scholarly journals Chironomus (diptera) polytene chromosomes functional activity under the influence of cholinotropic preparations

2009 ◽  
Vol 7 (3) ◽  
pp. 44-52
Author(s):  
Irina A Fyodorova ◽  
Natalia V Polukonova ◽  
Konstantin N Dvoretsky ◽  
Svetlana I Bogoslovskaya
Keyword(s):  
Morphometric Analysis ◽  
Functional Activity ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Antagonistic Effect ◽  
B Chromosomes ◽  
Activity Change ◽  
Balbiani Rings ◽  
Chromosome I ◽  
Period Duration

Morphometric analysis of nucleolar organizer (NO), Balbiani rings (BR) - BR<sub>B</sub>, BR<sub>1G</sub>, BR<sub>2G</sub>, chromosome I arm puff B, chromosomes compactness activity change under the influence of cholinotropic preparations was carried out. Most sensitive criterion - chromosomes compactness is, most stable under the influence of stress - NO is. Atropine and pilocarpine antagonistic effect on the polytene chromosomes (PC) sites activity pilocarpine manifested itself in functional activity and restoration period duration change: on cholinoblocker effect activity decreased, while on cholinomimetic effect activity increased.

Polytene chromosomes of Simulium (Psaroniocompsa) daltanhani (Diptera: Simuliidae) from Central Amazonia, Brazil

Zootaxa ◽  
2008 ◽  
Vol 1676 (1) ◽  
pp. 57 ◽  
Author(s):  
NEUSA HAMADA ◽  
ELENY DA SILVA PEREIRA ◽  
PETER H. ADLER
Keyword(s):  
Banding Pattern ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Species Group ◽  
Chromosomal Complement ◽  
Central Amazonia ◽  
Similar Banding Pattern ◽  
Chromosome I

Last-instar larvae of Simulium (Psaroniocompsa) daltanhani Hamada and Adler from a stream in Central Amazonia were analyzed cytologically by mapping their polytene chromosomes. Simulium daltanhani has the nucleolar organizer in the short arm of chromosome I, heterogametic females, and an absence of autosomal polymorphisms. The chromosomes carry multiple rearrangements relative to other analyzed members of the S. quadrifidum species group in the subgenus Psaroniocompsa. One-third of the chromosomal complement is rearranged relative to the sequence of S. ulyssesi, the species with the most similar banding pattern among studied members of the S. quadrifidum group.

Chironomus alchichica sp. n. (Diptera: Chironomidae) from Lake Alchichica, Mexico

Zootaxa ◽  
2017 ◽  
Vol 4365 (1) ◽  
pp. 53 ◽  
Author(s):  
RAÚL ACOSTA ◽  
NARCÍS PRAT ◽  
CARLES RIBERA ◽  
PARASKEVA MICHAILOVA ◽  
MARÍA DEL CARMEN HERNÁNDEZ-FONSECA ◽  
...  
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Abdominal Segment ◽  
Developmental Stages ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Bootstrap Support ◽  
Cytological Analysis ◽  
Balbiani Rings ◽  
Morphological Differences

Morphological analysis of all developmental stages (except female), mitochondrial DNA sequences from cytochrome c oxidase subunit I (cox1) and cytological analysis of the polytene chromosomes were used to describe a new species of Chironomus found in the littoral and profundal zones of an endorheic, warm-monomictic lake in Mexico. Male imago is distinguished by the shape of superior volsella and by an antennal and bristle ratio lower than two. The pupa is characterized by the spur morphology of abdominal segment VIII. There is also a continuous row of hooklets on abdominal segment II. The larva is distinguished by a combination of antenna, mentum, mandible, and pecten epipharyngis characteristics, and abdominal ventral tubules. Molecular and cytological analysis supported the morphological differences found. The maximum likelihood tree obtained shows that Chironomus alchichica sp. n. clusters together with Chironomus decorus-group sp. 2 Butler et al. (1995) (bootstrap support = 92%), but genetic p-distances within C. alchichica sp. n. (0.004) were lower than the p-distances between other species of the decorus-group (C. decorus-group sp. 2, Chironomus bifurcatus Wülker et al., 2009 and Chironomus maturus Johannsen, 1908) confirming that it is a different species. The new species belongs to thummi cytocomplex, (decorus-group), with chromosome set- 2n = 8 and chromosome arm combinations: AB CD EF G. Karyologically, the species is closest to Chironomus riihimaekiensis Wülker (1973). This species has very compact salivary gland chromosomes with well heterochromatinized centromere regions in chromosomes AB CD G. Several fixed homozygous inversions distinguish arm A of the species from that of C. riihimaekiensis. Arm E differs from that of C. riihimaekiensis by simple fixed homozygous inversion. Some similarities in band sequences of this arm were found with species from the decorus-group as Chironomus blaylocki Wülker et al., 2009 and C. bifurcatus (decorus-group). The position of the key constrictions in chromosome G: Nucleolar organizer (NOR) and Balbiani rings (BRs) is similar to the species of decorus-group. C. alchichica sp. n. has been found in soft sediments rich in organic matter in well mineralized waters (where conductivity >10 mS cm-1) and with a high pH (≥9). The profundal zone is inhabited only during the mixing period, when dissolved oxygen is present. 

