一种新的染色体制片永久封片法

细胞的有丝分裂和减数分裂制片是植物细胞学和细胞遗传学研究不可缺少的技术。对于一些重要的染色体制片进行永久封片,不仅为实验结果保存了必要的细胞学证据,而且也为特殊细胞学现象的重新观察和研究提供了可能性。传统染色体制片的封片剂主要有加拿大树脂(Canada balsam)、Euparal胶和DPX     

果蝇唾腺染色体的几种染色方法比较

《生物学通报》编委 :您好。笔者对贵刊 2 0 0 2年第 37卷第 2期第 2 3页刊登的“用 Feuglen染色法制作果蝇唾腺染色体”一文感兴趣 ,但笔者认为文中几处不妥 ,比如 1)水浴温度波幅偏高 ;2 )染色时间不确定 ;3)试剂配方不全 ;4 )盐酸的浓度单位有误 ,mol?M?;5 )注意事项影响实验结果表述不清。特撰写下文与各位读者商榷。双翅类昆虫如黑腹果蝇 (Drosophila melanogaster)的唾腺染色体 (Salivary chromosome)比普通染色体大的多 ,处于体细胞同源染色体的配对状态 ,是由于唾腺染色体经过多次复制而并不分开形成的 ,大约有 10 0 0～4 0 0 0根…     

果蝇唾腺染色体实验的改进

果蝇唾腺巨型染色体是大约1000-4000多条同源染色线精确配对聚集而成的多线染色体,这是染色体多次复制,但细胞只生长、不分裂的结果.染色体长达0.5mm.粗细是一般体细胞染色体的100-200倍左右,其上有深浅间隔、宽窄不等的染色带,果蝇4对唾腺染色体上已确定了6000多条染色带,它们宽窄、疏密、顺序、数目恒定,有种的特异性,同种个体的是相同的,不同的种则不一样,因此果蝇多线染色体可以建立染色带及间带分布图,它们的表现和遗传学图大致平行,多数遗传学家认为这些横纹与基因有对应关系,     

果蝇唾腺多线染色体研究进展及其在遗传学教学中的应用

果蝇唾腺多线染色体是细胞遗传学的3大经典染色体之一,从1934年至今因其具有显著的特点已经作为一个优异的模型用在不同的遗传学研究中。果蝇唾腺多线染色体最大的贡献就是为研究间期染色体结构和基因的表达调控提供了一个非凡的视角;另外,果蝇唾腺多线染色体还可以用于解释一些特殊的遗传现象,例如剂量补偿效应和花斑位置效应。文章一方面就以上进展作一简要总结,另一方面尝试将这一典型案例系统地用于遗传学教学中,引导和激发学生学习遗传学的兴趣。     

不同浓度的苯酚品红对果蝇唾腺染色体的染色效果

以不同浓度的苯酚品红为染色液,观察其对果蝇唾腺染色体的染色效果,结果表明,8％－12％苯酚品红为染色液,可获得背景清楚,染色体横纹清晰的图像。     

做好摇蚊染色体实验的几点体会

双翅目昆虫果蝇、摇蚊已成为观察染色体实验的经典材料,结合作者实践中的体会,谈几点做好本实验应注意的问题,重点是:幼虫要看颜色,唾腺要看形态及透明度,染色要把握好时间,压片要经过冷激等.     

介绍一种遗传学教学实验材料——油菜

近年来国外有人用油菜作为遗传学的教学材料,取得了较好的效果。我们在遗传学中用油菜作教学材料,特别是作实验材料,也取得了初步结果。 用油菜作教学材料,特别是作实验材料,具有下列优点:(一)油菜栽培广泛,取材方便。(二)某些油菜品种的染色体数较少,随体清晰;如白菜型油菜的染色体数是2n=20,便于进行染色体的观察和试验。(三)     

一种获得分散良好的植物染色体压片技术

植物染色体压片技术在染色体数目统计,染色体组型、核型分析及原位杂交等实验中极为重要。植物细胞膜外因包被有由纤维素、果胶等组成的细胞壁,增加了染色体制片的难度。无论是利用酸解法还是酶解法,人们通常都是将实验材料经一定的预处理、酶解、后低渗、染色之后,盖上盖玻片,用解剖针或镊子轻敲盖玻片直至染色体分散良好。此方法对于具有丰富经验的操作者作可能轻而一举。但是对一些新手(尤其是初次做染色体压片实验的学生)。要获得一张染色体分散良好的片子绝非易事。如何在进行学生实验课时,让学生在实验中通过1～2次操作就能获得分散良好的染色体片子,笔者在实践中摸索出下列经验以供参考。     

