Karyological investigations on seven weevil species (Coleoptera, Curculionidae)

Karyological studies were carried out on seven Palaearctic weevils. The following chromosome numbers were found in individual species, i.e. Otiorhynchus niger (F.), Phyllobius viridearis (Laich.), Phyllobius scutellaris Redt., Phyllobius calcaratus (F.), Polydrusus cervinus (L.), and Brachyderes incanus (L.) 2n = 22, n Male = 10 + Xyp, in Lixus elegantulus (Boh.) 2n = 22, n Male = 21 + Xyp. The heterochromosomes of all the examined species form, in the first meiotic metaphase, a typical parachute bivalent.     

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.     

A cytogenetic study on three Chilean species of Chrysomelinae (Coleoptera, Chrysomelidae)

Three species of Chilean leaf beetles were chromosomally analyzed. The endemic Araucanomela wellingtonensis displays a male meioformula of 13 + Xyp with 2n = 28 chromosomes and an asymmetric karyotype with two large autosome pairs and 12 medium/small pairs of autosomes and sex-chromosomes, a diploid number which had not been found among the other species of the subtribe Paropsina sensu lato studied to date. Strichosa eburata presents a meioformula of 11 + Xyp, 2n = 24 chromosomes, as occurs in many species of chrysomelines belonging to different subtribes. Furthermore, Phaedon cyanopterum has a 16 + Xyp meioformula, that is 2n = 34 chromosomes, of small size mostly, also in agreement with the karyological findings obtained in all the other congeneric species so far examined. These cytogenetic data are discussed with respect to the previous ones in this subfamily and with other characters of taxonomic and evolutionary value.     

C-banding patterns in chromosomes and sperm of Strophosoma capitatum (De Geer, 1775) (Coleoptera: Curculionidae, Brachyderinae)

An analysis was made of the C-banded karyotype of Strophosoma capitatum (Deg.). The results indicate that the chromosome number is 2n = 22 and n Male = 10 + Xyp. The examined karyotype shows a pericentromeric position of constitutive heterochromatin in all autosomes. The shorter arm of the X chromosome is heterochromatic while the y chromosome is wholly euchromatic. Successive stages of spermatogenesis were analysed.     

C-banding patterns in chromosomes of Paederius rubrothoracicus carpathicola Scheerpetz 1957 (Coleoptera, Staphylinidae: Paederinae)

An analysis was made of the C-banded karyotype of Paederius rubrothoracicus carpathicola Scheerp. The result indicates that the chromosome number is 2n = 36 and n Male = 17 + Xyp. The examined karyotype shows a paracentromeric position of constitutive heterochromatin in all autosomes. The y chromosome is wholly euchromatic.     

Ag-banded karyotypes in six species of jewel-beetles (Coleoptera, Buprestidae).

The male karyotypes of six species of the buprestid genera Sphenoptera (two species) and Acmaeoderella (four species) were studied after Ag-banding. The following karyotypes were found in individual species: n = 19-23, with predominance of 23, in Sphenoptera scovitzi Fald., 2n = 24 (22 + Xyp) in Sphenoptera mesopotamica Mars., 2n = 18 (16 + Xyr) in Acmaeoderella flavofasciata Pill. & Mitt., Acmaeoderella gibbulosa Men., Acmaeoderella boryi Brulle, Acmaeoderella vetusta Men. In Sph. scovitzi, two chromosome pairs were found to display stable argentophilous blocks. In Sph. mesopotamica, NOR-bearing is one of the large autosomal bivalents. In all species of the genus Acmaeoderella, a nucleolus-like argentophilous body is placed between the X and y chromosomes.     

Cytogenetics of the darkling beetles Zophobas aff. confusus and Nyctobates gigas (Coleoptera, Tenebrionidae)

Males of Zophobas aff. confusus and Nyctobates gigas (Tenebrionidae) collected in the State of Pernambuco, Brazil, were studied through conventional staining, C-banding, silver nitrate impregnation (AgNO(3)), and the base specific fluorochromes CMA(3) and DAPI. Z. aff. confusus was found to have 2n = 20 (9+Xyp) while N. gigas exhibited 2n = 18 (8+neoXY). Large pericentromeric blocks of constitutive heterochromatin (CH) were detected throughout the autosomal complement of the two species, except in one autosomal pair of N. gigas in which no heterochromatic block was observed. The sex chromosomes of both species were almost totally heterochromatic. Double staining with CMA(3)/DA (distamycin) and DAPI/DA marked CH in Z. aff. confusus. However, DAPI staining was more intense. N. gigas was found to possess blocks of CH-positive CMA(3) and homogeneous DAPI. AgNO(3) staining also revealed differences between the two species. In Z. confusus an NOR was observed in the sexual bivalent Xyp and N. gigas was found to have an autosomal NOR.     

