scholarly journals Reproductive relationships and degree of synapsis in the polytene chromosomes of the Drosophila buzzatii species cluster

2006 ◽  
Vol 66 (1b) ◽  
pp. 279-293 ◽  
Author(s):  
L. P. B. Machado ◽  
L. Madi-Ravazzi ◽  
W. J. Tadei
Keyword(s):  
Reproductive Isolation ◽  
Sibling Species ◽  
Polytene Chromosomes ◽  
Proximal Region ◽  
Interspecific Crosses ◽  
Variable Degree ◽  
Intraspecific Divergence ◽  
Allopatric Populations ◽  
Drosophila Buzzatii ◽  
Species Cluster

The process of speciation occurs through the evolution of any of several forms of reproductive isolation between taxa, including inviability of hybrids. In this work, strains derived from allopatric populations of Drosophila buzzatii cluster species were experimentally crossed in order to evaluate their reproductive and cytogenetic relationships, and to contribute toward understanding the reproductive isolation in this group of sibling species. Although intrastrain crosses were highly fertile, we consider it relevant to discuss the differences in intra- and interspecific fertility and fecundity here. Among 30 interspecific crosses, about 63% were partially or completely sterile. Fifty three percent of interspecific F1 crosses (female and male F1 crossed) were also partially or completely sterile, in contrast to only one out of 24 intraspecific F1 crosses that was partially sterile. An analysis of hybrid polytene chromosomes revealed complete synapsis, except in the microchromosomes (VI) and in the proximal region of the X chromosome. The intraspecific divergence observed in this study and the variable degree of chromosome pairing shown here reveal part of the complexity of the speciation process pertinent to Drosophila buzzatii cluster, which is consistent with different traits studied in this cluster.

scholarly journals Evaluation of the courtship and of the hybrid male sterility among Drosophila buzzatii cluster species (Diptera, Drosophilidae)

2002 ◽  
Vol 62 (4a) ◽  
pp. 601-608 ◽  
Author(s):  
L. P. de B. MACHADO ◽  
J. P.de CASTRO ◽  
L. MADI-RAVAZZI
Keyword(s):  
Reproductive Isolation ◽  
Male Sterility ◽  
F1 Hybrids ◽  
Interspecific Crosses ◽  
Hybrid Male ◽  
Hybrid Male Sterility ◽  
Drosophila Buzzatii ◽  
Repleta Group ◽  
Reproductive Isolation Mechanisms ◽  
Isolation Mechanisms

In the Drosophila repleta group the establishment of subgroups and complexes made on the basis of morphological and cytological evidences is supported by tests of reproductive isolation. Among species in the repleta group, the buzzatii cluster, due to its polymorphism and polytipism, is an excellent material for ecological and speciation studies. Some interspecific crosses involving Drosophila seriema, Drosophila sp. B, D. koepferae and D. buzzatii strains were completely sterile while others involving strains from these species produced F1 hybrids that did not yield F2. In the present work, data on courtship duration and copula occurrence obtained in the analysis of flies from parental sterile crosses and on spermatozoon mobility observed in F1 hybrids that did not yield F2 are presented. Copula did not occur during one hour of observation and the spermatozoon also did not show mobility at any of the analyzed stages (3, 7, 9 and 10 days old). There was a high variation in courtship average duration and in the percentage of males that courted the females. The reproductive isolation mechanisms indicated by these observations were pre and post-zygotic, as supported by the absence of copula and male sterility. Data obtained also showed the occurrence of different degrees of reproductive compatibility among the strains classified as the same species but from distinct geographic localities.

The evolutionary history of Drosophila buzzatii. XXIII. High content of nonsatellite repetitive DNA in D. buzzatii and in its sibling D. koepferae

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 967-974 ◽  
Author(s):  
I. Marin ◽  
M. Labrador ◽  
A. Fontdevila
Keyword(s):  
Repetitive Dna ◽  
Sibling Species ◽  
Genomic Dna ◽  
Repetitive Sequences ◽  
Polytene Chromosomes ◽  
Drosophila Buzzatii ◽  
Repleta Group ◽  
Wide Variability ◽  
History Of

The frequency and types of repetitive nonsatellite DNA of two sibling species of the repleta group of Drosophila, D. buzzatii, and D. koepferae have been determined. For each species, the analysis is based on a sample of more than 100 clones (400 kb) obtained from genomic DNA. A theoretical model has been developed to correct for the presence of a mixture of repetitive and unique DNA in these clones. After correction, a high content of repetitive DNA has been demonstrated for both species (D. buzzatii, 19–26%; D. koepferae, 27–32%). The repetitive sequences have been classified according to their hybridization pattern when used as probes against genomic DNA and by their in situ hybridization signals on polytene chromosomes. Data suggest that the main nonsatellite component of these species is simpler and more repetitive than that of D. melanogaster, pointing to a wide variability in content and class size distribution of repetitive DNA among Drosophila species.Key words: repetitive DNA, DNA evolution, Drosophila, repleta group, sibling species.

