A cytological description of Eusimulium vernum, E. decolletum, and the E. pugetense complex (Diptera: Simuliidae) in Alaska

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 550-558 ◽  
Author(s):  
Lizabeth A. Allison ◽  
Gerald F. Shields
Keyword(s):  
Polytene Chromosome ◽  
B Chromosomes ◽  
Black Flies ◽  
Sex Linkage ◽  
Chromosomal Inversions

Larval populations of the black flies Eusimulium vernum, E. decolletum, and E. pugetense in Alaska were analyzed using polytene chromosome cytology. One cytotype ("Knebworth") of E. vernum was found and cytotypes A and B of E. pugetense were found, with cytotype B having distinct northern and southern variants. No fixed inversions were found between E. decolletum and E. vernum, an interpretation that differs from a previous publication. Eusimulium decolletum is characterized cytologically by its profile of polymorphisms, the lack of B chromosomes, and partial sex linkage of IIIL-1de. Detailed collection information is also presented for E. vernum, E. decolletum, and E. pugetense.Key words: black flies, cytogenetics, chromosomal inversions, evolution.

Sibling species and sex chromosome differentiation in Simulium neornatipes (Diptera: Simuliidae)

1984 ◽  
Vol 26 (3) ◽  
pp. 318-325 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Polytene Chromosome ◽  
Sibling Species ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Close Association ◽  
Chromosome Analysis ◽  
Sex Linkage ◽  
Direct Role ◽  
Chromosome Differentiation ◽  
Close Relationship

Polytene chromosome analysis of five Simulium neornatipes populations not only confirms the existence of the two sibling species, S. neornatipes 1 and 2, proposed earlier but reveals a third. S. neornatipes 3. These sibling species share a common standard polytene chromosome banding sequence which differs from the Australian S. ornatipes complex standard by five fixed inversions. The sharing of polymorphic inversions between the ornatipes and neornatipes complexes indicates their close relationship. The neornatipes species are distinguished from each other by additional fixed inversions and differentiated sex chromosomes. Extensive sex chromosome differentiation involving chromosome III has occurred in S. neornatipes 1 and 2. A period of incomplete sex-linkage allowing reassortment of inversions must have preceded the currently observed strong sex-linkage of differentiated sex chromosomes to account for the complex array of sex chromosomes found. The close association of sex chromosome differentiation with speciation in black flies is discussed in relation to appropriate speciation mechanisms. It is concluded that the rearrangements themselves have no direct role in the speciation process.Key words: sibling species, sex chromosomes, Simuliidae.

Sex-Linkage in Pteromalus

1940 ◽  
Vol 74 (753) ◽  
pp. 377-379 ◽  
Author(s):  
P. W. Whiting
Keyword(s):  
Sex Linkage

Resistance to Pyrethroids and DDT in a Field-Mixed Population of Argentinean Black Flies (Diptera: Simuliidae)

1999 ◽  
Vol 92 (6) ◽  
pp. 1243-1245 ◽  
Author(s):  
Cristina M. Montagna ◽  
Olga L. Anguiano ◽  
Lidia E. Gauna ◽  
Ana M. Pechen De D'Angelo
Keyword(s):  
Mixed Population ◽  
Black Flies

Favism, Sex-Linkage, and the Indo-European

1962 ◽  
Vol 18 (3) ◽  
pp. 286-290 ◽  
Author(s):  
Kinship System ◽  
Eugene Giles
Keyword(s):  
Sex Linkage

scholarly journals CYTOGENETIC ANALYSIS OF CHROMOSOME 3 IN DROSOPHILA MELANOGASTER: THE HOMOEOTIC GENE COMPLEX IN POLYTENE CHROMOSOME INTERVAL 84A-B

Genetics ◽  
1980 ◽  
Vol 94 (1) ◽  
pp. 115-133 ◽  
Author(s):  
Thomas C Kaufman ◽  
Ricki Lewis ◽  
Barbara Wakimoto
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosome ◽  
Cytogenetic Analysis ◽  
Proximal Portion ◽  
Chromosome 3 ◽  
Gene Complex ◽  
Anterior Portion ◽  
Cytogenetic Evidence ◽  
The Right

