大熊猫与黑熊显带染色体的比较研究

以体外培养的大熊猫（Ａｉｌｕｒｏｐｏｄａｍｅｌａｎｏｌｅｕｃａ）与黑熊（Ｓｅｌｅｎａｒｃｔｏｓｔｈｉｂｅｔａｎｕｓ）外周血淋巴细胞为实验材料,应用ＢｒｄＵ复制带显示技术,研究了大熊猫和黑熊染色体晚复制带带型。通过对大熊猫与黑熊显带染色体带型的比较,发现黑熊部分具端着丝粒的染色体与大熊猫部分具中,亚中,或亚端着丝粒的染色体的整个短臂或整个长臂有明显的带型相似性,在黑熊具中,亚中着丝粒染色体中,仅３３     

Description of the Anser anser goose karyotype

The karyotype of the Italian goose originating from Anser anser was characterised on the basis of R and C bands. Chromosomal preparations obtained from an in vitro culture of blood lymphocytes were stained with the RBG and CBG techniques. The RBG technique enabled the analysis of the structure of nine pairs of chromosomes whereas the CBG technique - fourteen pairs ofchromosomes from the total ofeighty goose chromosomes. The morphology and the R and C banding patterns were described. The size and arrangement of the blocks of constitutive chromatin were determined. Ideograms of R and C banded patterns were drawn. The morphological structure of the analysed chromosomes was evaluated.     

Polymerase chain reaction based mapping of rye involving repeated DNA sequences.

A novel type of polymerase chain reaction (PCR) marker was developed for the mapping of cereal rye (Secale cereale). Primer pairs were synthesized targeting the insertion sites of three individual copies of the R173 family of rye specific repeated DNA sequences. While one primer was derived from a sequence within the respective R173 element, the second primer corresponded to a flanking region. The complex banding patterns obtained in rye allowed not only the mapping of the three R173 elements to certain chromosome regions of 1RS (the short arm of rye chromosome 1) but also the mapping of an additional 3-10 easily identifiable bands per primer pair to other rye chromosomes. Linkage mapping of a polymorphic 1R band derived from three rye cultivars demonstrated the presence of nonallelic, dominant markers in two independent crosses. Because of the high copy number of the R173 family (15,000 copies per diploid rye genome), its dispersion over the entire length of all chromosomes and the high number of markers obtained per primer pair, PCR markers based on the R173 family provide an almost unlimited source for well-spaced markers in rye mapping.     

Description of the mallard duck (Anas platyrhynchos) karyotype

The karyotype of the mallard duck, Anas platyrhynchos, was characterised on the basis of R and C bands. Chromosomal preparations obtained from in vitro blood lymphocyte cultures were RBG- and CBG-stained. The structures of nine and 14 pairs of chromosomes were analysed by the RBG and CBG chromosome banding techniques, respectively. The location of R bands, as well as the size and arrangement of constitutive heterochromatin blocks were determined. Ideograms of R and C banded patterns of the analysed chromosomes were drawn. The morphological makeup of the analysed chromosomes was assessed.     

Similarity of giemsa banding patterns of chromosomes in several species of the Genus Rattus

Giemsa banding patterns of chromosomes in seven Rattus species were compared. Four species (R. rattus tanezumi, R. norvegicus, R. exulans and R. muelleri) had all 2n=42 and their karyotypes and banding patterns were similar, although slight differences were observed. Another subspecies (R. rattus rattus) and two other species (R. fuscipes and R. conatus) had fewer chromosomes than the above species by having large biarmed chromosomes developed probably by Robertsonian fusion. The origin of the arms of biarmed chromosomes was recognized by their characteristic banding patterns. The remaining species, R. sabanus, had a karyotype markedly different from the other species by having two small metacentrics although in the others their number was 7. Banding patterns of the chromosomes in this species, however, were also very similar to those of the other, and therefore the 7 small metacentrics seemed to have originated by pericentric inversion of small acrocentrics.Contribution No. 912 from the National Institute of Genetics, Japan. Supported by a grant-in-aid from the Ministry of Education of Japan, Nos. 90183, 90375 and 744002.     

