露螽科四种昆虫的核型研究

本文以螽斯精巢为实验材料,经过低渗、固定、压片、空气干燥、Giemsa染色制备染色体标本,对螽斯总科露螽科4种螽斯的核型进行了研究,结果Phaneroptera falcata 2n♂=27, Phaneroptera gracilis 2n♂=25,Ducetia japonica 2n♂=29,Isopsera sp.2n♂=31,均为近端着丝粒染色体,性别决定机制均为XO♂/XX♀型, X染色体为染色体组中最大的染色体。作者认为,Isopsera sp.（2n♂=31）可能是露螽科中较原始的种类,Ducetia japonica(2n♂=29),Phaneroptera falcata (2n♂=27),Phaneroptera gracilis (2n♂=25)可能是由2n♂=31进化来的衔接融合在露螽科染色体进化中起着重要作用。 Abstract：Karyotypes of four species belonging to three genera of the Phaneropteridae were investigated.The diploid number of chromosomes is as follows: Phaneroptera falcata species 2n♂=27(XO),Phaneroptera gracilis 2n♂ =25 (XO),Ducetia japonica 2n =29 (XO) and Isopsera sp.2n♂=31(XO) ,all chromosomes are acrocentric,the X chromosomes are the largest members of the sets.It may be assumed that Isopsera sp. 2n♂=31 represents the basic number of chromosomes.The other species,Ducetia japonica 2n♂=29, Phaneroptera falcata 2n♂=27, Ph.gracilis 2n♂=25 could originate 2n♂=31 .Tandem fusions may be important in the karyotype evolution of Phaneropteridae.     

两种蛩螽的染色体核型(直翅目,螽斯科)

报道中国蛩螽亚科巨叉畸螽Teratura(Macroteratura)megafurcula(Tinkham,1944)和贺氏栖螽Xizicus(Eoxizicus) howardi(Tinkham,1956)的染色体核型,染色体数目2n(♂)=31,均为近端着丝粒染色体,性别决定机制为XO/XX型.研究显示,巨叉畸螽的性染色体,常染色体中的大型染色体和中型染色体相对较大,而小型染色体比贺氏栖螽的染色体相对较小.     

中华蝈螽与中华螽斯精子超微结构研究(直翅目,螽斯总科)

研究了中华蝈螽Gampsocleis sinensis与中华螽斯Tettigonia chinensis精子的超微结构.两种精子的顶体复合体侧生于核上且包裹了核的一部分,顶体复合体横切面两侧角分离或两侧角与细胞核远离,或仅见其一侧角;中华蝈螽顶体外层在顶体本体两侧角外多呈晕圈状;轴丝为典型的9 9 2型;轴丝两侧的副纤维结构为2副微管;轴丝与线粒体衍生体之间的连接带3条;中华蝈螽有的横切面中两扁平膜池连接在一起;两种精子的中心粒侧体部位具五纵层细胞器.     

中国两种波腿蝗（蝗总科：癞蝗科）染色体C带核型研究

报道中国两种波腿蝗的染色体C带核型,结果表明：红胫波腿蝗Asiotmethis zacharjini (Bei-Bienko, 1926) 2n ♂ =18, neo-X为亚中着丝粒染色体,其他均为近端着丝粒染色体,染色体除强染的着丝粒C带,S8染色体具强染端部C带带纹,neo-Y染色体还具有一条宽的弱染的近着丝粒端居间C带,性别决定机制是neo-XY ♂型,该种染色体组成和性别决定机制在我国癞蝗中为首次报道,蓝胫波腿蝗Asiotmethis jubatus (Uvarov, 1926) 2n＝19♂,均为近端着丝粒染色体,仅具有明显强染的着丝粒C带,性别决定机制是XO ♂型;两种波腿蝗的异染色质含量存在显著性差异（α=0.05）。     

