PURIFICATION AND PROPERTIES OF THE PROTHORACICOTROPIC HORMONE OF THE SILKWORM, BOMBYX MORI

A simple and highly reproducible procedure for partial purification of prothoracicotropic hormone (PTTH) was established starting with 96,000 male adult Bombyx heads. Approximately 28,500-fold purification of PTTH was accomplished with a yield of about 50% and 6 ng of the most purified preparation ("highly purified PTTH") caused adult development in a brainless Samia pupa. The peptidal nature of PTTH was reconfirmed through the effects of various enzymatic and chemical treatments on the biological activity of "highly purified PTTH". Gel-filtration indicated the molecular weight of PTTH to be 4,400.     

ENDOCRINOLOGICAL STUDIES ON SPERMATOGENESIS IN THE SILKWORM, BOMBYX MORI L.

When embryonic testes 1 or 2 days before hatching were transplanted into 5 kinds of hosts (5th instar larvae, “fresh” pupae just after pupation, isolated pupal abdomens and 3-day-old pupae with and without their original corpora allata), the testes transplanted into 5th instar larvae grew most conspicuously and spermiogenesis began in many cysts. A few spermatidal cysts were observed in the testes transplanted into fresh pupae. No signs of maturation were observed in the testes transplanted into other hosts. It is concluded that prothoracic gland hormone might be responsible for the precocious maturation of young testes. On the other hand, the initiation of spermiogenesis was delayed, in comparing with controls, in the 3rd instar larval testes as follows: the testes transplanted into 3-day-old pupae, the testes transplanted into isolated pupal abdomens together with adult corpora allata and the testis into which corpus allatum of a 3rd instar larva was inserted. It is concluded that corpora allata hormone exerts an inhibitory effect on spermatogenesis.     

SORBITOL IN THE EGGS OF THE SILKWORM, BOMBYX MORI

Sorbitol was found to be a normal and sole monosaccharide demonstrable in the late ovarian and in the early embryonic stages of the silkworm, Bombyx mori. This observation was first made on a line of non-diapausing polyvoltine Katsumata strain, but was later confirmed by the analysis of two other Katsumata lines and on several polyvoltine or bivoltine strains. The identification of the sugar extracted from the diapause eggs of a bivoltine strain and from the non-diapausing eggs of a Katsumata strain was based on analyses involving paper chromatography, paper electrophoresis and sorbitol dehydrogenase.     

CONJUGATED ECDYSONE IN THE EGGS OF THE SILKWORM, BOMBYX MORI

A high activity of molting hormone (ecdysone) was detected in the extract of unfertilized, diapausing and developing silkworm eggs. The active substance in the diapause eggs behaved as a highly polar molecule at partitioning between n -butanol and water, and also in TLC. The majority of the activity seems to be due to a conjugated ecdysone, since the polar active substance was changed to a less polar substance upon treatment with "snail enzymes".     

核多角体病毒(NPV)感染的家蚕中肠DNA多聚酶的研究

家蚕核多角体病毒(NPV)感染的中肠组织中的DNA多聚酶,经过磷酸纤维素柱层析纯化,正常家蚕中肠与NPV感染的家蚕中肠NPV多聚酶都表现了前和后两个活力峰,感染NPV的家蚕中肠DNA多聚酶前、后峰的比活力比正常家蚕中肠DNA多聚酶前,后峰的比活力分别提高10～15倍,总活力回收为56～60％。研究了DNA多聚酶的性质,讨论了与NPV复制的关系。     

家蚕核型多角体病毒及核衣壳的纯化和其结构蛋白的凝胶电泳分析

 用差速离心和蔗糖密度梯度离心提纯了家蚕核型多角体病毒及其核衣壳,并用SDS聚丙烯酰胺凝胶(均一胶和梯度胶)电泳分析了它们的结构蛋白。测量使用游标卡尺,计算使用微型计算机。凝胶用很染色方法染色。 结果表明,家蚕核型多角体病毒长381.2±17.81纳米,直径88.86±9.605纳米;核衣壳长328.9±5.917纳米,直径41.36±1.167纳米。两种凝胶电泳所得数据显示病毒粒子至少含有20组分子量不同的结构多肽,含量较多的是P31、P40、P28和P20。P45和一些小分子多肽看来主要存于囊膜上。P31的分子量与多角体蛋白相同,我们的实验表明它可能是病毒粒子和核衣壳的结构组分。     

家蚕血液过氧化氢酶活力及其与蚕体抗逆性的关系

家蚕召Bombyx mori(L.)血液过氧化氢酶(CAT)活力随发育时期呈现有规律的动态变化。在幼虫期,CAT活力以龄初、龄末较高,而龄中较低;化蛹后,CAT活力迅速上升,至中期达到峰值,随后迅速下降直至羽化。不同性别间CAT活力均以雄性较高;不同蚕品种间CAT活力有很大差异;饲料对CAT活力有一定影响,人工饲料育蚕CAT活力略大于桑叶育的;高温冲击和氟化物添食都能引起CAT活力的显著变化,但变化的幅度因品种、性别、时期和添食剂量而有所不同。研究认为,家蚕血液CAT活力与其发育变态、体内代谢均具有密切关系,逆境条件下CAT活力变化幅度的大小可以作为家蚕抗逆性强弱的一个重要生理指标。     

家蚕初级精母细胞内四个基体——轴丝复合体(英语)

应用细胞整装制备和穿透电子显微镜技术,在家蚕4龄幼虫睾丸育精囊的初级精母幼胞内检查出四个基体—轴丝复合体结构.呈两对,每对结构是由连结纤维将基体牢固地联结并使其相互成直角排列.生长的复合体呈现出丰满的远心端膨大.在此阶段,轴丝是由9个具有马达蛋白臂的双微管组成,缺乏辐射轴和两个中央单微管.在基体的三联体微管和轴丝的双微管的接合点,观察到连结节.     

