Garcia Carolina, Delprat Alejandra, Ruiz Alfredo, Valente Vera L S
Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Brazil 15053 Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Barcelona, Spain 08193.
Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Barcelona, Spain 08193.
G3 (Bethesda). 2015 Oct 4;5(12):2559-66. doi: 10.1534/g3.115.021311.
Drosophila willistoni is a geographically widespread Neotropical species. The genome of strain Gd-H4-1 from Guadeloupe Island (Caribbean) was sequenced in 2007 as part of the 12 Drosophila Genomes Project. The assembled scaffolds were joined based on conserved linkage and assigned to polytene chromosomes based on a handful of genetic and physical markers. This paucity of markers was particularly striking in the metacentric chromosome II, comprised two similarly sized arms, IIL and IIR, traditionally considered homologous to Muller elements C and B, respectively. In this paper we present the cytological mapping of 22 new gene markers to increase the number of markers mapped by in situ hybridization and to test the assignment of scaffolds to the polytene chromosome II arms. For this purpose, we generated, by polymerase chain reaction amplification, one or two gene probes from each scaffold assigned to the chromosome II arms and mapped these probes to the Gd-H4-1 strain's polytene chromosomes by nonfluorescent in situ hybridization. Our findings show that chromosome arms IIL and IIR correspond to Muller elements B and C, respectively, directly contrasting the current homology assignments in D. willistoni and constituting a major reassignment of the scaffolds to chromosome II arms.
威氏果蝇是一种在地理上广泛分布的新热带物种。作为12个果蝇基因组计划的一部分，来自瓜德罗普岛（加勒比地区）的Gd-H4-1菌株的基因组于2007年进行了测序。组装好的支架根据保守的连锁关系进行拼接，并根据少数遗传和物理标记分配到多线染色体上。标记的匮乏在中着丝粒的二号染色体上尤为明显，它由两条大小相似的臂组成，即IIL和IIR，传统上分别被认为与穆勒元件C和B同源。在本文中，我们展示了22个新基因标记的细胞学定位，以增加通过原位杂交定位的标记数量，并测试支架在多线染色体二号臂上的分配。为此，我们通过聚合酶链反应扩增，从分配到二号染色体臂的每个支架中生成一到两个基因探针，并通过非荧光原位杂交将这些探针定位到Gd-H4-1菌株的多线染色体上。我们的研究结果表明，染色体臂IIL和IIR分别对应于穆勒元件B和C，这与威氏果蝇目前的同源性分配直接相反，并构成了支架在二号染色体臂上的主要重新分配。