广东白腹巨鼠的G带核型和银染色

本文报道了广东白腹巨鼠的核型、G带和银染色。结果表明,二倍体染色体数目为2n=40,常染色体包括4对近端着丝粒染色体,6对末端着丝粒染色体,8对中着丝粒染色体,1对近中着丝粒染色体。性染色体XY为大小不等的末端着丝粒染色体。G分带可鉴别每对染色体的特征,Ag-NORs位于1对近端着丝粒染色体（3号）和2对中等大小的末端着丝粒染色体。     

中国云南果蝇属暗果蝇种组的核型分化

观察了新近发现于我国云南的果蝇属暗果蝇种组(Drosophila obscura species group)种类D．luguensis、D．dianensis和D．limingi的有丝分裂中期核型,并将3个种的核型与各自的近缘种类进行了比较。D．luguensis具2n=12条染色体,包括3对中央着丝粒(V形)染色体、2对近端着丝粒(棒状)染色体以及1对微小(点状)染色体。其中X和Y染色体均为中央着丝粒染色体。D．dianensis和D．limingi具2n=10条染色体,包括1对大的V形常染色体,1对小的V形常染色体,2对J形(亚中着丝粒型)常染色体和1对点状染色体。其中X染色体为J形,Y染色体为短棒状。基于核型比较的结果以及D．sinobscura亚组地理分布的资料,结合种间系统发育关系研究结果,认为D．luguensis可能保留了该亚组祖先种类的核型。D．sinobscum的核型(2n=12：2V,1J,2R,1D)可能由一个pre-“sinobscura-hubeiensis”谱系的一个分支通过臂间倒位演化而来,而D．hubeiensis的核型(2n=10：4V,1D)可能由该谱系的另一分支通过着丝粒融合(2对近端着丝粒常染色体的融合)而形成。推测在D．dianensis和近缘欧洲种D．subsilvestris(2n=12：3V,2R,1D)间、D．limingi和东亚近缘种D．tsukubaensis(2n=12：3V,2R,1D)间的物种分化过程中,可能有相似的染色体变异类型发生。     

五种蟋蟀染色体的研究 A Study on Chromosomes in Five Crickets

报道了中国4种蟋蟀的染色体C带核型,即黑脸油葫芦 Teleogryllus occipitalis (Serville,1838),2n=27,XO(♂);银川油葫芦 T.infernalis (Saussure,1877),2n=27,XO(♂);迷卡斗蟋 Velarifictorus micado (Saussure,1877),2n=29,XO(♂);泰康棺头蟋 Loxoblemmus taicoun (Saussure,1877),2n=17,XO(♂)及长颚斗蟋V.aspersus (Walker,1869)的核型即2n=23,XO(♂)。4种蟋蟀各染色体均显示强的着丝粒带,多数染色体显强或中的端带,斗蟋属(Velarifictorus)1种部分染色体显示居间带,油葫芦属(Teleogryllus)2种和棺头蟋属（Loxoblemmus）1种无居间带,各物种表现出明显的种类特异性。对蟋蟀染色体及C带核型在分类中的意义作了初步的探讨。 Abstract:This is a report on the chromosome C-banded karyotypes of four Gryllidae species in China.They are Teleogryllus occipitalis(Serville,1838),2n=27,XO(♂);T.infernalis(Saussure,1877),2n=27,XO(♂);Velarifictorus micado (Saussure,1877),2n=29,XO(♂);Loxoblemmus taicoun Saussure,1877,2n=17,XO(♂).And another karyotype is reported as well,it is V.aspersus（Walker,1869）,2n=23,XO(♂).All chromosomes of the four crickets show strong paracentric C-bands,lots of the arms show strong or median terminal C-bands,and some chromosomes of V.micado show middle C-bands.In addition,the total heterochromatin content of the four crickets was shown.The cytotaxonomic significance is discussed.     

