温度、清水和KCN对蓖麻蚕卵球发育的影响

我们曾研究了蓖麻蚕卵纯种受精的细胞学过程,知道卵球产出母体100±40分钟,在24—27℃、相对湿度(r.h.)80％±的环境里,形成雌性原核和极体;这时,精子也已核化为雄性原核,准备两性原核的合并。此后,接合核岛(二倍体)在卵前端的极区(也叫‘漏斗区’,Poleplasm)内开始分裂,经反复并发分裂和子核小岛的迁移,遂于10—12小时形成胚盘(Blastulation)。这是早期发育途程中的一个紧要阶段。本文仅就温度、水分和轻度的窒息(例如仿照家蚕新生卵用KCN处理)等环境条件对于蓖麻蚕卵发育的影响,作一简报外,并且正在从细胞学上追究夭殇的原因。     

柞蚕精核在蓖麻蚕卵质中的变化

中国柞蚕和蓖麻蚕是同科异属的绢丝昆虫.我们从柞蚕蛾交配拆对后的母蛾储精囊——导精管中取出有核精子和精液加昆虫生理盐水(PH7.8)稀释,置解剖镜下检查精子活力,将精液(含精子)吸入消毒后洁净的微玻管顺蓖麻蚕处女蛾产出不久的卵细胞的卵孔徐徐注入.于注射后60—90分钟取卵固定,按照常规制连续(8微米)切片标     

柞蚕精核在蓖麻蚕卵质中的变化

以适量柞蚕的精液(含:有核精子)注入蓖麻蚕卵细胞极区,精核在卵质作用下核被膜液泡化、精核膨胀,高度浓缩的染色质经松散作无数颗粒,然后再浓缩成染色体。但未见到两性原核融合现象以及功能健全的分裂器。     

人工授精杂交蚕及其母本5S rRNA的核苷酸顺序

蓖麻蚕、柞蚕和家蚕是天然丝生产的三个主要蚕种,蓖麻蚕、柞蚕隶属于天蚕蛾科(Saturniidae)家蚕隶属于家蚕蛾科(Bombycidae).这三种蚕不仅在形态上,而且在染色体对数上都是不同的.因此,在自然情况下,异种间是不能交配繁殖后代的.但三种蚕都各具不同的优越性能,蓖麻蚕抗高温;龄期短;柞蚕丝质坚韧;家蚕丝质好、经济价值高.为了改变这些蚕的品质.广西蚕业指导所、广西农学院蚕桑专业钱惠田等(1981)进行了异种间的人工授精试验,用注射计吸取精液注射到另一种处女蛾交配     

摩拉水牛精子顶体观察

家畜冷冻精液品质的好坏是影响受精力的重要因素之一。人们通常采用精子活力这一指标来评定精液品质及其受精力。近几年来,有的研究者认为,用精子顶体完整率评定精液品质及其受精力较活力评定理想,因为精子活力这一指标不能全面地反映精子顶体形态及其作用。当精子获能钻入卵细胞时,通过顶体反应释放出透明质酸酶(Hyaluronidase)、放射冠     

家蚕与蓖麻蚕的杂交试验(摘要)

在几千年的蚕丝生产中,应用常规杂交技术育出了千百个家蚕新品种,为蚕丝业的发展作出了巨大贡献,无疑地,它还将在今后的育种实践中发挥重要的作用。但是,由于常规杂交育种技术的局限性,积极开发包括种间杂交在内的家蚕育种新技术,乃是进一步发展蚕丝生产的一项重要任务。家蚕(蚕蛾科)和蓖麻蚕(大蚕蛾科)属不同科昆虫;家蚕与蓖麻蚕杂交(超远缘杂交)的研究还有着重要的理论意义。目前,有关蚕的种间杂交研究尚处初始阶段(Deodikar等,1977;钱惠田等,1981;张果,1986)。蚕类     

(蓖麻蚕蛾×樗蚕蛾)F_1受精卵的细胞学观察

<正> 驯养型多化性蓖麻蚕雌蛾和野生型蛹期滞育的樗蚕蛾杂交(下简称:蓖×樗)成功之后,我们曾对“蓖×蓖”、“樗×樗”(朱庆瑞)分别作细胞学观察,结果,它们都属生理的多精受精物种;前者N=14,后者(樗蚕,山东种)为13。本文将“蓖×樗”一代杂种受精过程中——成熟卵中期分裂时“染色质消失”、染色体的变异,以及精子中心体的光镜结构,简述之。     

