家蚕突变系统嵌合体MO的染色体研究

对家蚕突变系统嵌合体MO的染色体进行研究，观察到一个细胞有两条染色体分叉，一个细胞中含有明显异形二价体，推测为性染色体；并在第1、9、18、28号染色体上观察到次缢痕；由多倍体细胞中期染色体数推测其为四倍体。     

转基因猪银染核仁组织区的初步研究

采用外周血淋巴细胞培养技术，硝酸银银染法研究转基因猪的染色体银染核仁组织区（Ａｇ－ＮＯＲ）。结果表明：由湖北白猪Ｖ系经基因转移形成的转基因猪（以后简称转基因猪）与湖北自猪ＩＶ系普通猪（以后简称普通猪）银染点的数目和大小在个体、细胞、染色体水平上具有多态性，Ａｇ－ＮＯＲ位于第８号和第１０号染色体的次缢痕区；不同个体的Ａｇ－ＮＯＲ数不同，转基因猪平均每个细胞有二个银染点，普通猪平均每个细胞有三个银染点     

概论桑树多倍体新品种

1桑树多倍体的概念染色体是植物遗传基因的主要载体.植物细胞核内都有一定数目的染色体,其数目的多少视各个种或品种而不同,如桑树的体细胞内有28条染色体,水稻的体细胞内有24条染色体……,这些染色体常集合而成组,称为染色体组.在一般情况下,经过减数分裂后的细胞核内只有一个染色体组,而体细胞核内常有两个或两个以上的染色体组.细胞核内只有一个染色体组的称为单倍体,具有两个染色体组的称为二倍体,具有三个染色体组的称为三倍体,     

枫泾猪G带、C带及银染核仁组织区(NOR)的研究

以丹麦长白猪为对照,应用G带、C带、银染技术探讨了中国地方品种枫泾猪染色体的待征。用常规Giemsa和胰酶G带连续染色方法,测量了各号染色体的相对长度、着丝点指数及臂比。绘制了枫泾猪中期G带带型模式图。枫泾猪Ag-NOR定位于第8、10号染色体短臂次缢痕区。丹麦长白猪Ag-NOR仅定位于第10号染色体短臂次缢痕区。枫泾猪、丹麦长白猪Ag-NOR颗粒数是有差别的。     

中国北方黑白花奶牛银染核仁组织区(Ag-NOR_s)的研究

用修改的银氨染色法研究了11头中国北方黑白花奶牛染色体核仁组织区的位置和频率,以及核仁组织区染色体联合的频率。试验表明,Ag—NOR_s既定位在第2、3、4、5对和第28对常染色体端部,也定位在X—染色体的着丝点部位。据470个细胞计数结果;每细胞Ag—NOR_s为6.45±0.19,其中常染色体为6.17,X—染色体为0.28;每细胞核仁组织区染色体联合的频率为0.22。     

西北地区几个猪种银染核仁组织区（Ag—NORs）多态性的研究

本文用核仁组织区银染法对西北地区4个品种42头猪Ag-NORs的数目和分布作了较详细的研究。结果表明,猪的NOR位于8号和10号染色体的次缢痕区,每个细胞Ag-NORs的分布范围在1～4个之间。杜洛克、巴克夏、关中黑和八眉猪每个细胞Ag-NORs数平均为2.05、2.00、3.33和2.95个。Ag-NORs在品种、个体和细胞间具多态性,这种多态性与猪的起源和杂交育种时所用亲本品种的血缘有关。同时,对八眉猪以及中国猪种的起源问题作了初步探讨。     