The salivary gland chromosomes of seven taxa in the subgenus Stegopterna (Diptera, Simuliidae, Cnephia)

1969 ◽  
Vol 47 (1) ◽  
pp. 115-119 ◽  
Author(s):  
D. P. Madahar
Keyword(s):  
Salivary Gland ◽  
North American ◽  
Nucleolar Organizer ◽  
Close Relation ◽  
Standard Sequence ◽  
Y Chromosomes ◽  
Chromosome Ii ◽  
Chromosome I

The salivary gland chromosomes are described for seven taxa in the subgenus Stegopterna Enderlein of Cnephia Enderlein. All taxa have the typical blackfly complement with n = 3. The widely distributed North American Cnephia mutata Malloch has the nucleolar organizer in IL and the standard sequence in IS. All other taxa display a shift of the nucleolus to IS and homozygosity for the inversion IS-1. The Scandinavian C. richteri Enderlein apparently exhibits no further changes, the northern North American C. emergens Stone is characterized by the additional inversions, IS-2, IIIS-1, IIIL-1. The remaining four taxa, designated here as C. "Y", C. "X", C. "O", C. "W" are western North American, presumably undescribed and close to C. mutata. Their close relation to one another is indicated by the sharing of some inversion polymorphisms. They differ in certain floating autosomal inversions, and C. "O" and C. "W" in having distinctive and complex Y-chromosomes, based on chromosome I (C. "O") or chromosome II (C. "W"). A diagram illustrating the cytophylogenetic relations of the seven taxa is presented.

The interdependence of B chromosomes, nucleolar organizer expression, and larval development in the blackfly species Cnephia dacotensis and Cnephia ornithophilia (Diptera: Simuliidae)

1982 ◽  
Vol 60 (11) ◽  
pp. 2879-2896 ◽  
Author(s):  
William S. Procunier
Keyword(s):  
Nucleolar Organizer ◽  
B Chromosome ◽  
Sampling Time ◽  
B Chromosomes ◽  
Sex Bias ◽  
Larval Size ◽  
High Incidence ◽  
Population Comparisons ◽  
Group A ◽  
Primary Relationship

A primary relationship is found between nucleolar organizer (NO) expression (puffing) of the A complement and numbers of B chromosomes in Cnephia dacotensis, such that a high incidence of B's is associated with nonexpression of the NO independent of sampling time and larval size. NO expression can be categorized into three zygote classes: + +, + −, and − −, where + indicates puffing of one constituent and − indicates little or no puffing. The + + types generally mature earlier than the + − and − − types. These observations suggest that development rates are a function of NO expression: − − types do not mature at all unless they have B's and (or) secondary nucleoli. Population comparisons confirm the prediction that as the frequency of individuals with one or more B's decreases, the frequency of individuals with expressed constituents increases. A sex bias in NO expression exists with more expression in females. Additional plasticity is conferred to the system through an apparent conversion phenomenon which reduces X+X+ expression in females and dosage compensates X−Y− males. Both of these effects are B-chromosome dependent and are lost in zero B populations. It is proposed that B–A NO interactions constitute a system for more efficient rRNA production by optimizing synthesis between the sexes. This system may account for the wider range and occupation of more diversified habitats of C. dacotensis than for other members of the group. A similar but less dynamic role is proposed for the effects of B chromosomes in C. ornithophilia.

Cytotaxonomy of four European species in the Eusimulium vernum group (Diptera: Simuliidae)

1987 ◽  
Vol 65 (12) ◽  
pp. 3102-3115 ◽  
Author(s):  
Fiona F. Hunter
Keyword(s):  
Banding Pattern ◽  
Polytene Chromosomes ◽  
B Chromosomes ◽  
European Species ◽  
Y Chromosomes ◽  
Chromosomal Banding ◽  
Chromosome Iii ◽  
Interspecific Comparisons

The polytene chromosomes of four closely related Eusimulium (Roubaud) morphospecies from Europe have been examined. These are Eusimulium vernum (Macquart), E. costatum (Friedrichs), E. cryophilum (Rubtzov), and E. carpathicum (Knoz). Interspecific comparisons indicate that vernum and costatum are homosequential in chromosomal banding pattern; however, costatum does differ from vernum in possessing a conspicuous chromocenter. Both species may have B chromosomes, but these are not identical. Three kinds of vernum populations are found: pure X0Y0 (with undifferentiated X and Y chromosomes), pure X0Y1 (with males heterozygous for IIS-1 ve), and mixed X0Y0/X0Y1 populations. Only two European vernum cytotypes are indicated. Eusimulium cryophilum and E. carpathicum share a suite of autosomal polymorphisms as well as a fixed paracentric (IL-2) and a fixed pericentric (IIIP-1) inversion with respect to the vernum "Knebworth" standard. They differ from one another by three fixed inversions (IIS-1, IIIS-3, and IIIS-4). It is argued that at least two siblings, cryophilum A and cryophilum B, exist within cryophilum s.l. Sections 86B and 91C in the long arm of chromosome III appear to be extremely labile for breakage and reunion phenomena because several tandem or near-tandem inversions occur in this area. A cytophylogeny of the taxa under study is presented.

scholarly journals Balbiani ring hnRNP substructure visualized by selective staining and electron spectroscopic imaging.

