白花败酱染色体的核型分析

用去壁低渗染色体制片方法,对白花败酱(Patrinia villosa Juss)茎尖细胞染色体制片,研究其染色体组型.结果表明:白花败酱为二倍体、体细胞染色体数目为22;染色体组型公式为2n=2x=22=10m 4sm 4st 4t,第2、3、4、5、8号染色体为中间着丝点染色体,第6、11号染色体为近中着丝点染色体,第1、10号染色体为近端着丝点染色体,第7、9号染色体为端部着丝点染色体;染色体基数x=11,该染色体组内最长与最短染色体长度比值为3.037,臂比大于2:1的染色体共4条,占总数的36.4%,则白花败酱的核型类型为2B型.     

两性型天然雌核发育彭泽鲫染色体组型的研究

彭泽鲫是一种两性型天然雌核发育群体。染色体组型分析结果表明：雌、雄鱼的染色体数目均为１６６。它们的核型组成是：３２条中部着丝点染色体、４０条亚中部着丝点染色体、１８条亚端部着丝点染色体和７６条端部着丝点染色体。臂数（ＮＦ）为２３８。本研究结果与其它雌核发育类型的鲫鱼有明显的差别。     

百合‘Siberia’בManissa’种间杂交后代的染色体核型分析

以东方百合杂种系(Oriental hybrids group)品种‘Siberia’为母本,OT杂种系(interspecific hybrids betweenOriental and Longiflorum/OT group)品种‘Manissa’为父本杂交获得种间杂交F1代,对亲本及F1代株系的染色体数目和形态特征进行了分析。结果显示,母本东方百合‘Siberia’为二倍体即24条染色体,而父本‘Manissa’是高度杂合后代,为三倍体即36条染色体。杂交F1代的8个株系中有6个株系为二倍体即24条染色体,有2个株系为非整倍体,染色体条数分别为25和26条。母本‘Siberia’的核型为4m(1SAT)+10st(1SAT)+10t,父本‘Manis-sa’的核型为3m+18st(1SAT)+15t(1SAT),均属3B型。杂种F1代核型出现了多种类型,其中株系a、b、h为3B型,株系c、d、e、f为3A型,株系g为4B型。与亲本染色体形态相比,F1代株系出现了随体及端部着丝点染色体较多等染色体形态结构特征,而亲本没有这些特征。从染色体的形态、随体来看,子代为真杂种,在遗传上均偏向于母本。     

程序性细胞死亡抑制基因Dad-1在水稻和玉米中的FISH定位(英文)

Dad-1是一种在动物和植物中都非常保守的细胞程序性死亡 (PCD) 抑制基因。作者利用 FISH (荧光原位杂交)首次把单拷贝水稻Dad-1基因物理定位在水稻第2号染色体短臂的端部(Fig.2 A,B&C)。我们还分析了它在玉米基因组中的同源序列。Southern 杂交结果显示在玉米基因组中确实存在水稻Dad-1 的同源序列(Fig.1)。FISH进一步展示了三个杂交信号分别在玉米4、5号染色体长臂和9号染色体短臂上(Fig.2 D,E&F),其信号距着丝粒的百分距离(FL值)分别为 91、98和96。其杂交位点的位置与水稻Dad-1所处的相对位置是相似的,它们都处于染色体臂的端部。这表明在一定的程度上,Dad-1基因不仅在序列同源性上而且在所处的染色体位置上具有保守性。 水稻Dad-1基因在水稻中的杂交信号检出率 (38%) 高于玉米中的。这表明与玉米相比,水稻Dad-1 基因的编码序列更容易与水稻染色体杂交;它与玉米中的相应序列可能只是部分同源。     