论重新认识开发蓖麻蚕的价值和作用

蓖麻蚕(eri silkworm)是一种无滞育期多化性完全变态的绢丝昆虫。属鳞翅目，天蚕蛾科，学名为Samia cynthia ricini Boisduval．因主食蓖麻叶．故名蓖麻蚕。广西、广东、湖南等省(区)用木薯叶、马桑叶饲养，又称木薯蚕或马桑蚕。     

家蚕人工生殖及其利用——Ⅳ:精子和卵细胞的成熟

家蚕的精子,在精巢中几乎呈裸露状态,但当精子从精巢一出来到外面,就由厚的被膜所包被,整个精子体被保护起来,关于这一点已经讲过。下面来看看射精到雌体内以后的精子的行动和形态变化。交尾与精子的行动:精子一旦被射精到雌的交配囊内,有核精子束就渐渐地解开与无核精子相混合,但是,在此阶段尚未见显著的细微形态的变化。此后,这些精子通过精子导管到达受精囊。再经过一定时间,临近精子进入卵内(产卵)时,仅是有核精子显示出显著的形态变化。也就是说,此时,可观察到在紧紧包被有核精子周围的厚被膜上产生裂口,精子从被膜内部飞出。至此,在卵     

6种野生蚕类的RAPD分析

野生蚕类是我国重要的泌丝昆虫资源,研究其亲缘关系对于发掘和利用野生蚕类资源具有重要意义。利用随机扩增多态性DNA(RAPD)技术分析大蚕蛾科的柞蚕、栗蚕、野生柞蚕、天蚕、蓖麻蚕、透目天蚕间的亲缘关系,利用从54个引物中筛选出的30个重复性较好的随机引物对6种野生蚕类的基因组DNA进行扩增,共得到632个RAPD标记,其中可变条带数为632条,单个引物扩增的条带数为15～27,平均为21.1。6种野生蚕类相互间的遗传距离(D)较大,说明相互间的亲缘关系较远,其中:蓖麻蚕和栗蚕的遗传距离最大,为0.761 2;天蚕和透目天蚕的遗传距离最小,为0.671 1。采用UPGMA法构建的聚类图显示6种野生蚕类聚为4类,柞蚕与野生柞蚕聚为一类,天蚕与透目天蚕聚为一类,栗蚕、蓖麻蚕各自单独聚为一类。     

野桑蚕丝胶1基因Ser1A′及其上游调控序列的克隆和序列分析

家蚕由野桑蚕驯化而来,而野桑蚕sericin1及其上游调控序列的相关研究较少。本研究以家蚕sericin1及其上游调控序列设计引物克隆野桑蚕sericin1及其上游调控序列,将克隆得到的野桑蚕Sericin 1序列翻译后用muscle软件与家蚕Sericin 1蛋白序列比对,结果表明预测的野桑蚕Sericin 1氨基酸序列与家蚕Sericin 1 A′(Ser1 A′)氨基酸序列相似性很高,达98%。野桑蚕丝胶1基因上游调控序列与家蚕一样也存在多态性,克隆得到了1061bp和636bp的两条序列,中间存在425bp的插入序列,与家蚕丝胶1基因上游调控序列相似性分别为98%和97%。     

双酚A对体外培养家蚕生精囊形成精子的影响

为了探讨环境有害物质对家蚕生殖发育的影响,利用家蚕生精囊(spermatocyst)体外培养系统,研究塑料工业广泛使用的化合物双酚A(BPA)对体外培养家蚕生精囊精子形成的影响。在5龄第4天家蚕生精囊体外培养体系中添加100μg/mLBPA,可使生精囊全部不能伸长,绝大多数在72 h内死亡;添加10μg/mL BPA时,生精囊培养72 h后表现出明显伸长障碍,有核精子束数量减少且长度短;添加1μg/mL BPA时,有核精子束数量减少且长度短,还出现一些退化膨大的生精囊。在上蔟第2天的家蚕生精囊体外培养体系中添加0.1μg/mL BPA,可对无核精子形成产生毒性效应,明显影响到有核精子束的形成及精子束的浓缩成熟。实验结果显示:较低浓度的BPA对家蚕精子形成具有明显的毒害作用;上蔟第2天的家蚕生精囊体外培养体系对低浓度BPA的毒性反应敏感,可应用于家蚕以及昆虫的生殖毒理体外研究实验。     

家蚕桂灰卵基因的作用与卵壳构造

用扫描电镜观察了家蚕桂灰卵系中,球形卵(Gr~k/Gr~k)、桂灰卵(Gr~k/+)和正常卵+/+)卵壳表面及断面构造,结果:卵壳表面网状多边形小室的形状、大小及卵壳断面构造,因基因型而异.断面差异主要与卵壳中层的构造不同有关.笔者认为:Gr~k基因影响卵巢滤泡细胞的形态和大小,主要控制卵壳中层的构造.Gr~k和+Gr~k基因间可能是共显性的.     

