诱发斑点小球腔菌假囊壳生成的条件

自然界甘蓝茎点霉(Phoma lingam)的有性世代为斑点小球腔菌Leptosphaeriamaculans通常形成于甘蓝属植株的越冬残茎上。在实验室内其有性阶段不易培养或需要较长的时间,而且形成假囊壳的百分率也很低。为了在实验室内能短期诱发大量L.maculans的假囊壳,本实验研究了该菌假囊壳生成的条件,创造了双层培养方法。自澳大利亚采集到有该菌假囊壳的芸苔(Brassica napus)残基,分离得到子囊孢子单孢后代数十株,同时用保存的已知交配型665(+)和666(-)为材料,研究了(+)(-)配对结合的环境条件。实验结果表明16℃的温度,近紫外光照射(黑光灯)和V_(?)麦杆琼脂培养基上可以产生少量的假囊壳。但是,若配合以双层培养,则在培养4周后可产生大量成熟的假囊壳。实验还确定了该菌在性细胞形成、交配、子囊形成和成熟等阶段对环境因子都有不同的要求。双层培养对假囊壳的发育有重要作用。前期菌体营养生长与后期假囊壳的成熟紧密相关。     

赛蚊一新种(大叶赛蚊)的记述(双翅目:蚊科)

1972年,我们在宁夏回族自治区的银川采获一种新的赛蚊。由于新种赛蚊的第九背叶特大,因崦取名为大叶赛蚊Culista(Culiseta)megaloba新种。 大叶赛蚊Culiseta(Culiseta)megaloba新种形态特征 雌蚊 大型深褐色蚊虫,翅长6.3—7.0(平均6.5)毫米。 头部:头顶和后头覆盖淡色窄鳞,后头并有黑色竖鳞;沿复眼后缘有淡色鳞环,头侧为平铺的淡色宽鳞。触角蒂节(梗节)褐色,内面有淡色鳞,轮毛黑色。触须约为喙的1/8长,暗色,有时第三节基部和末端有少数淡色鳞。喙暗色,比前足股节赂长。 胸部:前胸前背片是淡色窄鳞和褐色宗毛,杂有少数淡色舌形鳞;前胸后背片具淡色窄鳞。中胸盾片的体壁黑色,具淡色或淡金黄色细鳞形成的不很明显的纵条,包括央、     

鱼类染色体G—显带的Brd U—BSG方法及白鲢G—带模式图的初步建立

本文报道了一种显示鱼类染色体G-带的BrdU-BsG方法。采用肾细胞短期培养,收获前12小时加入BrdU,使终浓度为10μg/ml。制片经HCl、Ba(OH)_2处理,4×SSC温育。Giemsa染色,显示出白鲢的G-带。其带纹细致清晰,一个细胞的单倍染色体上显示带纹达200条以上,是目前已报道的鱼类多重带中带纹最多的,且反差明显,带纹有特征性,结果较稳定。根据实验结果初步建立了白鲢的G-带模式图。     

中国拟盘多毛孢属真菌的七个新组合

作者按照Steyaert(1949)和Sutton(1980)的分类观点,对1987—1988年从我国广西、江西、浙江等地采集的Pestalotiopsis属真菌进行了研究,确认了拟盘多毛孢属真菌的7个新组合种,即Pestalotiopsis carveri(Guba)comb nov.,Pestalotiopsis elasticae(Koord.)comb.nov.,Pestalotiopsis langloisii(Guba)comb.nov.,Pestalotiopsis oleandri(Guba)comb.nov.,Pestalotiopsis sinensis(shen)comb.nov.,Pestalotiopsis sydowiana(Bres.)comb.nov.和Pestalotiopsis zahlbruckneriana(Bres.)comb.nov.     

Assembly and disassembly of brain tubulin is affected by high ammonia levels

Rats were fed a diet containing ammonium for up to 6 months. High ammonia levels were attained in brain. The amount of polymerized tubulin in microtubules increased, while the amount of free tubulin remained unchanged. Polymerization of tubulin from brain of ammonium fed rats (30 min, 37°C) was approximately 60% of control. Depolymerization of the microtubules was also affected and took approximately 3 times longer than in controls. These results indicate that both assembly and disassembly of tubulin in brain are impaired by high ammonia levels. Interestingly, the amount of microtubule-associated proteins was not affected.     

酪氨酸对人离体滋养层细胞孕酮与hCG分泌的影响

本文观察三种剂量(2×10~(-5)mol/L,2×10~(-4)mol/L和2×10~(-3)mol/L)的酪氮酸对离体培养的滋养层细胞孕酮及hCG分泌的影响,并对其抑制效应的机理作了初步探讨。实验结果表明,三种剂量的酪氨酸均可抑制滋养层细胞孕酮分泌(P<0.01),但是,在孕酮分泌受酪氨酸抑制的同时,未见对hCG分泌发生影响(P>0.05),进一步观察了酪氨酸对滋养层细胞3β-羟甾脱氢酶活性的影响,结果表明,酪氨酸能显著抑制3β-羟甾脱氢酶活性,提示酪氨酸对滋养层细胞孕酮生成的抑制作用与抑制3β-羟甾脱氢酶活性有关。     

A protein-free diet changes synaptosomal membrane fluidity and tyrosine and glutamate transport

Synaptosomes were isolated from cerebrums of rats fed standard (20% protein) or protein-free diets for 30 days. Arrhenius plots of their (Na⁺/K⁺)ATPase activities revealed a transition temperature of 25.5°C for control rats and 23.4°C for rats on protein-free diet, indicating that the latter increases synaptosomal membrane fluidity. The only change observed in the composition of the synaptosomal membranes was a 26% decrease of sialic acid. In synaptosomes from rats on protein-free diet the uptake of tyrosine was slightly reduced while that of glutamate was not affected. However, the exit of glutamate was reduced.