Metaphase karyotypes of fruit flies of Thailand. I. Five sibling species of the Bactrocera dorsalis complex

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 1015-1022 ◽  
Author(s):  
V. Baimai ◽  
W. Trinachartvanit ◽  
P. J. Grote ◽  
U. Kijchalao ◽  
S. Tigvattananont ◽  
...  
Keyword(s):  
X Chromosome ◽  
Related Species ◽  
Constitutive Heterochromatin ◽  
Chromosomal Evolution ◽  
Pericentric Heterochromatin ◽  
Bactrocera Dorsalis ◽  
Centromeric Heterochromatin ◽  
Chromosomal Variation ◽  
Closely Related Species ◽  
Group 3

Natural populations of fruit flies of the Bactrocera dorsalis complex exhibit chromosomal variation based on differences in the amount and distribution of constitutive heterochromatin in the centromeric regions of the autosomes and the sex chromosomes. The chromosomal variation, coupled with differences in external morphology and host plant specific preferences, strongly suggest the existence of 5 closely related species within the B. dorsalis complex that have provisionally been designated B. dorsalis species B, C, D, and E in contrast with B. dorsalis s.s. (species A). Analysis of heterochromatin in autosomes and sex chromosomes has revealed 4 distinct groups of mitotic karyotypes. Bactrocera dorsalis is the only representative of Group I, which is characterized by the typical metacentric X chromosome and major blocks of centromeric heterochromatin in autosomes 5 and 6. Group 2 consists of species B and C, which show prominent landmarks of pericentric heterochromatin in all autosomes and in the X chromosome. Group 3 comprises species D, which is characterized by conspicuous blocks of pericentric heterochromatin in all autosomes but the long arm of the subtelocentric X chromosome is euchromatic and lacks a major portion of centromeric heterochromatin. Species E belongs to Group 4, which differs from Group 3 in having major blocks of heterochromatin at the distal portion of the X chromosome in addition to the prominent landmarks of pericentric heterochromatin in all autosomes. Chromosomal evolution among closely related species within the B. dorsalis complex clearly involves the presence or absence of constitutive heterochromatin in the centromeric regions of autosomes as well as in the X chromosome.Key words: Bactrocera dorsalis complex, metaphase karyotype, heterochromatin, chromosomal evolution.

scholarly journals The Loci of Behavioral Evolution: Evidence That Fas2 and tilB Underlie Differences in Pupation Site Choice Behavior between Drosophila melanogaster and D. simulans

2019 ◽  
Vol 37 (3) ◽  
pp. 864-880
Author(s):  
Alison Pischedda ◽  
Michael P Shahandeh ◽  
Thomas L Turner
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Related Species ◽  
Choice Behavior ◽  
Genetic Basis ◽  
Association Studies ◽  
Single Gene ◽  
Closely Related Species ◽  
Environmentally Sensitive ◽  
Pupation Site

Abstract The behaviors of closely related species can be remarkably different, and these differences have important ecological and evolutionary consequences. Although the recent boom in genotype–phenotype studies has led to a greater understanding of the genetic architecture and evolution of a variety of traits, studies identifying the genetic basis of behaviors are, comparatively, still lacking. This is likely because they are complex and environmentally sensitive phenotypes, making them difficult to measure reliably for association studies. The Drosophila species complex holds promise for addressing these challenges, as the behaviors of closely related species can be readily assayed in a common environment. Here, we investigate the genetic basis of an evolved behavioral difference, pupation site choice, between Drosophila melanogaster and D. simulans. In this study, we demonstrate a significant contribution of the X chromosome to the difference in pupation site choice behavior between these species. Using a panel of X-chromosome deficiencies, we screened the majority of the X chromosome for causal loci and identified two regions associated with this X-effect. We then collect gene disruption and RNAi data supporting a single gene that affects pupation behavior within each region: Fas2 and tilB. Finally, we show that differences in tilB expression correlate with the differences in pupation site choice behavior between species. This evidence associating two genes with differences in a complex, environmentally sensitive behavior represents the first step toward a functional and evolutionary understanding of this behavioral divergence.

KARYOLOGY OF NORTH AMERICAN NATRICINE SNAKES (FAMILY COLUBRIDAE) OF THE GENERA NATRIX AND REGINA

1973 ◽  
Vol 15 (2) ◽  
pp. 355-361 ◽  
Author(s):  
C. William Kilpatrick ◽  
Earl G. Zimmerman
Keyword(s):  
Sex Chromosomes ◽  
North American ◽  
Related Species ◽  
Related Genus ◽  
Chromosomal Variation ◽  
Closely Related Species ◽  
Old World ◽  
Water Snake ◽  
The Family

Four species of the water snake genus Natrix have a distinctly different pattern of chromosomal morphology than found in two species of the related genus Regina. Natrix all have a karyotype with seven pairs of large or medium-sized submetacentric autosomes, three pairs of medium-sized subtelocentric autosomes, and seven pairs of small metacentric autosomes. All have a 2n of 36 with a submetacentric Z and submetacentric or subtelocentric W. The autosomal complement of Regina consists of seven pairs of large to medium-sized submetacentrics, five pairs of medium-sized submetacentrics, and five pairs of small metacentrics. The Z and W are both submetacentric chromosomes. The sex chromosomes are easily distinguished in both genera. The relationships of Natrix and Regina and Old World Natrix are discussed, as well as chromosomal variation in closely related species in the family Colubridae.

scholarly journals SEQUENCE OF CENTROMERE SEPARATION: ROLE OF CENTROMERIC HETEROCHROMATIN

