小麦属核型分析和BG染色体组及4A染色体的起源

应用植物有丝分裂染色体标本制备新方法和N—带技术对小麦属(Triticum)9个六倍体种(AABBDD),8个四倍体种(AABB,AAGG),3个二倍体种(AA,A~uA~u)及B组的可能供体沙融山羊草(Ae. shronensis)体细胞核型和N—带进行了分析。结果表明,小麦属全部为具中部或次中部着丝点染色体,核型属于“2A”类型,不对称性随倍性提高而有所增加。种问核型有一定差异。所有小麦B染色体组、G染色体组和4A染色体均显N—带,其它染色体则不显带或只显很浅的着丝点带。六倍体种B染色体组带型基本相同,四倍体小麦B组N—带种间有一定差异。提莫菲维小麦(T.Timopheevi)G组带纹数目和分布与B梁色体组有显著差别,作者认为两者非同源。沙融山羊草核型和带型都与小麦B组相近,是B组的可能供体。一粒系小麦A染色体组基本不显N—带,其中无与4A带型相同的染色体,4A起源尚待研究。     

Standard karyotype of sea trout (Salmo trutta morpha trutta) based on replication banding patterns

Replication banding patterns have been obtained from in vivo treatment of Salmo trutta morpha trutta chromosomes using a modification of the 5-BrdU technique and in kidney cultures using the fluorochrome photolysis Giemsa (FPG) staining method. Each chromosome pair was identified in the karyotype based on the banding pattern, chromosome size, and centromere position. The standard karyotype of sea trout has been proposed. Similarities of replication, and restriction enzyme banding patterns of chromosomes 8 and 9, and of chromosomes 11 and 12, are discussed. Fluorescence in situ hybridization was used to determine the location of telomeric sequences.     

Multicolor FISH mapping of the dioecious model plant,<Emphasis Type="Italic"> Silene latifolia</Emphasis>

Silene latifolia is a key plant model in the study of sex determination and sex chromosome evolution. Current studies have been based on genetic mapping of the sequences linked to sex chromosomes with analysis of their characters and relative positions on the X and Y chromosomes. Until recently, very few DNA sequences have been physically mapped to the sex chromosomes of S. latifolia. We have carried out multicolor fluorescent in situ hybridization (FISH) analysis of S. latifolia chromosomes based on the presence and intensity of FISH signals on individual chromosomes. We have generated new markers by constructing and screening a sample bacterial artificial chromosome (BAC) library for appropriate FISH probes. Five newly isolated BAC clones yielded discrete signals on the chromosomes: two were specific for one autosome pair and three hybridized preferentially to the sex chromosomes. We present the FISH hybridization patterns of these five BAC inserts together with previously described repetitive sequences (X-43.1, 25S rDNA and 5S rDNA) and use them to analyze the S. latifolia karyotype. The autosomes of S. latifolia are difficult to distinguish based on their relative arm lengths. Using one BAC insert and the three repetitive sequences, we have constructed a standard FISH karyotype that can be used to distinguish all autosome pairs. We also analyze the hybridization patterns of these sequences on the sex chromosomes and discuss the utility of the karyotype mapping strategy presented to study sex chromosome evolution and Y chromosome degeneration.Communicated by J.S. Heslop-Harrison     

臭鼩染色体的研究

本文采用骨髓染色体制片法,对捕自我国浙江萧山市的臭鼩进行了组型、G-带、C-带和核仁组织区银染的观察分析。结果表明,我国臭鼩染色体数目为2n=40,组型为8(m)+2(sm)+10(st)+18(t),性染色体为,(?):X(m或sm),Y(m或sm);♀:XX(m或sm)。G-带较为丰富,每一对染色体都有其特定的带型,较易于辨别与配对。在C-带方前,4对中间着丝粒染色体与5对亚端着丝粒染色体均具有不同程度的着丝粒带,1对亚中着丝粒染色体与9对端着丝粒染色体缺乏C-带物质,性染色体具丰富的远端带及中间带.银染的结果显示,第5、12和13对染色体具银染物质。     

Chromosome banding and compaction

Summary We have described a characteristic substructure of mitotic chromosomes, the chromosomal unit fibre, with lengths about five times the length of the corresponding metaphase chromosomes and a uniform diameter of 0.4 m. In order to study the relationship of chromosome banding to chromosome compaction, methods have been devised to obtain banding patterns on chromosomal unit fibres, similar to G-band patterns of intact mitotic chromosomes. The total number of bands plus interbands per haploid human karyotype is estimated at about 3000. The banding pattern of chromosomal unit fibres indicates a certain resemblance to the normal G-banding pattern of human chromosomes even if the details indicate a short-range random distribution.     

