Nucleolar organizing regions, 18S and 5S rDNA in Astyanax scabripinnis (Pisces, Characidae):: populations distribution and functional diversity

被引：0
作者：
Ferro, DAD [1 ]
Néo, DM [1 ]
Moreira, O [1 ]
Bertollo, LAC [1 ]
机构：
[1] Univ Fed Sao Carlos, Dept Genet & Evoluc, BR-13565905 Sao Carlos, SP, Brazil
来源：
GENETICA | 2000年 / 110卷 / 01期
关键词：
fishes; functional diversity; NORs; 18S & 5S rDNA;
D O I：
暂无
中图分类号：
Q3 [遗传学];
学科分类号：
071007 ; 090102 ;
摘要：
Astyanax scabripinnis specimens from four distinct populations in Brazil were studied with respect to their karyotype macrostructure, nucleolar organizer regions, and 18S and 5S rRNA genes. The four populations showed a 2n = 50 chromosomes (3 M + 11 SM + 5 ST + 6 A pairs) and 1-2 B chromosomes. No chromosomal differentiations were observed between sexes. Although a karyotypic diversity has been characterized in this fish group, the populations now analyzed presented the same macrokaryotypic pattern. Chromosome mapping of 5S rDNA showed a total of eight sites located in four distinct chromosomal pairs, with no apparent differences among populations. A comparative study on 18S rDNA locations and Ag-NORs showed some secondary NOR sites that are not usually expressed in karyotypes and a probable differential NOR activity among populations. Correlations between these data, environmental conditions and B chromosomes are discussed.
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页码：55 / 62
页数：8
相关论文
共 43 条
[1]  
ALMEIDATOLEDO LF, 1985, CIENCIA CULTURA, V37, P448
[2]   CHROMOMYCIN-A3 STAINS NUCLEOLUS ORGANIZER REGIONS OF FISH CHROMOSOMES [J].
AMEMIYA, CT ;
GOLD, JR .
COPEIA, 1986, (01) :226-231
[3]   CYTOGENETIC STUDIES IN NORTH-AMERICAN MINNOWS (CYPRINIDAE) .3. CHROMOSOMAL NORS AS TAXONOMIC AND SYSTEMATIC CHARACTERS IN NORTH-AMERICAN CYPRINID FISHES [J].
AMEMIYA, CT ;
GOLD, JR .
GENETICA, 1988, 76 (02) :81-90
[4]  
BERTOLLO L A C, 1978, Revista Brasileira de Genetica, V1, P103
[5]  
Bertollo Luiz Antonio Carlos, 1996, Cytologia (Tokyo), V61, P75
[6]   An XX/XY sex chromosome system in a fish species, Hoplias malabaricus, with a polymorphic NOR-bearing x chromosome [J].
Born, GG ;
Bertollo, LAC .
CHROMOSOME RESEARCH, 2000, 8 (02) :111-118
[7]   EFFECTS OF B-CHROMOSOMES ON THE ACTIVITY OF NUCLEOLAR ORGANIZER REGIONS IN THE GRASSHOPPER EYPREPOCNEMIS-PLORANS - ACTIVATION OF A LATENT NUCLEOLAR ORGANIZER REGION ON A B-CHROMOSOME FUSED TO AN AUTOSOME [J].
CABRERO, J ;
ALCHE, JD ;
CAMACHO, JPM .
GENOME, 1987, 29 (01) :116-121
[8]   B-chromosome evolution [J].
Camacho, JPM ;
Sharbel, TF ;
Beukeboom, LW .
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 2000, 355 (1394) :163-178
[9]   THE INFLUENCE OF B-CHROMOSOMES ON RDNA ORGANIZATION IN RYE INTERPHASE NUCLEI [J].
DELGADO, M ;
MORAISCECILIO, L ;
NEVES, N ;
JONES, RN ;
VIEGAS, W .
CHROMOSOME RESEARCH, 1995, 3 (08) :487-491
[10]  
Galetti Pedro M. Jr, 1993, Ichthyological Exploration of Freshwaters, V4, P269
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