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1

C-heterochromatin and extra (B) chromosome distribution in six species of the Nabis (Heteroptera, Nabidae) with the modal male karyotype 2n = 16 + XY

100%
Grozeva S., Nokkala S.
Folia Biologica
|
2002
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vol. 51
|
issue 1-2
13-21
EN
The basic male karyotype of the six Nabis species (Heteroptera, Nabidae) is confirmed as being 2n=16+XY. The chromosomes are holokinetic while male meiosis is achiasmatic. The sex chromosomes undergo postreduction and in second metaphase show distance pairing, registered in all nabid species examined so far. Using C-banding technique for the first time in the family Nabidae, the heterochromatin was revealed on chromosomes of six species. The species showed different amount and distribution of C-heterochromatin. Only in Nabis (Dolichonabis) limbatus did the C-bands distribution make possible the identification of every chromosome pair in the karyotype. In other species, C-bands were found in some of the autosomes and the X, localized either interstitially or at telomeres. Only theYusually showed relative stability of the C-banding pattern. In four of six species, extra (B) chromosomes were observed and their behaviour in meiosis described.
2

Automictic and apomictic parthenogenesis in psocids (Insecta: Psocoptera)

100%
Nokkala S., Golub N. V.
Folia Biologica
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2006
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vol. 54
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issue 1-2
19-22
EN
Karyotypes and meiosis patterns in three obligatory thelytokous Psocoptera species have been studied for the first time. Females of Aaroniella badonneli (Danks) display 9 chiasmatic bivalents in oocyte metaphase I (2n = 18), hence meiosis is of the automictic type. Females of Ectopsocus meridionalis Ribaga and Valenzuela sp. display 3n = 27, and 27 univalent chromosomes are present in oocyte metaphase I. Thus, meiosis in these species is of the apomictic type.
3

Chromosome numbers, sex determining systems, and patterns of the C-heterochromatin distribution in 13 species of lace bugs (Heteroptera, Tingidae)

100%
Grozeva S., Nokkala S.
Folia Biologica
|
2001
|
vol. 49
|
issue 1-2
29-41
EN
The karyotypes, sex chromosome systems, and male meiotic patterns in 13 species belonging to 10 genera of the family Tingidae were studied. Data on eleven species, one subgenus, and 5 genera are presented for the first time, and the chromosome formula of Acalypta parvula is revised. Karyotypes of all species included six pairs of autosomes. Most of the species displayed an XY sex chromosome system, in four species, belonging to genera of Acalypta and Kalama, the X0 system was found. Male meiosis is chiasmatic for autosomes. Sex chromosomes are achiasmatic and undergo pre-reductional meiosis. Using C-banding technique, for the first time constitutive heterochromatin was localized on chromosomes in all the species studied. The heterochromatin was found either in telomeres or in some species in interstitial locations, evidencing that a quite substantial redistribution of chromosome material within chromosomes might occur without fragmentations or fusions. In two species, a supernumerary (B) chromosome was found. In addition, the male reproductive system of four species was examined and the number of testicular follicles was determined as two per testis.
4

The karyotypes of two bark-lice species (Psocoptera, Psocomorpha, Amphipsocidae): the first description of the neo-XY sex chromosome system in Psocoptera

100%
Golub N. V., Nokkala S.
Folia Biologica
|
2001
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vol. 49
|
issue 3-4
153-156
EN
Karyotypes of two bark-lice species Amphipsocus japonicus End. and Dasypsocus japonicus End. (Amphipsocidae, Psocomorpha, Psocoptera) were studied for the first time. D. japonicus displayed 2n=16 (14+XX/X0). The XX/X0 sex chromosome system observed in this species is characteristic of the order Psocoptera. A. japonicus showed 2n=16 (14+neo-XY). This is the first observation of the neo-XY sex determination system in Psocoptera. In this species a large amount of constitutive heterochromatin was found in the original X-part of the neo-X chromosome.
5

Holocentric chromosomes of Psocids (Insecta, Psocoptera) analysed by C-banding, silver impregnation and sequence specific fluorochromes CMA3 and DAPI