A phylogenetic study of bird karyotypes

Karyotypes were compared in 48 species, including 6 subspecies, of birds from 12 orders: Casuariiformes, Rheiformes, Sphenisciformes, Pelecaniformes, Ciconiiformes, Anseriformes, Phoenicopteriformes, Gruiformes, Galliformes, Columbiformes, Falconiformes and Strigiformes. — With the exception of the family Accipitridae, all the species studied are characterized by typical bird karyotypes with several pairs of macrochromosomes and a number of microchromosomes, though the boundary between the two is not necessarily sharp. The comparative study of complements revealed that a karyotype with 3 morphologically distinct pairs of chromosomes is frequently encountered in all orders except the Strigiformes. Those 3 pairs, submetacentric nos. 1 and 2, and a subtelocentric or telocentric no. 3, are not only morphologically alike but also have conspicuous homology revealed by the G-banding patterns. Furthermore, G-banding analysis provided evidence for the derivation of the owl karyotype from a typical bird karyotype.—The above cytogenetic features led to the assumption that the 3 pairs of marker chromosomes had been incorporated into an ancestral bird karyotype. It seems probable that those chromosomes have been transmitted without much structural changes from a common ancestor of birds and turtles, since the presence of the same marker chromosomes in the fresh water turtle Geoclemys reevesii is ascertained by G-banding patterns. — A profile of a primitive bird karyotype emerged through the present findings. Hence, it has become possible to elucidate mechanisms involved in certain structural changes of macrochromosomes observed in birds. It was concluded that a major role had been played by centric fission as well as fusion, translocation, and pericentric inversion.     

Karyotyping of Brassica napus L. Based on C0t-1 DNA Banding by Fluorescence In Situ Hybridization

In order to precisely recognize and karyotype Brassica napus L. chromosomes, C0t-1 DNA was extracted from its genomic DNA, labeled with biotin-1 1-dUTP and in situ hybridized. The hybridized locations were detected by Cy3-conjugated streptavidin. Specific fluorescence in situ hybridization （FISH） signal bands were detected on all individual chromosome pairs. Each chromosome pair showed specific banding patterns. The B. napus karyotype has been constructed, for the first time, on the basis of both Cot-1 DNA FISH banding patterns and chromosome morphology.     

Chromosomal rearrangements in rock wallabies, Petrogale (Marsupialia: Macropodidae). VI. Determination of the plesiomorphic karyotype: G-banding comparison of Thylogale with Petrogale persephone, P. xanthopus, and P. l. lateralis.

G-banding has demonstrated the presence of a conserved (2n = 22) chromosome complement in the macropod genus Thylogale and in some Petrogale species. This plesiomorphic karyotype consists of acrocentric chromosomes 1, 2, 5, 6, 8, 9, and 10; submetacentric chromosomes 3 and 4; and a metacentric chromosome 7. It should now be possible to relate the G-banding patterns of all other Petrogale species to this plesiomorphic complement and thereby determine the number and types of changes that have occurred during the course of chromosome evolution in Petrogale. It is hypothesised that this 2n = 22 complement is plesiomorphic for all macropodids.     

NORs, heterochromatin, and R-bands in three species of Cervidae

Chromomycin A3 banding of the chromosomes of three species of Cervidae (red deer, fallow deer, roe deer) allows the demonstration of both centromeric constitutive heterochromatin and R-banding patterns useful for identifying all the chromosomes of a given karyotype. In all three species significant amounts of chromomycin-bright heterochromatin are present at the centromeres of all autosomes. The X chromosomes of all investigated species contained appreciable amounts of centromeric heterochromatin. AgNO3 staining was applied sequentially to detect the location of active nucleolus organizer regions (NORs). The distribution of NORs was reasonably conservative in the investigated species.     

B chromosome morphotypes of Apodemus peninsulae (Rodentia) from the Russian Far East

Polymorphism of B chromosome morphotypes in the natural populations of the Korean field mouse Apodemus peninsulae (n = 367) has been studied in five regions of the Russian Far East: Magadan and Amur regions, the Jewish Autonomous region, Khabarovsk and Primorskii regions. Six groups of B chromosome morphotypes have been described on the size and morphological parameters. On the basis of their combinations 78 cell clones have been revealed, 23 of which are found in the animals with a stable karyotype and 76--in mosaics. The mosaics have also more diverse and unique combinations of B chromosome morphotypes. No differences between the geographic and local populations of mice on the studied characteristics have been found. Homogeneous structure of DNA in the B chromosomes of this species at the territory of the Russian Far East, as shown previously, allowed us to combine the numerical and dimensional data for each clone by introduction conditional "mass quantity" of B chromosomes (mB index). The leading role of natural selection in production of "critical" mass of supernumerary chromosomes in individuals with a stable karyotype and the weakening of its role in mosaics has been suggested.     

