Karyotypic characterization of Iheringichthys labrosus (Pisces, Pimelodidae): C-, G- and restriction endonuclease banding

Various chromosomal banding techniques were utilized on the catfish, Iheringichthys labrosus, taken from the Capivara Reservoir. C-banding regions were evidenced in telomeric regions of most of the chromosomes. The B microchromosome appeared totally heterochromatic. The restriction endonuclease AluI produced a banding pattern similar to C-banding in some chromosomes; the B microchromosome, when present, was not digested by this enzyme and remained stained. G-banding was conspicuous in almost all the chromosomes, with the centromeres showing negative G-banding. When the restriction endonuclease BamHI was used, most of the telomeres remained intact, while some centromeres were weakly digested. The B chromosome was also not digested by this enzyme. The first pair of chromosomes showed a pattern of longitudinal bands, both with G-banding and BamHI; this was more evident with G-banding. This banding pattern can be considered a chromosomal marker for this population of I. labrosus.     

Prometaphase banding of human chromosomes with basic fuchsin

Summary A technique is described for the production of detailed and richly contrasting G-band patterns in human prometaphase chromosomes with the aid of the triphenylmethane dye basic fuchsin. The usefulness of this method is illustrated by its application for the precise analysis of two chromosome 11 rearrangements. It is also demonstrated that high-resolution banding with basic fuchsin can reveal bands not present in the international standard idiogram of human prophase chromosomes (ISCN 1981). The technique described can also be used for easy recognition of the late replicating X chromosome, which stains darker than its early replicating homologue. A preliminary analysis of the late replicating X chromosomes in a 49,XXXXY individual suggests that the three supernumerary X chromosomes do not necessarily replicate synchronously.     

Trypsin G- and C-banding for interchange analysis and sex identification in the chicken

The trypsin banding methods were applied to feather pulp and embryonic material of the chicken. Two contrasting types of chromosomal banding patterns were obtained by varying the duration of trypsin treatment. A short time treatment shows a G-banding pattern which has characteristic and distinctive bands along the chromosome arms. Prolonging the trypsin treatment causes the G-banding pattern to disappear, and only the centromeres and the W chromosome remained heterochromatic which is characteristic of the C-banding pattern. The application of the G-banding pattern analysis was used to identify regions of chromosomes involved in rearrangements. The simplified trypsin technique which produces the C-banding pattern makes it relatively easy to identify the W sex-chromosome and determine sex in avian species.     

BrdU处理的鱼类染色体高分辨G-带带型分析

本文应用鱼类染色体高分辨G-带技术,重点将黄鳝培养细胞具不同长度染色体的正中期分裂相做成G-带核型加以比较分析。随着染色体长度的增加,带纹数目也增加。但增加是有限度的。染色体带纹数目的增加,明显地表现在深染带再分为若干亚带。当染色体从前期向中、后期过渡收缩变短时,一些亚带融合为原来数目的带。染色体上各个带的收缩程度、收缩时间是不均等的。实验证明大剂量的BrdU不仅能阻断鱼类细胞于中S期,也可使染色体伸长、小剂量的伸长作用不明显。最后讨论了BrdU处理与G-显带的关系、染色体带纹数目相对恒定以及染色体伸长缩短问题。     

