Photoinduced bonding of endogenous ecdysterone to salivary gland chromosomes of Chironomus tentans

Endogenous ecdysterone has been bonded to chromosomal loci by irradiation of Ch. tentans salivary glands. The hormone has been localized on the polytene chromosomes by indirect immunofluorescence microscopy. Hormone binding to chromosomes is stage-specific. Seven chromosomal loci could be identified which specifically bound hormone in larval salivary glands, and 21 chromosomal loci which specifically bound hormone in prepupal salivary glands. All puffs that have been described by Clever (1961) as being inducible by ecdysterone have been found to contain irreversibly bound ecdysterone in prepupal salivary gland chromosomes. A small number of puff sites in larval salivary gland chromosomes exhibited varying amounts of bound ecdysterone, (as judged by fluorescence intensity) most notably 117B and Balbiani rings 1 and 3 on chromosome IV. In addition to stage specific binding sites, there were many others showing equal binding of the hormone in both, larval and prepupal, stages of development. — Fluorescence intensities (reflecting the amount of bonded hormone) at puff sites along the tip section of the prepupal salivary gland chromosome arm IR have been computed indicating that differences between fluorescence intensities of different puffs can be expressed as multiples of a basic fluorescence intensity. Thus, the amount of fluorescence intensity (bonded hormone) in the various puffs may be quantized. — The data indicate that in Ch. tentans salivary glands ecdysterone acts, at the chromosomal level. The development of larvae into prepupae generates more puff sites and more hormone binding. This is discussed in the light of current models of hormone-receptor function.     

Karyotype of the midge Chironomus heterodentatus Konstantinov from the group Obtusidens (Diptera, Chironomidae)

The karyotype of Chironomus heterodentatus, belonging to the obtusidens-group described by Konstantinov from the Volga in 1956, was studied in detail. Combinations of chromosomal arms are AB, CD, EF and G (cytocomplex thummi). The Ch. heterodentatus karyotype cleary differs from those of other members of the obtusidens-group with a species-specific banding pattern in arms A, B, C and D. Chromosomal polymorphism on homo- and heterozygous inversions was found in arms, A, B, D, E and G. 19 inversion banding sequences and their 27 genotypic combinations have been recorded. The shortest arm G is highly polymorphic. Heterozygotes on the Balbiani ring activity were found in arm G along with homo- and heterozygotes on inversions. B-chromosomes with a frequency equal to 2.7-25.0% were recorded in some Volga populations.     

The morphology of larvae and systematics of the leaf-beetles Chrysolina tundralis and Chrysolina roddi (Coleoptera, Chrysomelidae, Chrysomelinae)

The 1st- and 4th-instar larvae of Chrysolina tundralis and Ch. roddi and the egg of the latter species are described for the first time; the instar-related changes of the larval morphology are discussed. The 4th-instar larva of Ch. tundralis is very similar to that of Ch. septentrionalis, but differs in the smaller sclerite-like plates of the abdominal segments and wider spaces between them (4–7 times as wide as a sclerite-like plate). The 4th-instar larva of Ch. roddi is very similar to that of Ch. pedestris, but differs in the dark brown coloration of the body and a fewer number of setae (9–12) in the dorsolateral areas of the meso- and metathorax. Data on the habitats and host plants of the larvae are given.     

Effect of galactose treatment in the puffing pattern of Chironomus thummi Balbiani rings

Galactose feeding of Chironomus thummi larvae induces the regression of Balbiani ring c (BRc) and the full expansion of BRb, both localized in the IV salivary gland chromosome. This effect coincides with that described on BR2 and BR1 of Ch. pallidivittatus and Ch. tentans. The puffing changes of BRb and BRc throughout development have been studied and also show identical variations as in BR1 and BR2 of Ch. pallidivittatus and Ch. tentans. The similar behaviour of BRb and BR1, and of BRc and BR2 respectively after galactose treatment and throughout development strongly suggests that these BRs play the same physiological role in the three Chironomus species, with BRb = BR1 and BRc=BR2.     