Localization by FISH of the 31 Texas nomenclature type I markers to both Q- and R-banded bovine chromosomes

A series of 31 marker genes (one per chromosome) were localized precisely to both Q- and R-banded bovine chromosomes by fluorescence in situ hybridization (FISH), as a contribution to the revised chromosome nomenclature of the three major domestic bovidae (cattle, sheep and goat). All marker genes except one (LDHA) are taken from the Texas Nomenclature of the cattle karyotype published in 1996. Homologous probes for each marker gene were obtained by screening a bovine BAC library by PCR with specific primer pairs. After labeling with biotin, each probe preparation was divided into two fractions and hybridized to bovine chromosomes identified either by Q or R banding. Clear signals and good quality band patterns were observed in all cases. Results of the two series of hybridizations are totally concordant both for Q and R band chromosome numbering and precise band localization. This work permits an unambiguous correlation between the Q/G- and R-banded 31 bovine chromosomes, including chromosomes 25, 27 and 29 which remained unresolved in the Texas Nomenclature (1996). Hybridization of the chromosome 29 marker gene to metaphase spreads from a 1;29 Robertsonian translocation bull carrier showed a positive signal on the short arm of this rearranged chromosome, confirming that the numbering of this long-known translocation in cattle is correct when referring to the Texas Nomenclature (1996). Taking into account that cattle, goat and sheep have very similar banded karyotypes, the data presented here will help to establish a definite and complete reference chromosome nomenclature for these species.     

Intercalar satellites of human acrocentric chromosomes as a cytological manifestation of polymorphism in GC-rich material?

Summary Fifteen unrelated individuals were found among the patients of the Cytogenetics Laboratory who possessed multiple-satellited marker chrmosomes (14 with double satellites and 1 with triple satellites). Cytogenetic analysis was carried out by means of a conventional staining method and also by R, C, and Q banding and by the technique of silver staining. The intercalar structures of all 15 cases differed from the terminal satellites in their biochemical composition: they were resistant to heat denaturation, and stained heavily with the R-banding technique. Accordingly, they consisted of GC-rich material identical with that which in varying quantity is a regular constituent of the short arms of acrocentric chromosomes. The findings described indicate that any larger accumulation of such R band-positive material tends to dissociate from the basal segment of short arms by a proximal secondary constriction. We therefore assume that the formation of intercalar satellites may be interpreted as a cytological consequence of extreme natural R polymorphism.     

A New Technique for Orcein Banding with Acid Treatment

A rapid method for banding plant chromosomes using hydrochloric acid with orcein is suggested. The technique has been successful in both dioecious and monoecious families with short chromosomes. It involves pretreatment with an oxyquinoline-paradichlorobenzene mixture, fixation in acetic ethanol and treatment with hydrochloric acid at 60 C followed by staining with orcein. Stained chromosome bands and interbands are reproducible and species specific.     

A new technique for orcein banding with acid treatment

A rapid method for banding plant chromosomes using hydrochloric acid with orcein is suggested. The technique has been successful in both dioecious and monoecious families with short chromosomes. It involves pretreatment with an oxyquinoline-paradichlorobenzene mixture, fixation in acetic ethanol and treatment with hydrochloric acid at 60 C followed by staining with orcein. Stained chromosome bands and interbands are reproducible and species specific.     

Karyotype analysis of Nicotiana kawakamii Y. Ohashi using DAPI banding and rDNA FISH

Prometaphase cells were used to analyze the karyotype of Nicotiana kawakamii Y. Ohashi by means of sequential Giemsa/CMA/DAPI staining and multicolor fluorescence in situ hybridization with 5S and 18S rDNA. Observation of the DAPI-stained prometaphase spreads indicated that N. kawakamii had six pairs of large chromosomes, one pair of medium-sized chromosomes and five pairs of small chromosomes. The six pairs of large chromosomes possessed remarkable DAPI bands, and each could be identified from both the DAPI banding pattern and the length of the short arm. The DAPI banding pattern was approximately identical to the CMA and Giemsa banding patterns. Hybridization signals of the 18S rDNA probe were detected on two pairs of large chromosomes. In addition, two pairs of small chromosomes were identified based on the position of the 5S rDNA signals. An idiogram of N. kawakamii chromosomes was produced based on DAPI bands and rDNA loci. Received: 17 July 2000 / Accepted: 4 September 2000     

A comparison of the fluorescent karyotypes of the chimpanzee (Pan troglodytes) and man

Individual chimpanzee chromosomes have been identified by their characteristic banding revealed by quinacrine fluorescent staining. A fluorescent karyotype of this species was set up to be compared with the standard human fluorescent karyotype. It was found that chromosomes 1, 3, 11, 12, 14 and X-chromosome of the chimpanzee appear to have banding patterns similar to the equivalent human chromosomes. Chromosomes 6, 7, 8, 10 and 13 also had a fluorescent pattern corresponding to the human chromosomes of the same number, particularly in the long arm. Remarkable variation in intensity and/or size of fluorescent regions was frequently found in the short arm of satellited acrocentric chromosomes 13, 14, 15, 22 and 23. Variations occurred between homologues and between individuals. Such variable fluorescence in a specific chromosomal region of an individual animal is a reproducible characteristic. Unlike its human counterpart, the distal segment in the long arm of the chimp's Y-chromosome is not brightly fluorescent. An earlier report is thus confirmed.     