三种姬鼠的染色体比较研究

本文采用染色体分带技术（Ｇ－,Ｃ－带和银染色）,对中华姬鼠（Ａｐｏｄｅｍｕｓｄｒａｃｏ）、大林姬鼠（Ａ．ｐｅｎｉｎｓｕｌａｅ）和大耳姬鼠（Ａ．ｌａｔｒｏｎｕｍ）的核型进行了观察分析。结果表明：３种姬鼠的２ｎ均为４８。中华姬鼠的染色体均为端着丝点染色体。大林姬鼠的常规核型中,除１对中着丝点染色体（Ｎｏ．２３）外,其余均为端着丝点染色体。大耳姬鼠的核型中,有１３对端着丝点染色体,２对亚端着丝点染色体,１对亚中着丝点染色体和７对中着丝点染色体。中华姬鼠Ｃ－带核型中,所有染色体着丝点Ｃ－带都呈强阳性,异染色质非常丰富,Ｙ染色体整条深染。在大林姬鼠Ｃ－带核型中,Ｎｏｓ．７,１１,１５,２１,２２着丝点Ｃ－带弱化甚至近阴性,其余染色体着丝点异染色质Ｃ－带都呈现程度不同的阳性。且Ｎｏｓ．２,４,７有强弱不同的端位异染色质带。Ｘ染色体着丝点区有大块的异染色质斑带出现,Ｙ染色体整条深染。大耳姬鼠除Ｎｏｓ．３,４,１０,１２,１３染色体着丝点Ｃ－带很弱外,其余染色体着丝点Ｃ－带均呈阳性,并有８对（Ｎｏｓ．１６－２３）染色体出现异染色质短臂。从总体上看,大林姬鼠和大耳姬鼠的着丝点异染色质明显比中华姬鼠的少。中华姬鼠的Ａｇ－ＮＯＲ     

Analysis of human metaphase chromosomes using antibodies to double-stranded and single-stranded DNA: staining patterns are related to DNA conformation

Fresh and 6-day-old fixed chromosome spreads, both untreated and treated with various banding techniques and nucleases, were stained using monoclonal antibodies to double-stranded and single-stranded DNA. DNA in fixed chromosome preparations became progressively denatured with ageing. The staining pattern of untreated chromosomes with anti-double-stranded DNA antibodies (which resembles G-banding) was determined by the conformation of the chromosomal DNA.     

Heterochromatic banding pattern in two Brazilian populations of Aedes aegypti

We analysed samples of Aedes aegypti from São José do Rio Preto and Franca (Brazil) by C‐banding and Ag‐banding staining techniques. C‐banding pattern of Ae.aegypti from São José do Rio Preto examined in metaphase cells differed from Franca. The chromosomes 2, 3 and X showed centromeric C‐bands in both populations, but a slightly stained centromeric band in the Y chromosome was observed only in São José do Rio Preto. In addition, the X chromosome in both populations and the Y chromosome of all individuals from São José do Rio Preto showed an intercalary band on one of the arms that was absent in Franca. An intercalary, new band, lying on the secondary constriction of chromosome 3 was also present in mosquitoes of both populations. The comparison of the present data with data in the literature for Ae.aegypti from other regions of the world showed that they differ as to the banding pattern of sex chromosomes and the now described intercalary band in chromosome 3. The observations suggested that the heterochromatic regions of all chromosomes are associated to constitute a single C‐banded body in interphase cells. Ag‐banding technique stained the centromeric regions of all chromosomes (including the Y) and the intercalary C‐band region of the X chromosome in both populations. As Ae.aegypti populations are widespread in a great part of the world, the banding pattern variations indicate environmental interactions and may reveal both the chromosome evolutionary patterns in this species and the variations that may interfere with its vector activity.     

