Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus
<p>Abstract</p> <p>Background</p> <p>Cytogenetic studies were carried out on samples of <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil).</p> <p>Results<...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2009-11-01
|
| Series: | BMC Genetics |
| Online Access: | http://www.biomedcentral.com/1471-2156/10/74 |
| _version_ | 1818539964436054016 |
|---|---|
| author | Nagamachi Cleusa Y Pieczarka Julio C Milhomem Susana SR Silva Danillo S |
| author_facet | Nagamachi Cleusa Y Pieczarka Julio C Milhomem Susana SR Silva Danillo S |
| author_sort | Nagamachi Cleusa Y |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Cytogenetic studies were carried out on samples of <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil).</p> <p>Results</p> <p>All four populations had 2n = 38, with ZZ/ZW sex chromosomes (Z, acrocentric; W, submetacentric). Constitutive heterochromatin (CH) was found at the centromeric regions of all chromosomes. The W chromosome had a heterochromatic block in the proximal region of the short arm; this CH was positive for DAPI staining, indicating that it is rich in A-T base pairs. The nucleolar organizer region (NOR) was localized to the short arm of chromosome pair 15; this result was confirmed by fluorescent <it>in situ </it>hybridization (FISH) with human 45S rDNA, and CMA<sub>3 </sub>staining indicated that the region is G-C rich. FISH with telomeric probes did not show any evidence of interstitial telomeric sequences (ITS).</p> <p>Conclusion</p> <p>Previous studies have shown that the species <it>Eigenmannia </it>sp. 2 and <it>E. virescens </it>have differentiated sex chromosomes, and diverse sex chromosome systems have been described for <it>E. virescens </it>specimens obtained from different Brazilian rivers. A comparative analysis of the present data and prior reports suggests that the sex chromosomes of <it>Eigenmannia </it>may have arisen independently in the different populations.</p> |
| first_indexed | 2024-12-11T21:49:06Z |
| format | Article |
| id | doaj.art-b7d6ff14fbc941e48b2a54a3765e233d |
| institution | Directory Open Access Journal |
| issn | 1471-2156 |
| language | English |
| last_indexed | 2024-12-11T21:49:06Z |
| publishDate | 2009-11-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Genetics |
| spelling | doaj.art-b7d6ff14fbc941e48b2a54a3765e233d2022-12-22T00:49:32ZengBMCBMC Genetics1471-21562009-11-011017410.1186/1471-2156-10-74Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genusNagamachi Cleusa YPieczarka Julio CMilhomem Susana SRSilva Danillo S<p>Abstract</p> <p>Background</p> <p>Cytogenetic studies were carried out on samples of <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil).</p> <p>Results</p> <p>All four populations had 2n = 38, with ZZ/ZW sex chromosomes (Z, acrocentric; W, submetacentric). Constitutive heterochromatin (CH) was found at the centromeric regions of all chromosomes. The W chromosome had a heterochromatic block in the proximal region of the short arm; this CH was positive for DAPI staining, indicating that it is rich in A-T base pairs. The nucleolar organizer region (NOR) was localized to the short arm of chromosome pair 15; this result was confirmed by fluorescent <it>in situ </it>hybridization (FISH) with human 45S rDNA, and CMA<sub>3 </sub>staining indicated that the region is G-C rich. FISH with telomeric probes did not show any evidence of interstitial telomeric sequences (ITS).</p> <p>Conclusion</p> <p>Previous studies have shown that the species <it>Eigenmannia </it>sp. 2 and <it>E. virescens </it>have differentiated sex chromosomes, and diverse sex chromosome systems have been described for <it>E. virescens </it>specimens obtained from different Brazilian rivers. A comparative analysis of the present data and prior reports suggests that the sex chromosomes of <it>Eigenmannia </it>may have arisen independently in the different populations.</p>http://www.biomedcentral.com/1471-2156/10/74 |
| spellingShingle | Nagamachi Cleusa Y Pieczarka Julio C Milhomem Susana SR Silva Danillo S Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus BMC Genetics |
| title | Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus |
| title_full | Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus |
| title_fullStr | Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus |
| title_full_unstemmed | Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus |
| title_short | Cytogenetic studies in <it>Eigenmannia virescens </it>(Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the <it>Eigenmannia </it>genus |
| title_sort | cytogenetic studies in it eigenmannia virescens it sternopygidae gymnotiformes and new inferences on the origin of sex chromosomes in the it eigenmannia it genus |
| url | http://www.biomedcentral.com/1471-2156/10/74 |
| work_keys_str_mv | AT nagamachicleusay cytogeneticstudiesiniteigenmanniavirescensitsternopygidaegymnotiformesandnewinferencesontheoriginofsexchromosomesintheiteigenmanniaitgenus AT pieczarkajulioc cytogeneticstudiesiniteigenmanniavirescensitsternopygidaegymnotiformesandnewinferencesontheoriginofsexchromosomesintheiteigenmanniaitgenus AT milhomemsusanasr cytogeneticstudiesiniteigenmanniavirescensitsternopygidaegymnotiformesandnewinferencesontheoriginofsexchromosomesintheiteigenmanniaitgenus AT silvadanillos cytogeneticstudiesiniteigenmanniavirescensitsternopygidaegymnotiformesandnewinferencesontheoriginofsexchromosomesintheiteigenmanniaitgenus |