The polytene chromosomes of Simulium (Ectemnaspis) ignescens Roubaud and the related species Simulium "C," both from Colombia

1988 ◽  
Vol 66 (2) ◽  
pp. 300-309 ◽  
Author(s):  
Sofia Duque ◽  
Paulina Muñoz de Hoyos ◽  
Klaus Rothfels
Keyword(s):  
Related Species ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Onchocerca Volvulus ◽  
Sex Linkage ◽  
Undescribed Species ◽  
Banding Sequence ◽  
Chromosome Maps ◽  
Chromosome Iii

The paper describes the polytene chromosomes of Simulium (Ectemnaspis) ignescens from Colombia and compares them with those of a sympatric undescribed species designated Simulium "C." The two species share the entire banding sequence of chromosome arms IS, IL, and IIIS. Their IIIL arms differ by a single fixed inversion, but their second chromosomes exhibit multistep arrangement differences that were not completely resolved. The nucleolar organizer of S. ignescens is in the base of IIIS, that of Simulium "C" in the base of IS. Polymorphisms in IIS of S. ignescens exhibit partial sex linkage; no sex differential segments were demonstrated in Simulium "C." Common autosomal polymorphisms of both species involve preferentially chromosome III. Preliminary studies indicate that the chromosome maps of S. ignescens can serve as standards for other neotropical Simulium Latreille species including the important vectors of Onchocerca volvulus and Mansonella ozzardi.

A cytological description of 10 taxa in Metacnephia (Diptera: Simuliidae)

1982 ◽  
Vol 60 (11) ◽  
pp. 2852-2865 ◽  
Author(s):  
William S. Procunier
Keyword(s):  
Complex System ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Nucleolar Organizer ◽  
Sex Bias ◽  
Sex Linkage ◽  
Chromosome Differentiation ◽  
Species Association ◽  
Chromosome Maps ◽  
Sex Locus

Cytological descriptions and phylogenetic relationships are presented for 10 blackfly taxa in Metacnephia. These descriptions are given in terms of standard polytene chromosome maps based on M. pallipes. All members are male chiasmate and differ from related Cnephia by a whole arm interchange between chromosomes I and II. Sex chromosome differentiation varies from undefined changes resulting in a short, nonpairing centromeric segment in X0Y1 males of M. amphora to a complex system in M. borealis. The latter system involves Y chromosome differentiation by associated inversions and sex linkage of the nucleolar organizer (NO). Metacnephia borealis exhibits a sex bias in NO expression with excess expression in females and an apparent conversion phenomenon which dosage compensates males. The closest members of Metacnephia differ only in their sex chromosomes and share floating inversions; more distant taxa differ by fixed inversions as well as sex chromosomes. IIIS-1, IIIS-2, and IIIS-3 may be polymorphic, sex linked, or fixed in different species of the group. Nonhomology of sex chromosomes of different species, association of the sex locus and NO, and presence of an identical supernumerary block on nonhomologous chromosomes indicate a mobility phenomenon for certain loci.

scholarly journals Polytene chromosomes of an Indian Himalayan black fly Simulium (Nevermannia) praelargum (Diptera: Simuliidae)

2010 ◽  
Vol 56 (4) ◽  
pp. 437-444 ◽  
Author(s):  
Willie Henry ◽  
Subrata Kumar Dey ◽  
Rakesh Varma ◽  
Sachin Thapa ◽  
William S Procunier
Keyword(s):  
High Resolution ◽  
Polytene Chromosome ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Metacentric Chromosome ◽  
Double Bubble ◽  
High Quality ◽  
Chromosomal Markers ◽  
Total Complement ◽  
Chromosome Maps

Abstract High quality polytene chromosome maps (n=3) of a Himalayan Simuliid Simulium praelargum Datta, 1973 are presented and represent the first cytological description of a taxon found in the feuerborni group, subgenus Nevermannia. Polytene chromosomes one (I) and two (II) are metacentric, chromosome three (III) is submetacentric with the length of each chromosome occupying 37.25 %, 31.36 % and 31.34 % of the total complement length, respectively. Typical simuliid diagnostic intergeneric chromosomal markers are found within the polytene complement of this species. The nucleolar organizer (N.O.) is found at the base of the short arm of chromosome one (IS), the Ring of Balbiani (R.B.), double bubble (D.B.) and triad occur in the short arm of chromosome two (IIS), the Parabalbiani Ring (P.B.) and grey band (gb) occur in the long arm of chromosome two (IIL) and the Blister (BL) and Capsule (Ca) occur in the short arm of chromosome three (IIIS).Terminal bands at the end of IIIS are heterochromatinized and present atypically with respect to other simuliid fauna. Populations studied so far are unique among the Simuliidae in that they exhibit chromosome structural monomorphism. These high resolution polytene chromosome maps will form the basis for future cytological characterization and phylogenetic comparisons amongst members of the feuerborni group.

