Tempero-Spatial Sequentiality of Chromosomal Polymorphism in Chilocorus stigma Say (Coleoptera : Coccinellidae)

Nature ◽  
1962 ◽  
Vol 193 (4821) ◽  
pp. 1210-1211 ◽  
Author(s):  
STANLEY G. SMITH
Keyword(s):  
Chromosomal Polymorphism ◽  
Chilocorus Stigma

CHROMOSOMAL POLYMORPHISM IN DROSOPHILA EURONOTUS

Genetics ◽  
1964 ◽  
Vol 49 (4) ◽  
pp. 669-687
Author(s):  
Harrison D Stalker
Keyword(s):  
Chromosomal Polymorphism

Chromosomal Patterns of Microsatellite Variability Contrast Sharply in African and Non-African Populations of Drosophila melanogaster

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 247-256
Author(s):  
M Kauer ◽  
B Zangerl ◽  
D Dieringer ◽  
C Schlötterer
Keyword(s):  
Chromosomal Polymorphism ◽  
Background Selection ◽  
Selective Sweeps ◽  
X Chromosomes ◽  
Evolutionary Forces ◽  
Relative Contribution ◽  
African Populations ◽  
Neutral Variation ◽  
Colonization Process ◽  
The Subject

Abstract Levels of neutral variation are influenced by background selection and hitchhiking. The relative contribution of these evolutionary forces to the distribution of neutral variation is still the subject of ongoing debates. Using 133 microsatellites, we determined levels of variability on X chromosomes and autosomes in African and non-African D. melanogaster populations. In the ancestral African populations microsatellite variability was higher on X chromosomes than on autosomes. In non-African populations X-linked polymorphism is significantly more reduced than autosomal variation. In non-African populations we observed a significant positive correlation between X chromosomal polymorphism and recombination rate. These results are consistent with the interpretation that background selection shapes levels of neutral variability in the ancestral populations, while the pattern in derived populations is determined by multiple selective sweeps during the colonization process. Further research, however, is required to investigate the influence of inversion polymorphisms and unequal sex ratios.

CHROMOSOME STRUCTURE IN CHILOCORUS (COLEOPTERA: COCCINELLIDAE). II. THE ASYNCHRONOUS REPLICATION OF CONSTITUTIVE HETEROCHROMATIN

1976 ◽  
Vol 18 (1) ◽  
pp. 85-91 ◽  
Author(s):  
T. J. Ennis
Keyword(s):  
Chromosome Banding ◽  
Chromosome Structure ◽  
Constitutive Heterochromatin ◽  
Chromosome Replication ◽  
Data Models ◽  
Late Replication ◽  
Banding Patterns ◽  
Asynchronous Replication ◽  
Chilocorus Stigma

Chromosome replication has been analysed in four species of Chilocorus. In C. orbus Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic (= diphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic arm (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only.

scholarly journals CHROMOSOMAL POLYMORPHISM IN THE SU GENOME COMPLEX OF POLYPLOID TRILLIUMS

1974 ◽  
Vol 49 (6) ◽  
pp. 413-424 ◽  
Author(s):  
TUTOMU HAGA ◽  
HIROSHI WATANABE ◽  
AKINORI UCHINO
Keyword(s):  
Chromosomal Polymorphism

ADAPTIVE CHROMOSOMAL POLYMORPHISM INDROSOPHILA MELANICA

Evolution ◽  
1973 ◽  
Vol 27 (3) ◽  
pp. 486-494 ◽  
Author(s):  
John Tonzetich ◽  
Calvin L. Ward
Keyword(s):  
Chromosomal Polymorphism

CHROMOSOMAL POLYMORPHISM AND INTER-RELATIONSHIPS IN PISSODES WEEVILS: ADDITIONAL CYTOGENETIC EVIDENCE OF SYNONYMY

1973 ◽  
Vol 15 (1) ◽  
pp. 83-100 ◽  
Author(s):  
S. G. Smith
Keyword(s):  
Chromosomal Polymorphism ◽  
Valid Species ◽  
Cytogenetic Evidence

Chromosome comparison and crossability tests compel relegating 6 of 10 Hopkins' Pissodes taxa to synonymy, namely, utahensis with similis Hopk., nigrae and alascensis with rotundatus Lec., fraseri and piperi with dubius Rand., and curriei with affinis Rand. Two, dubius and rotundatus, and possibly a third, affinis, of the four valid species revealed meiotic markers of semi-incompatibility not previously encountered; presumably, as in the strobi complex, the fourth, similis, is merely devoid of the necessary chromosomal diagnostic.

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