Pisano Eva, Coscia Maria Rosaria, Mazzei Federico, Ghigliotti Laura, Coutanceau Jean-Pierre, Ozouf-Costaz Catherine, Oreste Umberto
Department of Biology, University of Genova, Viale Benedetto XV 5, Genova, Italy.
Genetica. 2007 May;130(1):9-17. doi: 10.1007/s10709-006-0015-4. Epub 2006 Aug 15.
The chromosomal location of the IgH locus has been analyzed in several bony fish of the Antarctic perciform group Notothenioidei. Two IgH probes were prepared from the species Trematomus bernacchii (family Nototheniidae, tribe Trematominae) and mapped onto the chromosomes of ten species belonging to the same genus (Trematomus) and in two outgroups, through one-color and two-color FISH. A single location of the IgH locus was found in the majority of the species examined, including the outgroups, whereas in four of them the IgH genes splited to two chromosomal loci. RT-PCR experiments revealed the presence of three allelic sequences in T. newnesi, a species in which the IgH genes were organized in two chromosomal loci. Possible pathways leading to IgH genes duplication during the diversification of trematomine fishes were inferred from the analysis of the FISH patterns in a phylogenetic context. The present work provides the first comprehensive picture of IgH genes organization at chromosomal level in a bony fish group.
已在南极鲈形目南极鱼亚目（Notothenioidei）的几种硬骨鱼中分析了免疫球蛋白重链（IgH）基因座的染色体定位。从伯氏南极鱼（Trematomus bernacchii，南极鱼科，南极鱼亚科）制备了两种IgH探针，并通过单色和双色荧光原位杂交（FISH）将其定位到属于同一属（南极鱼属）的10个物种以及两个外类群的染色体上。在所检查的大多数物种（包括外类群）中发现IgH基因座位于单一位置，而在其中4个物种中，IgH基因分散到两个染色体位点。逆转录聚合酶链反应（RT-PCR）实验揭示了新氏南极鱼（T. newnesi）中存在三个等位基因序列，该物种的IgH基因分布于两个染色体位点。通过在系统发育背景下对FISH模式的分析，推断出南极鱼亚科鱼类多样化过程中导致IgH基因重复的可能途径。本研究首次全面描绘了硬骨鱼群中染色体水平上IgH基因的组织情况。