The karyotype of the great sculpin, <Emphasis Type="Italic">Myoxocephalus polyacanthocephalus</Emphasis> (Pallas, 1814) (Pisces: Cottidae), from the Russian part of the species range

The karyotype of the great sculpin, Myoxocephalus polyacanthocephalus (Pallas, 1814) (Pisces: Cottidae) from the Sea of Okhotsk and the Sea of Japan has been studied for the first time. The karyotype is stable; it consists of 40 chromosomes (4 metacentric, 2 submeta-subtelocentric, 20 subtelocentric, and 14 acrocentric chromosomes); the number of chromosomal arms is 44 + 2. Nucleolar organizer regions (NOR) are found in the telomeric region of the arm in one homologue of a pair of small metacentric chromosomes, using the Ag-NOR banding technique. A comparative analysis of the karyotype of M. polyacanthocephalus and the karyotypes of other Myoxocephalus species (M. stelleri, M. brandtii, M. jaok, M. ochotensis, and M. scorpius) has been carried out based on the main karyotype characters, as well as on the number and localization of NORs. The identified differences make it possible to differentiate the studied species, whereas the general traits indicate their taxonomic proximity.     

Characterization of human heteroploid cell line J-111: Reverse banding patterns of marker chromosomes

The karyotype of the human cell line, J-111, has been studied employing R-banding by fluorescence using acridine orange technique (RFA). The model chromosome number of this line was 112. All human chromosomes except the Y were present in each metaphase. Twenty-one marker chromosomes were distinguished and their possible origins were investigated. Of these, twelve were consistently present in all cells. Nine markers were highly variable. Four typical marker chromosomes of HeLa cells were found and their origins were identified, indicating that the line is a HeLa contaminant. The reverse banding patterns of all marker chromosomes are presented and the value of the RFA technique is discussed.     

尼罗罗非鱼染色体的C带、Ag带和减数分裂联会复合体的研究

以Sumner法和界面铺张——硝酸银技术,对尼罗罗非鱼(Tilapia nilotica)染色体C带、Ag染带及减数分裂前期精母细胞联会复合体(SC)进行了显微和亚显微结构观察。 尼罗罗非鱼的2n=44,核型可分为三个组:第一组为4对亚中着丝粒染色体;第二组为17对亚端着丝粒染色体;第三组为具1对端着丝粒的特大染色体。 结构异染色质主要分布于着丝粒附近,其中Nos.6、8、15亚中着丝粒染色体短臂全部深染。带有银染核仁组织者(Ag-NORs)染色体的数目为2—6条,NORs均位于6、8、15亚中着丝粒染色体短臂。 银染色可清楚地显示尼罗罗非鱼的联会复合体(SC)结构和减数分裂行为。SC组型与有丝分裂染色体的组型有较好的一致性。     

Karyotype variation is indicative of subgenomic and ecotypic differentiation in switchgrass

ABSTRACT: BACKGROUND: Karyotypes can provide information about taxonomic relationships, genetic aberrations, and the evolutionary origins of species. However, differentiation of the tiny chromosomes of switchgrass (Panicum virgatum L.) and creation of a standard karyotype for this bioenergy crop has not been accomplished due to lack of distinguishing features and polyploidy. RESULTS: A cytogenetic study was conducted on a dihaploid individual (2n=2X=18) of switchgrass to establish a chromosome karyotype. Size differences, condensation patterns, and arm-length ratios were used as identifying features and fluorescence in-situ hybridization (FISH) assigned 5S and 45S rDNA loci to chromosomes 7 and 2 respectively. Both a maize CentC and a native switchgrass centromeric repeat (PviCentC) that shared 73% sequence identity demonstrated a strong signal on chromosome 3. However, only the PviCentC probe labeled the centromeres of all chromosomes. Unexpected PviCentC and 5S rDNA hybidization patterns were consistent with severe reduction or total deletion of these repeats in one subgenome. These patterns were maintained in tetraploid and octoploid individuals. The 45S rDNA repeat produced the expected number of loci in dihaploid, tetraploid and octoploid individuals. Differences observed at the 5S rDNA loci between the upland and lowland ecotypes of switchgrass provided a basis for distinguishing these subpopulations. CONCLUSION: Collectively, these results provide a quantitative karyotype of switchgrass chromosomes. FISH analyses indicate genetic divergence between subgenomes and allow for the classification of switchgrass plants belonging to divergent genetic pools. Furthermore, the karyotype structure and cytogenetic analysis of switchgrass provides a framework for future genetic and genomic studies.     

