Variation of Giemsa C-band and fluorochrome banded karyotypes,and relationships inAllium subgen.Molium

The somatic karyotypes of 10 taxa belonging toAllium subgen.Molium (Liliaceae) from the Mediterranean area have been investigated using Giemsa C-band and fluorochrome (Hoechst, Quinacrine) banding techniques. A wide range of banding patterns has been revealed. InAllium moly (2n = 14),A. oreophilum (2n = 16) andA. paradoxum (2n = 16) C-banding is restricted to a region on each side of the nucleolar organisers and the satellites show reduced fluorescence with fluorochromes. The satellites are also C-banded and with reduced fluorescence inA. triquetrum (2n = 18), but two other chromosome pairs also have telomeric bands which are not distinguished by fluorochrome treatment. InA. erdelii (2n = 16) 4 pairs of metacentric chromosomes have telomeric C-bands while 2 pairs of telocentric chromosomes have centromeric C-banding. InA. subhirsutum (2n = 14),A. neapolitanum (2n = 28),A. trifoliatum subsp.hirsutum (2n = 14) andA. trifoliatum subsp.trifoliatum (2n = 21) chromosomes with long centromeres, consisting of a centromere and nucleolar organiser are positively C-banded on each side of the constriction. InA. subhirsutum banding is confined to the pair of chromosomes with this feature, whereas inA. neapolitanum one additional chromosome pair has telomeric bands and inA. trifoliatum there are varying numbers of chromosomes with centromeric and telomeric bands, depending on the subspecies.A. zebdanense (2n = 18) shows no C-bands. The banding patterns in this subgenus are compared with those recorded for otherAllium species and with the sectional divisions in the genus. Evidence from the banding patterns for allopolyploidy inA. trifoliatum subsp.trifoliatum andA. neapolitanum is discussed.     

Specific Heterochromatic Banding of Metaphase Chromosomes Using Nuclear Yellow

The bis-benzimidazole compound nuclear yellow (NY) belongs to the same chemical family as the DNA binding fluorochromes Hoechst 33258 and Hoechst 33342. Spectroscopic studies of NY alone and in the presence of calf thymus DNA show high DNA binding affinity and behavior similar to the Hoechst fluorochromes above. Mitotic metaphase chromosomes from Balb/c mice stained with NY show C-banding and weak G/Q-banding, both of them disappearing after distamycin A (DA) or methyl green (MG) counterstaining. The same staining of human metaphase chromosomes from lymphocyte cultures, however, reveal only faint G/Q-banding (NY) and a characteristic DA-DAPI-like banding (NY-DA, NY-MG). Image analysis of NY stained human chromosomes, confirms that NY is suitable for studying polymorphisms affecting size in the pericentromeric hete-rochromatin of pairs 1, 9 and 16, and shows significant enhancement of NY fluorescence induced by DA in DA-DAPI heterochromatin. Our spectroscopic and cytological results show that NY, either alone or counterstained with DA or MG, can be used for DNA cytochemistry and chromosome banding. Possible mechanisms for the banding patterns induced by NY are discussed.     

Specific Heterochromatic Banding of Metaphase Chromosomes Using Nuclear Yellow

The bis-benzimidazole compound nuclear yellow (NY) belongs to the same chemical family as the DNA binding fluorochromes Hoechst 33258 and Hoechst 33342. Spectroscopic studies of NY alone and in the presence of calf thymus DNA show high DNA binding affinity and behavior similar to the Hoechst fluorochromes above. Mitotic metaphase chromosomes from Balb/c mice stained with NY show C-banding and weak G/Q-banding, both of them disappearing after distamycin A (DA) or methyl green (MG) counterstaining. The same staining of human metaphase chromosomes from lymphocyte cultures, however, reveal only faint G/Q-banding (NY) and a characteristic DA-DAPI-like banding (NY-DA, NY-MG). Image analysis of NY stained human chromosomes, confirms that NY is suitable for studying polymorphisms affecting size in the pericentromeric hete-rochromatin of pairs 1, 9 and 16, and shows significant enhancement of NY fluorescence induced by DA in DA-DAPI heterochromatin. Our spectroscopic and cytological results show that NY, either alone or counterstained with DA or MG, can be used for DNA cytochemistry and chromosome banding. Possible mechanisms for the banding patterns induced by NY are discussed.     