吴氏角叶蚤幼虫形态记述及其与同属另外三种的比较（蚤目：角叶蚤科）

描述了吴氏角叶蚤Ceratophyllus wui Wang et Liu 的幼虫形态,并与同属三种蚤幼虫作比较,标本采自湖北省西北部神农架海拔2 300 m 短嘴金丝燕四川亚种 Collocalia brevirostris innominata巢窝内。     

RNA TRANSPORT FROM NUCLEUS TO CYTOPLASM IN CHIRONOMUS SALIVARY GLANDS

The fine structure and cytochemistry of the extremely large RNA puffs, or Balbiani rings, in salivary gland nuclei of midge, Chironomus thummi, larvae have been investigated. The Balbiani rings are composed of a diffuse mass of electron-opaque 400 to 500 A granules, short threads about 180 to 220 A in diameter and associated fine chromatin fibrils. These components appear to be organized into brushlike elements which form the ring. Electron microscope cytochemistry has shown that the granules and short threads contain RNA. After ribonuclease digestion, only 50 to 100 A chromatin fibrils were apparent in the Balbiani ring, and the granules were no longer demonstrable. Deoxyribonuclease digestion had no apparent effect on these structures. Observations indicate that the granules are formed from the short threads and released into the nucleoplasm in which they are evenly distributed. At the nuclear envelope, many granules have been observed partially or completely within the nuclear pores. These granules become elongated and are shown to penetrate the center of the pore in a rodlike form, about 200 A in diameter. The Balbiani ring granules are not normally visible within the cytoplasm adjacent to the nuclear envelope, but have been rarely found in this region. It is suggested that the granules represent the product of the Balbiani ring, possibly a messenger RNA bound to protein, and that they regularly pass into the cytoplasm through a narrow central channel in the pores of the nuclear envelope.     

兴义维蚋多线染色体研究（英文）

首次在国内对兴义维蚋Simulium (Wilhelmia) xingyiense的多线染色体进行研究, 并提供其多线染色体标准图。选取兴义维蚋的成熟幼虫, 用改良苯酚品红染色法进行唾腺多线染色体制备, 并进行测量、 描述及分析。结果表明： 兴义维蚋多线染色体数目为3对（2n=6）。Ⅰ号染色体具中央着丝粒, Ⅱ和Ⅲ号染色体均为亚中央着丝粒染色体。核仁组织者区位于Ⅰ号染色体短臂近着丝粒端。巴尔比尼氏环和双泡位于Ⅱ号染色体短臂近中央位置。3对染色体的着丝粒区可形成明显的染色中心。兴义维蚋多线染色体具有多态性的倒位, 倒位频率为0.64。兴义维蚋多线染色体的着丝粒、 核仁组织区、 巴氏环、 双泡等主要特征性结构的位置及形态恒定一致,可作为该种的重要鉴别特征。其多态性的倒位可为该蚋种在细胞水平上进行蚋类分类鉴别和系统发育等研究提供基础资料。     

A review of the genusChironomus (Diptera,Chironomidae)

Two cytologically distinguishable species have been found in material ofChironomus australis. These species have been calledCh. australis andCh. duplex. Both belong to thepseudothummi-cytological grouping because they have the chromosome arm combinations AE, BF, CD, G.Ch. duplex shows a modified arm pattern due to a tandem fusion of arm G to arm E.—The banding patterns of the polytene chromosomes of the two species are compared to each other and to the Australian standard species,Ch. oppositus. Ch. australis is very close cytologically toCh. oppositus, whileCh. duplex, which is considered a derived species because of the tandem fusion, shows a number of inversion differences from the morphologically similarCh. australis. Ch. duplex is polymorphic for six inversions, four of which are simple inversions, the other two are complex involving also the transposition of some bands.Ch. australis appears to be monomorphic.     

Larval phases and ecology of Chrysolina (Pezocrosita) sahlbergiana (Coleoptera, Chrysomelidae)

Larvae of four instars are described in the little known leaf-beetle species Chrysolina sahlbergiana Jacobson from the Minusinsk Depression. Artemisia spp. is recorded as its host plant. Short setae on small scleroids distinguish the described larva from those of other species of the subgenus Pezocrosita. According to this character, this larva is closely related to larvae of species of the arcto-alpine subgenera of Chrysolina Motsch. Ch. sahlbergiana is regarded as a trans-Sayan, depression-steppe petrophilous species.     

