C-bands on chromosomes of 32 beetle species (Coleoptera: Elateridae, Cantharidae, Oedemeridae, Cerambycidae, Anthicidae, Chrysomelidae, Attelabidae and Curculionidae)

C-banding patterns of 32 beetle species from the families Elateridae, Cantharidae, Oedemeridae, Cerambycidae, Anthicidae, Chrysomelidae, Attelabidae and Curculionidae were studied using the C-banding technique. Mitotic and meiotic chromosomes were previously described for 14 species. From among 18 species that had never been cytogenetically studied, we determined the diploid and haploid chromosome numbers and the sex determination system for 12 beetles. The karyotype for 6 species is not described because of a lack of mitotic and meiotic metaphases. Results confirm that most of the beetle species possess a small amount of heterochromatin and C-positive segments are weakly visible in pachytene stages and weakly or imperceptible in mitotic and meiotic metaphases. In some species with a large amount of heterochromatin, C-bands were observed in the centromeric region in all autosomes and the X chromosome. The Y chromosome does not show C-bands with the exception of Oedemera viridis in which it possesses a small band of heterochromatin.     

Restrictive localization of centromeric heterochromatin (C-bands) in Presbytis e. entellus (Dufresne) as compared to Macaca mulatta (Zimmerman)

C-bands are observed in the centromeric regions of only three pairs of autosomes and the distal portion of the small acrocentric Y in a total complement of 44 chromosomes of a male Presbytis e. entellus. Simultaneously treated slides of a Rhesus monkey, however, have C-bands in all the 42 chromosomes. The lack of C-bands may be due to (1) absence of highly repetitive DNA in the centromeric region of certain chromosomes or (2) presence of minute quantity of such DNA which is imperceptible or (3) different types of centromeric heterochromatin with a varying degree of repetition of DNA sequences all of which do not react in similar manner to various techniques employed at present. It is hypothesized that the centromeric heterochromatin rich in satellite DNA helps in withstanding the force of excessive coiling of chromosomes at the centromere to facilitate the functioning of the genes for microtubular protein during cell division when other genes are rendered inactive due to compactness of chromosomes.     

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.     

Cytogenetic aspects of phylogeny in the Bovidae. II. C-banding

Constitutive heterochromatin in the Bovidae, as revealed by C-banding, was mostly located in the centromeric regions. Considerable variation was, however, evident in the size of the C-bands both within and between subfamilies. Some evidence was found for a reduction in the amount of centromeric heterochromatin in bi-armed relative to acrocentric autosomes, and these findings are discussed in relation to karyotype evolution in the group.     

Cytogenetic analysis of some Brazilian marsupials (Didelphidae: Marsupialia)

Three species of marsupials from the Amazon region (Marmosa cinerea, Caluromys lanatus, and Didelphis marsupialis) and two from the region of S?o Paulo (Didelphis marsupialis and Didelphis albiventris) were studied. The G-banding pattern of the species with 2n = 14 (M. cinerea and C. lanatus) was very similar, as well as the pattern of G-bands in the species with 22 chromosomes (Didelphis). All of the autosomes of M. cinerea and D. albiventris have centromeric C-bands and the Y chromosome is totally C-band positive. The long arm of the M. cinerea X chromosome is completely C-band positive except for a negative band close to the centromeric region. In D. albiventris the long arm of the X chromosome is C-band positive except for a negative band close to the telomeric region. In M. cinerea the silver-stained nucleolar organizer regions (Ag-NORs) are found in the acrocentric chromosomes, being located in the telomeric region of one pair and in the centromeric region of the other pair. Caluromys lanatus has centromeric Ag-NORs in one acrocentric and in one submetacentric chromosome pairs. Didelphis marsupialis has three chromosome pairs with telomeric Ag-NORs. In D. albiventris the Ag-NORs are terminal and located in both arms of one pair and in the long arm of two pairs of chromosomes.     

