Laboratório de Citogenética e Molecular de Insetos, Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho', São José do Rio Preto, SP Brazil.
Genet Mol Biol. 2010 Apr;33(2):244-52. doi: 10.1590/S1415-47572010005000025. Epub 2010 Jun 1.
Spittlebugs annually infest pastures and cause severe damage, representing a serious problem for the tropical American beef cattle industry. Spittlebugs are an important biotic constraint to forage production and there is a lack of cytogenetic data for this group of insects. For these reasons, we conducted this work, in which the spermatogenesis and nucleolar behavior of Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana were studied. The males possessed testes in the shape of a "bunch of grapes"; a variable number of testicular lobes per individual and polyploid nuclei composed of several heteropycnotic bodies. A heteropycnotic area was located in the periphery of the nucleus (prophase I); the chiasmata were terminal or interstitial; metaphases I were circular or linear and anaphase showed late migration of the sex chromosome. The chromosome complement had 2n = 19, except for N. entreriana (2n = 15); the spermatids were round with heteropycnotic material in the center and elongated with conspicuos chromatin. The analysis of testes after silver nitrate staining showed polyploid nuclei with three large and three smaller nucleolar bodies. Early prophase cells had an intensely stained nucleolar body located close to the chromatin and another less evident body located away from the chromatin. The nucleolar bodies disintegrated during diplotene. Silver staining occurred in two autosomes, in terminal and subterminal locations, the latter probably corresponding to the nucleolus organizer regions (NORs). The spermatids were round with a round nucleolar body and silver staining was observed in the medial and posterior region of the elongated part of the spermatid head.
沫蝉每年都会侵袭牧场,造成严重破坏,这对美洲热带国家的养牛业来说是一个严重的问题。沫蝉是牧草生产的一个重要生物限制因素,而对于这一类昆虫,我们缺乏细胞遗传学方面的数据。基于这些原因,我们进行了这项工作,研究了斑沫蝉、红彩丽沫蝉和宽缘沫蝉的精子发生和核仁行为。雄性具有呈“一串葡萄”形状的睾丸;每个个体的睾丸小叶数量不同,多倍体核由几个异染色质体组成。异染色质区位于核的外周(前期 I);交叉位于末端或间质;中期 I 呈圆形或线性,后期显示性染色体的迟移。染色体组型为 2n = 19,除了 N. entreriana(2n = 15);精子为圆形,中心有异染色质物质,伸长后有明显的染色质。经硝酸银染色后的睾丸分析显示,多倍体核有三个大核仁体和三个小核仁体。早期前期细胞的核仁体染色强烈,靠近染色质,另一个核仁体不太明显,远离染色质。在二价体期,核仁体解体。银染发生在两条常染色体上,位于末端和亚末端位置,后者可能对应于核仁组织区(NORs)。精子为圆形,有一个圆形核仁体,在精子头部伸长部分的中后部观察到银染。