介绍一种简易安全毒瓶的制作方法

1　材料和用具剪刀 1把 ,2 0 cm长镊子 1把 ,石膏粉 1袋 ,敌敌畏乳液 1瓶 ,乙醚 1瓶 ,薄海绵 1块 (可用旧沙发垫或仪器包装用后的废弃海绵代替 ) ,5 0 0 g装塑料广口试剂瓶(可用曾装过化学试剂的空药瓶代替 ) ,解剖针 1根 ,长滴管几支 ,酒精喷灯 1个。能通过长滴管的约 2 0 cm长细铁丝 1根、5 0 0 m L烧杯 1个 ,5 0 m L量筒 1个 , 9定性滤纸若干张 ,小透明胶 1个、玻棒 1根 ,脱脂棉少许 ,毛巾大的纱布 1块。2　制作方法1)把废弃的空 5 0 0 m L塑料广口瓶和旧薄海绵 (厚度约 2 cm)洗净 ,晾干。然后用剪刀剪取 1块海绵。大小与瓶底相同 ,把…     

A simple method of preparing permanent squash preparations using cellophane]

A technique to prepare permanent squashed preparations of cell nuclei and chromosomes is proposed. Fix a piece of material on the slide with acetic alcohol (1:3), macerate with a 45% acetic acid, cover with hydrophilic cellophane previously soaked in a 45% acetic acid and then with a cover slip and filter paper to squash finally as it is routinely performed. After that soak off the cover slip with alcohol, post-fix the squashed preparation together with cellophane in alcohol for 5-10 min, unstick the cellophane, pass the preparation through alcohol once again and dry it. The subsequent treatment of the squashed preparation depends on the purpose of investigation. The slide may be tinctured overlaid with photoemulsion for autoradiography, or processed by different ways.     

植物叶表皮永久制片技术的改进

对植物叶表皮永久装片的制作过程,在实践中通过摸索而进行了一些改进,克服了传统叶表皮制片中易出现的几点不足之处,完善并简化了整个制作过程。新的永久的制片技术可以为从事植物形态分类学基础研究的工作者们提供基础的技术支持。     

A coverslip culture technique for preparing permanent fungus mounts

A coverslip culture technique for the growth of fungi, with subsequent preparation of permanent mounts for microscopic examination, is described. This simplified technique allows examination at different stages of development of the fungus, or can be used in the preparation of large numbers of similar mounts for teaching purposes.     

A coverslip culture technique for preparing permanent fungus mounts

A coverslip culture technique for the growth of fungi, with subsequent preparation of permanent mounts for microscopic examination, is described. This simplified technique allows examination at different stages of development of the fungus, or can be used in the preparation of large numbers of similar mounts for teaching purposes.     

A new method for establishing a permanent laboratory culture of Chironomus riparius Meigen (Diptera: Chironomidae)

A new technique for the establishment of a permanent laboratory culture of Chirono-mus riparius is described. Larvae and pupae were reared in plastic tanks containing tap water, filamentous algae and a commercially prepared fishfood. The tanks were aerated, maintained at a constant temperature of 24°C and subjected to a constant lighting regime of 13 h of light followed by 11 h of darkness. Adults flew freely in a modified handling box, mated, and oviposited on strips of filter paper placed in the plastic tanks containing the aquatic stages. It has proved unnecessary to change the water or medium, which has saved both time and effort. Moreover, larvae established themselves in ail parts ofthe alga, and therefore more could be kept in each tank than when, as in previous methods, they are provided only with a substratum on the floor of the container.     

A simple method for preparing meiotic chromosomes from mammalian testis

Freshly removed testis tubules are treated with hypotonic citrate solution and fixed in 31 acetic alcohol without undue rupture. The material is transferred to 60% acetic acid and the resulting suspension is air-dried onto warm slides using a micropipette. Finally the slides are stained with lacto-acetic orcein. — Provided suitable storage is made, slides need not be prepared in the same week as fixation and this may facilitate the collection of material during field study.