Heterochromatin and nucleolus-organizer-region behaviour at male pachytene of Sus scrofa domestica

In the domestic pig (2n=38) two types of constitutive heterochromatin can be differentiated by fluorescence counterstaining techniques. All 24 biarmed autosomes and the X chromosome have chromomycin A₃-positive centromeric C-bands, whereas all 12 acrocentric chromosomes exhibit DA-DAPI-positive centromeric heterochromatin. Fluorescence analysis of male pachytene nuclei revealed that the DA-DAPI-positive C-bands form one or two large chromocentres per cell, while the chromomycin A₃-bright C-material is well scattered. Hence, the bivalents formed by the acrocentric chromosome pairs are centromerically associated, whilst the submetacentric bivalents are not. —Counce-Meyer spreading techniques were used to study the structure of synaptonemal complexes (SCs) both by light and electron microscopy. In general, the SCs of the domestic pig resemble those described for other mammals. The SC formed by the X and the Y may include up to 94.5% of the Y chromosome. In silver-stained microspreads each of the bivalents (nos. 8 and 10) bearing the nucleolus-organizer-regions (NORs) is connected to a pair of nucleoli, indicating that all four NORs are active during early meiotic stages. By contrast, in the majority of mitotic metaphases of phytohaemagglutinin-stimulated lymphocytes only one pair (no. 10) exhibited Ag-NOR staining. — The significance of the chromosome disposition in the pachytene nucleus is discussed with regard to heterochromatin composition and karyotype evolution.This paper is dedicated to Prof. Hans Bauer on the occasion of his 80th birthday     

中国五种锄足蟾科无尾两栖动物的细胞遗传学研究

本文对中国５种锄足蟾科无尾两栖动物的骨髓细胞有丝分裂中期作了细胞遗传学研究,内容包括核型、Ａｇ－ＮＯＲｓ和Ｃ－带。研究结果表明景东角蟾：２ｎ＝２６（２０Ｍ＋４ＳＭ＋２ＳＴ）,５＋８,ＳＣ和Ａｇ－ＮＯＲｓ位于６ｐ＾ｐｅｒ,同时呈Ｃ－带正染。Ｃ－带以着丝点区域正染为主;粗皮角蟾：２ｎ＝２６（２０Ｍ＋６ＳＭ）,５＋８,Ａｇ－ＮＯＲｓ在６ｑ＾ｉｎｔｅｒ,以着丝点Ｃ－带为主,但Ｎｏｓ．１２,１３有明显的端位     

Sterility in hybrid cattle. I. Distribution of constitutive heterochromatin and nucleolus organizer regions in somatic and meiotic chromosomes.

The distribution of constitutive heterochromatin and nucleolus organizer regions (NOR's) in somatic as well as in meiotic chromosomes of Bos taurus, Bos banteng, Bison bison, and their hybrids are analyzed. C-bands are present in the centromeric regions of every autosome. The X chromosome does not show a distinct C-band in the centromeric region, whereas the Y chromosome contains an appreciable amount of C-band material. In somatic metaphases, NOR's are present on the telomeric ends of five pairs of autosomes. During pachytene, five autosomal bivalents contain NOR's on their terminal ends. Meiotic preparations made from sterile bulls did not contain stages beyond the degenerating pachytene, which are C-banding, more frequently showed clustering of heterochromatin than did the pachytene stage in normal bulls.     

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     

Heterogeneity of constitutive heterochromatin in somatic Syrian hamster chromosomes.

Syrian hamster constitutive heterochromatin was analyzed for C-band distribution and for BrU late-replication pattern. Characteristic for this species is relatively large amounts of sex-chromosome and autosomal heterochromatin. The distribution of constitutive heterochromatin was determined. The long term of the X chromosome, the whole Y, the short arms of 8 autosomal pairs, the long arm of the smallest metacentric pair, and the centromeric regions of 12 pairs stained intensely dark on C-band preparations. In contrast to the heterochromatin in the centromeric regions, the autosomal short-arm heterochromatin has an increased susceptibility to the denaturation process, as indicated by prolonged exposure to NaOH or Ba(OH)2. Such further exposure to denaturing agents results in an intense dark stain only on the sex-chromosome heterochromatin and centromeric regions of the autosomes. The BrdU late-replication pattern demonstrated that the late-replicating regions correspond to C-bands. Centromeric regions replicate late in the S phase; however, no centromeric region is among the latest replicating segments of the complement. Centromeric and noncentromeric heterochromatin are two distinct categories of constitutive heterochromatin.     

