Identification and characterization of a hunchback orthologue, Lzf2, and its expression during leech embryogenesis.
Identification and characterization of a hunchback orthologue, Lzf2, and its expression during leech embryogenesis.
复制标题
驼背直系同源物 Lzf2 的鉴定和表征及其在水蛭胚胎发生过程中的表达。
DOI：
10.1006/dbio.1996.0108
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发表时间：
1996
影响因子：
2.7
通讯作者：
Shankland,M
中科院分区：
文献类型：
--
作者：
Savage,RM;Shankland,M
Lzf 1和Lzf 2是水蛭锌指基因（Lzf），与果蝇agap基因hunchback（hb）同源。原位杂交和RT-PCR均未检测到Lzf 1在水蛭胚胎和成体中的转录，原位杂交检测到Lzf 2在水蛭胚胎不同发育阶段的表达，Lzf 2在胚胎早期卵裂分裂中持续表达，包括胚胎形成干细胞的时期，这些干细胞将产生成体的分节组织。在节段模式形成时，Lzf 2 RNA在外胚层和中胚层组织中沿分节主干的长度沿着均匀表达。这与hbRNA的前限制梯度相反，该前限制梯度对昆虫胚胎的正常前后（AP）模式至关重要。因此，血红蛋白的这种水蛭直向同源物似乎在AP轴的模式中没有发挥类似的作用。此外，Lzf 2在器官发生过程中以节段限制的模式在中枢神经系统、肠道和表皮衍生结构中表达，是第一个在昆虫外被详细描述的同源基因，其表达模式表明，在节肢动物或昆虫从环节动物系统分离后，可能获得了gap基因的功能。
Lzf1andLzf2are leech zinc finger (Lzf) genes that are shown to be orthologues to theDrosophilagap genehunchback(hb). Neitherin situhybridization nor RT–PCR detectedLzf1transcripts in leech embryos or adults.Lzf2expression was examined in leech embryos at various stages byin situhybridization.Lzf2is expressed continually throughout the early embryonic cleavage divisions, including the period during which the embryo forms stem cells that will give rise to the segmented tissues of the adult. At the time of segmental pattern formation,Lzf2RNA is expressed uniformly along the length of the segmented trunk in both the ectodermal and mesodermal tissues. This is in contrast to the anteriorly restricted gradient ofhbRNA shown to be critical to the normal anteroposterior (AP) patterning of the insect embryo. Thus, this leech orthologue ofhbdoes not appear to play a comparable role in the patterning of the AP axis. In addition,Lzf2is expressed during organogenesis in segmentally restricted patterns in the central nervous system, the gut, and epidermally derived structures.Lzf2is the firsthborthologue to be characterized in detail outside of insects and its expression pattern suggests thathbmay have acquired a gap gene function in arthropods or insects after their phyletic separation from the annelids.