Genetics ◽  
1982 ◽  
Vol 102 (4) ◽  
pp. 795-806
Author(s):  
Baldev K Vig
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Mus Musculus ◽  
Constitutive Heterochromatin ◽  
Bos Taurus ◽  
Centromeric Heterochromatin ◽  
Early Anaphase ◽  
Wood Lemming ◽  
Myopus Schisticolor

ABSTRACT The late metaphase-early anaphase cells from various tissues of male Mus musculus, M. poschiavinus, M. spretus, M. castaneus, female and male Bos taurus (cattle) and female Myopus schisticolor (wood lemming) were analyzed for centromeres that showed separation into two daughter centromeres and those that did not show such separation. In all strains and species of mouse the Y chromosome is the first one to separate, as is the X or Y in the cattle. These sex chromosomes are devoid of constitutive heterochromatin, whereas all autosomes in these species carry detectable quantities. In cattle, the late replicating X chromosome appears to separate later than the active X. In the wood lemming the three pairs of autosomes with the least amount of centromeric constitutive heterochromatin separate first. These are followed by the separation of seven pairs of autosomes carrying medium amounts of constitutive heterochromatin. Five pairs of autosomes with the largest amounts of constitutive heterochromatin are the last in the sequence of separation. The sex chromosomes with medium amounts of constitutive heterochromatin around the centromere, and a very large amount of distal heterochromatin, separate among the very late ones but are not the last. These observations assign a specific role to centromeric constitutive heterochromatin and also indicate that nonproximal heterochromatin does not exert control over the sequence in which the centromeres in the genome separate. It appears that qualitative differences among various types of constitutive heterochromatin are as important as quantitative differences in controlling the separation of centromeres.

scholarly journals L Chromosome Behaviour and Chromosomal Imprinting in Sciara Coprophila

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 440 ◽  
Author(s):  
Prim Singh ◽  
Stepan Belyakin
Keyword(s):  
Related Species ◽  
Constitutive Heterochromatin ◽  
Germ Line ◽  
Chromosome Condensation ◽  
Genetic Constitution ◽  
Chromosome Behaviour ◽  
Stages Of Development ◽  
Closely Related Species ◽  
Supernumerary Chromosomes ◽  
Insight Into

The retention of supernumerary chromosomes in the germ-line of Sciara coprophila is part of a highly-intricate pattern of chromosome behaviours that have fascinated cytogeneticists for over 80 years. Germ-line limited (termed L or “limited”) chromosomes are cytologically heterochromatic and late-replicating, with more recent studies confirming they possess epigenetic hallmarks characteristic of constitutive heterochromatin. Little is known about their genetic constitution although they have been found to undergo cycles of condensation and de-condensation at different stages of development. Unlike most supernumeraries, the L chromosomes in S. coprophila are thought to be indispensable, although in two closely related species Sciara ocellaris and Sciara reynoldsi the L chromosomes, have been lost during evolution. Here, we review what we know about L chromosomes in Sciara coprophila. We end by discussing how study of the L chromosome condensation cycle has provided insight into the site and timing of both the erasure of parental “imprints” and also the placement of a putative “imprint” that might be carried by the sperm into the egg.

A cytogenetic analysis of the chromosomes in two related species of the genus Muscari (Liliaceae)

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 729-732 ◽  
Author(s):  
C. Ruiz Rejón ◽  
R. Lozano ◽  
M. Ruiz Rejón
Keyword(s):  
Related Species ◽  
Cytogenetic Analysis ◽  
Chromosome Pair ◽  
Chromosomal Evolution ◽  
Closely Related Species ◽  
Positive Band ◽  
Nucleolus Organizing Region ◽  
Cytogenetic Analyses

Muscari comosum L. and Muscari matritensis Ruiz Rejón et al. are two closely related species of the subgenus Leopoldia, belonging to the genus Muscari (Liliaceae). Cytogenetic analyses have been made to analyse the differences between these species. Major differences are that M. comosum has four or five dark intercalary 4,6-diamidino-2-phenylindole (DAPI) positive C-bands in the first chromosome pair, whereas M. matritensis has only three thin bands. Muscari comosum has a large chromomycin A3 positive C-band in the fifth, nucleolus organizing region (NOR) bearing chromosome pair, whereas M. matritensis has the CMA3-positive band and the NOR in the short arm of the second pair. The possible role played by occurrences of translocations and amplifications in the chromosomal evolution of these species is discussed.Key words: Muscari, Liliaceae, karyotypes, evolution.

scholarly journals Loss of Notum Macrochaetae as an Interspecific Hybrid Anomaly Between Drosophila melanogaster and D. simulans

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1435-1450 ◽  
Author(s):  
Toshiyuki S Takano
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Fate ◽  
X Chromosome ◽  
Related Species ◽  
Interspecific Hybrids ◽  
Closely Related Species ◽  
Cell Fate Decisions ◽  
Neural Fate ◽  
Wide Range ◽  
Mother Cells

Abstract With the aim of revealing genetic variation accumulated among closely related species during the course of evolution, this study focuses on loss of macrochaetae on the notum as one of the developmental anomalies seen in interspecific hybrids between Drosophila melanogaster and its closely related species. Interspecific hybrids between a line of D. melanogaster and D. simulans isofemale lines exhibited a wide range in the number of missing bristles. By contrast, D. mauritiana and D. sechellia lines showed almost no reduction in bristle number in hybrids with D. melanogaster. Genetic analysis showed that the D. simulans X chromosome confers a large effect on hybrid bristle loss, although X-autosome interaction may be involved. This suggests that at least one genetic factor contributing to hybrid anomalies arose recently on a D. simulans X chromosome. Moreover, the results indicate sex dependency: the male hybrids were more susceptible to bristle loss than the female hybrids were. Use of cell type markers suggests that the defect does not lie in cell fate decisions during bristle development, but in the maintenance of neural fate and/or differentiation of the descendants of sensory mother cells.

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