科学上的竞争让全人类受益

岁末年初,美日两个研究小组几乎同时宣布成功地将人体皮肤细胞改造成了几乎可以和胚胎干细胞相媲美的干细胞——“iPS细胞”,它也被通俗地称为“皮肤干细胞”。它的诞生仿佛给沉寂一时的国际干细胞研究打入了一剂强心剂。     

小鼠胚胎移植研究

目的研究不同时期胚胎对胚胎移植成功率的影响以提高胚胎移植率。方法采用经超量排卵的KM雌鼠与正常615雄鼠交配,取受精卵,分别将单胚卵、双胚卵、桑椹胚和囊胚、移入发情的假孕KM雌鼠的输卵管和子宫中妊娠产仔。结果移入单胚卵、双胚卵、桑椹胚和囊胚的假孕母鼠妊娠率分别为36.36%、42.86%、10%、27.27%,产仔率分别为46.58%、38.46%、58.33%、60%。结论移植双胚卵可提高小鼠的胚胎移植成功率。     

科学家『捉弄上帝』?

据2007年11月的媒体报道:美国俄勒冈州的科学家成功克隆出猴子胚胎,并从中提取了干细胞.这似乎意味着,我们朝着克隆人类胚胎又迈进了一步.或许某一天,克隆人也将成为事实.但这种情况不太可能出现在太平洋东岸.     

扬子鳄胚胎背部皮肤及鳞甲的发生

本文观察了１６例不同时间的扬子鳄（Ａｌｌｉｇａｔｏｒ ｓｉｎｅｎｓｉｓ）胚胎背部皮肤及鳞甲的形态和组织发生过程，孵化第２０天，来自胚胎中胚层生皮节的间充质细胞开始向有皮下迁移，表皮仅具周皮层与生发层两层细胞，第２８天背部鳞片开始明显，左右鳞片之间出现很浅的鳞间沟，前后鳞片交界处的原始表皮，真皮层开始向外突出形成鳞甲原基，第３４天鳞甲原基突出伸长，第４０天背鳞的纵嵴明显，第３４－５０天中，鳞甲后级基     

慢性酒精中毒对小鼠胚胎的损伤及影响

酒精能通过胚胎胎盘屏障侵犯胎仔，导致畸形的发生，给孕鼠注射２５％乙醇（酒精剂量）畸胎率增大，脑，肝，神经细胞损伤明显，所以孕期要避免接触酒精的危害。     

Agrobacterium-mediated transformation of herbicide resistance in creeping bentgrass and colonial bentgrass

Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds. ) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. F1. Oxen. ) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co-cultivated with Agrobacterium tumefaciens, LBA4404,which contains plasmid vector-pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR) . After 3 days of co-cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4-D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of ‘Regent‘ and ‘Ti-ger‘ were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4 % of herbi-cide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.     

乙醇对果蝇的胚胎毒性和维生素的解毒作用

乙醇在人和哺乳动物中可诱发胎儿乙醇综合症(FAS).乙醇对于果蝇亦能引起发育延迟、孵化率下降、形态结构异常和性比失调.但维生素B_1、烟酸和烟酰胺有一定的解毒作用.     

胚胎细胞移植大有前途

初步的临床试验表明,胚胎组织输入到患帕金逊氏病的病人大脑中能改善病人的病情,研究人员呼吁应对这项研究进行广泛试验。