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Papers by Elsa Pinna-Senn
The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose membe... more The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.
CYTOLOGIA, 2001
Akodon is the richest Sigmodontine genus in terms of number of species. This article analyzes the... more Akodon is the richest Sigmodontine genus in terms of number of species. This article analyzes the chromosomal banding produced in A. azarae, A. molinae and A. dolores by the fluorochromes 4,6-diamidino-2-phenylindole (DAPI) and chromomycin A3 (CMA), counterstained in some cases with distamycin A (DA). A. azarae populations have fertile XY females, and A. molinae and A. dolores, a pair of closely related species, show Robertsonian polymorphisms. In the 3 species, as generally observed in mammals, DAPI-treated chromosomes presented a G/Q-like fluorescent pattern, and DA-CMA treatment gave R-type banding. The constitutive heterochromatin of A. azarae, comprising the centric regions of the autosomes (excepting the small metacentric), the Ychromosome, and several bands of the X amounting to almost 38% of its length, fluoresced with DAPI and appeared negative with DA-CMA, indicating the relative AT-richness of their repetitive components. In A. molinae and A. dolores, no characteristic fluorescence was noticed in the small heterochromatic regions of the autosomes. The heterochromatic Y of these species could be differentiated into a centric portion (approximately one third of the chromosome) that fluoresced with DA-CMA, and was therefore relatively GC-rich, and a distal portion that fluoresced brightly with DAPI, which was thus relatively AT-rich; the small centric band of the X fluoresced with CMA. The response of the gonosomal centric regions indicates that these chromosomes associate by their centromeric ends in diakinesis-metaphase I. These observations confirm the utility of fluorochromes that are highly selective for DNA base pair composition in cytogenetic studies, and further our understanding of the chromosomal evolution in this genus.
CYTOLOGIA, 2007
The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose membe... more The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.
Cytogenetic and Genome Research, 2004
The distribution of the vertebrate telomeric sequence T2AG3 in three species of the rodent genus ... more The distribution of the vertebrate telomeric sequence T2AG3 in three species of the rodent genus Akodon was examined by FISH with a peptide nucleic acid probe. In addition to the expected telomeric hybridization, non-telomeric signals were observed in the three species. In A. dolores, centromeric signals were visible in two of the four biarmed autosome pairs featuring Robertsonian polymorphism, indicating the retention of at least part of the telomeric sequences during the fusion process, and an interstitial signal of lower intensity was observed in the short arm of another. In A. boliviensis, a strong signal was observed near the centromeric end of the first chromosome pair. The first pair of A. azarae (homologous to the first pair of A. boliviensis) showed a similar but markedly amplified signal, and a subcentromeric signal in the X chromosome corresponding to a heterochromatic region; additionally, interstitial signals of lower intensity were present in one to four chromosomes in...
Biotechnic & Histochemistry, 2000
Acta Histochemica, 2005
Numerous non-rigid and bow-shaped cationic fluorochromes exist which bind to chromatin DNA, but o... more Numerous non-rigid and bow-shaped cationic fluorochromes exist which bind to chromatin DNA, but only some of them are able to selectively label pericentromeric heterochromatin (C-bands) in metaphase chromosomes. Likewise, some DNA ligands allow the recognition of adenine-thymine sequences establishing hydrogen bonds with acceptor atoms in the minor groove. In the present study, we have employed cationic fluorochromes based on a variety of chemical groups to analyze comparatively their potential to demonstrate C-bands, as well as the relationship between this feature and structural parameters of fluorochromes such as curvature radius and hydrogenbonding ability. Only fluorochromes that bind DNA by hydrogen bonds demonstrated the characteristic C-banding pattern in mouse metaphase chromosomes (together with a weak G/Q-banding), whereas the other (non-hydrogen-bonding) cationic fluorochromes produced uniform emission without any visible banding.
Mammalian Biology, 2009
The populations of several species of Akodon present, besides XX females, a variable proportion o... more The populations of several species of Akodon present, besides XX females, a variable proportion of fertile XY females. In Akodon azarae, a correspondence exists between the X-chromosome C-banding pattern and the sexual phenotype of XY individuals: males carry a determinate X-chromosome type, defined by its C-banding pattern, and XY females, any of two others. To confirm the relation between X-chromosome type and the XY female condition and to investigate the hereditary transmission of these different X-chromosomes, we analyzed 50 animals captured in the field and 95 individuals corresponding to the F 1 and F 2 offspring of 16 crosses. It was seen that the correlation between X type and the sexual phenotype of XY animals is retained, and that the three X types are transmitted to the progeny. It was also observed that the male offspring of XY females receive the X-chromosome from their male parents and the Y from their mothers. These results strongly support the causal role of an X-borne mutation in A. azarae XY sex reversal, and discard a mutation of the Y-chromosome as the sole basis of this phenomenon.