ABSTRACT Cytogenetic evidence is presented demonstrating that the 84A-B interval in the proximal portion of the right arm of chromosome 3 is the residence of a homoeotic gene complex similar to the bithorax locus. This complex, originally defined by the Antennapedia (A n t p) mutation, controls segmentation in the anterior portion of the organism. Different lesions within this complex homoeotically transform portions OI the prothorax, proboscis, antenna and eye and present clear analogies to similar lesions within the bithorax locus.

scholarly journals Molecular Characterization of hobo-Mediated Inversions in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 647-656
Author(s):  
William B Eggleston ◽  
Nac R Rim ◽  
Johng K Lim
Keyword(s):  
X Chromosome ◽  
Polymerase Chain Reaction Amplification ◽  
Polytene Chromosomes ◽  
Chromosomal Inversions ◽  
Hobo Element ◽  
Reaction Amplification ◽  
Notch Locus ◽  
Polymerase Chain

Abstract The structure of chromosomal inversions mediated by hobo transposable elements in the Uc-1 X chromosome was investigated using cytogenetic and molecular methods. Uc-1 contains a phenotypically silent hobo element inserted in an intron of the Notch locus. Cytological screening identified six independent Notch mutations resulting from chromosomal inversions with one breakpoint at cytological position 3C7, the location of Notch. In situ hybridization to salivary gland polytene chromosomes determined that both ends of each inversion contained hobo and Notch sequences. Southern blot analyses showed that both breakpoints in each inversion had hobo-Notch junction fragments indistinguishable in structure from those present in the Uc-1 X chromosome prior to the rearrangements. Polymerase chain reaction amplification of the 12 hobo-Notch junction fragments in the six inversions, followed by DNA sequence analysis, determined that each was identical to one of the two hobo-Notch junctions present in Uc-1. These results are consistent with a model in which hobo-mediated inversions result from homologous pairing and recombination between a pair of hobo elements in reverse orientation.

scholarly journals Chromosomal Instability at Fragile Sites in Blue Foxes, Silver Foxes, and Their Interspecific Hybrids

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1743
Author(s):  
Marta Kuchta-Gładysz ◽  
Ewa Wójcik ◽  
Anna Grzesiakowska ◽  
Katarzyna Rymuza ◽  
Olga Szeleszczuk
Keyword(s):  
Interspecific Hybrids ◽  
Genome Stability ◽  
Diploid Number ◽  
Fragile Sites ◽  
B Chromosomes ◽  
Silver Fox ◽  
Chromosomal Breaks ◽  
Blue Fox ◽  
Chromosomal Fragile Sites ◽  
Karyotypic Variation

A cytogenetic assay based on fragile sites (FS) enables the identification of breaks, chromatid gaps, and deletions. In healthy individuals, the number of these instabilities remains low. Genome stability in these species is affected by Robertsonian translocations in the karyotype of the blue fox and by B chromosomes in the silver fox. The aims of the study were to characterise the karyotype of blue foxes, silver foxes, and their hybrids and to identify chromosomal fragile sites used to evaluate genome stability. The diploid number of A chromosomes in blue foxes ranged from 48 to 50, while the number of B chromosomes in silver foxes varied from one to four, with a constant number of A chromosomes (2n = 34). In interspecific hybrids, both types of karyotypic variation were identified, with the diploid number of A chromosomes ranging from 40 to 44 and the number of B chromosomes varying from 0 to 3. The mean frequency of FS in foxes was 4.06 ± 0.19: 4.61 ± 0.37 in blue foxes, 3.46 ± 0.28 in silver foxes, and 4.12 ± 0.22 in hybrids. A relationship was identified between an increased number of A chromosomes in the karyotype of the hybrids and the frequency of chromosomal breaks. The FS assay was used as a biomarker for the evaluation of genomic stability in the animals in the study.

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