Intraspecific and Interspecific Competition Between Cotesia flavipes and Cotesia sesamiae (Hymenoptera: Braconidae), Gregarious Larval Endoparasitoids of Lepidopteran Stemborers

Super and multiple parasitism of Chilo partellus (Lepidoptera: Pyralidae) and Sesamia calamistis (Lepidoptera: Noctuidae) by Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) were investigated in the laboratory. Progeny production of Co. flavipes increased as a result of increasing the number of ovipositions, from one to three per one Ch. partellus host larva, then decreased as a result of four and five ovipositions per larva. Cocoon weight, sex ratio and emergence of the parasitoid progeny were not affected by superparasitism. Low progeny production of Co. sesamiae and poor survival of Ch. partellus host larvae were found as a result of superparasitism. When S. calamistis was the host, the duration of immature stages of Co. flavipes , parasitoid emergence, progeny production and sex ratio were not affected by superparasitism, but cocoon weight, adult longevity and the potential fecundity of adult females decreased. Superparasitism of S. calamistis by Co. sesamiae did not affect emergence, longevity or sex ratio of adult progeny of the parasitoid, but prolonged immature development, lowered cocoon weight and decreased potential fecundity of adult female progeny. Co. flavipes out-competed Co. sesamiae when Ch. partellus was parasitized by both species. The potential for local displacement of Co. sesamiae by Co. flavipes in areas dominated by Ch. partellus in East Africa is discussed.     

谢氏宽漠王的生物学特性及行为

谢氏宽漠王Mantichorulasemenowi是荒漠半荒漠地区的有害昆虫之一。该文主要探讨了该虫的生物学特性和部分行为。该虫 2年发生 1代 ,世代不整齐 ,以成、幼虫越冬。卵期 1 0～ 1 8d ,幼虫共有 7龄 ,化蛹时间为 6月下旬至 8月上旬 ,蛹经过 1 1～ 1 7d羽化为成虫。食性杂。喜光 ,活动有明显的节律性。     

Osmium tetroxide/p-phenylenediamine staining of nucleoli and Balbiani Rings in Chironomus salivary glands.

This paper deals with the application of the osmium tetroxide fixation followed by p-phenylenediamine treatment to salivary gland cells from Chironomus larvae. After this procedure, cytoplasm, nucleoli and Balbiani rings show a high degree of staining both in light and electron microscopy, while chromatin remains unstained. Ethanol fixation followed by osmium tetroxide/p-phenylenediamine does not modify the above mentioned staining pattern. Under these conditions, extractive procedures for lipids do not affect the osmiophilia of nucleoli and Balbiani rings, while RNase or trichloroacetic acid treatment decreaes the staining degree of these structures. In osmium tetroxide/p-phenylenediamine treated salivary glands, the highest contrast within nuclei is seen to occur in the pars granulosa from normal or segregated nucleoli, as well as in Balbiani ring granules, which appear either as hollow granules or with a bipartite or horseshoe-like structure.     

Hatching and earliest larval stages of the priapulid worm Priapulus caudatus

Abstract. Here we describe the hatching and morphology of the earliest larval stages of the priapulid worm Priapulus caudatus for the first time. The hatching larva differs considerably from previously described larvae not only in its general body shape but also in its lack of a proper lorica including the typical lorica tubuli. Furthermore, no mouth opening or pharyngeal teeth have formed as yet, and the number and arrangement of scalids differ from that of later larvae. The hatching larva molts and emerges as the first lorica larva. This larva partially resembles earlier described lorica larvae, but there are a number of important differences; the first lorica larva is smaller, and the mouth opening as well as pharyngeal teeth are still yet to form. The second lorica larva is equipped with four rings of pharyngeal teeth; it shows striking similarity to the previously described larva of P. caudatus , i.e., the larva-type 2 , only differing in the scalid pattern. We conclude that the first two larval stages of P. caudatus have not been described previously. We suggest that discrepancies between the earliest lorica larvae described here and in earlier publications might depend on sub-speciation or ecophenotypic modification of larvae collected from different localities. Our findings highlight the importance of studying the development of non-model organisms such as priapulids under controlled laboratory conditions.     