雏蝗属黑翅亚属两种雏蝗染色体核型的比较研究

采用常规染色体制片方法,对雏蝗属黑翅亚属的黑翅雏蝗(Chorthippus(Megaulacobothrus)aethalinus(Zub.))和中华雏蝗(Ch.(M.)chinensis Tarb.)的染色体核型进行了分析比较,结果表明,两种雏蝗的染色体数目均为2n(♂)=17=16+XO;常染色体为中部着丝粒(m,6条)和端部着丝粒(t,10条)两种类型,性染色体类型为端部着丝粒,二者的相似性显示出该属的基本特征。但两种雏蝗的核型公式和染色体的相对长度组成则不相同,黑翅雏蝗K(2n,♂)=6m+11t=6L+6M+4S+XO;中华雏蝗K(2n,♂)=6m+11t=6L+8M+2S+XO。而且,二种雏蝗的性染色体位次及相对长度也有明显差异:黑翅雏蝗的性染色体位于第五位,相对长度为8.33%,而中华雏蝗的则位于第八位,相对长度为5.53%。由此看出,二种雏蝗不同物种间存在的不同遗传特征。     

豪猪（Hystris hodgsoni）染色体的研究

豪猪(Hystris hodgsoni)染色体的数目为2n=66,染色体的臂数NF=124。常染色体由8对中着丝粒染色体、16对亚中着丝粒染色体、6对亚末端着丝粒染色体及2对近端着丝粒染色体组成。X和Y性染色体是一对长度大小有明显差异的中着丝粒染色体。对染色体作了G、C、Ag显带处理。C带结果可以看出有些染色体上存在着整个的异染色质短臂。Ag-NORs的数目为3—5个。     

山瑞鳖Trionyx steidachneri染色体组型

本文以骨髓为材料,用秋水仙—低渗—空气干燥制片法,制备染色体标本,对山瑞鳖的染色体组型进行研究。其2n=66 NF=60,其中近中着丝粒染色体4对,近端着丝粒染色体4对和端部着丝粒14对。并有11对点状染色体。山瑞鳖与鳖的染色体数目是十分相近的。     

Saudi gazelle (Gazella saudiya) is not a subspecies of Dorcas gazelle

Karyotypes of Saudi gazelle (2n = 47 female, 2n = 50/51 male) are presented for the first time. The three karyotypes shown here vary in the numbers of metacentric chromosomes, but the cause of this variation is not yet known. Although Saudi gazelle are often regarded as a subspecies of Dorcas gazelle, the chromosome numbers and karyotypes of Saudi gazelle are too different from Dorcas gazelle (2n = 30 female, 2n = 31 male) for them to be considered a subspecies. It is also unlikely that these species would interbreed. In view of the present findings, the taxonomic status of this highly endangered gazelle needs to be resolved as soon as possible.     

Karyological notes on six beetle species from Armenia (Coleoptera: Tenebrionidae,Cerambycidae, Curculionidae)

Karyotypic details were studied in males of six beetle species from three families, viz. Tenebrionidae: Dailognatha pumila Bdy. (2n = 20, n(male) = 9 + Xy(p)), Pachyscelis musiva Ménétr. (2n = 18, n(male) = 8 + Xy(p)), Pimelia capito Kryn. (2n = 18, n(male) = 8 + Xy(p)); Cerambycidae: Agapanthia walteri Reitt. (2n = 20, n(male) = 9+Xy(p)), Agapanthia korostelevi Danilevsky (2n = 20, n(male) = 9 + Xy(p)); Curculionidae: Phyllobius caucasicus Stierl. (2n = 22, n(male) = 10 + Xy(p)). The chromosome number and sex determining system of all beetle species are described for the first time. Evolutionary trends in karyotypes of the studied beetle groups are briefly discussed.     

Cytogenetic investigations on seven Palaearctic weevil species (Coleoptera, Curculionidae).

Cytogenetic investigations were carried out on seven species of bisexual weevils from five subfamilies. The following numbers of chromosomes were found in individual species: 2n = 22, n male = 10 + Xyp in Ptochus porcellus Boh. (Otiorhynchinae); 2n = 40, n male = 19 + Xyp in Larinodontes turbinatus Gyll. (Cleoninae); 2n = 26, n male = 12 + Xyp in Curculio pellitus (Boh.) (Curculioninae); 2n = 30, n male = 14 + Xyp in Acalles camelus (F.), Acalles echinatus (Germ.), Acalles hypocrita Boh. (Cryptorhynchinae), and 2n = 40, n male = 19 + Xyp in Cionus hortulanus (Foucr.) (Mecininae). The heterochromosomes of all the examined species form, in the first meiotic metaphase, a parachute bivalent. The chromosome number and sex determining system of six species and two genera are described for the first time.     