Studies of Chromosome Banding with Giemsa in Vicia faba and Allium cepa

Giemsa dye is a complex mixture containing methylene blue, its oxidation products-azure Ⅰ, Ⅱ, Ⅲ, and their eosinate. The results of our experiments have demonstrated that staining with methylene blue alone can give a faint trace of banding as well as azure Ⅰ, Ⅱ. No bands are obtained with eosin. Nevertheless, good chromosome bandings can be often produced by staining with methylene blue-eosinate or azure Ⅱ-eosinate. These data indicate that eosinate has an important effect for the formation of C-banding on plant chromosomes. In our experiments, the treatments of chromosomes with trypsin or papain have also resulted in good C-banding pattern when slides are stained with Giemsa. We found that the slides untreated with proteinase showed homogeneous intense chromosome staining and, on the contrary, the slides treated with proteinase led to palestaining chromosomes and presenting bandings. It has shown that proteinase, especially trypsin, not only can remove a large amount of chromosomal protein but also can remove DNA and results in C-bandings. Treated properly with trypsin and followed by the Feulgen staining, chromosomes can also produce the C-bandings, but chromosomes treated overtime with trypsin are stained more palely in Feulgen reaction or lead to colourlessness. The above results have further proved that trypsin technique removes large amounts of chromosome DNA and removes less from the C-band regions than from the non-band regions. In this paper we mainly discussed the effects of protein on mechanism of plant chromosome banding. We consider that the production of plant C-banding is probably due to the differential accessibility of nucleoprotein between euehromatin and heteroehromatin regions. It brings about selective removal of nucleoprotein from the chromosome arms. We have compared the effect of trypsin with papain and pepsin on producing bands. Good bands are produced by Giemsa staining chromosomes with trypsin, but no bands are obtained by staining chromosomes treated with pepsin. So the results have expressed that histones are possibly playing more important role in C-bandings.     

Early and late replicative chromosomal banding patterns of Gallus domesticus.

Early and late replicating chromosomal banding patterns of Gallus domesticus were investigated by cell synchronization and incorporation of 5'-bromodeoxyuridine during early and late DNA synthesis. The early replicating chromosomal banding patterns observed, as revealed by either acridine orange or Hoechst 33258/propidium iodide staining, were similar to the structural G-banding patterns obtained by trypsin digestion and Giemsa staining. Late replicating chromosomal banding showed extensive reverse band complementarity to the G-banding pattern. Cell synchronization increased the number of prometaphase and metaphase plates available for analysis. G-banding obtained by Hoechst 33258/propidium iodide staining was investigated due to the fact that it is compatible with chromosomal in situ hybridization procedures that use nonisotopically-labeled DNA probes. Standard replicative G-banded and R-banded idiograms, as obtained after cell synchronization, are proposed.     

Chromosome organisation in the Australian plague locust,Chortoicetes terminifera

In Chortoicetes terminifera, G-banding, produced by the trypsin treatment of air-dried slides followed by Giemsa staining, leads to light staining gaps at the secondary constrictions on autosomal pair 6 and regions proximal to the centromere on the long arms of pair 4. The variable short arms of two of the three smallest pairs were usually flared and lightly stained after treatment. In contrast to the relatively minor response of the normal chromosome set to G-banding, the large supernumerary chromosomes of C. terminifera show a spectacular series of dark bands alternating with lightly stained gaps. Two G-band variants of the B-chromosome were found in a laboratory stock. These patterns of G-banding are discernable both at mitosis in adults and embryos of both sexes and at all stages of male meiosis. Some regions which are gaps after G-banding appear as dark bands after C-banding. Consequently the supernumerary chromosome is mainly darkly stained with C-banding. In addition the centromeres and some telomeres are C-banded along with narrow interstitial bands and polymorphic heterochromatic blocks. — C-banding was not always successful, the technique often yields a mixture of G- and C-banding. The disparity of banding between the normal complement and the B-chromosome implies that whatever the source of origin of the B it has undergone spectacular changes in organisation since its origin.     

Multicolor banding technique, spectral color banding (SCAN): new development and applications

Conventional banding techniques can characterize chromosomal aberrations associated with tumors and congenital diseases with considerable precision. However, chromosomal aberrations that have been overlooked or are difficult to analyze even by skilled cytogeneticists were also often noted. Following the introduction of multicolor karyotyping such as spectral karyotyping (SKY) and multiplex-fluorescence in situ hybridization (M-FISH), it is possible to identify this kind of cryptic or complex aberration comprehensively by a single analysis. To date, multicolor karyotyping techniques have been established as useful tools for cytogenetic analysis. However, since this technique depends on whole chromosome painting probes, it involves limitations in that the origin of aberrant segments can be identified only in units of chromosomes. To overcome these limitations, we have recently developed spectral color banding (SCAN) as a new multicolor banding technique based on the SKY methodology. This new technique may be deemed as an ideal chromosome banding technique since it allows representation of a multicolor banding pattern matching the corresponding G-banding pattern. We applied this technique to the analysis of chromosomal aberrations in tumors that had not been fully characterized by G-banding or SKY and found it capable of (1) detecting intrachromosomal aberrations; (2) identifying the origin of aberrant segments in units of bands; and (3) precisely determining the breakpoints of complex rearrangements. We also demonstrated that SCAN is expected to allow cytogenetic analysis with a constant adequate resolution close to the 400-band level regardless of the degree of chromosome condensation. As compared to the conventional SKY analysis, SCAN has remarkably higher accuracy for a particular chromosome, allowing analysis in units of bands instead of in units of chromosomes and is hence promising as a means of cytogenetic analysis.     