Osmium tetroxide/p-phenylenediamine staining of nucleoli and balbiani rings in Chironomus salivary glands

Summary This paper deals with the application of the osmium tetroxide fixation followed by p-phenylenediamine treatment to salivary gland cells from Chironomus larvae. After this procedure, cytoplasm, nucleoli and Balbiani rings show a high degree of staining both in light and electron microscopy, while chromatin remains unstained. Ethanol fixation followed by osmium tetroxide/p-phenylenediamine does not modify the above mentioned staining pattern. Under these conditions, extractive procedures for lipids do not affect the osmiophilia of nucleoli and Balbiani rings, while RNase or trichloroacetic acid treatment decreaes the staining degree of these structures. In osmium tetroxide/p-phenylenediamine treated salivary glands, the highest contrast within nuclei is seen to occur in the pars granulosa from normal or segregated nucleoli, as well as in Balbiani ring granules, which appear either as hollow granules or with a bipartite or horseshoe-like structure.     

陕西府谷发现的晚中新世维氏大唇犀(奇蹄目,犀科)新材料

新材料有丰富的头骨和下颌骨标本,因而对维氏大唇犀有了更加深入的了解。观察结果显示维氏大唇犀在大唇犀属中的地位相当特别,它具有极窄的顶嵴间平面、马鞍形的头骨顶面、发育的眶上结节和较高的枕面,这些特征显示出它是所有已知大唇犀中最原始的一个种。     

Inversion polymorphism in the midge Glyptotendipes barbipes (Staeger)

Summary The salivary gland nuclei of larvalGlyptotendipes barbipes from Stratford (Ontario) comprise 3 pairs of long metacentric chromosomes (I–III) and one pair of short acrocentrics (IV). Homologues are closely paired when homozygous, centromeres are expressed as heterochromatic drums. Each chromosome carries a nucleolus, and Chromosome IV in addition carries a Ring of Balbiani. The gross polytene idiogram is identical with that implicit inBauer's cytological analysis of the same species from Germany.In direct comparison the banding pattern of the German and Canadian larvae proved identical for at least one sequence in each chromosome arm.Three simple inversions are known in the species; one (III L-1) is endemic to Germany, a second (II L-3) has been found only once in Canada and a third (I S-1) is common in Canada but has not been reported from Germany. The remaining 2 inversions (II L-1,2 and III S-1,2) are complex and are here analysed as included types. Rearrangement II L-1,2 occurs both in Canada and in Germany and achieves heterozygous frequencies near 50% in both countries. It is the first inversion reported to be holarctic in distribution in insects not associated with man. The second complex inversion III S-1,2 has been found only in Canada where it is common. In each of the complex inversions at least one pair of breaks is near coincident.Meiosis is normal and chiasmatic in structurally homozygous males. It lacks conspicuous localization of chiasmata. No meiotic abnormalities were observed in inversion heterozygotes. It is postulated that complex heterozygous inversions interfere with pairing to such an extent that the residual ill-effects are out balanced by heterosis of co-adapted systems.A selective advantage of heterozygosis is directly indicated for II L by a significant (p=0.02) excess of II L/II L-1,2 larvae over the Hardy-Weinberg expectation.     

Gytogenetics of Chironomus riparius L. from the fishpond in Borok village (Diptera, Chironomidae)

We have found three inherited inversions in Chironomus riparius populations from the Borok fishpond, namely: (A3d-B1a) in the arm A (C5a-C6a) in the arm D and (B3b-4d/e) in the arm F. Increase of heterochromatin in some bands of chromosome F (B3h, B3h + B3c--C1a) and puffs appearance in the arms C, D and E have been observed. We saw also changes in functional activity of nucleolar organizer (N) and Balbiani rings (BRe/BRb). It has been found that some of inversion breakpoints coincide with the Alu and Hinf satellite DNA localization sites.     

A simple visual system without neurons in jellyfish larvae

Earlier detailed studies of cnidarian planula larvae have revealed a simple nervous system but no eyes or identifiable light sensing structures. Here, we describe the planula of a box jellyfish, Tripedalia cystophora, and report that these larvae have an extremely simple organization with no nervous system at all. Their only advanced feature is the presence of 10-15 pigment-cup ocelli, evenly spaced across the posterior half of the larval ectoderm. The ocelli are single cell structures containing a cup of screening pigment filled with presumably photosensory microvilli. These rhabdomeric photoreceptors have no neural connections to any other cells, but each has a well-developed motor-cilium, appearing to be the only means by which light can control the behaviour of the larva. The ocelli are thus self-contained sensory-motor entities, making a nervous system superfluous.