TETRAD BASAL BODY-AXONEME COMPLEXES IN THE PRIMARY SPERMATOCYTE OF THE SILKWORM, BOMBYX MORI

Abstract  Using cell whole mount preparation, tetrad basal boby-axoneme complexes in the primary spermatocyte from testicular cysts of fourth instar larvae of Bombyx mori are examined by transmission electron microscopy. There exist two paired basal body-axoneme complexes and the two orthogonally oriented basal bodies are linked together with distal and proximal linking fibers. The growing complex displays voluminous distal swelling. At this stage, the axoneme consists of nine microtubular doublets. A connecting nodule is found at the juncture of basal body's triplet and axoneme's doublet, and the A and B tubules of the former continue through the nodule to become the ones of the latter.     

BIOSYNTHESIS OF ECDYSONE IN THE ISOLATED ABDOMEN OF THE SILKWORM,BOMBYX MORI*

During pupal-adult development of the silkworm, Bombyx mori, the ecdysone titer changes, exhibiting two maxima in the females: one on the second day of pupal development and the other just before adult emergence. During the second maximum, ecdysone accumulates in the ovaries. It also accumulates in isolated abdomens, which were prepared just after pupal ecdysis and induced to initiate adult development by injection with β-ecdysone. Several lines of evidence suggest that ecdysone is synthesized in the ovary itself.     

CHANGES IN TITER OF THE BRAIN HORMONE DURING DEVELOPMENT OF THE SILKWORM, BOMBYX MORI

Changes in titer of brain hormone (BH) extracted from the brain, head, and thorax and abdomen during the development of Bombyx mori from the 4th larval molting up to 6 days after adult emergence were investigated. The hypothesis is presented that high secretory activity of the brain is not reflected in a corresponding change in its BH titer, while low secretory activity brings about an accumulation of BH in the brain. An interesting finding is that extremely high titers of BH were found in the thorax and abdomen, from 4 days after pupation to adult emergence, of females only. This sexual difference was, however, not found in all of the races examined.     

家蚕Bombyx mori酸性半胱氨酸蛋白酶的组织分布及合成部位研究

本文通过酶活性分析及免疫化学方法研究了家蚕Ｂｏｍｂｙｘ ｍｏｒｉ蛹期酸性半胱氨酸蛋白酶的组织分布、合成部位及在卵形成过程中的变化。结果表明在卵母细胞、雌、雄血淋巴及脂肪体中含有酸性半胱氨酸蛋白酶。在血细胞和卵母细胞中可合成该酶。酸性半胱氨酸蛋白酶在肾化第５天的卵母细胞中开始出现,但在血淋巴中,整个蛹期均可检测到该酶。     

家蚕微粒子病母蛾序贯抽样检验方法研究

本文根据统计学理论,设计了一套家蚕微粒子病母蛾序贯抽样检验方案,用此方案进行的抽样检验,不仅保证了将不合格蚕种判为合格蚕种的概率控制在1.5％以内,而且大大减少了将合格蚕种判为不合格蚕种的概率．并且镜检蛾数一般随总体病蛾率ρ而变化。当ρ较低或较高（相对于0.5％）时,需检验的数量就较少.本方案的实际检验工作量并未比现行检验方案有明显增加.     

家蚕（Bombyx mori）5龄幼虫丝腺染色质在核基质上的组构

家蚕(Bombyx mori)5龄幼虫丝腺的染色质高度多倍化,整个基因组达10~5至10~6个拷贝。依次经低盐和高盐抽提5龄幼虫中丝腺、后丝腺和蚕体的细胞核,得到其核晕 (nuclearhalo),限制性内切酶消化后还有一部分DNA片段与核基质紧密结合在一起,说明染色质的组织与核基质有关。通过测定核基质上残留的DNA片段的平均长度及其在全基因组DNA中所占的百分比计算出,核晕上DNAloop的平均大小在中丝腺、后丝腺以及蚕体细胞中均为67kb左右。丝腺中高度多倍化的染色质与二倍体蚕体组织之间并不存在差异,它们同样被错定在核基质上而分隔成长约67kb的染色质loop,从而保证整个基因组的有序排列。以丝素基因为探针进行DNA印迹杂交发现,在5龄后丝腺中丝素基因特异性地和核基质紧密结合,说明核基质与丝素基因的组织特异性表达有关。     

大肠杆菌及聚肌胞核苷酸对柞蚕、家蚕蛹诱导产生溶菌酶、抗菌肽及凝集素的动力学

大肠杆菌D₃₁诱导柞蚕蛹产生抗菌多肽。同时,溶菌酶和凝集素活性都比诱导前有明显增高.其活力高峰、抗菌多肽在第7天左右、溶菌酶在第5天,而凝集素在第3天即达最高水平。不同品种的柞蚕蛹,经诱导产生的三种活性物质其活力差异不明显,但741、河四和小混品种中的抗菌多肽P_9A及P_9B组成比例较高。上述三种活性物质的诱导变化与性别有关,雄性高于雌性。比较了柞蚕蛹和家蚕经细菌诱导后上述三种活性物质的变化,家蚕凝集素活力很低,诱导后活力增高不明显。抗菌活力及溶菌酶活力的提高程度柞蚕也高于家蚕。聚肌胞核苷酸(Poly I:C)也能诱导两种蚕产生抗菌多肽及溶菌酶,但活力提高的显著程度都不及大肠杆菌诱导,凝集素活力变化也不显著。