BIOSYSTEMATICS OF THE GENUS EUXOA (LEPIDOPTERA: NOCTUIDAE). XVIH. COMPARATIVE BIOLOGY AND EXPERIMENTAL TAXONOMY OF THE SIBLING SPECIES EUXOA RIDMGSIANA (GRT.) AND EUXOA MAIMES (SM.)

1985 ◽  
Vol 117 (4) ◽  
pp. 481-493 ◽  
Author(s):  
J.R. Byers ◽  
D.L. Struble ◽  
J.D. Lafontaine
Keyword(s):  
Life Cycle ◽  
Reproductive Isolation ◽  
Sibling Species ◽  
Mate Recognition ◽  
Recognition System ◽  
Flight Period ◽  
Interspecific Differences ◽  
Mate Recognition System ◽  
The Difference ◽  
Species Specific

AbstractThe species previously recognized as Euxoa ridingsiana (Grt.) is shown to be composed of a sympatric pair of sibling species, Euxoa ridingsiana (Grt.) and Euxoa maimes (Sm.), which in the laboratory will produce viable F1 hybrids but no F2. Results of F1 sib and backcrosses show that the F1 males are fertile and the F1 females are infertile. In mating-bias tests conducted in laboratory cages, 74% of matings were conspecific and 26% interspecific. Differences in the diel periodicities of mating, which are about 2 h out of phase, may account for the mating bias. The duration of development of E. ridingsiana in the laboratory and its seasonal flight period in the field are about 2 weeks in advance of that of E. maimes. However, there is considerable overlap of the flight periods and, with the tendency of females of both species to mate several times, it is unlikely that the difference in seasonal emergence is enough to effect reproductive isolation. It is evident that, under natural conditions, reproductive isolation can be maintained entirely by species-specific sex pheromones. This mechanism of reproductive isolation is, however, apparently ineffective when moths are confined in cages in the laboratory.Biogeographic considerations suggest that the differences in life-cycle timing and mating periodicities might have been adaptations to adjust development and reproduction to prevailing ancestral environments. If the initial differentiation of the 2 species occurred in isolation and included at least an incipient shift in the pheromonal mate-recognition system, it is possible that upon reestablishment of contact between ancestral populations the differences in life-cycle timing and mating periodicities acting in concert could have effected substantial, albeit incomplete, reproductive isolation. Subsequent selection to reinforce assortative mating to preserve coadapted gene complexes could then have resulted in differentiation of discrete pheromonal systems and attainment of species status.

No character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 849-852 ◽  
Author(s):  
B. N. Singh ◽  
Sujata Chatterjee
Keyword(s):  
Reproductive Isolation ◽  
Sexual Isolation ◽  
Character Displacement ◽  
Sympatric Populations ◽  
Allopatric Populations ◽  
Drosophila Bipectinata ◽  
Isolation Index ◽  
Drosophila Malerkotliana

To test whether character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana exists, the degree of sexual isolation was measured between their sympatric and allopatric populations. Although the isolation indices vary in different crosses, the average isolation index for sympatric populations is very close to that for allopatric populations. This shows no difference in the degree of sexual isolation between sympatric and allopatric populations of D. bipectinata and D. malerkotliana. Thus there is no evidence for the existence of character displacement for sexual isolation between these two closely related sympatric species.Key words: Drosophila bipectinata, Drosophila malerkotliana, sexual isolation, sympatric and allopatric populations.

THE EVOLUTIONARY HISTORY OF DROSOPHILA BUZZATII. XII. THE GENETIC BASIS OF STERILITY IN HYBRIDS BETWEEN D. BUZZATII AND ITS SIBLING D. SERIDO FROM ARGENTINA

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 841-857
Author(s):  
Horacio Naveira ◽  
Antonio Fontdevila
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Hybrid Sterility ◽  
Polytene Chromosomes ◽  
Chromosome Segment ◽  
Minimum Size ◽  
Drosophila Buzzatii ◽  
History Of ◽  
Male Hybrid ◽  
Chromosome Segments

ABSTRACT The genetic basis of hybrid sterility has been investigated in backcross segmental hybrids between two sibling species, Drosophila buzzatii and D. serido. Asynapsis of homologous bands in hybrid polytene chromosomes has been used to identify the D. serido chromosome segments introgressed into the D. buzzatti genome. All the investigated chromosomes contain male sterility factors. For autosomes, sterility is produced when an introgressed D. serido chromosome segment, or combination of segments, reaches a minimum size. On the other hand, any introgressed X chromosome segment from D. serido, irrespective of its size, produces either male hybrid sterility or inviability.