青海高原披碱草属种间天然杂种的细胞学鉴定

利用重复序列探针染色体荧光原位杂交（FISH）和基因组原位杂交（GISH）技术,对采自青海高原披碱草属种间天然杂种进行细胞学鉴定,同时结合物种分布及形态学特征,共揭示6种不同天然杂种的类型。第一类为垂穗披碱草（Elymus nutans Griseb.）和鹅观草属（Roegneria C.Koch）物种间的天然杂种,染色体数为35,染色体组成为StStYYH;第二类为垂穗披碱草和达乌力披碱草种（Elymus dahuricus Turcz.ex Griseb.）间杂种,染色体数为42,染色体组成为StStHHYY;第三类为达乌力披碱草和老芒麦（Elymus sibiricus L.）种间杂种,染色体数为35,染色体组成为StStHHY;第四类为垂穗披碱草和糙毛以礼草（Kengilia hirsuta Keng）种间杂种,染色体数为42,染色体组成为StStYYHP;第五类为垂穗披碱草和大颖草（Kengilia grandiglumis Keng）种间杂种,染色体数为42,染色体组成为StStYYHP;第六类为糙毛以礼草和赖草（Leymus secalinus（Georgi） Tzvel.）种间杂种,染色体数为35,染色体组成为StYPNsXm。研究结果为进一步研究披碱草属种间杂交渐渗提供了重要参考资料;同时鉴定出的天然杂种可以作为潜在的种质资源在牧草或生态草育种中加以利用。     

毛冠鹿染色体组型

毛冠鹿Elaphodus cephalophus是我国特有的珍稀鹿种。分布于我国东南及西南等省。有关它的核型中国科学院昆明动物研究所张锡然等人1983年作了报导,其中雄性鹿2n=48,雌性鹿2n=47,在核型中均有一条较大的亚中部着丝点染色体没有同源染色体可以配对,但表现形式在两性染色体组型中是不同的,在雌性鹿中是一条亚中部着丝点染色体,在雄性鹿中,则为两条断开的端部着丝点染色体。     

二倍体多年生类玉米及其与玉米的杂种的减数分裂研究

从二倍体多年生类玉米的减数分裂粗线期观察到,所有的异染色质结都位于染色体的端部。大多数染色体配对正常,没有缺失、重复、倒位和易位。在观察的植株中有两株的部分染色体长臂末端不联会。并观察到,在终变期有单价染色体,在中期Ⅰ和后期Ⅰ有落后染色体。 从玉米与二倍体多年生类玉米的杂种F_1的减数分裂粗线期观察到,所有的染色体配对正常。在第7染色体长臂末端部分常常不联会。杂种的花粉有90％是能育的。二倍体多年生类玉米应该被承认是zea perennis中的一个变种,而不是一个独立的种。这种二倍体多年生类玉米对玉米育种可能是有价值的原始材料。     

八倍体小偃麦与天蓝偃麦草杂交F1染色体组构型

首次获得麦草8号、麦草9号、远中2号八倍体小偃麦与天蓝偃麦草的属间杂种,杂交当代结实率为31.49%,39.28%和10.41%。杂种F1表现为两亲的中间型,植株高大、繁茂,穗长20~30 cm,小穗数25~30个,多年生,抗寒,在哈尔滨冬季无覆盖条件下可安全过冬。对F1植株进行减数分裂行为观察,结果发现,染色体配对不正常,单价体频率高,出现多价体。杂种F1减数分裂中期I染色体配对构型分别为:9.5Ⅰ+16.98Ⅱ+0.27Ⅲ、13.6Ⅰ+14.01Ⅱ+0.87Ⅲ、11.2Ⅰ+16.8Ⅱ+0.08Ⅲ。二价体数变动在13~18间、单价体数变动在11~17间、多价体变动在0.08~0.87间,二价体多数是棒状二价体,推测两亲有一对部分同源关系染色体组,其余为非同源染色体组,但有的染色体间有部分同源关系。小麦5B染色体上Ph基因可能受到E组染色体的抑制。     

玉米8个栽培亚种（类型）的核型和C—带带型的比较研究

本文首次报道了玉米8个亚种、2个亚型和2个杂交品种的核型和Giemsa C-带带型。所有材料的根尖细胞染色体数目均为2n=20。主要由中部和亚中部着丝点染色体组成。第6染色体短臂均具随体,但大小不同。所有材料均显示有亚端带和端带,在第6染色体的短臂上显示有NOR或/和随体带。C-带的分布、总数目和总长度各不相同。其总带数变异于6至18之间,C-带总长度为5.65—11.40％之间。在核型中,具中部着丝点的染色体数目及C-带总数,罕见栽培或原始的类型通常多于广泛栽培的类型。此外,有关核型和C-帝的变异和进化也进行了简略的讨论。     

