Liver regeneration is a complex physiological response that takes place after the loss of hepatocytes caused by toxic or viral injury or secondary to liver resection. This work purposed to investigate the implication of bcl-2 and bax expression as an important contribute in liver transplant donors and also the possible modulatory effect of licorice on their expression. Forty eight male albino rats weighing 250–320 g were divided into 6 groups (8 animals for each). The rats underwent partial hepatectomy (PH) represents 3 groups (sacrificed after 24, 48 and 72 h after PH) and other 3 groups after oral receiving of licorice extract for 4 weeks (2.4 g/kg b.w.). The resected liver was considered as control (zero time). The expression of bcl-2 and bax mRNA of normal liver and liver of PH were measured by reversed transcriptase polymerase chain reaction (RT-PCR). The distinct changes in the expression of the mRNA encoding these 2 genes were confirmed by an immunohistochemical staining of the liver tissues (streptavidin-biotin method). The analysis of mRNA level revealed a significant increase of anti-apoptotic bcl-2 mRNA expression after 24 h (p<0.05), while, it was declined in the following 2 d. In contrast, bax mRNA expression showed delayed increase reaching a peak at 48 h after PH. The pretreatment with licorice caused a statistically significant increase in bax mRNA expression; meanwhile, the change in bcl-2 expression was not significant when compared to the control. Furthermore, immunohistochemical staining of regenerating liver with bcl-2 and bax antibodies showed that the changes in the bcl-2 and bax protein levels were similar and consistent to that found for mRNA. It was suggested that licorice may provide a mechanism in the induction of apoptosis through modulation of bcl-2 and bax expression in regenerating liver as a model for chemopreventive drug of cancers.
An alternative chromatic variation to the wild-type phenotype of the livebearing fish Phalloceros caudimaculatus (Phalloceros caudimaculatus var. reticulata) was detected in a single female from “Bañados del Este” Reserve of Biosphere Site, in Uruguay. The founder mutant female, which presented a melanic spotted pattern overlapping the wild-type pigmentation, produced laboratory breed strains. Four phenotypes showing different degrees of spotted patterns were obtained. In order to determine the inheritance of this chromatic mutation, experimental crosses and cytogenetic analyses of these laboratory strains were carried out. The breeding experiments among the spotted phenotypic classes and backcrosses suggest the dominant and non-sex linked inheritance of this mutation. Statistical tests demonstrated that the inheritance mechanism of this mutation does not correspond to a 2-gene independent segregation hypothesis as it was proposed in Poecilia sphenops, or to a single dominant gene hypothesis. Additionally, cytogenetic analyses detected a partially heterochromatic biarmed chromosome associated to the inheritance of the pigmentation pattern in laboratory breed strains.
Non-permissible concentration of fluoride salts in ground water induces various anomalies in human beings. Bhagalpur city's ground water contains 1–2 ppm of fluoride. Its genotoxic effects were assessed in Swiss albino mice Mus Musculus. 25% (50 mg/l) and 50% (100 mg/l) concentrations were found to increase the frequency of abnormal cells by 10.33 and 19.33% and chromosome abnormalities by 10.33 and 20.00% in bone marrow cells. The increase in frequency of chromosome anomaly was mainly due to significant increase in individual type, viz. chromatid breaks, gaps and acentric fragments. The effect is dose dependent. Fluoride salts present in the ground water might have interfered the phagocytosis and produce oxygen free reactive radicals that attack the nucleophilic sites of the DNA leading to the loss of important gene segments responsible for cell growth and the ageing.
The ultrastructural analysis using ultra-thin section and transmission electron microscope was carried out to characterize the features of the reproductive cells in aposporous initial cell (AIC)-derived embryo sac (AES), i.e. egg, synergid and polar cells, in ovule of facultative apomictic Panicum maximum. At anthesis, the first AES located in micropylar end consists of egg apparatus with 2 synergids and 1 egg cell, and the central cell with 1 nucleus. The other AESs contain less than four cells. The egg cell contains high dense of cytoplasm, and around the nucleus plastids and mitochondria are remarkable. There exist lipid bodies, few rough endoplasmic reticulum (rER), dictyosomes, and big vacuoles distributed in cytoplasm. The polar cell is occupied almost by one big vacuole, the lower dense cytoplasm than that of egg cell wraps 1 or 2 nuclei and is distributed around egg apparatus. Only in micropylar end of the AES the cell wall of the central cell with one nucleus exists with ingrowth of cell wall, indicating that this structure transports the nutrition for the embryo development. Synergid usually contains lowest dense of cytoplasm, and lipid bodies, plastid and mitochondria are distributed along the filiform apparatus in micropylar end. Filiform apparatus is located in the top place of the 2 synergids that is same to that of sexual embryo sac. Extreme rER and vacuoles distributed in chalazal end are the characteristics of the synergids. These vacuoles and rER might contain abundant inorganic substances that are absorbed as a part of nutrition for the developing embryo.