Human chromosome banding specific for electron microscopy

Electron microscopy (EM) provides much higher resolution than that obtained with light microscopy (LM). Until now, however, no chromosome banding procedure specifically adapted for EM was available. To produce an easy and reproducible banding method that would allow accurate chromosome identification, we investigated the applicability of an immunochemical method. BrdU-substituted chromosomal regions can be accurately visualized by applying a monoclonal antibody against BrdU, followed by a gold-tagged secondary antibody. Since BrdU is incorporated during the last part of the S-phase, regions of darkly stained G- and C-bands are substituted. A characteristic C-banding pattern is revealed, and the G-banding obtained is sharp and allows discrimination between subbands. Its similarity with the classical G-banding observed by LM makes it easy to interpret and facilitates karyotyping.     

G-band-like structures and centromeric asymmetry in the BrdU containing mouse chromosomes

Mouse cells cultured in the presence of BrdU or BrdC for one replication cycle were stained in a 4Na-EDTA Giemsa solution which stains BrdU-containing chromatin preferentially (Takayama and Tachibana, 1980). With this treatment clear bands (B-bands) were revealed along the length of the chromosomes. The B-banding patterns were identical with the G-banding patterns of this species except for the centromeric region in which lateral asymmetry of Giemsa staining was seen. The concomitant occurrence of the lateral asymmetry with the B-banding supports the assumption that the B-bands visualized by the present technique reflect the BrdU-rich chromatin regions differentially localized along the chromosomes. Most of the chromosomes constituting the mouse karyotype showed their own characteristic appearance of the asymmetry, but in some of them the asymmetry was not clear and the Y did not show any specific, centromeric staining. The marked coincidence of the B- and G-banding patterns seems to provide evidence for the involvement of AT-rich chromatin in the induction of positive G-bands. The present technique also seems quite useful to analyze chromosomes of some species in which ordinary G-banding techniques have been known to bring about only unsatisfactory results.     

多色-FISH技术的进展及其在分子生物医学上的应用

传统显带分析技术以每条染色体独特的显带带型为依据,提供染色体形态结构的基本信息,用于染色体核型的初步分析。然而有些染色体重排由于涉及的片断太小或具有相似的带型,用该方法难以探测或准确描绘。多元荧光原位杂交(M-FISH),光谱核型分析(SKY),FISH-显带分析技术是染色体特异的多色荧光原位杂交技术(mFISH)。它们能够探测出传统显带分析不能发现的染色体异常,提供更准确的核型。M-FISH和SKY均以组合标记的染色体涂染探针共杂交为基础,二者的不同在于观察仪器和分析方法上。它们可对中期染色体涂片进行快速准确分析,描绘复杂核型,确认标记染色体,主要用于恶性疾病的细胞遗传学诊断分析。FISH-显带分析技术以FISH技术为基础,能同时检测多条比染色体臂短的染色体亚区域。符合该定义的FISH-显带分析技术各有特点,其共同特点是都能产生DNA特异的染色体条带。这些条带有更多色彩,能提供更多信息。FISH-显带分析技术已经成功地被用于进化生物学、放射生物学以及核结构的研究,同时也被用于产前、产后以及肿瘤细胞遗传学诊断,是很有潜力的工具。     