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.     

Genetic and cytogenetic analysis of the American cherry fruit fly, Rhagoletis cingulata (Diptera: Tephritidae)

The American eastern cherry fruit fly, Rhagoletis cingulata, a pest of cherries in the western hemisphere, invaded Europe in 1983, and since then dispersed to several European countries. Information on the genetics and cytogenetics of this pest is very scarce. The mitotic karyotype and detailed photographic maps of the salivary gland polytene chromosomes of R. cingulata are presented here. The mitotic metaphase complement consists of six pairs of chromosomes with the sex chromosomes being very small and similar in size. The analysis of the salivary gland polytene complement shows a total number of five long chromosomes (10 polytene arms), which correspond to the five autosomes of the mitotic nuclei and an extrachromosomal heterochromatic mass, which corresponds to the sex chromosomes. The banding patterns and the most characteristic features and prominent landmarks of each polytene chromosome are presented and discussed. Chromosomal homologies between R. cingulata, R. completa and R. cerasi are also proposed, based on the comparison of chromosome banding patterns. Furthermore, the detection and characterization of Wolbachia pipientis in the R. cingulata population studied is presented and the potential correlation with the asynaptic phenomena found in its polytene complement is discussed. In addition, 10 out of 24 microsatellite markers developed for other Rhagoletis species are cross-amplified, evaluated and proposed as useful markers for population and genetic studies in R. cingulata.     

Comparative karyology of Brazilian vampire bats Desmodus rotundus and Diphylla ecaudata (Phyllostomidae, Chiroptera): banding patterns, base-specific fluorochromes and FISH of ribosomal genes

This paper provides new data on chromosomes of Brazilian vampire bats Desmodus rotundus and Diphylla ecaudata. These species were analyzed by GTG, CBG- and CB-DAPI banding, AgNO3/CMA3 sequential staining, base-specific fluorochrome dyes and in situ hybridization with 18S rDNA probe. C-banding (CBG) revealed constitutive heterochromatin in the pericentromeric regions in all autosomes and the X and Y chromosomes appeared entirely heterochromatic in both species. CB-DAPI revealed a coincident banding pattern to that obtained by CBG. Triple staining CMA3/DA/DAPI revealed an R-banding and a weak G-banding pattern in the karyotypes. Sequential AgNO3/CMA3 staining showed a NOR located interstitially on the long arm of pair 8 in D. rotundus and on the short arm of pair 13 in D. ecaudata. FISH with a rDNA probe confirmed the location and number of NORs; a difference neither in intensity nor in size of hybridization signal was detected between homologues for both species.     

Dimeric bisbenzimidazole Hoechst 33258-related dyes as novel AT-specific DNA-binding fluorochromes for human and plant cytogenetics

Ten new fluorescent dyes have been tested as possible tools for human and plant chromosome banding; eight of the tested dyes were dimer derivatives of bisbenzimidazole (Hoechst 33248). The dimer compounds differed from each other by the length of the linker connecting benzimidazole moieties and by the structure of the moieties themselves. Four compounds selected for the study, namely, DB(7), DB(8), DB(17), and DB(18), upon UV excitation (365 nm) exhibited a bright blue fluorescence in nuclear heterochromatic granules, but at longer excitation wavelengths (blue or green) did not show any fluorescence in nucleus or cytoplasm. All these compounds were shown to produce a high-quality distinct banding in human and plant chromosomes, comparable to that obtained after standard DAPI staining. Further study was carried out so that to evaluate contrast of the band borders, fluorescence intensity, as well as a photobleaching rate for different dyes. As a result, we selected DB(17) as a fluorochrome of choice for chromosome banding. Spectral characteristics of this compound allow employing it in combination with FISH analysis. Investigation of linum karyotypes using DB(17) has demonstrated applicability of this dye for banding of very short plant chromosomes. The known higher stability of dimer DNA-binding fluorophors, as compared to that of monomer ones, suggests the possibility of using DB(17) for banding and identification of flow-sorted chromosomes.     

