| 查看: 379 | 回复: 0 | ||
宋伟同学铜虫 (著名写手)
|
[求助]
求助大神翻译。谢谢，急。
|
|
Glial cells exist throughout the nervous system,and play essential roles in various aspects of neural development and function.Distinct types of glia may govern diverse glial functions.To determine the roles of glia requires systematic characterization of glia diversity and development. In the adult Drosophila central brain, we identify five different types of glia based on its location, morphology, marker expression,anddevelopment.Perineurialandsubperineurialgliaresideintwoseparatesingle-celllayersonthebrainsurface,cortexglia form a glial mesh in the brain cortex where neuronal cell bodies reside, while ensheathing and astrocyte-like glia enwrap and infiltrate into neuropils, respectively. Clonal analysis reveals that distinct glial types derive from different precursors, and that most adult peri- neurial, ensheathing, and astrocyte-like glia are produced after embryogenesis. Notably, perineurial glial cells are made locally on the brain surface without the involvement of gcm(glialcellmissing).Incontrast,the widespread ensheathing and astrocyte-like glia derive from specific brain regions in a gcm-dependent manner. This study documents glia diversity in the adult fly brain and demonstrates involvement of different developmental programs in the derivation of distinct types of glia.It lays an essential foundation for studying glia development and function in the Drosophilabrain. Proper development and function of neural circuitry require glial cells. Although glial cells were originally believed to have just supporting roles in nourishing and insulating neurons, recent studies have revealed that glia contribute to virtually all aspects of nervous system development and function.However, our understanding of glial diversity and origin is far behind their neuronal counterparts.Drosophila, with its accessibility to genetic, molecular, and behavior analysis, has emerged as a powerful model system for studying brain development and function and its underlying molecular mechanisms.In contrast to vertebrates,in which neurons are outnumbered by glial cells, Drosophila have fewer neurons and exhibits a lower glia–neuron ratio with even fewer glial cells. The larval ventral ganglion constitutes a relatively simple model system for studying glial development and function up to individual cells. Based on the position of glial cell bodies and morphology, glial cells in the Drosophila ventral ganglion are classified into three types; surface-, cortex-, and neuropil associated glial cells (Ito et al., 1995). They are derived from specific neuroglioblasts and glioblasts (Schmidt et al., 1997;Schmid et al., 1999). The glial cell missing (gcm) gene governs the derivation of all embryonic glial cells except for one specific type of glia, midline glia (Hosoya et al., 1995; Jones et al., 1995; Vincent et al., 1996). Loss of gcm causes deficits in glial production while ectopic GCM transform neurons to glia. Thus, gcm is necessary and sufficient for driving glial development during embryogenesis. Embryonic glia also play essential roles in regulating neuronal viability and morphogenesis. Neuronal loss and connectivity defects are observed following ablation of glial cells (Booth et al.,2000; Hidalgo and Booth, 2000), although survival and functional differentiation of glial cells also require signals from neurons (Hidalgo et al., 2001). In addition, glial cells located at the midline, midline glia, secrete and present molecules to guide the growth cone of axons (Kidd et al., 1999).Defects in glial function affect various adult behaviors of Drosophila, including circadian rhythm, courtship behavior,and longevity (Ewer et al., 1992; Buchanan and Benzer, 1993;Kretzschmar et al., 1997; Suh and Jackson, 2007; Grosjean et al.,2008). Disruption of glial function in mature brains also induces neural degeneration (Xiong and Montell, 1995; Kretzschmar et al., 1997). In addition, glia play an essential role in the clearance of degenerating axons in both pupal and adult brains. Further elucidation of these glial functions and their underlying mechanisms requires better characterization of glial cells in the adult brain and their derivation through postembryonic development of the Drosophila brain. In this study, we show five different types of glial cells locate in the adult fly brain with specific patterns and are produced by distinct developmental programs. |
回复此楼» 猜你喜欢
生物学303求调剂，一志愿华中农微生物，六级已过，有科研有文章，党员
已经有3人回复
-
求调剂
已经有8人回复
-
求调剂
已经有6人回复
-
353求调剂
已经有10人回复
-
298求调剂
已经有6人回复
-
生物学308分求调剂（一志愿华东师大）
已经有5人回复
-
一志愿电子科技大学085600材料与化工 329分求调剂
已经有9人回复
-
284求调剂
已经有6人回复
-
0817化学工程与技术求调剂，一志愿中海洋319
已经有11人回复
-
304求调剂（085602，过四级，一志愿985）
已经有12人回复