13/17罗伯逊易位纯合子、杂合子猪及3个引进品种核仁组成区(Ag-NORs)的多态性

对 1 3/ 1 7易位纯合子猪、杂合子猪及杜洛克、长白、约克夏猪的核仁组成区 ( Ag-NORs)的多态性作了研究 ,结果表明 ,杜洛克、约克夏猪 Ag-NORs定位于 8号和 1 0号染色体的次缢痕区 ,而 1 3/ 1 7易位纯合子猪、1 3/ 1 7易位纯合子猪×约克夏猪 F1代 Ag-NORs的遗传方式符合孟德尔定律 ;Ag-NORs在细胞间、个体间及品种间数目均有差异 ,而且品种差异显著大于品种内个体间差异。 1 3/ 1 7易位纯合子猪、杂合子猪 ,以及长白、杜洛克、约克夏猪 Ag-NORs均数分别为 1 .99、1 .98、2 .0 0、2 .0 5、2 .0 6,说明 Ag-NORs在品种、个体及细胞间具有多态性。这种多态性与猪的起源和杂交育种时所用亲本品种的血缘成分有关 ,因此可作为遗传标记 ,用以分析家畜的亲缘关系     

云南保种山羊的银染核仁组织区研究

采用外周血淋巴细胞培养及Ａｇ－ＮＯＲｓ显带技术，分析了云南龙陵黄山羊、马关无角山羊、路南圭山山羊和宁蒗黑头山羊４个保种山羊银染核仁组织区（Ａｇ－ＮＯＲｓ）。结果表明，４个保种山羊核仁组织区银染有多态：龙陵黄山羊雌性核仁组织区银染分布于Ｎｏ．１、２、４、５、２５号染色体，雄性分布于Ｎｏ．１、２、２５号染色体，显示了性别及分布多态性；其余３个保种山羊雌雄均有相同的银染数目，并都分布于Ｎｏ．１、２、４、５和２５号染色体上。银染显示强度也不同；圭山羊、马关无角山羊最强，龙陵黄山羊次之，黑头山羊最弱。研究还发现染色体Ａｇ－ＮＯＲｓ联合的多态性，即黄山羊、圭山羊和马关无角山羊有联合现象，宁蒗黑头山羊无联合现象。山羊的银染显示强度和联合现象可能与山羊的近交有某种联系。     

用染色体Ag—NORs检测“军牧1号”瘦肉型新品种猪的遗传稳定性

本试验通过对"军牧1号"瘦肉型新品种猪及其亲代施格、三江白猪染色体Ag一NORs数目变化研究表明：亲代施格猪1个Ag-NORs占1．55％、2个Ag-NORs。占72．87％、3个As-NORs占12．40％、4个Ag-NORs13．18％；三江白猪2个Ag-NORS占97．56％、3个Ag-NORs占2．44％。Ag-NORs众数为2，平均数分别为2．40和2．03。亲代不同品种Ag-NORs存在多态性，体现了品种特征。"军牧1号"新品种猪1个和3个Ag-NORs均占0．35％、2个Ag-NORs占9930％，Ag-NORs众数为2．平均数为2．00；在个体间，群体内趋于一致、集中，达到稳定遗传．亲代猪Ag-NORs定位第8号、第10号染色体的次缢痕区[1,2,3,4,]，新品种猪Ag-NORs定位第10号染色体的次缢痕区。     

家蚕27、28号染色体基因的生物信息学分析

利用家蚕基因组精细图分析第27、28号染色体上的基因结构及其编码蛋白的功能结构域,可为在家蚕资源库中鉴定这两条染色体上的突变基因以及发现新的形态标记提供重要线索。基因预测及结构分析显示:家蚕第27和28号染色体是基因数目最少的两条染色体,预测基因数目分别是241个和288个,平均每个基因分别具有7.7和5.3个外显子;蛋白质全长编码区序列(CDS)长度主要分布于400-800 bp之间;CDS的GC含量分别是49.72%和46.54%。蛋白质功能结构域分析发现,家蚕第27、28号染色体上基因所编码的蛋白分别具有76和92种结构域,其中最多的3种结构域分别为Sugar_tr、MFS_1、zf-C2H2和UDPGT、DUF、Serpin。将家蚕第27、28号染色体上的预测基因与果蝇突变基因进行同源检索的结果显示,家蚕第27、28号染色体上分别有16和15个基因具有明显的可能突变表型。     

