Chromosomal Karyotypes of Fragaria Plants

[Objective]This study was to analyze the karyotypes of wild diploid strawberry species,so as to provide basis for revealing the ori- gins,evolvement and genetic breeding of strawberry. [Method] Four diploid strawberry species including Fragaria gracilis A. Los,Fragaria nilgerrensis Schidl,Fragaria pentaphylla A. Los. and Fragaria vesca L. were used as experimental materials to analyze their chromosomal kary- otypes. [Result]The karyotype formula for strawberry species tested was as follows： 2n =2x =14 =10m ＋2sm ＋2m＊ for F. gracilis A. Los, belonging to type 1B; 2n =2x =14 =14m for F. nilgerrensis Schidl,belonging to type 1A; 2n =2x =14 =12m ＋2sm for F. pentaphylla A. Loz. , belonging to type 1A; 2n =2x =14 =14m for F. vesca L. ,belonging to type 1A. Karyotype analysis showed that karyotypic asymmetry degree of the four species was F. gracilis A. Los. F. pentaphylla A. Loz. F. vesca L. F. nilgerrensis Schidl. [Conclusion] The evolution order of these four species was probably F. gracilis A. Los. ,F. pentaphylla A. Loz. ,F. vesca L. ,F. nilgerrensis Schidl.

Electron Microscopic Studies on the Silver-stained Nucleolar Cycle of Physarum polycephalum

The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated in the center of the nucleus in late G(2)-phase, and the fibrillar centers, dense fibrillar components and granular components could be observed in the nucleolus. During prophase, the nucleolus moved towards the periphery of the nucleus and in late prophase disintegrated near the nuclear envelope. in metaphase, the disintegrated nucleolar components were dispersed in masses and located at the periphery of the chromosomal region of the nucleus. No specifically silver-stained area and argentophilic protein sheath were observed on the chromosomes, but there were some big dispersed silver particles within the chromosomes. During telophase the nucleolar components moved towards the two poles along with the chromosomes and co-existed with the decondensing chromatin in daughter nuclei. The nucleolar components then gradually converged with one another and separated from the chromatin. A big nucleolus was formed in the nucleus about 120 min after the completion of mitosis.

Comparative study of the chromosome karyotypes of two species of grasshoppers in Megaulacobothrus Caudell (Orthoptera: Acridoidea)

The chromosome karyotypes of Chorthippus （Megaulacobothrus） aethalinus （Zubovsky） and Ch. （M.） chinensis Tarbinsky were compared. Results show that the chromosome numbers of the two species fit 2n （♂） = 17 = 16 ＋ XO, in which three pairs of autosomal and sex chromosomes were terminal chromosomes, and the other five pairs of autosomes were metacentric chromosomes. These are diagnosis characters for Chorthippus. However, these two species can be distinguished by the different chromosome formula （CF） and the relative length （RL）. The CF in Ch. （M.） aethalinus is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 6M ＋ 4S ＋ XO, whereas that of Ch. （M.） chinensis is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 8M ＋ 2S ＋ XO. In addition, we also found that the relative lengths of sex chromosomes in the two species were different from each other. The sex-chromosome of Ch. （M.） aethalinus is located at the fifth position and its relative length is 8.33% whereas that of Ch. （M.） chinensis is at the eighth position and its relative length is 5.53%. These results show that significantly different genetic features exist for the two species of Chorthippus.

