Analysis of genes differentially expressed during initial cellular dedifferentiation in cotton

The early phase of phytohormone induction is a vital stage of somatic embryogenesis. This phase includes a key process for acquiring cellular totipotency through cellular dedifferentiation. To unravel the molecular mechanism of cellular dedifferentiation in cotton, we constructed a cDNA library using the suppression subtractive hybridization method. A total of 286 differential cDNA clones were sequenced and identified. Among these clones, 112 unique ESTs were significantly up-regulated during the early phase of phytohormone induction, and 40.2% of the ESTs were first identified. GST was highly ex- pressed from 6 to 24 h after induction with phytohormone treatment. PRPs were predominantly ex- pressed and exhibited distinct expression patterns in different treatments, suggesting that they are closely related to cellular dedifferentiation in cotton. Putative GhSAMS, GhSAMDC, GhSAHH and GhAC03 involvement in SAM metabolism was identified in this library. The analysis of qRT-PCR showed that two remarkable increased expressions of the four SAM-related genes happened during the early phase of phytohormone induction, and that a highly positive correlation existed between GhSAMS and GhSAHHo The highest expression level of GhSAMS might be associated with its reentry into the cell cycle. The histological observations further showed that some cells accomplished cellular dedifferentiation and division within 72 h in 2,4-D treatment, and that cellular dedifferentiation might be regulated through two alterations in SAM-dependent transmethylation activity in cotton. In addition, the expression patterns of differential genes in different treatments disclosed the complicated interaction between 2, 4-D and kinetin.     

皱纹盘鲍（Haliotis discus hannai）、黑足鲍（Haliotis iris）及其杂交F1代同工酶比较分析

采用垂直板聚丙烯酰胺凝胶电泳技术,对皱纹盘鲍、黑足鲍及其杂交F1代的脏器和肌肉中的7种同工酶（ MDH、POD、EST、CAT、ODH、SOD和LDH）进行了比较分析,以探究双亲同工酶基因在杂交F1代中的表达情况以及3种鲍鱼品系之间产生差异的分子基础。结果表明,两亲本中部分同工酶谱表达相似,如ODH和肌肉中的POD、EST在父母本中酶谱相同;同时两个亲本之间的同工酶谱具有差别,MDH、LDH和内脏中EST的酶谱均存在稳定的种间差异。杂交F1代的同工酶谱与母本皱纹盘鲍的相似,其中POD、EST、LDH、SOD和肌肉中的MDH酶谱均与母本相同,而与父本黑足鲍的差别较大,说明主要是母本的同工酶基因在杂交F1代中表达。     

Construction of cDNA library from iron-deficiency induced maize roots and screening and identification of iron-stress geneFdr3

To isolate Fe-deficient related (Fdr) genes, an expression cDNA library of 4.5×10⁵ pfu/μg has been constructed from maize roots in iron-stress. 6 clones have been screened from the cDNA library by differential hybridization screening. It is proved that anFdr3 cDNA clone expressed stronger under iron-deficient condition than under iron-sufficient one by Northern blot and Western blot.     

杨树体细胞融合研究

为克服有性杂交障碍,利用原生质体电融合技术开发杨树体细胞融合研究。本研究选择杨树不同种或无性系分离原生质体,并应用ＩＯＡ和Ｘ－射线分别对融合双亲处理,使其失去分裂能力,筛选杂种细胞,并探索杨树原生质体融合的最适电场参数与培养条件,建立杨树体细胞电融合体系。首次得到了美洲黑杨＋胡杨、青杨＋胡杨、美洲黑杨＋青杨等体细胞杂种愈伤组织。其中美洲黑杨＋胡杨、青杨＋胡杨、美洲黑杨＋青杨等体细胞杂种愈伤组织。其     

药用植物石防风与柴胡不对称体细胞杂交的初步研究

经狭叶柴胡悬浮细胞系分离的原生质体用强度为 2 60 μW /cm2 紫外线照射 0 ,1 ,2 ,3min后 ,与石防风原生质体在PEG诱导下融合 .对融合再生的 56个单细胞克隆进行杂种形态学、染色体、同功酶分析表明 ,其中的 34个为体细胞杂种细胞系 .5个杂种愈伤组织 (不对称融合产物 )在培养 1 2个月时再生出完整小植株 .     

Hybridization of beaked redfish (Sebastes mentella) with small redfish (Sebastes viviparus) and diversification of redfish (Actinopterygii: Scorpaeniformes) in the Irminger Sea

We searched for Sebastes mentella and Sebastes viviparus hybrids in samples of redfish with external traits typical of S. mentella. The samples were collected in the Irminger Sea in 2007 (n = 131) and 2010 (n = 72). Hybrids were identified using MDH-2* locus coding malate dehydrogenase. Both samples contained hybrids (two and one individuals, respectively). The results of our investigations and previously published data show that interspecific hybridization may have a strong impact on the genetic structure of S. mentella in the Irminger Sea, presumably being one of the main reasons for the differentiation of allele frequencies of some genes between samples collected at different depths. This should be taken into consideration in studies of Irminger Sea redfish.     

细胞的增殖与凋亡在胎肺支气管上皮细胞发育过程的观察

目的：观察不同发育阶段人胎肺支气管粘膜上皮细胞的凋亡,以及增殖细胞核抗原（ＰＣＮＡ）的表达特征,并探讨细胞的凋亡与增殖在胎肺发育中的关系。方法：用原位核酸末端杂交,检测了１６～３２周人胎肺组织的凋亡细胞阳性表达率,用免疫细胞化学技术检测了同期人胎肺组织的ＰＣＮＡ阳性表达率。结果：人胎肺支气管粘膜上皮细胞在胎肺发育的早、中期（即假腺期和小管期）,细胞的凋亡与增殖均明显较晚期旺盛,而且两者均于胎肺发育的第２４周达到最高蜂,以后细胞的凋亡与增殖活动减弱;但凋亡与增殖细胞在不同发育时期定位有不同。结论：细胞的凋亡与增殖行为在胎肺支气管上皮细胞发育分化的整个过程中普遍存在,分工协作,对于胎肺的形态发生及功能完善共同起作用。     

利用分子轨道理论对MIM隧道结负阻特性的讨论

首次从轨道杂化的角度探讨了MIM隧道结负阻特性的成因,结合化学上的计算,并与实际测量结果进行对比分析,提出了MIM隧道结负阻特性的理论解释.