家蚕品种854B高良卵率新品系的建立

春制春用蚕种的良卵率受遗传和环境因素的影响。采用不良桑叶饲养诱导,通过单蛾育定向选择,并以自交继代的方法,对家蚕品种854B的良卵率性状进行遗传改良,期望从品种遗传改良的角度探索提高春制春用蚕种良卵率的技术。新建立的家蚕品种854B的高良卵率品系854B40系,其春制春用蚕种的不良卵率为1.98%,较同一品种的对照品系854B湘系的春制春用蚕种的不良卵率显著降低(P<0.05)。高良卵率品系854B40系的繁育成绩中,全茧量与茧层量较854B凉山、854B湘系显著下降,分别为1.560 g和0.376 g,但死笼率、虫蛹率、茧层率与对照品系间差异不明显。试验结果表明,在不良环境因素诱导下对品种的良卵率性状进行定向选择,可以达到稳定提高春制春用蚕种良卵率的目的。     

野蚕黑卵蜂繁育寄主的研究

室内、外试验研究均表明，野蚕黑卵蜂能寄生家蚕卵并顺利生长、发育、羽化。经分别用家蚕卵和野桑蚕卵作寄主连续繁殖3代后，野蚕黑卵蜂种群间并无显著差异产生。寄主卵的长时间冷藏并不影响寄生蜂的寄生和生长发育；家蚕卵和野桑蚕卵中卵浆游离氨基酸、卵浆蛋白氨基酸以及卵壳蛋白氨基酸在各类氨基酸组成上无差异存在，两者均能满足野蚕黑卵蜂的营养需要。总之家蚕卵是野蚕黑卵蜂进行室内大量繁殖的适宜寄主。     

Use of Powdered Egg Yolk vs Fresh Egg Yolk for the Cryopreservation of Ovine Semen

Egg yolk is a common additive to sperm cryopreservation diluents. Because of its animal origin, however, it also represents a potential risk of microbiological contamination in the diluent. This potential contamination can be avoided by using powdered egg yolk, instead of fresh egg yolk, as it is pasteurized. This study was conducted to determine ram sperm cryosurvival was affected by the type of egg yolk used (powdered egg yolk or fresh egg yolk) and by yolk concentration (10, 15 or 20%) in the diluent. Microbiological analyses were also performed to quantify the microbiological contamination in the diluents containing the two types of egg yolk. Sperm cryosurvival was determined by motility and morphology analyses after thawing. Motility parameters were assessed using a computer-assisted sperm analysis (CASA) system, and the percentage of sperm with a normal apical ridge was evaluated using a differential interference contrast microscope. No significant differences were observed between diluents in the percentage of sperm with normal apical ridge. However, higher percentages of total motile cells were observed for samples containing powdered egg yolk (69%) compared to samples containing fresh egg yolk (60%). However, sperm in diluents containing fresh egg yolk, exhibited higher values for average-path velocity, straight-line velocity and beat cross frequency and lower values for amplitude of lateral head displacement (p <0.05), compared to cells in diluents containing powdered egg yolk. Microbiological contamination was similar (<200 CFU/ml) in both diluents, and no bacterial growth was observed in either, when antibiotics were added. Therefore, powdered egg yolk can be effective used in diluents for the freezing of ram semen. However, the in vivo fertility of sperm frozen in diluents containing powdered egg yolk should be tested, as some motility parameters were different for sperm treated with powdered egg yolk compared to fresh egg yolk.     

Membrane stability and mitochondrial activity of bovine sperm frozen with low-density lipoproteins and trehalose

Cryopreservation results in the destabilization of the sperm plasma membrane, leading to negative side effects such as premature cryocapacitation, apoptosis and the low mitochondrial activity of bovine spermatozoa. Low-density lipoproteins (LDL) and trehalose have been used in seminal freezing to protect the integrity and stability of sperm membranes. Likewise, trehalose can increase the mitochondrial activity of sperm. The objective of this study was to evaluate the membrane stability and mitochondrial activity of bovine sperm after being frozen and treated with LDL sources and trehalose. Ten ejaculates from five bulls were cryopreserved under the treatments, CEY: chicken egg yolk (20% v/v); CCEY: centrifuged CEY (20% v/v); LDL: LDL (8% v/v); T: trehalose (100 mM); and TLDL: T (100 mM) plus LDL (8% v/v). After thawing, membrane stability and mitochondrial membrane potential (ΔΨM) were assessed by flow cytometry through the M-540/Yopro-1 and DiOC6/PI probes. The structural membrane integrity (SMI) was evaluated by fluorescence microscopy using SYBR14/PI dyes. A generalized linear model was adjusted, and the means were compared using the Tukey test. Centrifuged chicken egg yolk and LDL had a higher proportion of non-cryocapacitated non-apoptotic sperm (M−Y−), while CEY and T had the largest populations of cryocapacitated non-apoptotic sperm (M+Y−) and cryocapacitated apoptotic sperm (M+Y+). Centrifuged chicken egg yolk also showed a higher proportion of sperm with high-ΔΨM. Treatments that included egg yolk or purified LDL had a positive effect on SMI. Centrifuged chicken egg yolk has a superior cryoprotective effect on membrane stability and mitochondrial activity of bovine semen over the conventional use of CEY or the individual or simultaneous use of LDL and trehalose.     