Comparative study of the karyotypes of two species of grasshoppers in the genera Chorthippus Fieber and Euchorthippus Tarbinsky(Orthoptera: Arcypteridae)

The chromosome karyotypes of Chorthippus albomarginatus （De Geer） which represents the genus Chorthippus Fieber and Euchorthippus unicolor （Ikonnikov） which represents the genus Euchorthippus Tarbinsky were compared. The chromosome numbers for these two species fit 2n （♂） = 17 = 16 ＋ XO, in which five pairs of autosomal and sex chromosomes are terminal chromosomes, and the other three pairs of autosomes are metacentric chromosomes. This similarity between the two genera indicates that they have a close phylogenetic relationship. However, these two species can be distinguished by their different chromosome formula （CF） and the relative sex chromosome length （RL）. The CF in C. albomarginatus is K （2n,♂） = 6m ＋ 11t = 8L ＋ 4M ＋ 4S ＋ XO, whereas that ofE. unicolor is K （2n, ♂） = 6m ＋ 11t = 8L ＋ 6M ＋ 2S ＋ XO. The relative lengths of sex chromosomes in the two species are different. The sex-chromosome of C. albomarginatus is located at the ninth position and its relative length is 2.96% whereas that ofE. unicolor is at the eighth position and its relative length is 4.26%. These results show that significantly different genetic features exist for the two genera.

Chromosomes and Karyotypes of Three Seagrass Species of Hydrocharitaceae

[Objective] This study aimed to investigate the chromosomes and karyotypes of three seagrass species of hydrocharitaceae-Enhalus acoroides, Thalassia hemprichii and Halophila minor collected from Li’an Lagoon, Hainan Province, China. [Method] The root-tips of E. acoroides, T. hemprichii and the axillary buds of H. minor were selected as the materials in this study. The conventional crushing method was used to prepare the slice specimens of chromosomes, and the karyotypes of the three species were analyzed. [Result] The chromosome numbers of E. acoroides, T. hemprichii and H. minor were 2n=18, 18, 28, respectively. The karyotype formulas were K （2n）=18= 12m＋6sm, K（2n）=18=12m＋6sm and K（2n）=28=16m＋8sm＋4st, respectively. According to the standard of Stebbins, the karyotypes of E. acoroides and T. hemprichii were 2A, and that of H. minor was 2B. There was no B chromosome and satellite in these three species. [Conclusion] According to the comparison on the karyotypes of this three species, E. acoroides and T. hemprichii are similar in karyotypes to each other, indicating that there is close, inter-relationship between E. acoroides and T. hemprichii.

A COMPARATIVE STUDY ON KARYOTYPES AND CHROMOSOME BANDING PATTERN OF THREE ODOR FROGS OF Rana

The chromosomes of three odor frogs, Luetuosae- group of Rana were analyzed by conventional, as well as Obanding and silver staining techniques. The three species here examined all had 26 chromosome karyotypes encompassing 5 large and 8 small homologous pairs. Differences among them were found in gross shapes of chromosomes and positions of secondary constrictions. Generally speaking, karyotypes of R. andersonii and R. grahami resembled each other, while the karyotype of R. tiannanensis differed from the former two in several respects.Analyses of karyotypes by C-banding technique indicated that, centromeric areas of every chromosome and interstitial parts of some chromosomes of each species were hetero-chromatinized, and differences of distribution of heterochromatin were found among species. In early metaphase plates of R. andersonii, much more heterochromatinized areas were observed, and when it reached late metaphase, the numbers of heterochromatin sections in each chromosome pair reduced to a limited level, e. g. centromeres and a few interstitial parts.The active nucleolar organizer regions (NORs) were localized in long arms of pair No. 10, in connection with secondary constrictions for R. andersonii and R. grahami as in other odor frogs previously reported, but in the long arm of pair No. 6 for R. tiannanensis.The cytogenetic and taxonomic implications of the findings were discussed based on comparisons with each other, and with published literature.

Karyotypes of three species of the marine Veneroida molluscs

The karyotypes of three species of marine Veneroida molluscs, Solen grandis Dunker, Saxidomus purpuratus Sowerby and Mactra chinensis Philippi were studied by using the adult gill tissues. The chromosomes were-prepared through injecting phytohemagglutinin (PHA) and colchicine, hypotonic treatment, chopping air-dry, and squashing technology. The results show that the diploid chromosome numbers of the three Veneroida species are the same as 2n = 38. The karyotype of Solen grandis is 26m + 6sm + 2st + 4t, NF = 70, the karyotype of Saxidomus purpuratus is 32m + 2sm + 4st/t, NF = 72, and the karyotype of Mactra chinensis is 20m + 16sm + 2st/t, NF = 74. Satellite and sex chromosome were not found among the chromosomes of three species.

