The Experts below are selected from a list of 3642 Experts worldwide ranked by ideXlab platform
Ruiz M Rejon - One of the best experts on this subject based on the ideXlab platform.
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Roberto Herrán, J P M Camacho, Ruiz M RejonAbstract:Inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in Muscari comosum (Liliaceae)
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Ruiz M Rejon, Roberto Herrán, J P M CamachoAbstract:The inheritance and the effects on fitness of a pericentric inversion and a Supernumerary Chromosome segment (SCS) involving the second Chromosome pair of Muscari comosum, have been analysed in an experimental population. Whereas the inversion is inherited in a Mendelian fashion through the female side, the SCS shows a powerful accumulation mechanism (k=0.796). Cases of nonrandom pollination were observed in homozygous bulbs for the standard Chromosomes (++) and also in those homozygous for the inverted Chromosomes (ii), which may be caused by a certain rate of self-pollination. The different karyotypes for both the inversion and the SCS showed similar values for several life-history traits related to female fitness, such as bulb weight, number of fruits, number of seeds and seed weight. However, plants carrying the inversion had heavier bulbs than those lacking it. The significance of these observations is discussed in relation to the maintenance of the two types of polymorphism in natural populations.
M A Garridoramos - One of the best experts on this subject based on the ideXlab platform.
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Roberto Herrán, J P M Camacho, Ruiz M RejonAbstract:Inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in Muscari comosum (Liliaceae)
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Ruiz M Rejon, Roberto Herrán, J P M CamachoAbstract:The inheritance and the effects on fitness of a pericentric inversion and a Supernumerary Chromosome segment (SCS) involving the second Chromosome pair of Muscari comosum, have been analysed in an experimental population. Whereas the inversion is inherited in a Mendelian fashion through the female side, the SCS shows a powerful accumulation mechanism (k=0.796). Cases of nonrandom pollination were observed in homozygous bulbs for the standard Chromosomes (++) and also in those homozygous for the inverted Chromosomes (ii), which may be caused by a certain rate of self-pollination. The different karyotypes for both the inversion and the SCS showed similar values for several life-history traits related to female fitness, such as bulb weight, number of fruits, number of seeds and seed weight. However, plants carrying the inversion had heavier bulbs than those lacking it. The significance of these observations is discussed in relation to the maintenance of the two types of polymorphism in natural populations.
M. Schmid - One of the best experts on this subject based on the ideXlab platform.
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Cytogenetics of the bleak (Alburnus alburnus), with special emphasis on the B Chromosomes
2006Co-Authors: M. Schmid, C. G. Ziegler, C. Steinlein, I. Nanda, M. SchartlAbstract:Some of the largest B Chromosomes so far discovered in vertebrates are present in the cyprinid fish Alburnus alburnus . Previous cytogenetic analyses revealed a diploid Chromosome number of 2n = 50. In addition, in some individuals one or two unusually large B Chromosomes are present. Two morphologically different types of B Chromosomes were observed. The frequency of animals bearing a Supernumerary Chromosome was found to vary considerably between different populations. A more detailed analysis of the A and B Chromosomes of A. alburnus by conventional banding techniques, as well as fluorescence in-situ hybridization (FISH) with the telomeric DNA repeats (GGGTTA)_7/(TAACCC)_7, 18S + 28S rDNA and 5S rDNA were performed in the present study. Furthermore, a B Chromosome-specific DNA probe obtained by amplified length polymorphism (AFLP) was hybridized on metaphases of A. alburnus carrying Supernumerary B Chromosomes. The banding analyses showed that the B Chromosomes are completely heterochromatic, consist of GC-rich DNA sequences, replicate their DNA in the very late S-phase of the cell cycle and are composed mainly of a specific retrotransposable DNA element. Finally, blood probes from A. alburnus were collected for DNA-flow cytometric measurements. It could be shown that the huge Supernumerary Chromosomes represent nearly 10% of the total genome size of A. alburnus .
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The giant B Chromosome of the cyprinid fish Alburnus alburnus harbours a retrotransposon-derived repetitive DNA sequence
2003Co-Authors: C. G. Ziegler, C. Steinlein, M. Schartl, D. K. Lamatsch, W. Engel, M. SchmidAbstract:The cyprinid fish Alburnus alburnus possesses one of the largest Supernumerary Chromosomes in all vertebrates. In the present study, amplified fragment length polymorphism analyses (AFLP) and fluorescence in-situ hybridization (FISH) were performed in order to characterize these extraordinary Chromosomes in detail. Sequence analysis of the B Chromosome-specific DNA revealed a strong homology to a Drosophila Gypsy/Ty3 retrotransposon and also to a medaka ( Oryzias latipes ) one. The sequence is highly abundant on the B Chromosome but undetectable in the normal A Chromosome complement. It is also absent from the B Chromosome of the closely related species, Rutilus rutilus , suggesting a specific spreading of the mobile element during evolution of the giant Supernumerary Chromosome within A. alburnus . Meitotic Chromosomes were in-situ hybridized with the B Chromosome-specific probe, documenting that the additional Chromosome behaves as an autopaired ring Chromosome in diakineses. Our results suggest that the Supernumerary Chromosome of A. alburnus is not derived from the normal Chromosome complement but has evolved independently.