81%
Golub N. V., Nokkala S., Kuznetsova V. G.
Folia Biologica
|
2004
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vol. 52
|
issue 3-4
143-149
EN
The pattern of nucleolus attachment and C-heterochromatin distribution and molecular composition in the karyotypes of psocid species Psococerastis gibbosa (2n = 16+X), Blaste conspurcata (2n = 16+X) and Amphipsocus japonicus (2n = 14+neo-XY) were studied by C-banding, silver impregnation and sequence specific fluorochromes CMA3 and DAPI. Every species was found to have a single nucleolus in male meiosis. In P. gibbosa the nucleolus is attached to an autosomal bivalent; in B. conspurcata to the X-chromosome; in A. japonicus to the neo-XY bivalent. The species show a rather small amount of constitutive heterochromatin, C-blocks demonstrating telomeric localization with rare exceptions. P. gibbosa is characterized by a polymorphism for C-blocks occurrence and distribution. In the autosomes of this species, C-heterochromatin consists of AT-rich DNA except for the nucleolus organizing region, which is also GC-rich; the X-chromosome shows both AT- and GC-rich clusters. In A. japonicus and B. conspurcata, C-heterochromatin of the autosomes and sex chromosomes consists of both GC-rich and AT-rich DNA clusters, which are largely co-localized.
6

A new approach to the Auchenorrhyncha (Hemiptera, Insecta) cytogenetics: Chromosomes of the meadow spittlebug Philaenus spumarius (L.) examined using various chromosome banding techniques

81%
Kuznetsova V. G., Maryanska-Nadachowska A., Nokkala S.
Folia Biologica
|
2002
|
vol. 51
|
issue 1-2
33-40
EN
The karyotype of the meadow spittlebug Philaenus spumarius (L.) was studied using conventional chromosome staining, C- and AgNOR- banding, and fluorescent CMA3- and DAPI- techniques. This is the first report on differential staining of the holocentric chromosomes of Auchenorrhyncha. The karyotype of Ph. spumarius includes 2n = 22 + XX/X0. The autosomal pair 1 is large and carries a gap in every homologue. After silver staining, NORs were revealed in both this chromosome pair and a middle-sized pair, most likely 6 or 7. In spermatocyte meiosis, the majority of bivalents formed one chiasma each. The bivalent 1 showed from 1 to 4 chiasmata, the value of 1 or 2 being prevalent. Two further bivalents also showed two chiasmata in some cells. After C-banding, terminal and interstitial dot-type C-heterochromatic blocks were revealed in the chromosomes. In 4 of 11 studied males, the autosomal pair 1 was polymorphic for an extra segment attached to one of the homologues. The segment consisted of both heterochromatic and euchromatic portions. No defined signals were observed in any chromosome treated with DAPI. After CMA3- staining, bright fluorescent signals were obtained in the NOR-bearing chromosomes, suggesting GC-rich DNA bound to the NORs.
7

First evidence of sex chromosome pre-reduction in male meiosis in the Miridae bugs (Heteroptera)

81%
Grozeva S., Nokkala S., Simov N.
Folia Biologica
|
2006
|
vol. 54
|
issue 1-2
9-12
EN
The karyotype and male meiosis of Macrolophus costalis Fieber (Insecta, Heteroptera, Miridae) were studied using C-banding, AgNOR-banding and DNA sequence specific fluorochrome staining. The chromosome formula of the species is 2n=28(24+X1X2X3Y). Male meiotic prophase is characterized by a prominent condensation stage. At this stage, two sex chromosomes, 'X' and Y are positively heteropycnotic and always appeared together, while in autosomal bivalents homologous chromosomes were aligned side by side along their entire length, that is, meiosis is achiasmatic. At metaphase I, 'X' and Y form a pseudobivalent and orient to the opposite poles. At early anaphase I, the 'X' chromosome disintegrates into three separate small chromosomes, X1, X2, and X3. Hence both the autosomes and sex chromosomes segregate reductionally in the first anaphase, and separate equationally in the second anaphase. This is the first evidence of sex chromosome pre-reduction in the family Miridae. Data on C-heterochromatin distribution and its composition in the chromosomes of this species are discussed.
8

Cytogenetic characterization of the trinidad endemic, Arachnocoris trinitatus Bergroth: the first data for the tribe arachnocorini (Heteroptera: Cimicomorpha: Nabidae)

