Fontana P G
Can J Genet Cytol. 1976 Sep;18(3):537-44. doi: 10.1139/g76-067.
An air drying and Giemsa staining technique produces consistently good quality cytological preparations when applied to different species of Euxoa (Lepidoptera: Noctuidae) and, in particular, it allows an imporved resolution of the meiotic chromosomes in both sexes. All species so far investigated have a basic haploid chromosome complement of n (male) = 31(XX): n(female) = (XY). A single chiasma per individual bivalent is clearly visible in the male sex. Some chiasmata are formed in interstitial positions, but, by metaphase I, they have all undergone complete terminalization while the bivalents orient axially on the first division spindle. Direct evidence for lack of chiasma formation in the 31 hormorphic bivalents in the female sex is reported for the first time for species of Noctuidae. Evidence in favor of an XY system in the female sex is discussed. Preliminary studies of the meiotic divisions in hybrid material reveal the presence of cryptic structural differences between certain taxa, and will help to elucidate taxonomic problems within this complex genus.
一种空气干燥和吉姆萨染色技术应用于不同种类的尤夜蛾属（鳞翅目：夜蛾科）时，能始终如一地产生高质量的细胞学标本，特别是它能提高两性减数分裂染色体的分辨率。迄今为止研究的所有物种都有一个基本的单倍体染色体组，雄性为n = 31(XX)，雌性为n = 31(XY)。在雄性个体中，每个二价体上单个交叉清晰可见。一些交叉形成于中间位置，但到中期I时，它们都已完全端化，而二价体在第一次分裂纺锤体上轴向排列。首次报道了夜蛾科物种雌性中31个同形二价体缺乏交叉形成的直接证据。讨论了支持雌性中XY系统的证据。杂交材料减数分裂的初步研究揭示了某些分类群之间存在隐性结构差异，这将有助于阐明这个复杂属内的分类问题。