Chromosome homology and heterochromatin in goat,sheep and ox studied by banding techniques

Peripheral blood lymphocyte metaphase chromosomes of three Bovoidean species have been studied using Quinacrine fluorescence and Giemsa banding techniques to give Q-, G-, and C-banding patterns. Q- and G-banding characteristics, coupled with chromosome length, enabled all of the chromosomes in each of the chromosome complements to be clearly distinguished, although some difficulties were encountered with the very smallest chromosomes. A comparison of G-banding patterns between the species revealed a remarkable degree of homology of banding patterns. Each of the 23 different acrocentric autosomes of the domestic sheep (2n=54) was represented by an identical chromosome in the goat (2n=60) and the arms of the 3 pairs of sheep metacentric autosomes were identical matches with the remaining 6 goat acrocentrics. A similar interspecies homology was evident for all but two of the autosomes in the ox (2n=60). This homology between sheep metacentric and goat acrocentric elements confirms a previously suggested Robertsonian variation. The close homology in G-banding patterns between these related species indicates that the banding patterns are evolutionarily conservative and may be a useful guide in assessing interspecific relationships. —The centromeric heterochromatin in the autosomes of the three species was found to show little or no Q-or G-staining, in contrast to the sex chromosomes. This lack of centromeric staining with the G-technique (ASG) contrasts markedly with results obtained with other mammalian species. However, with the C-banding technique these regions show a normal intense Giemsa stain and the C-bands in the sex chromosomes are inconspicuous. The amount of centromeric heterochromatin in the sheep metacentric chromosomes is considerable less than in the acrocentric autosomes or in a newly derived metacentric element discovered in a goat. It is suggested that the pale G-staining of the centromeric heterochromatin in these species might be related to the presence of G-Crich satellite DNA.     

茅舍血厉螨核型及染色体的C带、G带的研究

本文首次报道了一种革螨——茅舍血厉螨核型及染色体C带、G带的研究。用剖腹取卵法、玻璃纸压片、Giemsa染色,经分析茅舍血厉螨的核型,单倍体n=7,二倍体2n=14。 用氢氧化钡—吉姆萨技术显示茅舍血厉螨染色体C带。在第1、2、4、5染色体上出现恒定的C带部分,第3、6、7染色体上出现不恒定的C带部分。根据C带带型,茅舍血厉螨着丝点的位置可分为近中区域(sm),近端区域(St),末端区域(t)和末端点(T)四类。 G带分析用胰蛋白酶—吉姆萨技术显示。 本文对茅舍血厉螨的核型、革螨染色体研究中螨卵的收集方法和染液的改进、C带带型与着丝粒位置的确定和G带显带问题进行了讨论。     

Cytogenetic studies in the speciesCercopithecus pogonias (Bennet 1833) andCercopithecus nictitans (Linnaeus 1966)

We describe the banding patterns of the chromosomes of Cercopithecus pogonias(2n = 72) and Cercopithecus nictitans nictitans(2n = 70), the two species which exhibit the highest diploid numbers among the Cercopithecidae, using G-banding, C-banding, and nucleolar organizing region (NOR)-staining techniques. The karyotypes of these two species show a large number of morphological homologies, but several chromosome pairs cannot be matched. It is suggested that translocations and insertions may have been important in the chromosomal evolution of this group.     