Hematoxylin Staining Reveals a Decrease in Nucleolar Diameter of Pig Oocytes Before Germinal Vesicle Breakdown

During oocyte growth, the morphology of the nucleolus changes into a compact and homogenous structure. The compact nucleoli in full-grown oocytes are not stained by aceto-orcein staining or immunofluorescence staining. In this study, we developed a hematoxylin staining method for pig oocytes in whole-mount preparations to visualize the nucleoli. Nucleoli of growing and full-grown oocytes were stained blue with hematoxylin. Using this staining method, the changes in the oocyte nucleolus during maturation were examined. The nucleolar diameter gradually decreased in maturing oocytes (10.7 ± 0.1 μm to 9.0 ± 0.7 μm, P<0.05) before germinal vesicle breakdown (GVBD). The results suggest that the nucleolar volume of oocytes decreases before GVBD.     

Production of giant mouse oocyte nucleoli and assessment of their protein content

Compared with advanced developmental stage embryos and somatic cells, fully grown mammalian oocytes contain specific nucleolus-like structures (NPB - nucleolus precursor bodies). It is commonly accepted that they serve as a store of material(s) from which typical nucleoli are gradually formed. Whilst nucleoli from somatic cells can be collected relatively easily for further biochemical analyses, a sufficient number of oocyte nucleoli is very difficult to obtain. We have found that isolated oocytes nucleoli fuse very efficiently when contact is established between them. Thus, well visible giant nucleoli can be obtained, relatively easily handled and then used for further biochemical analyses. With the use of colloidal gold staining, we estimated that a single fully grown mouse oocyte nucleolus contains approximately 1.6 ng of protein. We do believe that this approach will accelerate further research aiming at analyzing the composition of oocyte nucleoli in more detail.     

The karyotype and character of chromosome bands in mountain sheep in Czechoslovakia

Thirty-one moufflon (Ovis musimon) coming from eight localities in Bohemia and Moravia were examined. All animals had a diploid number of chromosomes without any numerical or structural aberrations from the standard set. On the basis of G-banding, all chromosomes were arranged into homologous pairs. C-banding was used to prove the localization of constitutive heterochromatin in the centromeric regions of the majority of chromosomes. Nucleolus organizers, demonstrated by means of A-staining, were located telometrically on the chromosomes in three big two-arm pairs and two acrocentric pairs. The number of active nucleolus organizers in individual cells ranged from 2 to 7. When these results were compared with the published data on the karyotype of sheep, the two forms were found to have much in common. It can be supposed that the karyotypes of moufflon and domestic sheep differ in the frequency of the occurrence of Ag-positive sections with nucleolus organizers.     

Fine Structure of Spermatogonia and Spermatocytes in the Rlue Fox (Alopex Lagopus)

The ultrastructural features, characterizing the different types of spermatogonia and spermatocytes in the blue fox, have been studied within and near the reproductive season, and also in the summer and autumn.Two distinct types of spermatogonia — A and Β — are described. The A-spermatogonia often have a prominent nucleolus and numerous cytoplasmic organelles including characteristic whorls of AER. Large vacuoles containing electron dense particles are sometimes observed. In the B-spermatogonia the chromatin forms condensed areas of varying size, and the nucleolus is usually absent. The number of cytoplasmic organelles is generally small.Ultrastructural characteristics are further used to distinguish between the different stages in the prophase of the primary spermatocytes. In leptotene the nucleus contains a thread-like chromatin with electron dense peripheral areas. Towards the end of the stage the mitochondria display dilated cristae, and aggregations of a granular material can be observed in the intermitochondrial matrix. Zytogene is characterized by the appearance of syniaptinemal complexes in the nucleus, and of the chromatoid body and piles of annulate lamellae in the juxtanuclear cytoplasm. In pachytene the chromosomes become apparent as aggregations of condensed chromatin associated with the synaptinemal complexes. The Golgi complex is more prominent than in the previous stages, and the number of the other cytoplasmic organelles is increasing. In the last stages of the prophase (diplotene and diakenesis) the chromosomes become still more electron dense, the nucleolus appears as a very prominent structure, and there is a marked vesiculation of the cytoplasm.The secondary spermatocytes have a characteristic nucleus with a somewhat irregular outline and larger peripheral areas of condensed chromatin. In the cytoplasm a double Golgi complex is frequently observed.In the summer and autumn spermatocytes in zygotene seem to represent the most advanced form of spermatogenic cells.     