Supernumerary chromosome evolution in the Simulium vernum group (Diptera: Simuliidae)

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 516-521 ◽  
Author(s):  
Charles Brockhouse ◽  
J. A. B. Bass ◽  
R. M. Feraday ◽  
N. A. Straus
Keyword(s):  
Sibling Species ◽  
Related Species ◽  
Chromosome Evolution ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Chromosome Analysis ◽  
B Chromosome ◽  
Supernumerary Chromosome ◽  
Closely Related Species ◽  
Black Fly

B chromosomes are present in a cluster of closely related species of black fly in the Simulium vernum group including six sibling species within the S. vernum complex, Simulium costatum, and Simulium juxtacrenobium. The S. vernum siblings all possess the same small metacentric supernumerary, while S. juxtacrenobium carries three different supernumeraries (two telocentrics and one metacentric) and S. costatum has both a metacentric and a telocentric B chromosome. Analysis of the polytene chromosomes in the larval salivary glands has revealed relationships between the supernumeraries of the different species. The metacentric B chromosome of the S. vernum siblings apparently results from a fusion of the two telocentric supernumeraries of S. juxtacrenobium. Acquisition of a nucleolar organizer then gave rise to the metacentric B chromosome in S. juxtacrenobium. The acquisition of a nucleolus by a S. juxtacrenobium telocentric gave rise to one of the S. costatum supernumeraries. Two alternate models for the origin of black fly supernumeraries are presented.Key words: supernumerary chromosome, black fly, polytene chromosome, chromosome evolution.

Expansions and contractions of the genetic map relative to the physical map of yeast chromosome III

1988 ◽  
Vol 8 (2) ◽  
pp. 595-604
Author(s):  
L S Symington ◽  
T D Petes
Keyword(s):  
Gene Conversion ◽  
Restriction Site ◽  
Physical Map ◽  
Minimum Length ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Chromosome ◽  
Chromosome Maps ◽  
Chromosome Iii ◽  
The Relationship

To examine the relationship between genetic and physical chromosome maps, we constructed a diploid strain of the yeast Saccharomyces cerevisiae heterozygous for 12 restriction site mutations within a 23-kilobase (5-centimorgan) interval of chromosome III. Crossovers were not uniformly distributed along the chromosome, one interval containing significantly more and one interval significantly fewer crossovers than expected. One-third of these crossovers occurred within 6 kilobases of the centromere. Approximately half of the exchanges were associated with gene conversion events. The minimum length of gene conversion tracts varied from 4 base pairs to more than 12 kilobases, and these tracts were nonuniformly distributed along the chromosome. We conclude that the chromosomal sequence or structure has a dramatic effect on meiotic recombination.

Four new species of the genus Tumicla Wallengren, 1863 (Lepidoptera: Erebidae: Arctiinae: Lithosiini)

Zootaxa ◽  
2019 ◽  
Vol 4668 (3) ◽  
pp. 421-434
Author(s):  
ANTON V. VOLYNKIN ◽  
GYULA M. LÁSZLÓ
Keyword(s):  
New Species ◽  
Related Species ◽  
Democratic Republic ◽  
Female Genitalia ◽  
Undescribed Species ◽  
Male And Female ◽  
Holotype Female ◽  
Female Holotype ◽  
Republic Of The Congo

The present paper contains descriptions of four new species of the genus Tumicla Wallengren, 1863: T. elephantina sp. nov. (South Mozambique), T. mbeghai sp. nov. (NE Tanzania), T. admiranda sp. nov. (SE Democratic Republic of the Congo) and T. smithi sp. nov. (Central Zambia). The male paratype specimen of T. doa Kühne 2007 is proved to be not conspecific with the holotype female but belongs to an undescribed species described here as T. mbeghai sp. nov. rendering Tumicla doa to be known by the female holotype only. Adults, male and female genitalia of the new and related species are illustrated. 

scholarly journals MULTIPLE GENE SITES FOR 5S AND 18 + 28S RNA ON CHROMOSOMES OF GLYPTOTENDIPES BARBIPES (STAEGER)

1974 ◽  
Vol 62 (1) ◽  
pp. 132-144 ◽  
Author(s):  
Wu-Nan Wen ◽  
Pedro E. León ◽  
Donald R. Hague
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Nucleolar Organizer ◽  
Balbiani Ring ◽  
5S Rna ◽  
Multiple Gene ◽  
Main Site ◽  
Chromosome Iii ◽  
The Right

Ribosomal RNAs (28 + 18S and 5S) and 4S RNA extracted from the chironomid Glyptotendipes barbipes were iodinated in vitro with 125I and hybridized to the salivary gland chromosomes of G. barbipes and Drosophila melanogaster. Iodinated 18 + 28 S RNA labeled three puffed sites with associated nucleoli on chromosomes IR, IIL, and IIIL of G. barbipes and the nucleolar organizer of Drosophila. Labeled 5S RNA hybridized to three sites on chromosome IIIR, two sites on chromosome IIR and one site in a Balbiani ring on chromosome IV of Glyptotendipes. Most of the label produced by this RNA was localized seven bands away from the centromere on the right arm of chromosome III, and we consider this to be the main site complementary to 5S RNA in the chironomid. This same RNA preparation specifically labeled the 56 EF region of chromosome IIR of Drosophila which has been shown previously to be the only site labeled when hybridized with homologous 5S RNA. Hybridization of G. barbipes chromosomes with iodinated 4S RNA produced no clearly localized labeled sites over the exposure periods studied.