A new chromosomal race (2n=44) of Nannospalax xanthodon from Turkey (Mammalia: Rodentia)

A new karyotype for blind mole rats was recorded in Tunceli province in Eastern Turkey. The karyotype contained 44 chromosomes, including 13 biarmed pairs, 7 acrocentric pairs, and one heteromorphic pair with a submetacentric and an acrocentric homologue in the autosomal complement (FNa=69). The X chromosome was submetacentric and the Y chromosome medium-sized subtelocentric (FN=73). Distinct dark centromeric C-bands were observed on most of the biarmed and three pairs of the acrocentric autosomes. The NORs were detected on short arms of three subtelocentric pairs and one acrocentric pair of autosomes. The diploid number of chromosomes and the karyotype characteristics observed are obviously unique among hitherto studied populations of blind mole rats and the complement can be evaluated as a new chromosome race of Nannospalax xanthodon. The distribution ranges of individual chromosome races of the species recorded in Eastern Anatolia are revised and possible interracial hybridization is discussed in respect of the finding of a new race.     

小熊猫染色体异染色质的显示

以培养的小熊猫外周淋巴细胞为实验材料,结合Ｃ－显带技术及ＣＭＡ３／ＤＡ／ＤＡＰＩ三竽荧光杂色的方法,对小熊猫的染色体组型、Ｃ－带带型及ＣＭＡ３／ＤＡ／ＤＡＰＩ荧光带带型进行了研究,发现：（１）经Ｃ－显带技术处理,可在小熊猫染色体上呈现出一种极为独特的Ｃ－带带型。在多数染色体上可见到丰富的插入Ｃ－带及端粒Ｃ－带。而着丝区仅显示弱阳性Ｃ－带;（２）除着丝粒区外,ＣＭＡ３诱导的大多数强荧光带纹与Ｃ－阳性     

Characterization of heterochromatin in Schistocerca gregaria by C- and N-banding methods

Mitotic and meiotic chromosomes of Schistocerca gregaria were C-, mild N- and strong N-banded. After C-banding, three out of eleven autosomes show, in addition to the centromeric C-bands, a second C-band. — The mild N-banding method produces a single N-band in each of only four chromosomes. With the exception of one N-band these mild N-bands correspond to the non-centromeric, second C-bands, indicating the heterochromatic character of at least three mild N-band regions. — The strong N-banding technique produces bands both at the C- and mild N-band positions and additionally a third band in one chromosome (M₈), not present after C- or mild N-banding. — The N-bands do not correspond to the nucleolus organizer regions. Because of the mechanisms of the N-banding methods, it is concluded that the centromeric heterochromatin, as well as the non-centromeric N-band regions, contain high quantities of non-histone proteins. Presumably a specific difference exists between the non-histone proteins in the centromeric and non-centromeric N-band regions because the centromeres are banded by the strong N-banding technique, but not after mild N-banding. It is concluded that the N-band regions (two exceptions) contain a heterochromatin type which has the following features in common with the -heterochromatin of Drosophila: C- as well as N-banding positive, high nonhistone protein content, repetitive and late replicating DNA. It is discussed whether the N-banded heterochromatin regions of Schistocerca contain that DNA fraction which is, like the Drosophila -heterochromatin, underreplicated in polyploid nuclei.     

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     

The characteristics of karyotype and telomeric satellite DNA sequences in the cricket, Gryllus bimaculatus (Orthoptera, Gryllidae)

The chromosomes derived from the Japanese population of Gryllus bimaculatus were characterized by C-banding and Ag-NOR staining. The chromosome number, 2n = 28 + XX (female)/XO (male), corresponded with that of other populations of G. bimaculatus, but the chromosome configuration in idiograms varied between the populations. NORs were carried on one pair of autosomes and appeared polymorphous. The positive C-bands located at the centromere of all chromosomes and the distal regions of many chromosome pairs, and the size and the distribution pattern of the distal C-heterochromatin showed differences among the chromosomes. In addition, this paper reports on the characteristics of HindIII satellite DNA isolated from the genome of G. bimaculatus. The HindIII repetitive fragments were about 0.54 kb long, and localized at the distal C-bands of the autosomes and the interstitial C-bands of the X chromosome. Molecular analysis showed two distinct satellite DNA sequences, named the GBH535 and GBH542 families, with high AT contents of about 67 and 66%, respectively. The two repetitive families seem to be derived from a common ancestral sequence, and both families possessed the same 13-bp palindrome sequence. The results of Southern blot hybridization suggest that the sequence of the GBH535 family is conserved in the genomic DNAs of Gryllus species, whereas the GBH542 family is a species-specific sequence.     