Induction of chromosome banding by trypsin/EDTA for gene mapping by in situ hybridization

We describe an easy and reproducible procedure that utilizes trypsin/EDTA for the induction of chromosome banding in conjunction with in situ hybridization. The high quality banding resolution required for grain localization is obtained on both elongated and contracted chromosomes derived from synchronized or nonsynchronized human lymphocytes or fibroblasts. This procedure can also be useful for gene localization on chromosomes from cancer cells.     

The mechanism and pattern of banding induced by restriction endonucleases in human chromosomes

The mechanism of chromosome banding induced by restriction endonucleases was analyzed by measuring the amount of radioactivity extracted from [¹⁴C]thymidine-labeled chromosomes digested first with restriction enzymes and subsequently with proteinase K and DNase I. Restriction enzymes with a high frequency of recognition sites in the DNA produced a large number of short DNA fragments, which were extracted from chromosomes during incubation with the enzyme. This loss of DNA resulted in decreased chromosomal staining, which did not occur in regions resistant to restriction enzyme digestion and thus led to banding. Subsequent digestion of chromosomes with proteinase K produced a further loss of DNA, which probably corresponded to long fragments retained in the chromosome by the proteins of fixed chromatin. Restriction enzymes induce chromatin digestion and banding in G1 and metaphase chromosomes, and they induce digestion and the appearance of chromocenters in interphase nuclei. This suggests that the spatial organization and folding of the chromatin fibril plays little or no role in the mechanism of chromosome banding.It was confirmed that the pattern of chromosome banding induced by AluI, MboI, HaeIII, DdeI, RsaI, and HinfI is characteristic for each endonuclease. Moreover, several restriction banding polymorphisms that were not found by conventional C-banding were detected, indicating that there may be a range of variability in the frequency and distribution of restriction sites in homologous chromosome regions.     

Karyotype and chromosomal banding pattern in Heteropeza pygmaea

The chromosomes of somatic and germ line cells of female embryos produced by paedogenesis were studied. The haploid set in somatic cells consists of one long submetacentric chromosome, one large acrocentric, one medium metacentric and two small acrocentrics. The length vs arm index karyogram makes it possible to distinguish all but the two pairs of small acrocentric chromosomes. — Attempts were made to develope a method for banding pattern visualization. The best result was obtained using trypsin which induced banding in the chromosomes of the somatic cells and occasionally also of the germ line cells. The resulting banding patterns were frequently not identical in members of a chromosome pair. There was also a variation between metaphases within an embryo as well as from different embryos. Some tentative explanations for these results are discussed.     

The karyotype of the golden monkey (Rhinopithecus r. roxellanae)

In this paper, the karyotype and G-banding pattern of the chromosomes of cultured peripheral blood lymphocytes in R. r. roxellanae were investigated. The chromosome number of this species is 44 in both sexes. In R. r. roxellanae, as in other monkeys, sex is determined by specific sex chromosomes, i.e. the male is XY and the female is XX. The 21 pairs of autosomes consist of 7 pairs of metacentric chromoomes, 13 pairs of submetacentric chromosomes and one acrocentric pair. Chromosome measurements were made from highly enlarged photographic prints. They included the relative length, arm ratio and centromere index of each chromosome. Both chromosomal and chromatid aberrations were observed. They were 0·67 and 2%, respectively. Finally, G-banding pattern analysis of chromosomes of R. r. roxellanae were carried out. The results show that each homologous pair has its own special banding pattern, so that each of them is easily recognizable. Idiograms of chromosome complements with the Giemsa banding pattern are constructed.     

Chromosome banding in Amphibia

The mitotic and meiotic chromosomes of the marsupial frog Gastrotheca riobambae were analysed with various banding techniques. The karyotype of this species is distinguished by considerable amounts of constitutive heterochromatin and unusual, heteromorphic XY sex chromosomes. The Y chromosome is considerably larger than the X chromosome and almost completely heterochromatic. The analysis of the banding patterns obtained with GC- and AT-base-pair-specific fluorochromes shows that the constitutive heterochromatin in the Y chromosome consists of at least three different structural categories. The only nucleolus organizer region (NOR) of the karyotype is localized in the short arm of the X chromosome. This causes a sex-specific difference in the number of NOR: female animals have two NORs in diploid cells, male animals one. No cytological indications were found for the inactivation of one of the two X chromosomes in the female cells. In male meiosis, the heteromorphic sex chromosomes form a characteristic sex-bivalent by pairing their telomeres in an end-to-end arrangement. The significance of the XY/XX sex chromosomes of G. riobambae for the study of X-linked genes in Amphibia, the evolution of sex chromosomes and their specific DNA sequences, and the significance of the meiotic process of sex chromosomes are discussed.