天牛染色体核型研究及其核型快速检测在检疫中的应用

本文研究了天牛科3亚科9族20种的染色体核型。在所研究的20种天牛核型中,染色体以10对为主,其性染色体决定机制以Xyp为主。这种性别决定机制被认为是最原始的形式。Xyp,是大X染色体和小y染色体形成的降落伞状（parachute-like）的二价体。在细胞减数分裂中,雄性细胞呈现单倍体数目。研究发现,20种染色体中1/2种类其雄性单倍体数目为10,并且由Xyp型性染色体的性别决定机制。生物活细胞在24 h内均能制作成核型玻片。由于不同生物种类间的核型差异显著,本文对应用核型检测方法检测和鉴定有害生物的可行性进行探讨。     

Cytogenetic analysis of Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) with Xyp sex determination system using standard staining, C-bands, NOR and synaptonemal complex microspreading techniques

The mitotic and meiotic chromosomes of the beetles Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) were analysed using standard staining, C-banding and silver impregnation techniques. We determine the diploid and haploid chromosome numbers, the sex determination system and describe the chromosomal morphology, the C-banding pattern and the chromosome(s) bearing NORs (nucleolar organizer regions). Both species shown 2n = 20 chromosomes, the chromosomal meioformula 9 + Xyp, and regular chromosome segregation during anaphases I and II. The chromosomes of E. atomaria are basically metacentric or submetacentric and P. dermestoides chromosomes are submetacentric or subtelocentric. In both beetles the constitutive heterochromatin is located in the pericentromeric region in all autosomes and in the Xp chromosome; additional C-bands were observed in telomeric region of the short arm in some autosomes in P. dermestoides. The yp chromosome did not show typical C-bands in these species. As for the synaptonemal complex, the nucleolar material is associated to the 7th bivalent in E. atomaria and 3rd and 7th bivalents in P. dermestoides. Strong silver impregnated material was observed in association with Xyp in light and electron microscopy preparations in these species and this material was interpreted to be related to nucleolar material.     

Chromosomal polymorphism in Cassida syrtica Boh. (Coleoptera: Chrysomelidae)

Intraspecific polymorphism with regard to autosomes has been observed in Cassida syrtica, where an additional large autosome (marker chromosome) has been encountered in the diploid as well as the haploid set of chromosomes. The diploid number for the normal type is 18 (n = 8 + Xyp). Its polymorphic form reveals a diploid set of ninetten chromosomes with an exceptional karyotype (n = 8 + 1 Mt + Xyp).     

Karyotypic characterization by mitosis, meiosis and C-banding of Eriopis connexa Mulsant (Coccinellidae: Coleoptera: Polyphaga), a predator of insect pests

Eriopis connexa presents a chromosome number of 2n = 18 + XX for most females analyzed and a meioformula of n = 9 + Xyp for all males. A small metacentric B chromosome restricted to females occurred in 10% of our sample and, when submitted to C-banding, it was shown to be almost completely euchromatic. Chromosome pairs 2 and 3 had satellites and probably contained the nucleolar organizer regions (NORs). C-band analysis also revealed that the constitutive heterochromatin was localized in the centromeres of all chromosomes in the complement.     

Some aspects of karyotype of Liarina (Orthoptera: Tettigoniidae, Agraeciini) from Vietnam

Karyotypes (chromosome number and shape) of four species of the subtribe Liarina were studied. The chromosome numbers and NF (Fundamental Number) in this group of species range from 2n Male = 33 (34) to 27(30): Liaromorpha buonluoiensis 2n Male = 33 (34), Sialaiana transiens 2n Male = 29 (34), Liara tramlapensis 2n Male = 29 (32), and Anelytra (Perianelytra) propria 2n Male = 27 (30). Cyto-taxonomy analysis indicates an intensive karyotype evolution among species belonging to three different groups of the genera. Differences of karyotypes are connected with Robertsonian fusion and tandem fusion in autosomes. Additionally, C-banding distribution and location of the NORs were studied.     

松墨天牛和光肩星天牛染色体核型

以松墨天牛Monochamus alternatus Hope和光肩星天牛Anoplophora glabripennis Motschulsky为研究对象,以各种天牛的最适条件和最佳材料进行染色体的制备和观察。试验结果如下:松墨天牛的最佳试验材料为7日龄蛹的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体5对,中型染色体4对,性染色体在其大小排列中位于最末位,为中型染色体,染色体组式为5L+4M+Xyp;光肩星天牛的最佳试验材料为初羽化成虫的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体6对,中型染色体3对,性染色体在其大小排列中位于最末位,但也为中型染色体,染色体组式:6L+3M+Xyp。     

Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA(3) ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO (3) staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent.     