X chromosomes of American marsupials contain minimal amounts of euchromatin

The karyotypes of four South American didelphid marsupials, representing diploid numbers of 2n = 14 and 18, have been analyzed by a variety of banding techniques. The 2n = 14 karyotypes display a high degree of homoeology, but there also exist distinct similarities between the 2n = 14 and 2n = 18 karyotypes. The interspecific differences found are due to centric fissions, pericentric inversions, and variations in the amount and composition of the constitutive heterochromatin. Contrary to the evolutionary conservation of the banding patterns in all autosomal arms, there are multiple differences in the number and chromosomal location of the nucleolus organizer regions. In species with X-linked nucleolus organizers, the 18S + 28S ribosomal RNA genes escape inactivation in female cells. Measurements on the X chromosomes of Marmosa fuscata and Micoureus demerarae unexpectedly reveal the lowest quantities of euchromatin so far determined in the X chromosomes of mammals: 1.5% and 1.8%, respectively, of their haploid female genomes. This is significantly less than the amount of euchromatin in the basic X chromosomes of other marsupials (3%) or eutherians (5%).     

中国几种棘蛙的核型C—带和Ag—NORs研究

本文对４种棘蛙的核型、Ｃ－带和Ａｇ－ＮＯＲｓ作了观察分析,结果表明无声囊棘蛙２ｎ＝６４Ｔ,Ａｇ－ＮＯＲｓ在２０ｑ＾ｉｎｔｅｒ,全部着丝点区域Ｃ－带正染。云南的棘腹蛙、察隅棘蛙和河南太行山隆肛蛙３者,其２ｎ＝２６,５＋８模式,但相互间ＳＭ的对数和顺序有所不同;前二者的Ａｇ－ＮＯＲｓ均在６ｐ＾ｐｅｒ,但Ｃ－带有很大的不同：察隅棘蛙的着丝点Ｃ－带浅染,但有较多的端部和居间型Ｃ－带。隆肛蛙的Ａｇ－ＮＯＲｓ     

Computer assisted karyotype analysis of Pyrrhopappus carolinianus

With the help of Computer Aided Karyotyping procedures, Ag-NOR staining and C-banding techniques, the karyotype of Pyrrhopappus carolinianus (Asteraceae, Lactuceae) has been studied. The species has 2n=12 chromosomes. Silver staining reveals that the two shortest pairs of chromosomes possess NOR's. On the basis of chromosome length and centromere position, only the longest chromosome pair and the satellite chromosomes can be identified. Two types of C-banding can be obtained, dependent on the temperature of the hydrochloric acid hydrolysis of the root tips. Hydrolysis at 60°C results exclusively in centromeric bands, whereas a treatment at room temperature reveals a pattern of intercalary bands. A computer assisted analysis of the intercalary banding pattern resulted in the construction of schematic representation of the average C-banding pattern. This banding pattern allows an easy identification of each of the chromosome pairs.     

C,Q and H-banding in the analysis of Y chromosome rearrangements in Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)

In Lucilia cuprina C-banding produces procentric bands on all autosomes and deep staining over most of the X and Y chromosomes which conciderably facilitates the analysis of complex Y chromosome rearrangements. The Y chromosome is generally darkly C-banded throughout while in the X chromosome a pale staining segment is found in the distal portion of the long arm. Modulation of the banding reaction results in grey areas in both X and Y. When C-banding is compared with allocycly it is clear that not all heteropycnotic regions in the sex chromosomes C-band to the same extent. Secondary constrictions in the short arms of both X and Y chromosomes are clearly revealed by C-banding, the X satellite being polymorphic for size.— Q-banding results in a brightly fluorescing band in the short arm of structurally normal Y chromosomes. This band loses its fluorescence in some translocations, probably through a position effect. Hoechst 33258 staining does not produce any brightly fluorescing bands.     

中国五种高山锄足蟾的核型、Ag-NORs和C-带的研究

作者用核型、Ag-NORs和C-带,对分布于川、滇两省的二属(齿突蟾、齿蟾)五种(胸腺齿突蟾、圆疣齿突蟾、凉北齿蟾、秉志齿蟾、疣刺齿蟾)锄足蟾作了属间和种间关系的比较分析,并讨论了它们的核型演化机制。结果表明:(1)齿突蟾和齿蟾两属间在核型和带型上都有明显的差异,演化途径主要的可能是含有重复DNA染色体片段的相互易位或臂间倒位;(2)属内不同种之间带型无显著差异,但某些对应染色体对间,其相对长度和臂比值差异明显,十分可能是常染色质片段的易位和臂间倒位所致;(3)凉北齿蟾有染色体数目变异多态现象;(4)五种锄足蟾均未发现异形性染色体。     

Bandign isolated metaphase chromosomes by a sequential flurescent G/Q technique.

