大叶相思体细胞胚胎发生的初步研究

以种子萌发的无菌苗下胚轴为外植体，在Ｂ５＋２，４－Ｄ（１０－４ｍｏｌ／Ｌ）＋ＢＡ（１０－６ｍｏｌ／Ｌ）＋ＣＨ０．５ｇ／Ｌ的固体培养基上培养４周，获得了胚性愈伤组织．该愈伤组织经Ｂ５＋２．４－Ｄ（１０－４ｍｏｌ／Ｌ）的液体培养基７ｄ的诱导在Ｂ５＋Ｌ－谷氨酰胺（２００ｍｇ／Ｌ）＋ＣＨ（０．５ｇ／Ｌ）的液体培养基上培养１４ｄ产生了球形胚．球形胚具有明显的两极，但只是根端发育，苗端并没有发育     

甘薯品种“白星”体细胞胚的诱导

将甘薯品种“白星”带2个叶原基的茎尖接种于含5μmol/L 2,4-D的修改的MS培养基上能诱导出胚性俞伤组织;胚性愈伤组织在不含生长素类的修改的MS培养基上进一步发育成子叶胚;子叶胚在1/2MS培养基上能发育成试管植株.     

Comparative pluripotency analysis of mouse embryonic stem cells derived from wild-type and infertile hermaphrodite somatic cell nuclear transfer blastocysts

Therapeutic cloning, whereby embryonic stem cells （ESCs） are derived from patient-specific cloned blastocysts via somatic cell nuclear transfer （SCNT）, holds great promise for treating many human diseases using regenerative medicine. Teratoma formation and germline transmission have been used to confirm the pluripotency of mouse stem cells, but human embryonic stem cells （hESCs） have not been proven to be fully pluripotent owing to the ethical impossibility of testing for germ line transmis- sion, which would be the strongest evidence for full pluripotency. Therefore, formation of differentiated cells from the three somatic germ layers within a teratoma is taken as the best indicator of pluripotency in hESC lines. The possibility that these lines lack full multi- or pluripotency has not yet been evaluated. In this study, we established 16 mouse ESC lines, including 3 genetically defective nuclear transfer- ESC （ntESC） lines derived from SCNT blastocysts of infertile hermaphrodite F1 mice and 13 ntESC lines derived from SCNT blastocysts of normal F1 mice. We found that the defective ntESCs expressed all in vitro markers of pluripotency and could form teratomas that included derivatives from all three germ layers, but could not be transmitted via the germ line, in contrast with normal ntESCs. Our results in- dicate that teratoma formation assays with hESCs might be an insufficient standard to assess full pluripotency, although they do define multipotency to some degree. More rigorous standards are required to assess the safety of hESCs for therapeutic cloning.     

仙客来(Cyclamen persicum Mill)体细胞胚的发生及组织细胞学的研究

以仙客来开花植株新生叶片为外植体,成功诱导、筛选出体细胞胚发生的胚性愈伤组织,胚性愈伤组织的形态有两种:微棕红色松软愈伤和松脆愈伤.显微镜下观察松软胚性愈伤多为含有数十个胚性细胞的胚性细胞团,而松脆胚性愈伤的胚性细胞团的胚性细胞数目只有几个或十几个.细胞学观察二者均包含前胚性细胞团、二细胞、四细胞、八细胞,进一步继代培养2周可观察到多细胞原胚、球形胚、梨形胚、心形胚、鱼雷胚的出现,大多数体胚60～90 d可发育成完整的小植株.     

DNA methylation status of H19 and Xist genes in lungs of somatic cell nuclear transfer bovines

In somatic cell nuclear transfer （SCNT） technologies, the donor cell＇s nuclei need to be epigenetically reprogrsmmed for embryonic development. The incomplete reprogramming of donor cell nuclei has been Implicated as s primary reason for the low efficiency of SCNT. DNA methylstion is s major epigenetic modification of the genome that regulates crucial aspects of genome function, including establishment of genomic imprinting. In order to make sure whether the DNA methylstion reprogramming is efficient in SCNT animals, we analyzed the DNA methylstion status of two imprinting genes, H19 and Xist, in lungs of deceased SCNT bovines that died within 48 h of birth using bisulfite sequencing analysis. Our findings demonstrated that cloned bovines showed significantly lower DNA methylstion of H19 than controls （P〈0.05）, and three tested CpGs sites （1, 2, 3） exhibited unmethylstion in one cloned bovine （9C3）; however, Xist showed similar DNA methylation levels between clones and controis, and both showed hypermethylstion （96.11% and 86.67%）.     