The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose membe... more The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.
CYTOLOGIA, 2001
Akodon is the richest Sigmodontine genus in terms of number of species. This article analyzes the... more Akodon is the richest Sigmodontine genus in terms of number of species. This article analyzes the chromosomal banding produced in A. azarae, A. molinae and A. dolores by the fluorochromes 4,6-diamidino-2-phenylindole (DAPI) and chromomycin A3 (CMA), counterstained in some cases with distamycin A (DA). A. azarae populations have fertile XY females, and A. molinae and A. dolores, a pair of closely related species, show Robertsonian polymorphisms. In the 3 species, as generally observed in mammals, DAPI-treated chromosomes presented a G/Q-like fluorescent pattern, and DA-CMA treatment gave R-type banding. The constitutive heterochromatin of A. azarae, comprising the centric regions of the autosomes (excepting the small metacentric), the Ychromosome, and several bands of the X amounting to almost 38% of its length, fluoresced with DAPI and appeared negative with DA-CMA, indicating the relative AT-richness of their repetitive components. In A. molinae and A. dolores, no characteristic fluorescence was noticed in the small heterochromatic regions of the autosomes. The heterochromatic Y of these species could be differentiated into a centric portion (approximately one third of the chromosome) that fluoresced with DA-CMA, and was therefore relatively GC-rich, and a distal portion that fluoresced brightly with DAPI, which was thus relatively AT-rich; the small centric band of the X fluoresced with CMA. The response of the gonosomal centric regions indicates that these chromosomes associate by their centromeric ends in diakinesis-metaphase I. These observations confirm the utility of fluorochromes that are highly selective for DNA base pair composition in cytogenetic studies, and further our understanding of the chromosomal evolution in this genus.
CYTOLOGIA, 2007
The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose membe... more The distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.
Cytogenetic and Genome Research, 2004
The distribution of the vertebrate telomeric sequence T2AG3 in three species of the rodent genus ... more The distribution of the vertebrate telomeric sequence T2AG3 in three species of the rodent genus Akodon was examined by FISH with a peptide nucleic acid probe. In addition to the expected telomeric hybridization, non-telomeric signals were observed in the three species. In A. dolores, centromeric signals were visible in two of the four biarmed autosome pairs featuring Robertsonian polymorphism, indicating the retention of at least part of the telomeric sequences during the fusion process, and an interstitial signal of lower intensity was observed in the short arm of another. In A. boliviensis, a strong signal was observed near the centromeric end of the first chromosome pair. The first pair of A. azarae (homologous to the first pair of A. boliviensis) showed a similar but markedly amplified signal, and a subcentromeric signal in the X chromosome corresponding to a heterochromatic region; additionally, interstitial signals of lower intensity were present in one to four chromosomes in...
Biotechnic & Histochemistry, 2000
Acta Histochemica, 2005
Numerous non-rigid and bow-shaped cationic fluorochromes exist which bind to chromatin DNA, but o... more Numerous non-rigid and bow-shaped cationic fluorochromes exist which bind to chromatin DNA, but only some of them are able to selectively label pericentromeric heterochromatin (C-bands) in metaphase chromosomes. Likewise, some DNA ligands allow the recognition of adenine-thymine sequences establishing hydrogen bonds with acceptor atoms in the minor groove. In the present study, we have employed cationic fluorochromes based on a variety of chemical groups to analyze comparatively their potential to demonstrate C-bands, as well as the relationship between this feature and structural parameters of fluorochromes such as curvature radius and hydrogenbonding ability. Only fluorochromes that bind DNA by hydrogen bonds demonstrated the characteristic C-banding pattern in mouse metaphase chromosomes (together with a weak G/Q-banding), whereas the other (non-hydrogen-bonding) cationic fluorochromes produced uniform emission without any visible banding.
Mammalian Biology, 2009
The populations of several species of Akodon present, besides XX females, a variable proportion o... more The populations of several species of Akodon present, besides XX females, a variable proportion of fertile XY females. In Akodon azarae, a correspondence exists between the X-chromosome C-banding pattern and the sexual phenotype of XY individuals: males carry a determinate X-chromosome type, defined by its C-banding pattern, and XY females, any of two others. To confirm the relation between X-chromosome type and the XY female condition and to investigate the hereditary transmission of these different X-chromosomes, we analyzed 50 animals captured in the field and 95 individuals corresponding to the F 1 and F 2 offspring of 16 crosses. It was seen that the correlation between X type and the sexual phenotype of XY animals is retained, and that the three X types are transmitted to the progeny. It was also observed that the male offspring of XY females receive the X-chromosome from their male parents and the Y from their mothers. These results strongly support the causal role of an X-borne mutation in A. azarae XY sex reversal, and discard a mutation of the Y-chromosome as the sole basis of this phenomenon.