Cisplatin is an antineoplastic agent used to treat solid malignancies, such as ovarian, testicular and bladder tumors. Studies have been shown that cisplatin induces genotoxic effects and chromosomal alterations that can result in genetic and chromosomal instability. In this work, we investigated the effects of cisplatin on the cytogenetic traits of cultured V79 cells based on the modal chromosome number, mitotic index, frequency of polyploidy and number of aneuploid metaphases. Cisplatin-treated V79 cells showed an altered chromosome number distribution, as well as an enhanced mitotic index, frequency of polyploidy and number of aneuploid metaphases. These alterations were probably related to the genetic instability produced by cisplatin. In addition, these cells showed characteristics associated with neoplastic development that corresponded to neoplastic processes related to the use of cisplatin in chemotherapy.
The diploid (2n=720) and haploid (2n=360) chromosome numbers were determined in Ophioglossum nudicaule. The somatic chromosome count was made on the plant for the first time. O. nudicaule is a very high polyploid plant, either exhibiting 48-ploidy, if the basic chromosome number is x2=15 or a 24-ploid, originating from the basic chromosome number of x3=30.
The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.
Maintaining oocytes at germinal vesicle (GV) stage without damaging their quality would allow synchronization of maturation and homogenization of the oocyte population. Activation of the oocyte is very important for a number of oocyte or embryo related technologies including intracytoplasmic sperm injection and cloning by nuclear transfer. This work will focus on induction of meiotic inhibition and oocyte activation by cycloheximide (CHX), in buffalo. For this purpose 2 experiments were conducted. In experiment I, buffalo cumulus-oocyte complexes (COCs) were cultured in 100 μl droplets of tissue culture medium 199 enriched with 10% v/v fetal calf serum, FSH and LH (0, 05 iu/ml, PERGOVET 75, Serono, Rome, Italy) and 50 μg/ml gentamycin for 24–26 h at 38.5°C in 5% CO2 and humidified air for 24 h in the presence of 2 μg/ml CHX. COCs were significantly blocked at the GV stage (20.85% vs. 82.72% in control). Reversibility of the CHX effect was assessed by culturing COCs an additional 24 h in CHX-free culture medium. About 65.0% of treated oocytes (control 80.1%) resumed meiosis and progressed to the MII stage. In experiment II, buffalo oocytes were activated by 10 μM calcium ionophore A23187 for 5 min followed by 10 μg/ml CHX for 3 h. Control oocytes were exposed to conventional in vitro fertilization (IVF) in BO medium. After 48 h of culture, significantly more oocytes (p<0.05) were cleaved in the IVF group than in treated group and spontaneous activated one. In conclusion, CHX can be used to block spontaneous resumption of meiosis in buffalo oocytes and its effect is reversible. Also, CHX in combination with calcium ionophore have the ability to induce parthenogenetic activation in buffalo oocytes.
To clarify the chromosomal evolution among the 3 sections (Absinthium, Artemisia, Dracunculus) of Japanese Artemisia, we use numerical cytogenetic analysis based on karyotypes. The intra- (A1) and interchromosomal (A2) asymmetry index, which does not depend on chromosome number or chromosome size. Our asymmetry index based on A1 value has indicated that the chromosomes in some Japanese Artemisia evolved in order of section Dracunculus, Absinthium and Artemisia. The A1 index indicated that x=9 was the ancestral basic chromosome number of this genus while x=8 was advanced, and based on x=17 was plotted between speies with x=9 and x=8.