赤斑羚和斑羚核型比较研究

本文对赤斑羚（ＮａｅｍｏｒｈｅｄｕｓＣｒａｎｂｒｏｏｋｉ）和斑羚（Ｎ．ｇｏｒａｌｇｒｉｓｅｕｓ）的染色体Ｇ带、Ｃ带和Ａｇ－ＮＯＲｓ的数目、分布等作了较详细的比较研究。赤斑羚２ｎ＝５６全部为近端着丝粒染色体,Ｎ．Ｆ＝５４;斑羚２ｎ＝５４,除Ｎｏ．３是亚中着丝粒染色体外,具有丰富的异染色质;二者Ｇ带带纹相似程度高,其Ｎｏ．３长臂Ｇ带带纹相似。斑羚的Ｎｏ．３短臂与赤斑羚Ｎｏ．２７近端着丝粒染色体的大小、     

Chromosomal and NOR patterns in the polyclonal stick insect Bacillus atticus atticus (Insecta; Phasmatodea).

Bacillus atticus atticus is a complex of thelytokous parthenogens, related to the bisexual Bacillus grandii, that ranges from Sardinia to Near Eastern countries. Karyotypic and cytogenetic differentiation of the B. atticus atticus diploid unisexual "isolates" is really higher than expected. Its standard karyotype has 2n = 34 chromosomes, but several instances of repatterned or even aneuploid complements have been found. The number and location of silver-stained NORs are particularly intriguing, since in addition to homozygous NOR patterns, simple or double hemizygous strains are found spread over specific and wide regions. The odd patterns are not due to Ag-NOR staining technique artifacts, since the FISH method, using rDNA probes, apparently labels the same ribosomal clusters. Transpositions and translocations have been suggested to account for some NOR patterns, but hybridizations between different NOR-bearing races are also a possible cause. This chromosomal survey clearly contributes to a better understanding of B. atticus phylogeny.     

Comparing the karyotype of the European domestic goose and the Asian goose on the basis of the karyotype of their interspecific cross-breed, using the RBG chromosome staining technique

The aim of the research was to compare the karyotypes of two goose species: the European domestic goose and the Asian goose on the basis of the karyotype of their interspecific cross-breed, using the RBG chromosome staining technique. The karyotype standard for Anseriformes has not been determined yet. The RBG technique is considered as one of the standard methods for analysing chromosomes. It is a dynamic method. The R bands appear during the cell growth cycle in the early S phase. The formation of the characteristic band configuration for each chromosome facilitates chromosome segregation and analysis. The mitotic chromosomes for experiments were obtained from an in vitro blood lymphocyte culture and stained according to the RBG technique. The first eight largest autosome pairs and the ZW sex chromosomes were analysed. No differences were found between the band patterns of the analysed chromosomes, except for the fourth autosome pair.     

Chromosome variation in the plethodontid salamander,Aneides ferreus

Karyotype variation in the plethodontid salamander, Aneides ferreus, has been analysed. 358 individuals from 14 populations, representing the major portion of the range of this salamander, have been karyologically examined. In A. ferreus, n=14. When the chromosomes are arranged in a decreasing relative length series, the karyotype is heteromorphic with respect to chromosome number 13, which may be either telocentric (T) or subtelocentric (ST). Variation in the heteromorphism over the range of the species is sex related, and probably also reflects relative population sizes. The heteromorphism in the isolated populations of A. ferreus on Vancouver Island, British Columbia, Canada, resembles a WZfemale/ZZmale sex chromosome dimorphism, suggesting the possibility that chromosome number 13 may be involved in sex determination in this population. The possibility that chromosome number 13 is involved in sex determination in all populations of A. ferreus is discussed. Our data suggest that the ancestral A. ferreus karyotype was homomorphic for T (T/T), and that the ST was derived from the T by a pericentric inversion. In peripheral populations, only the W homologue has been affected, whereas in central populations both the W and the Z chromosomes have been rearranged. Comparisons are made with other species of Aneides for which karyological information is available, and it is concluded that chromosome rearrangements have played an important role in the evolution of the genus. In C-banded chromosomes of A. ferreus, staining is most intense at the centromere regions of the larger chromosomes and is absent only in some of the smaller chromosomes. Implications of this C-banding pattern are discussed.