G/Q-banding is a new, rapid, fluorescent technique for banding isolated chromosomes that incorporates characteristics of both G- and Q- banding. G-bands, while easily characterized, are often inconsistent when using isolated chromosomes, and Q-bands, while reliable, fade rapidly under UV exposure, making prolonged observation and photography difficult. G/Q-banding combines these techniques to sequentially utilize quinacrine staining over Giemsa banding to produce slow-fading fluorescent G/Q-bands. The background fluorescence in G/Q preparations fades quickly under continued UV exposure, while the chromosomes remain brightly banded and can be observed and photographed for at least five minutes. G/Q-banding was extended to whole cell chromosome spreads and produced results identical to those obtained with isolated chromosomes. Whole cell karyotypes indicate that G/Q-bands generally correspond to Q-bands. Advantages of G/Q-banding as a unique and universal technique over current double-staining procedures are discussed.     

中国两种掌突蟾(锄足蟾科Pelobatidae,无尾目Anura)的细胞遗传学研究

本文对分布于云南境内的两种Leptolalax——L.ventripunctatus和L.alpinus的常规Giemsa核型、C-带和Ag-NORs作了研究,结果表明L.ventripunctatus的2n=22,20M 2T,NF=42,1对Ag-NORs位于5(?),并呈现异形现象,该区域亦显C-带正染;L.alpinus 2n=24,14M 4SM 6T,NF=42,1对Ag-NORs位于No.8短臂端部,并有随体联合现象。两种的着丝点区域均呈现C-带正染。     

The Research of Giemsa C-Banding Technigue Used in Plant Chromosome Banding Pattern

The Giemsa banding technique used by Fiskesjo in Allium cepa (1974) was modified, and used successfully in band showing of Vicia faba, Secale cereale, Zea mays. Hordeum vulgare, Triticum aestivum, and Triticale. The C-banding characteristics of these crops have been analysed.The band showing effects of ItSG method have been compared with those of BSG method.The banding conditions in plant chromosomes have been discussed.     

C-Banding/DAPI and in situ hybridization reflect karyotype structure and sex chromosome differentiation in Humulus japonicus Siebold & Zucc

Japanese hop (Humulus japonicus Siebold & Zucc.) was karyotyped by chromosome measurements, fluorescence in situ hybridization with rDNA and telomeric probes, and C-banding/DAPI. The karyotype of this species consists of sex chromosomes (XX in female and XY1Y2 in male plants) and 14 autosomes difficult to distinguish by morphology. The chromosome complement also shows a rather monotonous terminal distribution of telomeric repeats, with the exception of a pair of autosomes possessing an additional cluster of telomeric sequences located within the shorter arm. Using C-banding/DAPI staining and 5S and 45S rDNA probes we constructed a fluorescent karyotype that can be used to distinguish all autosome pairs of this species except for the 2 largest autosome pairs, lacking rDNA signals and having similar size and DAPI-banding patterns. Sex chromosomes of H. japonicus display a unique banding pattern and different DAPI fluorescence intensity. The X chromosome possesses only one brightly stained AT-rich terminal segment, the Y1 has 2 such segments, and the Y2 is completely devoid of DAPI signal. After C-banding/DAPI, both Y chromosomes can be easily distinguished from the rest of the chromosome complement by the increased fluorescence of their arms. We discuss the utility of these methods for studying karyotype and sex chromosome evolution in hops.     