Standardized karyotype and idiogram of the pileated gibbon (Hylobates pileatus) Nakhon Ratchasima Zoo, Thailand was studied. Blood sample were taken from 2 females and 2 males. After standard whole blood lymphocyte culture at 37°C for 72 h in the presence of colchicine, the metaphase spreads were performed on microscopic slides and air-dried. G-banding and high-resolution technique were applied to stain the chromosomes. The results showed that the number of diploid chromosomes of pileated gibbon was 2n (diploid)=44. The type of autosomes were 30 metacentric, 10 submetacentric and 2 acrocentric chromosomes, with X and Y chromosome being submetacentric and acrocentric chromosome, respectively. From the G-banding and high-resolution technique, the numbers of bands and locations in the pileated gibbon were 183 and 236 respectively, each chromosome pair could be clearly differentiated.
Interspecific hybrids between 2 cultivated varieties (MCU 5 and MCU 7) of tetraploid cotton (Gossypium hirsutum) and diploid perennial species G. raimondii were synthesized. The resulting triploid F1s were pollen sterile and exhibited irregular meiosis with frequent formation of univalents and multivalents. Mean chromosome association of the triploid hybrids were 11.50 I+9.97 II+2.31 III+0.16 IV and 0.50 I+11.35 II+0.96 I. Successful synthesis of hexaploids involoving G. raimondii by doubling the genomes of the triploid hybrids with 0.1% colchicine and enhancement of fertility status in hybrids is reported for the first time. The mean chromosomal association of hexaploid hybrids were 4.05 I+26.91 II+4.45 III+1.23 IV+0.32 V and 1.26 I+25.81 II+1.18 III+5.19 IV respectively. The heterozygosity of triploid and hexaploid hybrids was also confirmed through SSR marker analysis. Further utility of the developed hybrids with respect to jassid resistance breeding in cotton is discussed.
Lacerta princeps subsp. princeps is endemic to Iran and found from the new locality of north slops of Dena mountain near Cisakhat in this study. Mitotic chromosome studies on bone marrow cells of male and female revealed 2n=35 and 2n=36 chromosomes respectively. The karyotype consists of 34 autosome chromosomes including: one pair of biarmed metacentric macrochromosome, 15 pairs of uniarmed chromosomes and one pair of microchromosome. in addition, it seems that male has 1 uniarmed X chromosome and female has 2 uniarmed XY chromosomes, which Y chromosome was smaller than X. The presence of 1 pair biarmed metacentric macrochromosome in L. perinceps princeps separates this species from another species that examined from karyologically point of view. It seems that this pair chromosome originate from the fusion of 2 telocentric chromosomes. Chromosome count for this subspecies is reported here for the first time.
A higher copy number of the rbcL gene in Chlamydomonas reinhardtii genome upregulates synthesis of Rubisco gene products (Uchida et al. 2005). To determine the influence of rbcL gene number increase on the viability and morphology of the cell, we examined the growth speed, size of pyrenoid and density of antigen to Rubisco holoenzyme antibody in the three-rbcL (3L) transformant. There were no differences detected in these phenotypes between the 3L transformant and the control transformant.
Two species of the genus Solanum viz. S. nigrum and S. villosum found in Bangladesh were cytogenetically investigated to confirm their taxonomic status. S. nigrum and S. villosum were found to possess 2n=24 and 2n=48 chromosomes, respectively. The centromeric formula 22m+2sm was found in S. nigrum and 48m in S. villosum. No gradual decrease of chromosomal length was observed in both the species indicated their karyotypes as primitive type. The individual chromosomal length ranged from 1.66 to 2.34 μm in S. nigrum and 1.66 to 2.66 μm in S. villosum. The total chromatin length in S. villosum (97.8 μm) was almost double to that of S. nigrum (48.94 μm). The range of relative length of chromosomes was similar in these two species. Solanum nigrum and S. villosum possessed 18 and 17 CMA positive bands, respectively. Most of the CMA-bands were present at the terminal region in both the species. The percentage of CMA banded region in S. villosum (35.43) was almost double to that of S. nigrum (18.69). A pair of DAPI positive bands was found on both the end of all the chromosomes in these 2 species. Each band was 0.5 μm in length. The karyotype of S. nigrum studied here indicated that the specimen was not actually S. nigrum rather it has much simillarities with S. americanum. Solanum villosum showed regular bivalent formation at metaphase-I and segregation at anaphase-I. The overall karyotypic features suggested S. villosum as an ancient auto-tetraploid of S. americanum which in course of time has started regular meiosis.