串叶松香草Giemsa C带和染色中心研究

以Giemsa C带技术处理串叶松香草根尖细胞染色体(2n=14),全部着丝点及第5和第7对染色体短臂端部显稳定的C带,第6对染色体长臂有两条明显的居间带,其他居间带小而不稳定(重复率不高)。间期细胞核染色体呈Rable构型,其着丝点一极最多出现20个染色中心。统计分析表明,靠近着丝点的短臂端带区和居间带区异染色质有易与着丝点区异染色质融合的倾向。分裂中期Giemsa C带数目与间期染色中心数目存在数量对应关系。     

Chromosome banding in Amphibia

The karyotypes of 14 species of Anura from 9 genera of the suborders Amphicoela, Aglossa, Opisthocoela and Anomocoela were analysed with various banding techniques and conventional cytogenetic methods. The 18S + 28S and 5S ribosomal RNA genes were localized by means of in situ hybridization. No Q-, R- and G-banding patterns in the euchromatic segments of the metaphase chromosomes could be demonstrated in any of the species; this does not seem to be caused by a higher degree of spiralization of the amphibian chromosomes, but by the special DNA organization in these organisms. In most karyotypes, constitutive heterochromatin is present at centromeres, telomeres and nucleolus organizer regions (NORs), but rarely in interstitial positions. The heterochromatic regions are either quinacrine positive and mithramycin negative or vice versa. All species examined possess only one homologous pair of NORs; these display the brightest mithramycin fluorescence in the karyotypes. Many specimens exhibited unequal labelling of the two NORs both after silver and mithramycin staining as well as after in situ hybridization with ³H-18S + 28S rRNA. In four species, between one and six chromosome pairs with homologous 5S rRNA sites could be identified. The 5S rRNA genes and the 18S + 28S rRNA genes are closely linked in two species. In the male meiosis of the Amphicoela and Opisthocoela, there are intersitial, subterminal and terminal chiasmata in the bivalents, whereas only terminal chiasmata are observed in the bivalents of the Aglossa and Anomocoela. No heteromorphic sex-specific chromosomes could be demonstrated in any of the species. The differential staining techniques revealed that the chromosomal structure in these four suborders is largely the same as in the highly evolved anuran suborders Procoela and Diplasiocoela.     

中国水龟类的核型与银带带型研究

以血培养细胞为材料,研究了三种水龟的核型与ＮＯＲｓ,结果表明,染色体数均为２ｎ＝５２,核型模式９＋５＋１２,属龟科核型中的原始类型,但眼斑水龟ＮＦ＝７６,而四眼斑水龟和黄喉拟水龟的ＮＦ＝７８。从核型结构看,眼斑水龟与四眼斑水龟相似,而黄喉拟水龟则有较大差别,作者还发现黄喉拟水龟核型的一些重要特征,即其Ａ组Ｎｏ．３和Ｎｏ．６染色体有次缢痕,Ｎ．别,作者还发现黄喉拟水龟核型的一些重要特征,即Ａ组这些是     

Comparative cytogenetics of the African elephant (Loxodonta africana) and Asiatic elephant (Elephas maximus)

G- and C-banded karyotypes of the two extant species of the mammalian order Proboscidea are presented for the first time. Chromosome complements were 2n = 56 in both Loxodonta africana and Elephas maximus. Comparisons between the species demonstrated a high level of chromosome band homology, with 26 conserved autosomal pairs. The normal diploid karyotype of L. africana had 25 acrocentric/telocentric and two metacentric/submetacentric autosomal pairs. E. maximus differed by having one less acrocentric and one additional submetacentric pair due to either a heterochromatic arm addition or deletion involving autosomal pair 27. Several acrocentric autosomes of L. africana exhibited small short arms that were absent in homologous chromosomes of E. maximus. The X chromosomes in both species were large submetacentric elements and were homologous. However, the small acrocentric Y chromosomes differed; in E. maximus it was slightly larger and had more distinct G-bands than its counterpart in L. africana. Extant Elephantidae appear to be relatively conservative in their rates of chromosomal change compared to some other mammalian families. The high-quality banded karyotypes presented here should prove useful as references in future chromosome analyses of elephant populations and in comparative cytogenetic studies with other ungulate orders.     

