Chromosome banding in Amphibia -: XXVIII.: Homomorphic XY sex chromosomes and a derived Y-autosome translocation in Eleutherodactylus riveroi (Anura, Leptodactylidae)
Chromosome banding in Amphibia -: XXVIII.: Homomorphic XY sex chromosomes and a derived Y-autosome translocation in Eleutherodactylus riveroi (Anura, Leptodactylidae)
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DOI：
10.1159/000073420
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发表时间：
2003-01-01
影响因子：
1.7
通讯作者：
Badillo, AF
中科院分区：
文献类型：
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作者：
Schmid, M;Feichtinger, W;Badillo, AF
对委内瑞拉北方的一群细趾蛙Eleutherodactylus riveroi进行了广泛的细胞遗传学分析，发现存在多条XXA雌性/XYAAmale/XAA（Y）雄性性染色体。XAA（Y）核型起源于原始游离Y染色体和常染色体之间的着丝粒（罗伯逊）融合。该群体中46.2%的男性个体是这种Y常染色体融合的携带者。在雄性减数分裂中，XAA（Y）性染色体以预期的三价构型配对。在同一种群中，53.8%的雄性动物仍然拥有原始的游离XY性染色体。E riveroi是第二个发现Y-常染色体融合与祖先游离XY性染色体共存的脊椎动物物种。游离的XY性染色体，以及多个XA（Y）性染色体仍然处于非常原始的（同型）分化阶段。在没有应用显带技术的情况下，有可能区分Y和X。各种显带技术和原位杂交已经进行了核型的特点。DNA流式细胞仪检测表明，E. riveroi与其他Eleutherodactylus物种相似。对E. riveroi与其他唯一已知拥有极其罕见的多个XXAAfemale/XYAAmale/XAA（Y）雄性性染色体的脊椎动物进行了比较。令人惊讶的是，这种脊椎动物又是一种属于Eleutherodactylus [E（maussi）biporcatus]的青蛙，它与E生活在委内瑞拉北方的同一栖息地。riveroi。版权所有（C）2003 S. Karger AG，巴塞尔。
Extensive cytogenetic analyses on a population of the leptodactylid frog Eleutherodactylus riveroi in northern Venezuela revealed the existence of multiple XXAAfemale/XYAAmale/XAA(Y)male, sex chromosomes. The XAA(Y) karyotype originated by a centric (Robertsonian) fusion between the original, free Y chromosome and an autosome. 46.2% of the male individuals in this population are carriers of this Y-autosome fusion. In male meiosis the XAA(Y) sex chromosomes pair in the expected trivalent configuration. In the same population 53.8% of the male animals still possess the original, free XY sex chromosomes. E riveroi is only the second vertebrate species discovered in which a derived Y-autosome fusion coexists with the ancestral free XY sex chromosomes. The free XY sex chromosomes, as well as the multiple XA(Y) sex chromosomes are still in a very primitive (homomorphic) stage of differentiation. With no banding technique applied it is possible to distinguish the Y from the X. Various banding techniques and in situ hybridizations have been carried out to characterize the karyotypes. DNA flow cytometric measurements show that the genome size of E. riveroi resembles that of other Eleutherodactylus species. The cytogenetic data obtained in E. riveroi are compared with those of the sole other vertebrate known to possess the extremely rare, multiple XXAAfemale/XYAAmale/XAA(Y)male sex chromosomes. Surprisingly enough, this vertebrate again is a frog belonging to the genus Eleutherodactylus [E (maussi) biporcatus] which lives exactly in the same habitat in northern Venezuela as does E. riveroi. Copyright (C) 2003 S. Karger AG, Basel.