眼斑拟石首鱼重复DNA序列的染色体定位  

LOCATION OF REPETITIVE DNA SEQUENCES ON THE CHROMOSOME OF SCIAENOPS OCELLATUS

作　　者：朱齐春 郑娇 张静 刘贤德 王志勇 蔡明夷 

机构地区：[1]集美大学水产学院,农业部东海海水健康养殖重点实验室,厦门361021

出　　处：《水生生物学报》2017年第6期1218-1224,共7页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(41706157和31272653);福建省自然科学基金(2017J01449)资助~~

摘　　要：针对眼斑拟石首鱼Sciaenops ocellatus染色体标记匮乏的问题,利用荧光原位杂交(FISH)定位了眼斑拟石首鱼的18S r DNA、5S r DNA和端粒序列。结果显示,眼斑拟石首鱼的核型公式为2n=48t;仅有1对18S r DNA位点,位于第1对染色体的次缢痕部位;有2对5S r DNA位点,FISH信号强度不等,强信号位于第8对染色体的近着丝粒端,弱信号位于第3对染色体的臂间。端粒FISH信号出现于所有染色体的两端,但表现出染色体两端信号不平衡的特点,着丝粒端FISH信号明显强于远端信号。这一特点为判定染色体的方向提供了便利。结合其他石首鱼的核型数据可以推断,2n=48t的核型及单对近着丝粒分布的18S r DNA位点是石首鱼的共同祖征;在石首鱼进化过程中,曾发生活跃但不影响宏观核型的小规模重排。研究结果丰富了眼斑拟石首鱼染色体的辨识标记,并为研究石首鱼染色体进化提供了基础数据。The chromosome characteristics of red drum（Sciaenops ocellatus） were analyzed to enhance the cytogenetic markers in Sciaenops ocellatus by fluorescence in situ hybridization（FISH） with 18 S r DNA, 5 S r DNA and telomeric repetitive DNA as probes. The karyotype of red drum consists of 48 telomeric chromosomes. FISH with 18 S r DNA probes showed a single pair of signals at the secondary constriction sites of Chromosome 1. Whereas, two pairs of signal with different intensity were detected with the 5 S r DNA probes： the strong signals were on the proximal of Chromosome 8, and the weak ones were on the interstitial of Chromosome 3. The signals of telomeric repetitive DNA appeared at both ends of all chromosomes with uneven intensity, and signals at the centromeric ended stronger than those at the distal ends, which facilitated determining the direction of the chromosome. These results, together with the available cytogenetic data of other sciaenids, suggested that the karyotype of 2 n=48 t and single 18 S r DNA locus were the symplesiomorphic cytogenetic features of sciaenids, and the active and cryptic chromosomal rearrangements may have occurred along the evolution of sciaenids. The distribution patterns of these three kinds of repetitive DNAs would be useful to assist identifying the chromosomes of red drum, and be the basic data for studying chromosome evolution in Sciaenidae.

关 键 词：眼斑拟石首鱼 核型 染色体 荧光原位杂交 核糖体DNA 端粒 

分 类 号：Q343.2[生物学—遗传学]