萝卜蚜和豆蚜染色体C-带带型比较与分析

本研究利用C-带技术,显示出萝卜蚜和豆蚜的染色体C-带带型,并进行了初步分析。萝卜蚜与豆蚜的染色体在组型上只有第4对染色体稍有区别;在带型上两者有很明显的差异。萝卜蚜有2对散漫着丝粒染色体,豆蚜没有该种染色体。豆蚜的第4对染色体在端部缺少-C带带纹。萝卜蚜的第2对染色体与豆蚜的第2对染色体带型相似。根据萝卜蚜和豆蚜的C-带带型,讨论了二者在进化中的亲缘关系。     

Constitutive heterochromatin,G-bands and nucleolus-organizer regions in four species of Didelphidae (Marsupialia)

Chromosomes of Didelphis albiventris, D. marsupialis, Philander opossum and Lutreolina crassicaudata, four species of marsupials with very similar karyotypes and 2n=22 were studied. All the chromosomes were acrocentrics except the X in L. crassicaudata, which is a metacentric.The G-band patterns of these species are similar but the distribution of constitutive heterochromatin differs among them as shown by C-banding. The hypothesis that the X in L. crassicaudata might be an isochromosome derived from the acrocentric X in the other species is discarded since G-and C-banding patterns differ in the two arms.In D. marsupialis the Ag-NORs are terminal and located in both arms of one pair and in the long arms of two pairs of medium-sized autosomes. In P. opossum the NOR-bearing chromosomes could be precisely identified through simultaneous silver staining and G-banding. The Ag-NORs are terminal and located at the short arm of pair 5 and the long arm of pair 7.     

油桐和木油数核型的研究

油桐Vernicia fordii (Hemsl.) Airy-Shaw (Aleurites fordii Hemsl.)和木油树V. montana Lour. (A. montana (Lour.) Wils.)为大戟科油桐属Vernicia Lour. 植物,全世界共3种,上述两种为原产我国的重要木本油料植物,长江以南各省(区)广为栽培。细胞学方面,这两个种的染色体计数有过不少报道,均为n=11。本文旨在提供这两种植物核型比较分析的资料,以冀有助于它们选种育种工作。     

A Chromosomal Study on 7 Species of Smilax L.