Karyotype analysis of 3 released varieties in Vigna radiata L. viz. Barimung-2, Barimung-3, Barimung-5 has been carried out after staining with orcein, CMA and DAPI. These varieties were found to possess 2n=22 chromosomes. Four terminal CMA-positive bands were found in Barimung-2, 3 such bands in Barimung-3 and 4 in Barimung-5. The terminal CMA positive bands showed deep DAPI-negative reversible bands in the 3 varieties of V. radiata. One chromosome of Barimung-5 was fluoresced entirely with CMA and DAPI. DAPI-positive and DAPI-negative band occurred in another chromosome of Barimung-5. A pair of interstitial CMA-negative band was observed in chromosome pair V of only Barimung-2. These portions were stained brightly with DAPI. These kinds of reversible banded chromosomes could be easily identified. Polymorphism regarding the number and location of DAPI-positive bands were observed in these varieties. That may due to either minute deletion or high condensation of heterochromatic region at the respective loci. Few chromosomes of each variety showed characteristic CMA and DAPI bands. Therefore, with the help of CMA and DAPI it was possible to develop marker chromosomes for authentic identification of three varieties in V. radiata.
Differential staining with orcein, CMA and DAPI were used to characterize the karyotypes of three cultivated varieties of Lens culinaris Medik viz. Barimasur-2, Barimasur-3, Barimasur-4. In Barimasur-2 and Barimasur-3, 2n=14 chromosomes were found. Whereas in Barimasur-4, 2n=15 chromosomes were observed indicates the variety as trisomic. Two CMA-positive bands were found at the pericentric region of 2 metacentric chromosomes in Barimasur-2. Barimasur-3 had 2 terminal CMA-positive bands in 2 different sub-metacentric chromosomes. The size of CMA-bands, total CMA-banded area, percentage of CMA-positive banded region of Barimasur-2 and Barimasur-3 were almost similar. The total chromatin length of Barimasur-3 (97.83 μm) was found to be less than that of Barimasur-2 (107.05 μm). These data revealed that deletion near the banded region of metacentric chromosomes of Barimasur-2 might result the formation of terminal CMA-banded sub-metacentric chromosomes in Barimasur-3. No CMA-positive band was found in Barimasur-4. Six DAPI-positive bands were found in Barimasur-2. Barimasur-3 and Barimasur-4 had 11 and 13 DAPI-positive bands, respectively. Heteromorphicity in respect of DAPI bands between the homologue members was found in several chromosome pairs in these three varieties. With the help of DAPI banding it was possible to identify the pair-II of Barimasur-2 and pair-I in Barimasur-4. Therefore, different CMA and DAPI banding patterns were observed in 3 varieties.
Typhonium trilobatum (Typical form) and its 2 morphological forms viz. Tall and Slender were cytogenetically investigated. The Typical and the Tall form were found to possess 2n=18 chromosomes whereas the Slender one has 2n=19 chromosomes. The extra chromosome of the Slender form was a regular member of pair IX. The centromeric formula of the Tall form was 12m+6sm. It was 16m+2sm and 17m+2sm in the Typical and the Slender form, respectively. The orcein-stained interphase nuclei and prophase chromosomes revealed that the Tall form had much less heterochromatins than the other 2 forms. The Tall form possessed a pair of satellites which were found in orcein and CMA-staining. In DAPI staining, satellites showed negative banding which indicated its GC-rich nature. Satellite was not found in other 2 forms. Few chromosomes in the Typical and the Tall form fluoresced entirely with CMA. It indicated that these forms might have derived those chromosomes from a common ancestor. Due to the unique nature, those chromosomes could be used as marker. DAPI banded karyotypes showed similarities between the Typical form and the Slender form. It was much different in the Tall form. The overall karyotypic features indicated that the Tall form is quite different from the other 2 and thus it may be placed in different taxonomic rank. However, the Slender form may be considered as a trisomic variety of T. trilobatum (Typical form).
Aneuploid variation of chromosome number in somatic cells at growing root tips of Piper magnificum Trel., a South American Piper species of ornamental value is reported. Of the total 142 mitotic metaphase plates examined, about 62% of the cells were having normal chromosome number of 2n=26. The variations observed were 2n=22, 24, 25, 27, and 28 among which 2n=24 was the most frequent (27.46%) and others were in less than 5.0%. Higher frequency of the cells with 2n=24 is attributed as a reason for the dual chromosome numbers (2n=24 and 2n=26) reported for the species. The role of precocious segregation of chromosomes and lagging during anaphase in generating aneuploid variation of chromosomes is discussed. This is the first report of such variation in P. magnificum.