81%
Kuznetsova V. G., Grozeva S., Sewlal J. N., Nokkala S.
Folia Biologica
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2007
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vol. 55
|
issue 1-2
17-26
EN
Cimicomorpha), the first evidence for the tribe Arachnocorini (the subfamily Nabinae), with reference to the Trinidad endemic, Arachnocoris trinitatus Bergroth, is provided. This is an attempt to gain a better insight into the evolution, systematics and within-family relationships of the family Nabidae. The studies were conducted using a number of cytogenetic techniques. The male karyotype (chromosome number and size; sex chromosome system; NOR location; C-heterochromatin amount, distribution and characterization in terms of the presence of AT-rich and GC-rich DNA), and male meiosis with particular emphasis on the behavior of the sex chromosomes in metaphase II are described. Also investigated are the male and female internal reproductive organs with special reference to the number of follicles in a testis and the number of ovarioles in an ovary. A. trinitatus was found to display a number of characters differentiating it from all hitherto studied nabid species placed in the tribe Nabini of the subfamily Nabinae, and in the tribe Prostemmatini of the subfamily Prostemmatinae. Among these characters are chromosome number 2n = 12 (10 + XY), the lowest within the family, nucleolus organizer regions (NORs) situated on the autosomes rather than on the sex chromosomes as is the case in other nabid species, and testes composed of 3 follicles but not of 7 as in other nabids. All the data obtained suggest many transformations during the evolution of A. trinitatus.
9

Standard and C-banded meiotic karyotypes of Psylloidea (Sternorrhyncha, Homoptera, Insecta)

81%
Maryanska-Nadachowska A., Kuznetsova V., Nokkala S.
Folia Biologica
|
2001
|
vol. 49
|
issue 1-2
53-62
EN
Meiotic karyotypes were studied in males of Craspedolepta sonchi (Foerster, 1848), Diaphorina chobauti Puton, 1898, D. lamproptera Burckhardt, 1981, Psylla hartigii Flor, 1861, Cacopsylla palmeni (Loew, 1878), C. hippophaes (Foerster, 1848), C. melanoneura (Foerster, 1868), C. pyricola (Foerster 1848), C. moscovita (Andrianova, 1848), Bactericera salicivora (Reuter, 1876), Trioza abdominalis Flor, 1861, T. lauri = Lauritrioza alacris (Flor, 1861). Karyotypes were 2n = 25 (24 + XO) in all species except B. salicivora with 2n = 26 (24 + neo-XY). Testes consisted of two follicles each in all species but P. hartigii with four-follicular testes in males. The discussion covers the problems of chromosome numbers, sex-determining chromosome systems, B-chromosomes, patterns of C- banding, testis structure, and spermatid development in Psylloidea.
10

Karyotypes, sex chromosome systems, and male meiosis in Finnish psyllids (Homoptera, Psylloidea)

81%
Kuznestsova V. G., Nokkala S., Maryanska-Nadachowska A.
|
EN
The karyotypes and structure of the testes were studied in 12 species of Psylloidea belonging to the families Aphalaridae, Psyllidae and Triozidae. Males of ten species, namely Aphalara avicularis Oss., A. rumicicola Klimasz., Camaratoscena speciosa (Flor), Cacopsylla ambiqua Frst., C. peregrina Frst., Bactericera curvatinervis Frst., B. striola Flor., Trioza anthrisci Burckhardt, and T. apicalis Frst. have two seminal follicles per testis, this being the most typical testis structure in Psylloidea. Males of Psylla betulaenanae Oss. and P. ledi Flor. were found to display 4 follicles per testis. Ten species share 2n=24+X0 in males, which is the basic karyotype in Psylloidea as a whole, whereas Bactericera curvatinervis Frst. and B. striola Flor. have 2n=24+neo-XY. In some karyotypes, one B-chromosome was found. Its peculiar behaviour during some stages of the first meiotic division was examined. The karyotype of A. rumicicola was studied after Giemsa C-banding. Using C-band in an autosome pair as the marker of one of the telomeres it was proved that holokinetic chromosomes of psyllids are in fact dikinetic in the first meiotic division.
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