The chromosome numbers and karyotypes of 7 species of Smilax L. in Liliaceae (s. 1.) are cytotaxonomically studied in this work. Their karyotypic characters, distinction between the species and the chromosomal basis of sexual differentiation are discussed. The karyotypes of most species are first reported. The results are shown as follows (see Tables 1-4 for the chromosome parameters and the karyotype constitution; Fig. 1 for their idiograms): 1. Smilax nipponica Miq. The species is one of the herbaceous species distributed in East Asia. Two karyotypes, 2n = 26(type A) and 2n = 32 (type B), are found in the species (Plate 1: 1-7). The karyotype of No. 88032 (uncertain of -L--M--S- sexuality) is 2n = 26 = 2m + 6st + 6m + 4sm + 6sm + 2st. The karyotype has 4 pairs of L chromosomes, of which the first three pairs are subterminal, and the 4th is median. The karyotype belongs to 3B. No. 88045 (the male) and No. 88046 (the female) have 2n = 32. Their karyotypes are basically uniform, and both are -L--M-- S 2n=32= 2m+4sm+ 2st+ 2m+4sm+ 6m+ 10sm + 2st, also with 4 pairs of L chromosomes, but the 2nd pair is median, and thus different from the type A. The karyotype belongs to 3B. The first pair of chromosomes of the male are distinctly unequal in length, with the D. V. (0.93) of relative length between them obviously greater than that of the female (0.1). The pair seems to be of sex-chromosomes. Sixteen bivalents (n= 16) were observed at PMCs MI of No. 88045 (Plate 1: 4). The major difference between the karyotypes A and B are greater relative length of L chromosomes in the type A than in the type B, and the increase of chromosome number in the karyotype B mainly due to the increase of st chromosomes. Nakajima (1937)reports 2n= 30 for S. hederacea var. nipponica (=S. nipponica, Wang and Tang, 1980). 2. S. riparia A. DC. This species is also herbaceous, distributed in East Asia. Thirty chromosomes were found in root-tip cells (uncertain of sexuality). The kar -L--M--S-yotype is 2n = 30 = 8st + 6sm + 2st + 6m + 6sm + 2st (Plate 3: 1, 5), consisting mainly of sm and st chromosomes. There are 4 pairs of L chromosomes which are all subterminal and the m chromosomes appear to fall all into S category. Though the karyotype belongs to 3B, it is less symmetrical than that of S. nipponica. The species is karyologically rather different from S. nipponica, therefore. The first pair of chromosomes of this material are unequal in length, and it may be a male. The karyotype of this species is first reported. 3. S. sieboldii Miq. The species is a thorny climbing shrub, distributed in East Asia. At PMCs All, 16 chromosomes (n= 16) were found (Plate 2: 6), in accordance with Nakajima's (1933) report for a Japanese material. 4. S. china L. This species, a thorny climbing shrub, is of a wide distribution range mainly in East Asia and Southeast Asia. Two karyotypes were observed in different populations. (1) The population from Xikou has 2n = 96(6x) = 20st+L- -M- 6t + 6sm + 12st + 52(S) (Plate 3:7), of which the first three pairs of chromosomes are terminal, different from those in the other species. The arm ratios of both L and M chromosomes are larger than 2.0, which resembles those of S. davidiana. (2) PMCs MI of the population from Shangyu shew 15 chromosomes (n 15). The hexaploid of the species is recorded for the first time. Hsu (1967,1971) reported 2n = 30 from Taiwai and Nakajima (1937) recorded n = 30 from Japan, which indicates that the karyotype of the species varies not only in ploidy, but also in number. 5. S. davidiana A. DC. The somatic cells were found to have 32 chromosomes, and PMCs MI shew 16 bivalents (Plate 2: 1-5). The karyotype is 2n = 32=-L- -M- -S 8st + 4sm + 4st + 8sm + 8st. The karyotype belongs to 3B, and is less symmetrical than those in herbaceous species. The D. V. (0.20) of relative length between the two homologues of the first pair is slightly larger in the male than in the female (0.14), and it is thus difficult to determine whether they are sexual chromosomes or not. 6. S. glabra Roxb. The species is a non-thorny climbing shrub, distributed in East Asia and Southeast Asia. 32 chromosomes were found in somatic cells. The -L- -M- - Skaryotype is 2n= 32= 8st + 10st+6sm+8st (Plate 3: 2, 6),with only 3 pairs of sm chromosomes (12, 13 and 16th). The karyotype is more asymmetric than that of S. davidiana, although it is also of 3B (Table 1). The karyotype is first reported for the species. 7. S. nervo-marginata Hay. var. liukiuensis (Hay.) Wang et Tang The variety has a relatively narrow distribution range, mainly occurring in eastern China. The chromosomal number of somatic cells is 2n= 32 (Plate 3: 3-4). The karyotype is -L- -M- -S 2n = 32 = 2sm + 6st + 2sm + 2st + 2m + 6sm + 12st, evidently different from that of S. glabra. The first pair of chromosomes are submedian, and much longer than the 2nd to 4th pairs. The ratio in length of the largest chromosome to the smallest one is 4.3. The symmetric degree is of 3C, a unique type. The karyotype of the species is reported for the first time. In Smilax, the known basic numbers are 13, 15, 16 and 17. The two herbaceous species distributed in East Asia have three basic numbers: 13, 15 and 16, while the woody species studied mainly have 16, with no 13 recorded. Mangaly (1968) studied 8 herbaceous species in North America and reported 2n=26 for them except S. pseudo-china with 2n=30. Mangaly considered that a probably ancestral home of Smilax, both the herbaceous and woody, is in Southeast Asia and the eastern Himalayas, and speculated that the ancestral type of Sect. Coprosmanthus is possibly an Asian species, S. riparia. The karyotypes of the two herbaceous species in East Asia consist mostly of sm and m chromosomes, whereas those for the North American species are all of st chromosomes. Based on the general rule of karyotypic evolution, i.e. from symmetry to asymmetry, his speculation seems reasonable. Researches on sex-chromosomes of Smilax have been carried out since 1930 (Lindsay, 1930; Jensen, 1937; Nakajima, 1937; Mangaly, 1968), and they are generally considered to be the largest pair, but there is still no adequate evidence. The result of our observation on S. nipponica may confirm that the first pair of chromosomes of this species is XY type of sex-chromosomes. Chromosomes of the genus are small and medium-sized, varying between 1-6 μm, slightly larger in herbaceous species than in woody ones, larger in the karyotype of 2n=26 than in that of 2n=32. Based on karyotype constitution of the above 5 species, the karyotype in the genus is characterized by 4 pairs of L chromosomes and 2-5 pairs of M chromosomes, and mostly st and sm chromosomes, and by rather asymmetrical 3B type. The degree of symmetry in the above 5 species is from Sect. Coprosmanthus to Sect. Coilanthus, and herbaceous species towoody ones.     