Cytogenetics of fleas (Siphonaptera: Pulicidae). 1. Rat fleas of the genus Xenopsylla

Five populations of Xenopsylla cheopis exhibit a chromosome complement of 2n = 17, X1X2Y (male), and 2n = 18, X1X1X2X2 (female). A detailed analysis of populations of X. astia from Bombay and Trivandrum led to the identification of two distinct cytotypes which hybridisation studies indicated were sibling species. These are referred to as X. astia with a diploid chromosome number of 2n = 18, X1X2X3Y (male), and 2n = 20, X1X1X2X2X3X3 (female) and X. prasadii with 2n = 10, X1X2Y1Y2 (male), and 2n = 10 X1X1X2X2 (female). It is proposed that X. prasadii is derived from X. astia through translocation/fusion events since the average total chromosome lengths are remarkably similar in all three species.     

Two permanent linear chains of sex chromosomes in Neotermes fulvescens and karyotypes of two other neotropical Kalotermitidae species (Insecta, Isoptera).

Meiosis and (or) mitosis of males and females of Cryptotermes brevis, Eucryptotermes wheeleri, and Neotermes fulvescens, all of them from the neotropical region, were analyzed. Cryptotermes brevis showed a similar karyotype to that obtained by other authors for specimens of the neartic and Australian regions (2n = 36 for females and 2n = 37 for males, with XX and XYY sex mechanisms, respectively). Eucryptotermes wheeleri, the only species that has been described in this genus, showed the lowest number of chromosomes reported for Isoptera (2n = 22) until now. The male meiosis of this species presents a linear chain of six sex chromosomes, three of them being X and three of them Y chromosomes. Neotermes fulvescens showed a diploid number of 40 for males and 42 for females and, in the first male meiosis, two linear chains of chromosomes, both related to sex. One of the chains, named A, presented nine chromosomes and the other, named B, seven chromosomes. Hypotheses to explain these mechanisms are formulated in this paper and putative ancestral relationships with other species of Kalotermitidae are presented.     

Improved resolution of the meiotic chromsomes in both sexes of Euxoa species and their hybrids (Lepidoptera: noctuidae).

An air drying and Giemsa staining technique produces consistently good quality cytological preparations when applied to different species of Euxoa (Lepidoptera: Noctuidae) and, in particular, it allows an imporved resolution of the meiotic chromosomes in both sexes. All species so far investigated have a basic haploid chromosome complement of n (male) = 31(XX): n(female) = (XY). A single chiasma per individual bivalent is clearly visible in the male sex. Some chiasmata are formed in interstitial positions, but, by metaphase I, they have all undergone complete terminalization while the bivalents orient axially on the first division spindle. Direct evidence for lack of chiasma formation in the 31 hormorphic bivalents in the female sex is reported for the first time for species of Noctuidae. Evidence in favor of an XY system in the female sex is discussed. Preliminary studies of the meiotic divisions in hybrid material reveal the presence of cryptic structural differences between certain taxa, and will help to elucidate taxonomic problems within this complex genus.     

Production and genetic analysis of partial hybrids in intertribal crosses between Brassica species (B. rapa, B. napus) and Capsella bursa-pastoris