M. Schartl - One of the best experts on this subject based on the ideXlab platform.
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Cytogenetics of the bleak (Alburnus alburnus), with special emphasis on the B Chromosomes
2006Co-Authors: M. Schmid, C. G. Ziegler, C. Steinlein, I. Nanda, M. SchartlAbstract:Some of the largest B Chromosomes so far discovered in vertebrates are present in the cyprinid fish Alburnus alburnus . Previous cytogenetic analyses revealed a diploid Chromosome number of 2n = 50. In addition, in some individuals one or two unusually large B Chromosomes are present. Two morphologically different types of B Chromosomes were observed. The frequency of animals bearing a Supernumerary Chromosome was found to vary considerably between different populations. A more detailed analysis of the A and B Chromosomes of A. alburnus by conventional banding techniques, as well as fluorescence in-situ hybridization (FISH) with the telomeric DNA repeats (GGGTTA)_7/(TAACCC)_7, 18S + 28S rDNA and 5S rDNA were performed in the present study. Furthermore, a B Chromosome-specific DNA probe obtained by amplified length polymorphism (AFLP) was hybridized on metaphases of A. alburnus carrying Supernumerary B Chromosomes. The banding analyses showed that the B Chromosomes are completely heterochromatic, consist of GC-rich DNA sequences, replicate their DNA in the very late S-phase of the cell cycle and are composed mainly of a specific retrotransposable DNA element. Finally, blood probes from A. alburnus were collected for DNA-flow cytometric measurements. It could be shown that the huge Supernumerary Chromosomes represent nearly 10% of the total genome size of A. alburnus .
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The giant B Chromosome of the cyprinid fish Alburnus alburnus harbours a retrotransposon-derived repetitive DNA sequence
2003Co-Authors: C. G. Ziegler, C. Steinlein, M. Schartl, D. K. Lamatsch, W. Engel, M. SchmidAbstract:The cyprinid fish Alburnus alburnus possesses one of the largest Supernumerary Chromosomes in all vertebrates. In the present study, amplified fragment length polymorphism analyses (AFLP) and fluorescence in-situ hybridization (FISH) were performed in order to characterize these extraordinary Chromosomes in detail. Sequence analysis of the B Chromosome-specific DNA revealed a strong homology to a Drosophila Gypsy/Ty3 retrotransposon and also to a medaka ( Oryzias latipes ) one. The sequence is highly abundant on the B Chromosome but undetectable in the normal A Chromosome complement. It is also absent from the B Chromosome of the closely related species, Rutilus rutilus , suggesting a specific spreading of the mobile element during evolution of the giant Supernumerary Chromosome within A. alburnus . Meitotic Chromosomes were in-situ hybridized with the B Chromosome-specific probe, documenting that the additional Chromosome behaves as an autopaired ring Chromosome in diakineses. Our results suggest that the Supernumerary Chromosome of A. alburnus is not derived from the normal Chromosome complement but has evolved independently.
J P M Camacho - One of the best experts on this subject based on the ideXlab platform.
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three sympatric karyomorphs in the fish astyanax fasciatus teleostei characidae do not seem to hybridize in natural populations
2012Co-Authors: Maressa Ferreiraneto, J P M Camacho, Roberto Ferreira Artoni, Marcelo Ricardo Vicari, Orlando Moreira Filho, Mohammed Bakkali, Claudio Oliveira, Fausto ForestiAbstract:Ninety individuals of the characid fish Astyanax fasciatus (Cuvier, 1819) were collected at Agua da Madalena stream (Botucatu, Sao Paulo, Brazil) and analyzed for diploid Chromosome number 2n and karyotype composition as well as for the chromosomal location of the 5S and 18S ribosomal DNA (rDNA). Whereas no Chromosome differences were associated with sex, three different karyomorphs with diploid Chromosome numbers 2n=46, 2n=48 and 2n=50 were found. No intermediate 2n numbers were discovered. The 2n=50 karyomorph showed some differences in 18S rDNA location compared to the two other karyomorphs. Finally, all specimens with the 2n=46 karyomorph showed the presence of a partly heterochromatic macro Supernumerary Chromosome, which was absent in all individuals with the two other karyomorphs. All these results suggest that indviduals of the three different karyomorphs are not likely to hybridize in the examined populations. Our findings strongly suggest the presence of three separate species (sensu biological species concept) easily diagnosed on the basis of differences in the diploid Chromosome numbers and other chromosomal markers.
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Roberto Herrán, J P M Camacho, Ruiz M RejonAbstract:Inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in Muscari comosum (Liliaceae)
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inheritance and fitness effects of a pericentric inversion and a Supernumerary Chromosome segment in muscari comosum liliaceae
1998Co-Authors: M A Garridoramos, Manuel Jamilena, Ruiz M Rejon, Roberto Herrán, J P M CamachoAbstract:The inheritance and the effects on fitness of a pericentric inversion and a Supernumerary Chromosome segment (SCS) involving the second Chromosome pair of Muscari comosum, have been analysed in an experimental population. Whereas the inversion is inherited in a Mendelian fashion through the female side, the SCS shows a powerful accumulation mechanism (k=0.796). Cases of nonrandom pollination were observed in homozygous bulbs for the standard Chromosomes (++) and also in those homozygous for the inverted Chromosomes (ii), which may be caused by a certain rate of self-pollination. The different karyotypes for both the inversion and the SCS showed similar values for several life-history traits related to female fitness, such as bulb weight, number of fruits, number of seeds and seed weight. However, plants carrying the inversion had heavier bulbs than those lacking it. The significance of these observations is discussed in relation to the maintenance of the two types of polymorphism in natural populations.
