Morphological differentiation and possible origin of B chromosomes in natural Brazilian population of Astyanax scabripinnis (PISCES, CHARACIDAE)

被引：30

作者：

Néo, DM ^{[1
]}

Bertollo, LAC ^{[1
]}

Moreira, O ^{[1
]}

机构：

[1] Univ Fed Sao Carlos, Dept Genet & Evolucao, BR-13565905 Sao Carlos, SP, Brazil

来源：

GENETICA | 2000年 / 108卷 / 03期

基金：

巴西圣保罗研究基金会;

关键词：

Astyanax scabripinnis; B chromosome; Characidae; cytogenetic; fish;

D O I：

10.1023/A:1004157901097

中图分类号：

Q3 [遗传学];

学科分类号：

071007 ; 090102 ;

摘要：

Specimens of Astyanax scabripinnis from three different altitudes (1920, 1800 and 700 m) along the Ribeirao Grande stream in the Campos do Jordao region (Sao Paulo State, Brazil) were investigated. The same diploid number, 2n = 50, was detected in the three populations, with the following karyotypic constitution: 6M, 22SM, 10ST and 12A. The populations located at 1920 and 1800 m altitude presented a high incidence of B chromosomes varying in number (0-2), shape (meta- and submetacentrics), size (large and small) and sex-related frequency (they were more frequent among females). The two morphologically variant B chromosomes probably evolved from a metacentric macrochromosome, which is the most commonly observed B chromosome in several A. scabripinnis populations.

引用

页码：211 / 215

页数：5