Three-dimensional Organization of Polytene Chromosomes in Somatic and Germline Tissues of Malaria Mosquitoes
Three-dimensional Organization of Polytene Chromosomes in Somatic and Germline Tissues of Malaria Mosquitoes
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DOI：
10.3390/cells9020339
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发表时间：
2020-02-01
期刊：
影响因子：
6
通讯作者：
Sharakhov, Igor V.
中科院分区：
文献类型：
--
作者：
George, Phillip;Kinney, Nicholas A.;Sharakhov, Igor V.
染色体区域的空间组织、间期染色体之间的相互作用以及与细胞核外周的相互作用在基因组功能的表观遗传调控中起着重要作用。然而，在生物体发育过程中染色体间接触和染色体-核膜附着之间的相互作用尚不清楚。为了解决这个问题，我们对疟蚊的三维染色体组织进行了显微镜分析。我们采用多色寡核苷酸染色探针，沿常染色质间隔1mb，定量研究了冈比亚按蚊（Anopheles gambiae, An）幼虫唾液腺细胞和成年卵巢护理细胞的染色体区域。coluzzi和An。长节。我们发现X染色体区域的体积明显小于常染色体臂区域，并且比常染色体臂区域更紧凑。染色体间接触的数量和染色体-核膜接触的百分比在同一细胞类型内的种间是保守的。然而，与卵巢护理细胞相比，唾液腺细胞位于核周围的染色体区域的百分比通常较高，而染色体间接触的数量则较低。对于常染色体来说，这种负相关更强。与先前的理论观点一致，我们的数据表明，在全基因组水平上，染色体-核膜附着和染色体-染色体相互作用之间存在反比关系，这是细胞类型特异性核结构的关键特征。
Spatial organization of chromosome territories and interactions between interphase chromosomes themselves, as well as with the nuclear periphery, play important roles in epigenetic regulation of the genome function. However, the interplay between inter-chromosomal contacts and chromosome-nuclear envelope attachments in an organism's development is not well-understood. To address this question, we conducted microscopic analyses of the three-dimensional chromosome organization in malaria mosquitoes. We employed multi-colored oligonucleotide painting probes, spaced 1 Mb apart along the euchromatin, to quantitatively study chromosome territories in larval salivary gland cells and adult ovarian nurse cells of Anopheles gambiae, An. coluzzii, and An. merus. We found that the X chromosome territory has a significantly smaller volume and is more compact than the autosomal arm territories. The number of inter-chromosomal, and the percentage of the chromosome-nuclear envelope, contacts were conserved among the species within the same cell type. However, the percentage of chromosome regions located at the nuclear periphery was typically higher, while the number of inter-chromosomal contacts was lower, in salivary gland cells than in ovarian nurse cells. The inverse correlation was considerably stronger for the autosomes. Consistent with previous theoretical arguments, our data indicate that, at the genome-wide level, there is an inverse relationship between chromosome-nuclear envelope attachments and chromosome-chromosome interactions, which is a key feature of the cell type-specific nuclear architecture.