Banding isolated metaphase chromosomes by a sequential fluorescent G/Q technique

Summary G/Q-banding is a new, rapid, fluorescent technique for banding isolated chromosomes that incorporates characteristics of both G- and Q-banding. G-bands, while easily characterized, are often inconsistent when using isolated chromosomes, and Q-bands, while reliable, fade rapidly under UV exposure, making prolonged observation and photography difficult. G/Q-banding combines these techniques to sequentially utilize quinacrine staining over Giemsa banding to produce slow-fading fluorescent G/Q-bands. The background fluorescence in G/Q preparations fades quickly under continued UV exposure, while the chromosomes remain brightly banded and can be observed and photographed for at least five minutes. G/Q-banding was extended to whole cell chromosome spreads and produced results identical to those obtained with isolated chromosomes. Whole cell karyotypes indicate that G/Q-bands generally correspond to Q-bands. Advantages of G/Q-banding as a unique and universal technique over current double-staining procedures are discussed.     

Development of Wheat-alien Lines with Added Leymus racemosus Chromosomes and 6VS/6AL Translocation Chromosomes

By chromosome C-banding and bi-color fluorescence in situ hybridization (FISH) using digoxigenin-labelled total genomic DNA of Leymus racemosus (Lam.) Tzvel. and biotinylated total genomic DNA of Haynaldia villosa (L.) Schur as probes, three wheat-alien lines with L. racemosus Lr.7 addition and H.　villosa 6VS/6AL translocated chromosomes, and eight lines with L.　racemosus Lr.14 addition and H.villosa 6VS/6AL translocated chromosomes were respectively identified from DALr.7×T6VS/6AL (93G51-4×P64) and DALr.14×T6VS/6AL （94G15×P64）F2 or F3 hybrids. Fluorescein-isothiocyanate-conjugated avidin and rhodamine-conjugated sheep anti-digoxigenin Fab fragment were used in bi-color FISH detection. The chromosomes of L.racemosus and 6VS fragment of H.　villosa were simultaneously detected by their red and green fluorescence. Powdery mildew and scab resistance were also evaluated. The result showed that the obtained plants had high resistance to these two diseases. The potential usage of bi-color FISH in identifying chromatin of L.racemosus and H.villosa was discussed.     

Recognition of Two Types of Positive Staining Chromosomal Material by Manipulation of Critical Steps in the N-Banding Technique

The nucleolar regions on chromosomes 1B and 6B of Triticum aestivum L. cv Chinese Spring wheat can reliably be observed after careful control of the Giemsa N-banding technique. Identification of rye (Secale cereaie) chromosomes using N-banding is demonstrated and compared to a simple C-banding method. The N-banding in rye chromosomes and the nucleolar sites on IB and 6B of wheat differ from the normal N-banding sites of wheat chromosomes. Further, the banding of these nucleolar regions and of the rye chromosomes does not reappear in preparations that have been retreated with hot acid buffer. These differences provide evidence for at least two types of chromatin that stain darkly (positively) using N-banding. The critical procedures in the N-banding technique and the use of alternatives to 1 M NaH₂PO₄ buffer are discussed along with the possible basis of N-band formation.     

Comparative cytogenetic analysis on four tree frog species (Anura, Hylidae, Hylinae) from Brazil

A comparative cytogenetic analysis was carried out on four Hylinae tree frogs from Brazil ((Aparasphenodon brunoi, Corythomantis greeningi, Osteocephalus langsdorffii, and Scinax fuscovarius) using Giemsa staining, BrdU replication banding, Ag-NOR staining, C-banding, DAPI and CMA(3) fluorochrome staining, and fluorescence in situ hybridization (FISH) with an rDNA probe. All the species share closely similar 2n = 24 karyotypes, almost indistinguishable by standard staining. The technique of BrdU incorporation allowed the identification of each pair of homologs and the establishment of extensive homeology for the great majority of the chromosomes, mainly of A. brunoi, C. greeningi, and O. langsdorffii. Despite highly conserved replication banding patterns, the use of the other banding techniques disclosed some minor differences, which reinforces the importance of extensive cytogenetic analyses for the karyotypic characterization of Anuran species. The present cytogenetic data confirm the closer proximity of A. brunoi, C. greeningi, and O. langsdorffii, whereas S. fuscovarius is phylogenetically more distant.