Sequential FISH analysis with rDNA genes and Ag-NOR banding in the lady beetle Olla v-nigrum (Coleoptera: Coccinellidae)

We have characterized the meiosis of Olla v-nigrum by standard analysis, performed a NOR study using NOR banding, FISH of rDNA genes and sequential FISH/AgNOR analysis, and adapted the FISH methodology to Coccinellidae. The chromosome number determined at metaphase I was n = 9 + Xyp. At zygotene it was possible to identify the sex vesicle which presented a deeply stained heteropycnotic block. Chromosome X is much larger than the y and the two combine, forming a "parachute" in metaphase I. FISH analysis using a probe of rDNA genes 18S, 28S and 5.8S of D. melanogaster was used to map the genes in the sex vesicle. The NOR band showed high gene activity in this region. These results were confirmed using sequential FISH/Ag NOR analysis. The data obtained for Olla v-nigrum agree with the classical hypothesis raised to explain the type of sex chromosome association in a parachute format (Xyp) as being due to the presence of nucleolar material. The chromosome number and parachute configuration during metaphase I in this species agree with the basic karyotype of most Coleopterans. The major adaptation of the FISH method was the simultaneous denaturation and hybridization that permitted preservation of chromosome morphology, an essential factor when the chromosomes are small.     

Patterns of chromosome banding in four nabid species (Heteroptera, Cimicomorpha, Nabidae) with high chromosome number karyotypes

Male Nabis (Aspilaspis) indicus (St?l), N. (A.) viridulus Spinola, Himacerus (Himacerus) mirmicoides (O. Costa) (2n=32+XY) and Prostemma guttula (Fabricius) (2n=26+XY) were studied using C-banding, silver nitrate staining and base-specific fluorochrome (DAPI and CMA(3)) staining. N. indicus differed from N. viridulus in distribution pattern of C-bands, which were telomeric in the former while interstitial in the latter. H. mirmicoides showed interstitial C-bands in the majority of autosomes. P. guttula had no conspicuous C-bands in other chromosomes, but only in the Y, which was totally heterochromatic. C-heterochromatin was labelled with DAPI, indicating that it was AT-rich. In every species, both X and Y chromosomes were NOR-bearing, and the NOR regions were GC-rich. In H.mirmicoides and P. guttula, NORs showed sub-median location in the X and distal in the Y, such a pattern being probably common in Nabidae. The present paper provides new information on the genome organization and new cytological markers useful for a better insight into karyotype evolution of nabid species.     

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.     

中国海南岛13种菊科植物的细胞学研究

对海南岛13种菊科植物进行了染色体研究,对其中9种植物进行了核型分析,结果为: 树菊Tithoni-a diversifolia A.Gray,2n=34=26m+8sm（2sat）;鳢肠Eclipta prostrata（L.）L.,2n=22=18m+4sm;金腰箭Synedrella nodiflora（L.）Gaertn.,2n=40=6m+30sm（2sat）+4st;三叶鬼针草黄花类型Bidens pilosa L.（yel-low flower）,2n=72=46m+26sm（2sat）;羽     

香港喜盐草属植物的核型分析

报道了分布于我国香港特别行政区的喜盐草属(Halophila Thou.) 2种植物的染色体数目和核型,其体细胞中期染色体数目均为2n=18。它们的核型公式分别为：喜盐草(H. ovalis (R. Br.) Hook. f.) 2n=2x=18=4m+14sm;贝克喜盐草(H. beccarii Asch) 2n=2x=18=8m+10sm(首次报道)。核型均属于2B型。     

Karyotype evolution in Curimatidae (Teleostei, Characiformes) from the Amazon region. II. Centric fissions in the genus Potamorhina

Using cytogenetic analysis following Giemsa staining, nucleolar organizer region (NOR) staining, and C-banding, three distinct karyotypes in three species of curimatids belonging to the fish genus Potamorhina were identified: 2n = 54/44 M + 10 SM (P. pristigaster), 2n = 56/52 M + 2 SM + 2 ST (P. latior), and 2n = 102/2 M + 2 SM + 98 A (P. altamazonica). A 2n = 54 was considered to be the ancestral diploid number and the different karyotypes were probably the result of centric fissions. Both the NOR pattern and constitutive heterochromatin pattern are species specific.