Light intensity as a factor in the choice of an oviposition site by Drosophila pseudoobscura and Drosophila persimilis

1983 ◽  
Vol 25 (4) ◽  
pp. 370-377 ◽  
Author(s):  
Dennis J. Wogaman ◽  
Marvin B. Seiger
Keyword(s):  
Light Intensity ◽  
Genetic Variability ◽  
Sibling Species ◽  
Light Response ◽  
Drosophila Pseudoobscura ◽  
Isofemale Lines ◽  
Sympatric Populations ◽  
Allopatric Populations ◽  
Behavioral Differentiation ◽  
Drosophila Persimilis

Light preferences for ovipositing of the sibling species Drosophila pseudoobscura and D. persimilis were measured in a multichoice chamber. Behavioral differentiation was found among sympatric populations of D. pseudoobscura and D. persimilis and between allopatric populations of D. pseudoobscura. Differences among isofemale lines within populations indicated genetic variability for the behavior. Both D. pseudoobscura populations were less fecund in a uniform light environment than in the multichoice environment while D. persimilis showed no difference in fecundity in the two environments. The patterns for general photoresponse and ovipositional light response were shown to be different for each population. Thus, the motivation to oviposit may affect photopreference differentially in each population.

scholarly journals Contact-Chemosensory Evolution Underlying Reproductive Isolation in Drosophila Species

2020 ◽  
Vol 14 ◽  
Author(s):  
Kosei Sato ◽  
Daisuke Yamamoto
Keyword(s):  
Decision Making ◽  
Mate Choice ◽  
Reproductive Isolation ◽  
Sibling Species ◽  
Related Species ◽  
Main Theme ◽  
Biological Factors ◽  
Premating Isolation ◽  
Closely Related Species ◽  
Neural Activities

The main theme of the review is how changes in pheromone biochemistry and the sensory circuits underlying pheromone detection contribute to mate choice and reproductive isolation. The review focuses primarily on gustatory and non-volatile signals in Drosophila. Premating isolation is prevalent among closely related species. In Drosophila, preference for conspecifics against other species in mate choice underlies premating isolation, and such preference relies on contact chemosensory communications between a female and male along with other biological factors. For example, although D. simulans and D. melanogaster are sibling species that yield hybrids, their premating isolation is maintained primarily by the contrasting effects of 7,11-heptacosadiene (7,11-HD), a predominant female pheromone in D. melanogaster, on males of the two species: it attracts D. melanogaster males and repels D. simulans males. The contrasting preference for 7,11-HD in males of these two species is mainly ascribed to opposite effects of 7,11-HD on neural activities in the courtship decision-making neurons in the male brain: 7,11-HD provokes both excitatory and inhibitory inputs in these neurons and differences in the balance between the two counteracting inputs result in the contrasting preference for 7,11-HD, i.e., attraction in D. melanogaster and repulsion in D. simulans. Introduction of two double bonds is a key step in 7,11-HD biosynthesis and is mediated by the desaturase desatF, which is active in D. melanogaster females but transcriptionally inactivated in D. simulans females. Thus, 7,11-HD biosynthesis diversified in females and 7,11-HD perception diversified in males, yet it remains elusive how concordance of the changes in the two sexes was attained in evolution.

scholarly journals The distribution of two morphological forms of Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae)

1985 ◽  
Vol 80 (2) ◽  
pp. 145-148 ◽  
Author(s):  
R. D. Ward ◽  
A. L. Ribeiro ◽  
L. Ryan ◽  
A. L. Falcão ◽  
E. F. Rangel
Keyword(s):  
Reproductive Isolation ◽  
Lutzomyia Longipalpis ◽  
Single Pair ◽  
Museum Collections ◽  
Southern Brazil ◽  
Eastern Area ◽  
Allopatric Populations ◽  
North Brazil ◽  
The One ◽  
Cuticular Structures

The males of the sandfly Lutzomyia longipalpis occur in two forms, one which bears a single pair of pale spots on tergite 4 and another in which an additional pair of spots characterizes tergite 3. Almost complete reproductive isolation between sumpatric populations of the two forms and between allopatric populations of the one-spot form has been reported (Ward et al., 1983). Micromorphological differences in cuticular structures on the spots have also been observed and may be sites of pheromone release (Lane & Ward, 1984). Detais of the known distribution of the two are based on the examination of new specimens captured in Brazil during 1982, as well as museum collections and specimens from other laboratories. Males with a single pair of pale spots have been found from Mexico to southern Brazil, whilst the two-spot form is found only from the state of Maranhão in North Brazil to Minas Gerais and the border with Paraguay. In the eastern area of Brazil the two forms occur sympatrically in some locations and separately in others.

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