1992 ◽  
Vol 117 (3) ◽  
pp. 483-491 ◽  
Author(s):  
A L Olins ◽  
D E Olins ◽  
D P Bazett-Jones
Keyword(s):  
Nucleic Acid ◽  
Polytene Chromosomes ◽  
Particle Diameter ◽  
Balbiani Ring ◽  
Electron Spectroscopic Imaging ◽  
Selective Staining ◽  
Elemental Imaging ◽  
Mature Transcript ◽  
Balbiani Rings ◽  
Relationship Of

The Balbiani Rings (BR) in the polytene chromosomes of Chironomus salivary glands are intense sites of transcription. The nascent RNPs fold during transcription into 40-50-nm granules, containing in the mature transcript approximately 37-kb RNA. Using a new nucleic acid specific stain, osmium ammine B on Lowicryl sections, in combination with electron energy filtered imaging of sections containing BR granules, we demonstrate a RNA-rich particulate substructure (10-nm particle diameter; 10-12 particles per BR granule). Elemental imaging supports that these particles are enriched in phosphorus. The possible relationship of these RNA-rich particles to ribonucleosomes is discussed, as well as models for their arrangement in the mature BR granules.

Population cytogenetic studies on Simulium feuerborni Edwards (Diptera: Simuliidae) from northern Thailand

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Chaliow Kuvangkadilok ◽  
Suwannee Phayuhasena ◽  
Visut Baimai
Keyword(s):  
Polytene Chromosomes ◽  
Natural Populations ◽  
Gene Pools ◽  
Northern Thailand ◽  
Y Chromosomes ◽  
Larval Salivary Gland ◽  
Hardy Weinberg Equilibrium ◽  
Chiang Mai Province ◽  
Chromosome I ◽  
Paracentric Inversions

A standard photographic map of Simulium feuerborni (Diptera: Simuliidae) was constructed from larval salivary gland polytene chromosomes and is described herein. Analysis of polytene chromosomes was made from wild larvae collected from the four populations at Doi Inthanon National Park, Chiang Mai Province, northern Thailand. Simulium feuerborni has three pairs of chromosomes (2n = 6) which are arranged from the longest to the shortest. Chromosome I is metacentric while chromosomes II and III are submetacentric. A total of six simple paracentric inversions have been detected in these natural populations of S. feuerborni. These inversions (IS-1, IL-1, IIL-1, IIL-2, IIIS-1, IIIL-1) occurred in all chromosome arms except for the arm IIS. Significant deviation from Hardy-Weinberg equilibrium has been observed in inversion IIIL-1 at Hui Sai Luaeng suggesting the existence of two gene pools in this population. There is no indication of sex linkage associated with an inversion sequence in these populations. Thus, the X and Y chromosomes of S. feuerborni could not be recognized in this study.Key words: Simulium, polytene chromosome map, inversion polymorphisms

scholarly journals Physicochemical characteristics of the Dombrovska pit lake (Ukraine) formed in an opencast potassium salt mine and the genome response of Chironomus salinarius Kieffer (Chironomidae, Diptera) to these conditions

2020 ◽  
Vol 28 (1) ◽  
pp. 446-458
Author(s):  
Paraskeva Michailova ◽  
Ewa Szarek-Gwiazda ◽  
Andrzej Kownacki
Keyword(s):  
Potassium Salt ◽  
Major Ions ◽  
Genome Instability ◽  
Polytene Chromosomes ◽  
Benthic Fauna ◽  
Nucleolar Organizer ◽  
Salt Mine ◽  
Pit Lake ◽  
Functional Changes ◽  
Chironomus Salinarius

AbstractThis study focuses on the Dombrovska pit lake, near the city of Kalush in Ukraine, which is a former potassium salt mine filled with brine and freshwater. The water level is still increasing and as a result the salinity is decreasing. We analyzed the benthic fauna communities and the genome instability by assessing the rearrangements in the polytene chromosomes of Chironomus salinarius and the physicochemical parameters of the near-bottom water (pH, conductivity, mineralization, major ions, NO3−, NH4+, metals Cd, Pb, Cu, Mn, and Fe) and sediment (pH, organic matter and metals Cd, Pb, Cu, Zn, Mn, and Fe) at four sites. The water mineralization ranged from 17.3 to 26.2 g dm−3 which are classified as mesohaline and polyhaline waters, respectively. The biodiversity of the benthic fauna was low, and the dominant species was C. salinarius. The density of C. salinarius varied spatially and changed from 637 ind./m2 at a depth of 5 m to 8167 ind./m2 at a depth of 2.5 m. The genome instability was analyzed by examining the structural and functional changes in the salivary gland chromosomes of C. salinarius. The exposure of C. salinarius damaged the chromosomes and the activities of key structures, such as the Balbiani ring and nucleolar organizer, were partially or completely suppressed.

Sign in / Sign up

Export Citation Format

Share Document