. crus-galli, where the heterogenis structure and genetic instability negatively affect seed production at open conditions. Significant low seed set at self-pollination conditions insures that the two species undergo open pollination rather than self-pollination, as common in the grass family.
Chytrids are an early diverging group of fungi possessing a flagellated spore stage in their life cycle. Chytrid infections in amphibian species and algae are currently a major problem worldwide. Lectin binding patterns are key factors involved in host-parasite interactions. However, there are no analyses of the lectin binding pattern for core chytrids (e.g., species belonging to Chytridiales). Here we present time-lapse observations of the early development of the vegetative stage and lectin binding patterns to examine sugar composition during the asexual life cycle of the core chytrid Chytriomyces hyalinus ATCC 28165. The lectin binding assay showed that the signal of wheat germ agglutinin was detected in the chytrid cell wall and basal part of the rhizoidal system, but not in the zoospore and rhizoid system. This result indicated that N-acetyl-d-glucosamine was accumulated highly at the basal part of the rhizoid system in C. hyalinus.