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.

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.

药用植物丹参的核型分析和C-banding研究

采用传统的核型分析技术，分析了栽培丹参有丝分裂中期染色体的核型和C—banding。结果表明：丹参中期染色体长度为1．30-2．39μm，核型公式是2n=16=4m＋2sm＋2st，其核型为2A型；单套染色体组显示出19条清晰稳定的C—bands，其中包括13条末端带，1条着丝粒带和5条中间带。

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.

Correlation between Reasons for Prescription and Karyotype Results in Patients Referred for Suspected Chromosomal Abnormalities

Karyotype prescription is based on clinical signs (or reasons for karyotype prescription) which are phenotypic manifestations associated with chromosomal abnormalities. The aim of this study was to establish a correspondence between karyotype indications and their results in patients. This was a retrospective study that was carried out in the Histology-Embryology-Cytogenetics laboratory of the University Hospital of Cocody-Abidjan from 2014 to 2019. 58 patient files were identified and included the indication or reason for prescribing a constitutional karyotype and the biological result obtained. An individual data sheet was used to collect the data. 17 reasons for prescription were identified and divided into 2 groups. Sexual ambiguity was the most frequent reason (29.3%). The first group (G1) represented the 10 reasons for which the karyotype results were normal. The second group (G2) corresponded of the 7 motives with normal or abnormal karyotype results. Several anomalies were listed according to these reasons: inversions, mosaics (anomalies of number and structure) and trisomy 21. The last was the most frequent chromosomal anomaly (69.24%). It was found in several reasons for karyotype prescription: malformations, neurological disorders, suspected trisomy and cardiac pathology. Several factors could explain these results, among which are the limits of the karyotype and the non-genetic causes that can induce these abnormal phenotypes. Complementary examinations to the karyotype are molecular cytogenetic techniques, notably fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (Array-CGH).

胎儿末端染色体非平衡易位遗传方式的CNV-seq联合G显带核型分析

目的:通过拷贝数变异检测(CNV-seq)联合G显带核型分析对产前诊断和流产的胎儿末端染色体非平衡易位发生频率以及遗传方式进行分析。方法:选取2018年6月至2021年12月在郑州大学第一附属医院经CNV-Seq判定为末端染色体非平衡易位的病例,采用外周血G显带核型分析或FISH检测对胎儿父母进行溯源分析。结果:17248例产前诊断和流产病例中,88例检出末端染色体非平衡易位,检出率为0.51%。其中59例行父母G显带核型分析或FISH检测,32例(54.24%)是由于父母为平衡易位导致,27例(45.76%)为新发变异。结论:诊断为末端染色体非平衡易位的病例,父母行G显带核型分析或FISH检测可提高染色体平衡易位携带者的检出率。

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.

颈项透明层增厚胎儿的绒毛染色体及微阵列结果分析

目的 探讨核型分析及染色体微阵列分析(CMA)技术在颈项透明层(NT)增厚胎儿产前诊断中的应用价值,评价NT增厚在产前筛查中的作用。方法 选取2018年1月至2020年12月孕11~13+6周在广州市花都区妇幼保健院筛查NT增厚(NT≥2.5 mm)胎儿137例,经胎盘绒毛穿刺,行“核型分析+CMA”检测,按NT值和临床指征分组,分别分为2.5~2.9 mm、3.0~3.9 mm、4.0~4.9 mm、NT≥5.0 mm组和孤立性NT增厚组、非孤立性NT增厚组,分析各组核型分析和CMA结果。结果 核型分析检出率为10.95%(15/137),CMA检出率为16.79%(23/137),CMA联合核型分析异常检出率为18.25%(25/137)。2.5~2.9 mm、3.0~3.9 mm、4.0~4.9 mm、NT≥5.0 mm组的检出率分别为7.89%(3/38)、8.20%(5/61)、33.33%(7/21)、52.94%(9/17),各组间差异有统计学意义(χ^(2)=22.54,P<0.05)。孤立性NT增厚组和非孤立性NT增厚组的检出率分别为12.24%(12/98)和26.67%(12/45),差异有统计学意义(χ^(2)=4.59,P<0.05)。结论 染色体核型分析联合CMA技术能提高NT增厚胎儿异常检出率,染色体异常发生率随NT值增高及合并其他超声异常明显增高。

基于网格重构学习的染色体分类模型

染色体的分类是核型分析的重要任务之一.因其柔软易弯曲,且类间差异小、类内差异大等特点,其精准分类仍然是一个具有挑战性的难题.对此,提出一种基于网格重构学习(Grid reconstruction learning,GRiCoL)的染色体分类模型.该模型首先将染色体图像网格化,提取局部分类特征;然后通过重构网络对全局特征进行二次提取;最后完成分类.相比于现有几种先进方法,GRiCoL同时兼顾局部和全局特征提取更有效的分类特征,有效改善染色体弯曲导致的分类性能下降,参数规模合理.通过基于G带、荧光原位杂交(Fluorescence in situ hybridization,FISH)、Q带染色体公开数据集的实验表明:GRiCoL能够更好地弱化染色体弯曲带来的影响,在不同数据集上的分类准确度均优于现有分类方法.

邯郸地区染色体易位与不良孕产的研究

目的探讨邯郸地区染色体易位与不良孕产的相互关系。方法回顾性分析2011年8月至2023年8月来邯郸市中心医院遗传咨询的8960例患者,对患者外周血进行淋巴细胞培养,收获后制备染色体标本,进行染色体核型分析,选取确诊的79例染色体易位患者作为观察组,随机选取染色体核型分析结果正常的79例受试者作为对照组,对两组不良孕产的差异性进行探讨研究。结果8960例遗传咨询患者中检出染色体易位79例,异常率0.88%,包括平衡易位56例(70.89%)和罗伯逊易位23例(29.11%)。观察组发生自然流产、胚胎停育、生育畸形儿及不孕不育等不良孕产的概率显著高于对照组(P<0.05),对照组无不良孕产发生的概率显著高于观察组(P<0.05)。结论染色体易位是影响自然流产、胚胎停育、生育畸形儿、不孕不育等不良孕产的重要原因之一,对不良孕产的夫妇双方早期进行染色体检查及辅助生殖有着非常重要的意义。