Use of Penicillin and Streptomycin to Reduce Spread of Bacterial Coldwater Disease I: Antibiotics in Sperm Extenders

Bacterial coldwater disease caused by Flavobacterium psychrophilum has led to the loss of significant numbers of hatchery-reared salmonids. The bacteria can be spread from parent to progeny within contaminated sperm and ovarian fluid. Methods for disinfecting ovarian fluid and unfertilized eggs are available, but methods for disinfecting sperm have not been described. In this study we determined whether sperm extenders containing a mixture of penicillin and streptomycin can be used to eliminate F. psychrophilum. In vitro trials demonstrated that when Rainbow Trout Oncorhynchus mykiss sperm is mixed with an extender, a 15-min exposure to 0.197 mg penicillin plus 0.313 mg/mL streptomycin is effective at killing the bacteria and has no effect on sperm motility. Small-scale trials showed that egg fertilization rates were not reduced when sperm held in an extender solution containing the same antibiotic mixture for 15 min was used to fertilize eggs. Production-scale trials, however, showed a roughly 18% decrease in egg fertilization rate when sperm stored in an antibiotic containing extender was used. To determine why a reduction in fertilization capacity was observed, a small-scale experiment testing the fertilization of eggs with larger quantities of sperm was performed and showed that increasing the volume of sperm used did not increase fertilization rates. Our results demonstrate that extenders containing penicillin and streptomycin can be used to disinfect sperm, especially when small quantities of eggs are fertilized, but factors negatively affecting egg fertilization and survival on a production scale still need further investigation.

Received May 1, 2014; accepted August 10, 2014     

家蚕bHLH基因的染色体定位与系统发生分析

bHLH转录因子在真核生物生长发育调控中具有重要作用。以原有家蚕bHLH基序为查询序列,从最新版本的家蚕基因组数据库(SilkDB)中鉴定出52个家蚕bHLH家族成员,并将其中47个成员的编码区域定位到家蚕染色体上。分析家蚕与黑腹果蝇、蜜蜂、赤拟谷盗bHLH基序氨基酸序列的系统发生,结果呈现如下特点:(1)4种昆虫ASCa家族中的Ase蛋白功能相近,家蚕中有2种果蝇Ac蛋白的同源蛋白,而没有果蝇Sc和Lsc的同源蛋白;(2)4种昆虫HES家族中的Hairy蛋白功能相近,家蚕BmHES3可能是果蝇Dpn或Side的同源蛋白,家蚕BmHES1和BmHES2分别是赤拟谷盗HES1和蜜蜂HES2的同源蛋白;(3)家蚕比其它3种昆虫分别多出1个Clock家族与AHR家族成员,意味着家蚕在长期的人工驯化过程中可能在昼夜节律的调控与对外源毒素刺激的响应方面演化出了新的机理。汇总了与家蚕52个bHLH成员对应的果蝇、蜜蜂和赤拟谷盗同源蛋白序列及44种家蚕bHLH蛋白序列登录号。以上结果可为进一步开展家蚕bHLH基因结构与功能研究提供较为系统、完整的背景资料。     

家蚕卵突变体“明”死卵(l-e~m)的卵壳构造和遗传分析

在家蚕品种"明"中发现一种卵突变体,其卵产下后10 min左右即出现失水凹陷,1 h左右完全失水,全部溃死。解剖观察母蛾卵巢管,卵在其内排列整齐,大小和色泽都与正常卵无异;电镜观察死卵,精孔、后极部与正常卵无差异,但卵壳表面凹陷处网格皲裂,其切面的中层可见有裂纹。遗传分析表明:该家蚕卵突变体由一个隐性遗传基因控制,纯合致死,遵循伪母性遗传模式。该突变体是一个不同于溃卵(Grcol)突变体的卵壳新突变,暂命名为"明"死卵(lethal egg of"ming",l-em)。