花生(Arachis hypogea L.)体细胞胚胚性特异蛋白的研究

花生萌发３ｄ的胚叶在诱导培养基上出现高频率的体细胞胚发生．ＳＤＳ－ＰＡＧＥ分析结果表明：在体细胞胚发生过程中，诱导第三天开始出现３条新的蛋白谱带，７ｄ后出现２条新带，１５ｄ后又出现３条；而在非胚性组织中检测到抑制性的特异蛋白条带．     

诱导性多潜能干细胞(iPS)研究：现状与展望

通过特定的基因组合与转染可以将已分化的体细胞诱导重编程为多潜能干细胞（iPS）,是近年来干细胞研究领域最令人瞩目的一项新的干细胞制造技术。与胚胎干细胞（ES）不同,iPS细胞的制造不需要毁损胚胎,因而不会涉及更多的伦理学问题。iPS的出现不仅为体细胞重编程去分化机制的研究注入了新的活力,而且为疾病发生发展相关机制研究与特异的细胞治疗,特别是再生医学带来新的曙光。目前,iPS的研究尚处于初级阶段,文章就iPS的研究现状与应用前景进行综述和展望。     

Effects of pigment glands and gossypol on somatic cell culture of upland cotton (Gossypium hirsutum L.)

The effects of pigment glands and gossypol on the somatic cell culture of upland cotton were studied, using the materials as follows: three pairs of glanded and glandless upland cotton near isogenic lines, TM-1, and Coker 312. The results showed that the pigment glands and gossypol contents in the explants had great inhibiting effect on the induction and growth of callus in somatic cell culture of upland cotton, and the induction rate of callus and the single callus weight of glandless cotton were much higher than those of their glanded near isogenic lines. It was easier to obtain regeneration plants from glandless cotton than from their glanded near isogenic lines. There was a significant inverse correlation between the gossypol contents in the explants and callus induction rate, with the correlation coefficient of -0.84. The vitro gossypol in the medium had some inhibiting effect on the induction and growth of callus, especially for the glandless cotton. However, a certain concentration of vitro gossypol in the medium (0.1 mg/L) was an aid to the steadiness growth of callus in glandless cotton somatic cell culture, with a high rate of embryogenic cells which was in favor of plant regeneration, and it was also relatively easy to obtain regeneration plants when they were transferred into differentiation medium with 0.1 mg/L of vitro gossypol, even for some cultivars which are difficult in somatic cell culture. In addition, the gossypol content and its variation in the seedlings and callus during culture of Coker 312 were discussed, as well as the relationship between gossypol variation in the explants and its somatic cell culture. The probability of vitro gossypol used in cotton somatic cell culture for the improvement of somatic cell culture was suggested.     

花生体细胞胚发生发育过程中淀粉代谢的动态变化

将花生实生苗的幼对接种于MS固体诱导培养基上诱导体细胞胚发生 ,用PAS染色法观察了体细胞胚发生发育过程中的淀粉代谢的动态变化 .结果表明 ,在体细胞胚的发育过程中 ,淀粉表现出两次积累高峰 ,第一次在胚性细胞团中 ,淀粉粒大而密集 ;随着胚性细胞的分裂 ,淀粉逐渐被消耗 ,到多细胞原胚期胚体内淀粉趋于消失 .球形胚期 ,淀粉粒又开始积累 ,出现第二次积累高峰 ;到成熟胚期 ,淀粉积累只限于生长点区域淀粉的两次积累高峰为体细胞胚的发育提供了物质和能量基础     

旱芹直播土壤人工种子及胚状体分化过程中的POD、PAL活性变化

旱芹（Apiumgraveolens）无菌苗子叶为外植体，在MS＋1．0mg／L2．4－D＋0．5mg／LKT上诱导产生愈伤组织，然后转入MS＋1．0mg／LABA诱导产生胚状体后用于人工种子包埋，在有菌土壤中获得7％左右的转株＄．当人工种子外面包裹一层酯类共聚物作外膜，并在人工胚乳中加入6％的麦芽糖和1％的活性炭后，使人工种子在有菌蛭石土中的转株率提高到51％．还测定了芹菜胚状体分化过程中的苯丙氨酸解氨酶（PAL）活性、过氧化物酶（POD）活性、以及木质素和可溶性蛋白质含量的变化．POD及PAL的第二个活性峰在第八天前后出现，似可作为组织启动分化的标志酶．结果表明：PAL、POD活性，木质素合成和管状分子之间有紧密的相关性．