毁灭泰泽球虫内生发育的超微结构研究 Ⅲ.小配子生殖与小配子

毁灭泰泽球虫的小配子生殖发生在小肠上皮细胞内由单层膜围成的带虫空泡中。其细胞核的分裂过程与裂殖生殖时期的相似,但小配子体的细胞核缺少核仁,染色质在核的浅层聚集成致密的斑块。在小配子的形成过程中,核附近的中心粒转变为基粒,其中央微管消失。随后,两根鞭毛从基粒长出,突入带虫空泡。细胞核的致密部分逐渐地进入小配子体的表面突起,并最终发育为小配子的细胞核;而核的疏浅部分则留在小配子体的细胞质中,成为残体的成份。成熟的小配子拥有两根纤长的鞭毛和香蕉形的身体,体内含有长形的细胞核及在其尖端嵌入的线粒体,一组微管(4 1 1)自基粒附近向体后延伸,但仅约3根微管抵达身体的末端。     

Ultrastructural Study of the Early Development of the Sheep Embryo

An ultrastructural study of the different stages of pre-implantation in sheep was carried out, analysing the changes brought about mainly in the morula and blastocyst stages. The analysis of the embryos obtained showed a series of common characteristics in all stages, most noticeable being the presence of a high number of vesicles distributed in a uniform way in the cytoplasm, and also the presence of numerous electron-dense mitochondria in many varied forms. The most important ultrastructural modifications took place at the 16-cell stage and affected, principally, the nucleus, which presented numerous condensations of chromatin distributed along the nucleoplasm. The nucleoli adopted a reticular morphology, abandoning the compact aspects presented in the previous stage. These changes might be involved in the synthesis of embryonic RNA, and, accordingly, in the activation of the genome of this species. These data indicate that this stage is critical to the embryonic development and might be related to the blockage produced in the development of cultivated sheep embryos at the point of transition from 8 to 16 cells. Nevertheless, it should be pointed out that the first signs of modifications in the aspect of the nucleus are observed at the four-cell stage, being characterized by the appearance of vacuolated areas in the nucleolus, indicating the first signs of embryonic nucleic activity, which would anticipate the main change in the control of the protein synthesis.     

Feinstruktur der Trigeminuskerne vom Haushuhn

The trigeminal nerve nuclei are examined light- and electron-microscopically in the adult domestic fowl. The nucleus sen-sibilis principalis nervi trigemini is formed by scarce, mediumsized, round-to-ovoid polygonal neurons. The Nissl bodies are concentrated around the nucleus and consist of short cisterns of the rough endoplasmic reticulum densely bordered with ribosomes. The nucleus tractus spinalis nervi trigemini extends to the first segments of the cervical cord. The rostral part of the nucleus is characterized by medium-sized polygonal neurons. Their cell bodies are densely packed with coarse Nissl bodies. Small multiforme cell types with large nuclei frequently showing two nucleoli predominate in the caudal part. The motorical main portion, nucleus motorius nervi trigemini consists of medium-sized as well as great polygonal neurons. The accessory portion, nucleus motorius dorsalis nervi trigemini, consists of medium-sized polygonal neurons. Both nuclei show the typical motoneuron cytomorphology. In the neuropil, the axodendritic synapses can be differentiated into five types. Occasionally, densely packed glial lamellae and giant mitochondria occur.