C-banding analysis on wild Emmer (Triticum dicoccoides Körn) strains with and without spontaneous reciprocal translocations

C-banding polymorphism was analyzed in eight strains of wild Emmer, Triticum dicoccoides Körn, which included six translocation homozygotes reported previously. Polymorphisms were detected in all of the strains examined, and the breakpoints of five spontaneous translocations were successfully identified by C-bands. Of the eight breakpoints that could be precisely identified, one was located in the centromeric region while the remaining seven were located in proximal to distal euchromatic regions. The two breakpoints of one translocation could only be approximately localized to proximal regions due to the scarcity of C-bands. The present results are in contrast with those observed on T. araraticum, another wild tetraploid wheat belonging to the Timopheevi group, in which most of the breakpoints were located in centromeric regions. In T. dicoccoides, the six translocation chromosome types were derived from the standard karyotype primarily by a mechanism other than centric breakage-fusion.     

甘肃紫斑牡丹品种与中原牡丹品种银带和Giemsa C带的研究

分别对甘肃紫斑牡丹品种和中原牡丹品种进行了核型,Ａｇｇｋｐｈｔ Ｇｉｅｎｓａ Ｃ带的研究。发现紫斑牡丹品种核型组成为２ ＝１０＝８ｍ＋２ｓｔ;中原牡丹品种核型组成为２ｎ＝１０＝６ｍ＋２ｓｍ＋２ｓｔ。ＧｉｅｍｓａＣ带带型显示,供试品种均能显示染色体端带,但天染色体端带的数目及分布位置上具品种特异性。     

Cytogenetic analysis of Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) with Xyp sex determination system using standard staining, C-bands, NOR and synaptonemal complex microspreading techniques

The mitotic and meiotic chromosomes of the beetles Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) were analysed using standard staining, C-banding and silver impregnation techniques. We determine the diploid and haploid chromosome numbers, the sex determination system and describe the chromosomal morphology, the C-banding pattern and the chromosome(s) bearing NORs (nucleolar organizer regions). Both species shown 2n = 20 chromosomes, the chromosomal meioformula 9 + Xyp, and regular chromosome segregation during anaphases I and II. The chromosomes of E. atomaria are basically metacentric or submetacentric and P. dermestoides chromosomes are submetacentric or subtelocentric. In both beetles the constitutive heterochromatin is located in the pericentromeric region in all autosomes and in the Xp chromosome; additional C-bands were observed in telomeric region of the short arm in some autosomes in P. dermestoides. The yp chromosome did not show typical C-bands in these species. As for the synaptonemal complex, the nucleolar material is associated to the 7th bivalent in E. atomaria and 3rd and 7th bivalents in P. dermestoides. Strong silver impregnated material was observed in association with Xyp in light and electron microscopy preparations in these species and this material was interpreted to be related to nucleolar material.     

Differential staining of tick chromosomes: techniques for C-banding and silver-staining and karyology of Rhipicephalus sanguineus (Latreille)

A new karyotypic procedure is described for tick chromosomes along with modifications of accepted techniques for C-banding and silver-staining. The staining procedures produce patterns with staining limited to the centromeric regions and the nucleolar organizer regions (NORs). The possible reasons for the concordant patterns are discussed based on the staining characteristics of the 2 techniques. The karyotype of Rhipicephalus sanguineus possesses 20 acrocentric autosomes with a single pair of NORs located proximal to the centromere on the largest autosomal pair. The sex-determining system is XX:XO with the X chromosome being the largest chromosome in the complement and subtelocentric.     

Autosomal and sex-chromosomal polymorphism in a wild population of the Norway rat,Rattus norvegicus

The karyotypes of 33 specimens of Rattus norvegicus captured in a wild population, were studied by means of conventional Giemsa staining and G- and C-banding methods. A chromosomal polymorphism for the presence or absence of extra segments in autosomes 3 and 12 and the X chromosome was found, beside a polymorphism for centromeric C-bands in pair no. 6.The frequency of different chromosome types found in this population was compared with that found in a wild population in Japan as well as with that found in some inbred strains.