Karyotypes of field mice of the genus Apodemus (Mammalia： Rodentia) from China

Karyotypes of four Chinese species of field mice of the genus Apodemus were examined,including Apodemus chevrieri （diploid chromosome number,2n=48,fundamental number of autosomal arms,FNa=56）,A.draco （2n=48,FNa=48）,A.ilex （2n=48,FNa=48）,and A.latronum （2n=48,FNa=48）.Karyotypes of A.chevrieri,A.draco,and A.ilex are reported here for the first time,providing useful information for their species taxonomy.Determining the karyotypes of all species of Apodemus in Asia,both in this and previous studies,provides a solid overview of the chromosome evolution and species differentiation of the genus in East Asia.In addition to allopatric speciation,chromosome rearrangements likely played an important role in the formation of the four Apodemus species groups as well as speciation within each group in East Asia.For example,increased centromeric heterochromatin in A.latronum may have contributed to the post-mating reproductive isolation from the A.draco-A.ilex-A.semotus clade.

Experimental Researches on Carcinogenesis or Tumorigenicity of MDCK Canine Kidney Cell(CKC) Lines and Analysis of Their Chromosome Karyotypes

The chromosomal number variations & structural aberrations of the MDCK cell line, primary feline or canine kidney cell(FKC or CKC) and Hela cell line were investigated and their karyotypes of conventional chromosome bands were analyzed. The carcinogenesis or tumorigenicity testing of these cell lines in about 232 nude mice and for colony formation in soft agarose and for haemagglutination under different concentration of plant lectins of these cells were carried out. Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0 (0/10), respectively. The incidence of the progressively-growing malignant tumor(MT) in positive-control nude mice inoculated subcutaneously with Hela cell cultures of KB, X, or NM20/X strain was 10/10, 25/25 and 5/51, respectively. The results showed that the incidence of tumor in nude mice with tetraploid YA strain of MDCK cell during 20 - 45 passages, with hy-podiploid JB strain of MDCK cell on passage 25, with di-and hypoploid JC strain of MDCK cell during 2-15 passages or with hypoploid M strain of MDCK cell during 9 - 27 passages was 28/58, 1/5, 4/18 and 0/31, respectively. The chromosomal analysis results showed that the ratio of difference in the rate of modal chromosome number between high(mcs+ n) and lowest (mcs) passages was not more than 5% - 15% and the structure aberrations was generally 0 - 3% . These results proved that the genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species-specific. MDCK line has tumorigenicity no matter what its chromosome karyotype is, at least it has very low tumorigenicity even when its modal chromosome number is hypoploid. The repeatedly frozen, thawed and split controls of tumorigenicity-positive cell lines(X strain of Hela, M strain of BHK-21, JA strain of Vero, YA strain of MDCK) have much lower tumorigenicity or are even non-carcinogenesis, and the repeatedly frozen, thawed and split controls of very low tumorigenicity cell lines (M or JC strain of MDCK) are certainly non-carcinogenic and never have increased tumorigenicity. It is thus evident that MDCK cell of M, JB or JC strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YA strain can not be approved as substrate for the preparation of attenuated viral vaccines. In summary, all strains of MDCK cell line have tunorigenicity, at least have low tumor igencity , never have non-cancinogenic MDCK, but very low tumorigenicity MDCK cell strains can certainly be used for the approval production of canine viral vaccines if the DNA content in viral cell cultures was remarkably decreased through conventional means in manufacturing process. Therefore, the master cell stock and working cell bank of MDCK line used for vaccine manufacture were established in China, which are free of infectious agents, and described with respect to cytogenetic characteristics and tumorigenicity.Tests showed that there were correlations among cell line chromosome number variations, anchorage independence in soft a-garose, haemagglutination under plant lectins, and tumor-forming ability in nude mice, thus all the in vitro tests are economic, simple and reliable means for monitoring the tumor-forming ability of MDCK line in nude mice.