Photographic polytene chromosome maps for Glossina morsitans submorsitans (Diptera: Glossinidae): cytogenetic analysis of a colony with sex-ratio distortion

Genome ◽  
2002 ◽  
Vol 45 (5) ◽  
pp. 871-880 ◽  
Author(s):  
A Gariou-Papalexiou ◽  
G Yannopoulos ◽  
A Zacharopoulou ◽  
R H Gooding
Keyword(s):  
Sex Ratio ◽  
Polytene Chromosome ◽  
X Chromosome ◽  
Polytene Chromosomes ◽  
Glossina Morsitans ◽  
Glossina Morsitans Submorsitans ◽  
Ratio Distortion ◽  
Chromosome Maps ◽  
Sex Ratio Distortion ◽  
Pharate Adult

Photographic polytene chromosome maps from trichogen cells of pharate adult Glossina morsitans submorsitans were constructed. Using the standard system employed to map polytene chromosomes of Drosophila, the characteristic landmarks were described for the X chromosome and the two autosomes (L1 and L2). Sex-ratio distortion, which is expressed in male G. m. submorsitans, was found to be associated with an X chromosome (XB) that contains three inversions in each arm. Preliminary data indicate no differences in the fecundity of XAXA and XAXB females, but there are indications that G. m. submorsitans in colonies originating from Burkina Faso and Nigeria have genes on the autosomes and (or) the Y chromosome that suppress expression of sex-ratio distortion.Key words: tsetse, Glossina morsitans submorsitans, polytene chromosome maps, inversions, sex-ratio distortion.

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.

Étude caryologique de trois espèces d’Hypochoeris originaires d'Argentine : H. chillensis, H. microcephala var. albiflora et H. megapotamica

1994 ◽  
Vol 72 (10) ◽  
pp. 1496-1502 ◽  
Author(s):  
S. Siljak-Yakovlev ◽  
A. Bartoli ◽  
G. Roitman ◽  
N. Barghi ◽  
C. Mugnier
Keyword(s):  
Chromosome Number ◽  
Related Species ◽  
Secondary Constriction ◽  
Nucleolar Organizer ◽  
Asymmetry Index ◽  
Evolutionary Trend ◽  
Closely Related Species ◽  
Nucleolar Organizers ◽  
Morphological Differences ◽  
Secondary Constrictions

Three Hypochoeris species from Argentina with the same chromosome number (x = 4) and similar karyotypes (typically bimodal) show significant ecological and morphological differences. Comparative cytogenetic analysis was done for these taxa, producing karyotypes with correlated idiograms. The number of secondary constrictions and nucleolar organizers varied. The results from this study are discussed in terms of the mechanisms of microevolution within this group of closely related species, and in terms of the evolutionary trend in the genus and in the tribe Cichorieae. Key words: Hypochoeris, Cichorieae, bimodal karyotype, secondary constriction, nucleolar organizer, asymmetry index.

scholarly journals UNDER-REPLICATION OF RIBOSOMAL CISTRONS IN POLYTENE CHROMOSOMES OF RHYNCHOSCIARA

1974 ◽  
Vol 62 (1) ◽  
pp. 215-222 ◽  
Author(s):  
A. G. Gambarini ◽  
F. J. S. Lara
Keyword(s):  
Salivary Gland ◽  
In Situ Hybridization ◽  
Xenopus Laevis ◽  
Related Species ◽  
Polytene Chromosomes ◽  
Chromosome X ◽  
Heterologous Hybridization ◽  
Ribosomal Cistrons ◽  
Rhynchosciara Americana

DNA preparations obtained from several tissues of Rhynchosciara americana and two related species, R. milleri and R. papaveroi, were hybridized to R. americana rRNA. The percentage of hybridization was found to be higher in tissues with low polyteny than in tissues with high polyteny, suggesting a relationship between the amount of rDNA and the tissue polyteny. This could be explained by under-replication of ribosomal cistrons in polytene cells, such as those from the salivary gland. Only slight tissue-dependent changes in the percentages of hybridization can be observed in heterologous hybridization using Xenopus laevis rRNA. The possibility that these experiments could not detect differences in the amount of ribosomal cistrons among tissues is discussed. The female:male ratio for the percentages of hybridization in the salivary gland of R. americana agrees with the results obtained by in situ hybridization experiments (16, 17) which have shown that the rRNA cistrons are distributed among chromosomes other than chromosome X.

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