CHROMOSOMES,HYBRIDS AND PLOIDY OF SEDUM CREMNOPHILA AND ECHEVERIA LINGUIFOLIA (CRASSULACEAE)

Sedum cremnophila and Echeveria linguifolia have generally been placed in different genera on the basis of their flowers—largely because the petals are spreading in one and erect in the other—and the genera have been placed in different subfamilies. However, they are very similar vegetatively and in their unusual inflorescence, their karyotypes are similar (n = 33), and they readily hybridize to produce fertile F₁ hybrids. Study of hybrids of these two species with numerous others leads to the conclusion that each of the two is effectively diploid, with a genome consisting of 33 chromosomes that are all different and that do not pair with each other. Therefore, the good chromosome pairing and the fertility of the hybrid between them are the result of close structural and genetic homology between the corresponding chromosomes of the two species. Taxonomic revision to reflect their very close relationship is desirable. Some other species of Sedum and Echeveria also may need to be reclassified.     

五种稻蝗染色体核型和C带带型的比较

本文研究了五种稻蝗Oxya chinensis、O. shanghaiensis、O. adentata、O. hyla intricara、O. agavisa的染色体核型和C带带型.玻片制备采用压片法,BSG法C带处理.结果表明:五种稻蝗染色体核型差异较小,具有属的保守性,但在C带方面则显示出一定的差别,种间染色体带型的差异大小与形态学上的差异程度具明显的正相关.其中小稻蝗和山稻蝗各自具有独特的带型结构,与其余三种显然不同,而中华稻蝗、上海稻蝗、无齿稻蝗虽在主要标志性染色体上带纹趋于一致,但在一些细微结构和统计数据方面存在一定差异.本文对五种稻蝗减数分裂中期Ⅰ的染色体数目和交叉定位也作了统计和比较,在染色体行为分析方面做了初步工作.据此,本文讨论了五种稻蝗的染色体分类问题.     

Chromosomal localization of 5S and 45S ribosomal DNA in species of Linum L. section Linum (syn=Protolinum and Adenolinum)

Fluorescence in situ hybridization (FISH) was for the first time used to study the chromosomal location of the 45S (18-2.5S-26S) and 5S ribosomal genes in the genomes of five flax species of the section Linum (syn. Protolinum and Adenolinum). In L. usitatissimum L. (2n = 30), L. angustifolium Huds. (2n = 30), and L. bienne Mill. (2n = 30), a major hybridization site of 45S rDNA was observed in the pericentric region of a large metacentric chromosome. A polymorphic minor locus of 45S rDNA was found on one of the small chromosomes. Sites of 5S rDNA colocalized with those of 45S rDNA, but direct correlation between signal intensities from the 45S and 5S rDNA sites was observed only in some cases. Other 5S rDNA sites mapped to two chromosomes in these flax species. In L. grandiflorum Desf. (2n = 16) and L. austriacum L. (2n = 18), large regions of 45S and 5S rDNA were similarly located on a pair of homologous satellite-bearing chromosomes. An additional large polymorphic site of 45S and 5S rDNA was found in the proximal region of one arm of a small chromosome in the L. usitatissimum. L. angustifolium, and L. bienne karyotypes. The other arm of this chromosome contained a large 5S rDNA cluster. A similar location of the ribosomal genes in the pericentric region of the pair of satellite-bearing metacentrics confirmed the close relationships of the species examined. The difference in chromosomal location of the ribosomal genes between flax species with 2n = 30 and those with 2n = 16 or 18 testified to their assignment to different sections. The use of ribosomal genes as chromosome markers was assumed to be of importance for comparative genomic studies in cultivated flax, a valuable crop species of Russia, and in its wild relatives.