Karyotypes of nineteen species of Asteraceae in the Hengduan Mountains and adjacent regions

The Hengduan Mountains region is a biodiversity hotspot. In this study, we report the karyotypes of 19 species(21 populations) of Asteraceae from this region, 14 of which are reported for the first time. We also examined polyploidy in Asteraceae plants and summarized karyotype data in the literature for 69 congeneric taxa. In these genera, there were five different ploidy levels in the region, though the most dominant was diploid(73.08%). There is no direct evidence that ploidy level and karyotype asymmetry are associated with the distribution of recorded Asteraceae species from the Hengduan Mountains. This suggests that polyploidy(26.92%) may not play an important role in the evolutionary history of these plants, even though, among these genera, the ratio of paleopolyploidy was high(46.15%).

Chromosomal Karyotypes of Medicinal Plant Gynura medica

[ Objective] This study aimed at investigating the chromosomal characteristics and karyotypes of Gynura medica. [ Method ] Stem tips of G. medica seedlings were taken every 20 min from 6：30 to 10：30 am, and then were treated and squashed. The slices were observed under a microscope for investigating the chromosomal number and karyotypes of the cells in metaphase in which the chromosomes were well dispersed. [ Result] In the total 102 stem tip cells in meta- phase, 96.08% of cells were with 20 chromosomes, and 3.92% of cells were with 40 chromosomes. Optimal time for sampling was from 7：50 to 9：30 am, when more cells were in metaphase. [Conclusion] C. medica is the diploid plant with 20 chromosomes. Karyotype analysis gets formula 2n = 2x = 20m, and all 10 pairs of chromosomes belong to type 1A. The article reporls the chromosomes characteristics of G. rnedica firstly.

A Study on Karyotypes and Ag-NORs of Odontobutis potamophila

In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amount of transcriptionally active nucleolar organizer regions on chromosomes were analyzed by Giemsa staining and Ag-NORs. The results showed that the number of diploid chromosomes of O. potamophila was 44; the genome of O. potamophila was composed of 44 telocentric chromosomes; the karyotype formula was 2 n = 44 t,NF = 44; Ag-NORs were found in the paracentromeric region of chromosome. The results may lay the foundation for revealing the genetic pattern and chromosomal evolution of O. potamophila and contribute to further genetic breeding of O. potamophila.

Karyotype establishment and development of specific molecular markers of Aegilops geniculata Roth based on SLAF-seq

The constant evolution of pathogens poses a threat to wheat resistance against diseases,endangering food security.Developing resistant wheat varieties is the most practical approach for circumventing this problem.As a close relative of wheat,Aegilops geniculata,particularly accession SY159,has evolved numerous beneficial traits that could be applied to improve wheat.In this study,we established the karyotype of SY159 by fluorescence in situ hybridization(FISH)using the oligonucleotide probes Oligo-pTa535 and Oligo-pSc119.2 and a complete set of wheat–Ae.geniculata accession TA2899 addition lines as a reference.Using specific-locus amplified fragment sequencing(SLAF-seq)technology,400 specific markers were established for detecting the SY159 chromosomes with efficiencies reaching 81.5%.The SY159-specific markers were used to classify the different homologous groups of SY159 against the wheat-Ae.geniculata addition lines.We used these specific markers on the 7Mg chromosome after classification,and successfully confirmed their suitability for studying the different chromosomes of SY159.This study provides a foundation for accelerating the application of SY159 in genetic breeding programs designed to improve wheat.