云南兔(Lepus comus)的染色体研究

本文以染色体分带技术(G-,C-带和银染色),对云南兔(Lepus comus)的核型进行了观察分析。结果表明t：2n=48,NF=88。常染色体由6对中着丝粒染色体, 5对亚中着丝粒染色体,10对亚端着丝粒染色体和2对端着丝粒染色体组成;X染色体为亚中着丝粒染色体。除少数几对染色体(Nos．9,14,16,20)着丝粒C-带呈阴性外,其余均呈阳性或浅染,但异染色质的含量差异较大。Ag-NORs的数目为5-6个,分别位于Nos．1 7,19,21。通过与兔科其它属种核型的比较,对其染色体进化作了讨论。     

大麦G—显带核型的研究

本文报道了 ASG 法处理的三个栽培大麦(Hordeum Vulgare)品种 G-带的核型研究。结果表明无论是早中期或中期染色体都显示出了密切邻近的、多重的 G-带带纹。在有丝分裂过程中染色体愈浓缩带纹数目愈少。同源染色体之间带纹分布的位置、染色深浅以及带纹数目都基本一致,可以较为准确地进行配对。同一分裂时期不同染色体的 G-带带纹各具一定的特点,可以作为鉴别的标记。讨论了显带技术和中期染色体的 G-带等问题。     

Studies on G-Banding Karyotype in Barley (Hordeum vulgare)

G-banding karyotypes of three cultivars in barley were analyzed. Multiple closely adjacent G-bands were able to be observed in each early metaphase or metaphase chromosome treatted by an ASG method. The more concentrated the chromosome, the less was the number of G-bands during mitosis. The position of band distribution, staining degree and band numbers between homologous chromosomes were basically identical. Chromosome pairing for karyotype analysis could be carried out more accurately. G-banding patterns of different chromosome pairs were not the same, they could be used as the markers to distinguish one from another chromosome pair. During the same mitotic stage the banding patterns including number, relative position and staining degree of the bands between different cultivars were basically the same, but they had differences in the size and staining degree of some bands near centromeres. G-banding technique and G-banding of metaphase chromosomes were discussed.     

An approach to the G-Banding Technique in Rye Chromosome

The G-banding technique has not yet been broken through in studying plant chromosomes. in this paper, we have described a new banding method in Secale cereale. The rye root tips were treated with actinomycin D (40-100 μg/ml) for two hours and with colchicine (0.01%) for 0.5 hour and then fixed with methanol-acetic acid (3:1). After cell wall degradation by cellulase and pectinase, the chromosome sample were made by a hypotonic and flame-drying method (hypotonic treatment→preparation of cell suspension→dropping suspension on slide flame-drying). Following an air-drying period of about a week, the slides were incubated in trypsin-EDTA solution (0.01–0.05%) at 30℃ for 10–15 sec. and subsequently stained with Giemsa. Lots of deep stained bands along the arms of many prophase and late prophase chromosomes were seen. The position of them was obviously different from that of the C-band and the number of them was approximately in proportion to the longitude of chromosomes. Such bands were not seen in metaphase chromosomes. We thought it preferable to use prophase chromosomes to probe G-banding technique in plant and this paper has proposed a possible way for studying G-banding technique in plant chromosome. We also discuss why metaphase chromosomes of plant do not show G-bands.     

C- and G-bands of the opossum chromosomes: terminal sequences of DNA replication.

The sex chromosomes of the opossum, Didelphys virginiana, are the only elements that exhibit C-banding. In contrast, the sex chromosomes as well as the autosomes bear specific G-Bands. However, unlike other mammalian species different types of G-banding are observed if the chromosomes are pretreated with trypsin and SSC solution The SSC-pretreated chromosomes show discrete bands only when stained with Giemsa at certain pH values. An asynchronous pattern of terminal DNA replication is observed among the three C-banding regions of the X-chromosome. The inter- and intrapositive G-banding areas of the chromosomes are not always late in DNA replication in comparison to those negatively stained G-banding areas.