鼠颚毛厉螨染色体组型及其C-带、G-带的研究(蜱螨亚纲:厉螨科)

本文首次报道了厉螨科鼠颚毛厉螨 Tricholaelaps myonyssognathus 染色体组型及其C-带、G-带的研究。结果表明其为单二倍体性决定系统(n=6,2n=12),雄性体细胞具有6条染色体,雌性体细胞具有12条染色体。所有染色体均为单着丝粒,其着丝粒位置分别为中部(1和2号)、亚中部(3号)、亚端部(4号)及端点(5和6号)。C-带为着丝粒带。G-带的有35条深带。     

染色体核型异常、Th17/Treg免疫失衡与复发性流产的关系及其影响因素分析

摘要 目的：研究染色体核型异常、辅助性T细胞17（Th17）/调节性T细胞（Treg）免疫失衡与复发性流产（RSA）的关系及其影响因素。方法：选择石家庄市妇幼保健院从2019年2月～2022年2月收治的421例RSA患者,记作研究组。另取同期无生殖系统异常女性400例作为对照组。比较两组染色体核型异常、Th17/Treg免疫情况以及各项基线资料。采用多因素Logistic回归分析明确RSA的影响因素。结果：研究组染色体核型异常发生率为10.21%,高于对照组的1.50%（P＜0.05）。研究组Th17、Th17/Treg比值高于对照组,而Treg低于对照组（均P＜0.05）。研究组文化程度初中及以下、生殖道感染、难闻性气味以及噪音人数占比均高于对照组（均P＜0.05）。经多因素Logistic回归分析可得：RSA的危险因素有文化程度初中及以下、生殖道感染、难闻性气味、噪音、染色体核型异常、Th17/Treg比值升高（均P＜0.05）。结论：染色体核型异常以及Th17/Treg免疫失衡均会增加RSA的发生风险,且文化程度初中及以下、生殖道感染、难闻性气味、噪音亦会增加RSA的发生风险,临床工作中可根据上述因素制定针对性干预措施,以达到降低RSA发生率的目的。     

朱顶红染色体数目和核型

朱顶红是石蒜科朱顶红属植物。我们对它进行了核型分析,结果表明,它是一个三倍体种,核型公式为：２ｎ＝３ｘ＝３３＝１２ｍ＋９ｓｍ＋１２ｓｔ。     

同步化技术在草鱼染色体显带中的应用及草鱼核型的初步分析

对草鱼细胞进行同步化处理,并在DNA复制的早期和晚期分别掺入BrdU,制备的染色体标本置于CaCl_2溶液中温浴同时用紫外线照射,然后用Giemsa染色即可分别显示出G带和R带。标本中的部分晚前期和早中期分裂相具有高分辨染色体显带特征。用这一技术对草鱼每条染色体进行识别和分析,提出了初步的草鱼核型,发现了四对草鱼染色体具有随体。     

Numerical analyses of karyotypic diversity in the genusEupatorium (Compositae,Eupatorieae)

Somatic metaphase karyotypes were analyzed for 22 diploid species ofEupatorium. The karyotypic comparisons were made using two indices: minimal chromosomal distance (MCD), measuring overall dissimilarities, and chromosomal identity (CI), measuring number of morphologically identical chromosomes between species. The resulting phenograms from these indices are largely compatible. The 22 species cluster into four groups in the phenogram using MCD, and the grouping corresponds well with morphology or geographic distribution into the three N. American groupsEutrochium, Uncasia, Traganthes, and the E. Asian group. These results suggest that karyotypes in perennialEupatorium have been considerably conservative and changed not through large chromosomal mutations but through small chromosomal mutations gradually fixed.     

Chromosome banding patterns of the aye-aye,Daubentonia madagascariensis (primates,Daubentoniidae)

The aye-aye (Daubentonia madagascariensis) is an endangered prosimian primate found only on the island of Madagascar. It is the only extant representative of its family Daubentoniidae. The phylogenetic relationship of this species with other prosimians is unclear. Because a G-banded karyotype forDaubentonia has not previously been reported, blood for preparation of lymphocyte cultures was obtained from one of the four aye-ayes in captivity in the United States. The diploid chromosome number was 30. The karyotype consisted of 14 autosomal metacentrics, 10 autosomal submetacentrics, and 4 autosomal acrocentrics. The similarities between the G-banded chromosomes ofDaubentonia and those ofPropithecus, a member of the Indriidae, support the notion thatDaubentonia has a closer relationship with the Indriidae than with other Lemuriformes or the lorisoids.     

Clonal derivatives of a human B-lymphoblastoid cell line producing prolactin—A cytogenetic characterization

The IM-9-P cell line is a variant of the human B-lymphoblastoid cell line IM-9 which ectopically secretes prolactin (hPRL). The heterogeneous line IM-9-P and three sublines of clonal origin, two of them positive and one negative for PRL gene expression, were subjected to cytogenetic analysis and compared with the reference line IM-9 which showed a normal female diploid karyotype. G-banding revealed several rearrangements in the chromosomes. Nine altered chromosomes including one stable marker chromosome were common to all analysed karyotypes of IM-9-P cells and their clones. A second marker chromosome mar2 occurred only in the karyotypes of the hPRL producing clones, but not in the non-producing clone. None of the visible alterations involve chromosome 6 which carries the PRL gene in humans.     

亚洲苦草与刺苦草的染色体数目和核型

本文以亚洲苦草和刺苦草根尖为实验材料,对其染色体数目及核型进行了研究,结果表明,两个种均为2n=20,同属Stebbins的不对称核型,亚洲苦草为“3B”,刺苦草为“2B”。核型公式分别为:K(2n)=20=2m+12sm+6st,K(2n)=20=2M+2m+14sm+2st。     

Sequence, organization and expression of the core histone genes of Aspergillus nidulans

Summary The core histone gene family ofAspergillus nidulans was characterized. The H2A, H2B and H3 genes are unique in theA. nidulans genome. In contrast there are two H4 genes, H4.1 and H4.2. As previously reported for the H2A gene (May and Morris 1987) introns also interrupt the other core histone genes. The H2B gene, like the H2A gene, is interrupted by three introns, the H3 and H4.1 gene are each interrupted by two introns and the H4.2 gene contains one intron. The position of the single intron in H4.2 is the same as that the first intron of the H4.1 gene. The H2A and H2B genes are arranged as a gene pair separated by approximately 600 by and are divergently transcribed. The H3 and H4.1 genes are similarly arranged and are separated by approximately 800 bp. The H4.2 gene is not closely linked to either the H2A-H2B or H3-H4.1 gene pairs. Using pulse field gel electrophoresis an electrophoretic karyotype was established forA. nidulans. This karyotype was used to assign the H3–H4.1 gene pair and the H4.2 gene to linkage group VIII and the H2A–H2B gene pair to either linkage group III or VI. The abundance of each of the histone messenger RNAs was determined to be cell cycle regulated but the abundance of the H4.2 mRNA appears to be regulated differently from the others.     

海南(开鸟)的核型分析

通过染色体研究方法,首次报道了海南鳽的核型,其二倍体染色体数日为58,属异型性核型,雌性为58,ZW,雄性为58,ZZ。核型对比分析表明,海南鳽是一种较为特化的鸟类。