Capsella bursa-pastoris (L.) Medic (2n = 4x = 32) is a natural double-low (erucic acid < 1%, glucosinolates < 30 micromol/g) germplasm and shows high degree of resistance to Sclerotinia sclerotiorum. Hybridizations were carried out between two Brassica species viz. B. rapa (2n = 20) and B. napus (2n = 38) as female and C. bursa-pastoris as male parent to introduce these desirable traits into cultivated Brassica species. Majority of F(1) plants resembled female parents in morphology and only a few expressed some characters of male parent, including the white petals. Based on cytological observation of somatic cells, the F(1) plants were classified into five types: two types from the cross with B. rapa, type I had 2n = 27-29; type II had 2n = 20; three types from the crosses with B. napus, type III was haploids with 2n = 19; type IV had 2n = 29; type V had 2n = 38. One to two chromosomes of C. bursa-pastoris were detected in pollen mother cells (PMCs) of type I plant by genomic in situ hybridization (GISH), together with chromosomal segments in ovary cells and PMCs of some F1 plants. Amplified fragment length polymorphism (AFLP) bands specific for the male parent, novel for two parents and absent bands in Brassica parents were generated in majority of F1 plants, even in Brassica-types and haploids, indicating the introgressions at various levels from C. bursa-pastoris and genomic alterations following hybridization. Some Brassica-type progeny plants had reduced contents of erucic acid and glucosinolates associated with improved resistance to S. sclerotiorum. The cytological and molecular mechanisms behind these results are discussed.     

Effect of (-)-para-fluoro-deprenyl on survival and copulation in male rats.

Six-month old male rats were treated with 0.25 mg/kg, s.c., (-)p-fluoro-deprenyl (n = 40) or salt solution (n = 20) three times a week for 25 months. Three of the 20 saline-treated and 15 of the 40 drug-treated males survived (p = 0.05). Sexual activity of the survivors was tested at the end of the experiment. Three of the (-)p-fluoro-deprenyl-treated 31-month-old males proved to be sexually fully active, though, Wistar rats lose their ability to ejaculate by completing their second year of life. Non-copulator, 13 month old male rats were treated instead of the usually used 0.25 mg/kg dose with 0.01 mg/kg, s.c., (-)deprenyl (n = 9), (-)p-fluoro-deprenyl (n = 9) and salt solution (n = 9), three times a week, for 82 weeks and mating activity was tested weekly. The lifespan of the non-copulators was very short: 102 weeks for saline (n = 9), 106 weeks for (-)deprenyl (n = 8) and 104 weeks for (-)p-fluoro-deprenyl (n = 7). Survival was lightly changed by this very small dose treatment, one (-)deprenyl-treated male and two (-)p-fluoro-deprenyl-treated rats remained alive. The copulatory activity, however, was substantially improved.     

Chromosome numbers of thirty-one species of Indian Lepidoptera

Chromosome numbers are reported for 31 Indian species. Results forPsara stultalis (2n=60, n=30),Malacosoma indica (50, 25) andPygaera fulgurita (62, 31) differ from data reported by earlier workers. Eighteen species are new to cytology.     

The effect of protein and salt loading on urinary concentrating ability in four chromosomal species of Spalax ehrenbergi

Urinary concentrating ability was tested under protein and salt load in the four chromosomal species of subterranean mole-rats ( Spalax ehrenbergi superspecies) found in Israel. Protein stress induced by a diet of soyabeans supplemented by agar gel, demonstrated a significant increase in urinary osmolarity (UO). In the species living in the driest and warmest region (2n = 60). UO (1423·101 mOsmol/kg) was significantly (P<0·05) higher than in the other three species (2n = 52. 1172·31 mOsmol/kg; 2n = 54, 1160·116 mOsmol kg; and 2n = 58, 1216·145 mOsmol/kg). Upon salt loading this diet with 0·3 mol NaCl, UO increased significantly. However, when the salt load was increased to 0·45 mol NaCl, UO decreased significantly in all but one species (2n = 60) which maintained UO at 1522·65 mOsmol/kg. A decline in UO was attributed to diuresis resulting from a significant increase in urine and sodium excretion. The kidney, of only the xeric ranging species (2n = 60), demonstrated the ability to produce a hyperosmotic urine, in spite of the high salt load. These results might explain the restricted distribution of S. ehrenbergi: the only species (2n = 60) found in an environment rich in succulents and halophyte plants (steppe). This species appears to push speciation and adaptive radiation to the southern limit of its superspecies.