Bressa Maria José, Larramendy Marcelo Luis, Papeschi Alba Graciela
Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Int. Güiraldes y Costanera Norte, C1428EHA Argentina.
Genetica. 2005 Jul;124(2-3):307-17. doi: 10.1007/s10709-005-4524-3.
The amount, composition and location of heterochromatin in Athaumastus haematicus (Stål, 1859), Leptoglossus impictus (Stål, 1859), Phthia picta (Drury, 1770) (Coreidae), Largus rufipennis Laporte, 1832 (Largidae) and Jadera sanguinolenta (Fabricius, 1775) (Rhopalidae) are analyzed by C-banding and DAPI/ CMA fluorescent banding. As the rule for Heteroptera the possession of holokinetic chromosomes and a pre-reductional type of meiosis cytogenetically characterize these five species. Besides, all of them (except L. rufipennis) present a pair of m chromosomes. C-banding technique reveals the absence of constitutive heterochromatin in A. haematicus, scarce C-positive blocks in L. impictus and J. sanguinolenta, and C-positive heterochromatin terminally located in P. picta and L. rufipennis. All C-bands are DAPI bright, except for a DAPI dull/CMA bright band at one telomeric end of the X chromosome in L. rufipennis, which probably corresponds to a nucleolar organizing region. The results of the banding techniques are analyzed in relation to the chiasma frequency and distribution in the five species, and it is concluded that there should exist some constraints to the acquisition and/ or accumulation of heterochromatin in their karyotypes.
通过C带和DAPI/CMA荧光带技术，对血点扁蝽（Athaumastus haematicus，（施塔尔，1859年））、斑纹长蝽（Leptoglossus impictus，（施塔尔，1859年））、彩蝽（Phthia picta，德鲁里，1770年）（缘蝽科）、红翅大缘蝽（Largus rufipennis，拉波特，1832年）（大缘蝽科）和血斑扁蝽（Jadera sanguinolenta，（法布尔，1775年））（红蝽科）的异染色质数量、组成和位置进行了分析。作为半翅目的规则，具有全动染色体和减数分裂前期还原类型在细胞遗传学上是这五个物种的特征。此外，它们所有（除红翅大缘蝽外）都有一对m染色体。C带技术显示，血点扁蝽中不存在组成型异染色质，斑纹长蝽和血斑扁蝽中有稀少的C阳性块，而彩蝽和红翅大缘蝽中的C阳性异染色质位于末端。除红翅大缘蝽X染色体一个端粒末端有一条DAPI暗/CMA亮带外，所有C带在DAPI下均为亮带，这条带可能对应一个核仁组织区。结合这五个物种的交叉频率和分布情况，对带技术的结果进行了分析，得出结论：在它们的核型中，异染色质的获得和/或积累应该存在一些限制。