A Comparative Study of the Karyotypes from Four Egg-type Fowl Breeds

By adopting the method based on colchicine-hypotonic-air drying technique with bone marrow cells, the paper presents the chromosome of four egg-type fowl breeds. The diploid chromosome 2n=78, chromosomal morphology are very similar and sex chromosome type are ZZ (♂) and ZW(♀) in four egg-type fowl breeds. According to standard of Leven in 1964, the euchromosome and sex chromosome of four breeds are measured and compared in relative length arm ratio and centromere index of each chromosome including all the microchromosome. The morphology of these chromosome is described as follows: pair1, 2, 8 and ZW are metacentric, pair 4 and 6 are submetacentric, and the rest is telocentric.

Studies on the Karyotype of Two Species in Orius Wolff (Hemiptera: Heteroptera: Anthocoridae)

The karyotype of two Chinese species in Orius were studied in male germ cells prepared on air dried slides stained with Giemsa. It is reported that two species have 24 chromosomes in diploid and X Y sex chromosomal mechanism. But the beha vior of chromosomes during meiosis between two species is different. Which show in the arrangment and location of the X chromosome and autosome at the late diakinesis as well as metaphase stage respectively and so on. These characteristics may be used in ta xonomy among species of Orius .

Karyotype Study on Scilla scilloides (Lindl.) Druce in Yantai

[Objective] The aim of this study was to investigate the chromosome number and the karyotype of Scilla scilloides in Yantai.[Method]Root tips of Scilla scilloides were pretreated by 8-hydroxyquinoline,then fixed,dissociated and stained for slice production.The chromosome number was analyzed by microscopic examination,and then cells with good chromosomal morphology and dispersal chromosome were studied by microscopic photos.[Result]The somatic chromosome number of Scilla scilloides in Yantai was 2n=16+1Bs,while the karyotype formula was K(2n)=2x=16+1Bs=6m+4sm(2SAT)+4st+2t+1Bs and the karyotype classification was "3B" type.[Conclusion]Karyotype comparison,division of cell type and evolution of Scilla scilloides in Yantai are discussed,which provides basis for cytogenetics,evolutionary genetics,modern taxonomy and genetic breeding.

Studies on the Karyotype of Three Species in the Genus Orius Wolff (Hemiptera:Anthocoridae)

Karyotype of 3 species of the genus Orius Wolff were firstly studied using the Giemsa staining and squashing slides method in male germ cell. It is reported that number of chromosome and system of sex chromosome of haploid chromosome complement of these species is n=11A＋X （Y） in the first meiotic stage. However, the behavior of chromosomes among the species are different distinctly, thus cytotaxonomic character can be adopted to the identification among the three species.

Karyotype Analysis of Lycium ruthenicum Murr.

Karyotype analysis of Lycium ruthenicum Murr. was carried out in this study. The results showed that the chromosome number was 2n=2x=24; the arm index was 48; the ratio of the longest chromosome to the shortest one was 1.31; the proportions of chromosomes with arm ratio higher than 2 was 0.08; the asymmetry index was 57.02; the karyotype type was 2A; and the karyotype formula was 2n=-24=20m＋4sm.

Morphological Difference and Karyotype of Pelteobagrus fulvidraco in Dongting Lake Water System

[Objective] The research aimed to study the morphological characteristics and karyotype of Pelteobagrus fulvidraco in Dongting Lake water system.[Method] By using the conventional biological morphometry,PHA and colchicine injection method in vivo,the morphological characteristics and karyotype of P.fulvidraco in Yuanshui River and Lishui River of Dongting Lake were analyzed.[Result] In three ratio traits including standard length/head length,standard length/caudal peduncle depth,head length/snout length,P.fulvidraco of Yuanshui River and Lishui River had significant differences（P0.05）.However,the number and karyotype of their chromosomes were same.The chromosome number was 2n = 52,and the karyotype formula was 20M＋12SM＋10ST＋10T.The number of chromosome arm was 84.[Conclusion] The research result had certain theoretical guidance significance for the protection and utilization of wild P.resource in Dongting Lake water system.