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| Prado,Fernanda Dotti do; Nunes,Tatiana Leite; Senhorini,José Augusto; Bortolozzi,Jehud; Foresti,Fausto; Porto-Foresti,Fábio. |
| The cytogenetic characteristics of Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum and their F1, F2 and backcross hybrids were assessed by using chromosome banding techniques. The diploid number of 56 chromosomes was constant in all species and lineages, with a karyotypic formula containing 20 metacentric, 12 submetacentric, 12 subtelocentric and 12 acrocentric chromosomes. Nucleolar organizer regions (NORs) were identified in two subtelocentric chromosomes in the parents and hybrids, with partial nucleolar dominance in F1 and F2 specimens. Heterochromatic blocks were detected in the terminal and centromeric regions of some chromosomes in all individuals. For parental and hybrid lineages, 18S ribosomal clusters corresponding to NORs and 5S... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Backcrossing; Cytogenetics; Interspecific hybrids; Post-F1 hybrids; Pseudoplatystoma. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100008 |
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| Bem,Jaqueline Cristina de; Fontanetti,Carmem Silvia; Senhorini,José Augusto; Parise-Maltempi,Patricia Pasquali. |
| The objective of this study was to evaluate the effectiveness of estradiol valerate in an attempt to feminize the male Astyanax altiparanae. One thousand newly-hatched larvae were randomly distributed in four incubators. During a period of 30 days, estradiol valerate was administered in different dosages (20, 40, and 80 mg/kg of diet); the control group did not receive hormone in the diet. After 161 days of hatching, biometry was performed on 50 fishes per treatment group, and the gonads were analyzed. The hormone treatments were effective in feminizing A. altiparanae, achieving 70-76% of the desired sex, while the control treatment had 44% females. The hormone did not affect the growth of fish. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax altiparanae; Characidae; Feminization; Sex Reversion; Estrogen. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000200015 |
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| Voltolin,Tatiana Aparecida; Senhorini,José Augusto; Foresti,Fausto; Bortolozzi,Jehud; Porto-Foresti,Fábio. |
| B chromosomes are supernumerary elements present in about 15% of eukaryotic species and are most frequently heterochromatic, behave parasitically, show a transmission rate higher than standard (A) chromosomes, and can provoke harmful effects on carriers. In the current work, Prochilodus lineatus individuals carrying eight and nine B chromosomes were obtained by induced crossing performed involving breeders with different B chromosome numbers in their cells. The high B chromosome numbers found in the offspring were recorded for the first time in this species. The use of cytogenetic techniques applied in the present study revealed that regardless of the increase in number of B chromosomes in the genome of these individuals, those elements did not presented... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Supernumerary chromosome; Heterochromatic chromosome; Cross-fertilization. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200009 |
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| Voltolin,Tatiana Aparecida; Penitente,Manolo; Mendonça,Bruna Bueno; Senhorini,José Augusto; Foresti,Fausto; Porto-Foresti,Fábio. |
| The family Prochilodontidae is considered a group with well conserved chromosomes characterized by their number, morphology and banding patterns. Thence, our study aimed at accomplishing a cytogenetic analysis with conventional methods (Giemsa staining, silver staining of the nucleolus organizer regions-AgNOR, and C-banding) and fluorescence in situ hybridization (FISH) with 18S and 5S ribosomal DNA probes in five species of the Prochilodus genus (Prochilodus argenteus, Prochilodus brevis, Prochilodus costatus, Prochilodus lineatus and Prochilodus nigricans) collected from different Brazilian hydrographic basins. The results revealed conservatism in chromosome number, morphology, AgNORs 18S and 5S rDNAs location and constitutive heterochromatin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: AgNOR; C-banding; Hydrographic basins; Conserved karyotype; FISH. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000300008 |
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| Ninhaus-Silveira,Alexandre; Foresti,Fausto; Veríssimo-Silveira,Rosicleire; Senhorini,José Augusto. |
| Aiming to improve fish reproduction techniques, the characterization and cryopreservation of semen of Brycon cephalus were performed. The seminal characteristics observed were: an almost transparent, milky semen with a mean volume of 4mL, and sperm concentration of 9.617±1.630 x 10(6) spermatozoa/mm³. Spermatozoa (length = 31.288 ±4.47µm) were of the aquasperm type and displayed a small, round head (length = 1.727 ±0.18 µm; width = 1.752 ±0.17µm) without acrosomal vesicle, nucleus with highly condensed chromatin forming coarse clots and centriolar complex located in the nuclear fossa; a midpiece (length = 2.561±0.44µm), narrowed rearward, with a cytoplasmic canal; and a flagellum (length = 29.521 ±4.37µm). Fertilization tests with thawed semen demonstrated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Semen characteristics; Cryopreservation; Brycon cephalus; Ultrastructure; Fish. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000500015 |
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| Soares,Maria do Carmo Figueredo; Urbinati,Elisabeth Criscuolo; Senhorini,José Augusto. |
| O matrinxã, Brycon cephalus, espécie nativa oriunda da Bacia Amazônica, apresenta características adequadas para a piscicultura. Entretanto, trata-se de peixe reofílico, sendo necessário manejo adequado para induzir à reprodução. O objetivo deste trabalho foi caracterizar o perfil da triiodotironina (T3) plasmática no matrinxã, durante 16 meses (outubro/97 a janeiro/99), relacionando-o com a maturação sexual, além de testar a ação do T3 associado ao extrato pituitário de carpa na reprodução induzida da espécie. O experimento foi conduzido no Centro Nacional de Pesquisa de Peixes Tropicais - CEPTA, Pirassununga, SP, e no Departamento de Morfologia e Fisiologia Animal, da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal - UNESP. Foram amostrados,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gônadas; Peixe de água doce; Temperatura; Triiodotironina (T3 ). |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982003000800004 |
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