Chromosomal mapping of major ribosomal rRNA genes in the hard clam (<Emphasis Type="Italic">Mercenaria mercenaria</Emphasis>) using fluorescence in situ hybridization |
| |
Authors: | Yongping Wang Ximing Guo |
| |
Institution: | (1) Haskin Shellfish Research Laboratory, Institute of Marine and Coastal Sciences, Rutgers University, 6959 Miller Avenue, Port Norris, NJ 08349, USA;(2) Experimental Marine Biology Laboratory, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, Shandong, 266071, People’s Republic of China |
| |
Abstract: | Karyotype and chromosomal location of the major ribosomal RNA genes were studied in the hard clam (Mercenaria mercenaria Linnaeus) using fluorescence in situ hybridization (FISH). Metaphase chromosomes were obtained from early embryos. Internal
transcribed spacers (ITS) between major RNA genes were amplified and used as FISH probes. The probes were labeled with digoxigenin-11-dUTP
by polymerase chain reaction and detected with fluorescein-labeled anti-digoxigenin antibodies. FISH with the ITS probes produced
two to four signals per nucleus or metaphase. M. mercenaria had a haploid number of 19 chromosomes with a karyotype of seven metacentric, four metacentric or submetacentric, seven submetacentric,
and one submetacentric or subtelocentric chromosomes (7M + 4M/SM + 7SM + 1SM/ST). Two ITS loci were observed: one located
near the centromere on the long arm of Chromosome 10 and the other at the telomere of the short arm of Chromosome 12. FISH
signals on Chromosome 10 are strong and consistent, while signals on Chromosome 12 are variable. This study provides the first
karyotype and chromosomal assignment of the major RNA genes in M. mercenaria. Similar studies in a wide range of species are needed to understand the role of chromosomal changes in bivalve evolution. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|