Supp D M, Witte D P, Branford W W, Smith E P, Potter S S
Division of Developmental Biology,Children's Hospital Research Foundation, University of Cincinnati College of Medicine, Ohio 45229, USA.
Dev Biol. 1996 Jun 15;176(2):284-99. doi: 10.1006/dbio.1996.0134.
We report the cloning, characterization, and targeting of an Sp1-related zinc finger transcription factor gene from the distal arm of mouse chromosome 12. This gene, previously identified in rats and humans and designated sp4, is homologous to the Drosophila buttonhead (btd) gene, which is expressed in the head region of developing flies. Similarly, in situ hybridizations show that sp4 is highly expressed in mouse embryos in the developing central nervous system (CNS). Expression of sp4 is seen as early as Day 9 of development, where transcripts are abundant in the posterior neuropore. Expression in later embryos is detected throughout the CNS as well as in other structures, including the nasal mucosa, the vomeronasal organ, the epithelium of the lung and intestinal tract, the testes, and the developing teeth. Northern blot analysis showed sp4 expression in the adult brain and other tissues. Gene targeting by homologous recombination was used to determine the role of sp4 during mouse development. Two-thirds of homozygous mutants die within the first few days after birth and those that survive are smaller than their wild-type littermates. While fertility of the female mutants appears normal, homozygous mutant males do not breed, despite having histologically intact testes containing mature sperm. sp4/sp4 mutant males fail to copulate, indicating that this gene is required for normal male reproductive behavior.
我们报告了从小鼠12号染色体远端臂克隆、鉴定和靶向一个与Sp1相关的锌指转录因子基因的过程。这个基因先前已在大鼠和人类中鉴定出来并命名为sp4，它与果蝇的钮头（btd）基因同源，后者在发育中的果蝇头部区域表达。同样，原位杂交显示sp4在发育中的小鼠胚胎中枢神经系统（CNS）中高度表达。sp4的表达最早在发育的第9天可见，此时转录本在后神经孔中大量存在。在后期胚胎中，在整个中枢神经系统以及其他结构中都检测到了表达，包括鼻粘膜、犁鼻器、肺和肠道上皮、睾丸以及发育中的牙齿。Northern印迹分析显示sp4在成年大脑和其他组织中表达。通过同源重组进行基因靶向，以确定sp4在小鼠发育过程中的作用。三分之二的纯合突变体在出生后的头几天内死亡，存活下来的比它们的野生型同窝小鼠小。虽然雌性突变体的生育能力似乎正常，但纯合突变体雄性尽管组织学上睾丸完整且含有成熟精子，却不能繁殖。sp4/sp4突变体雄性无法交配，表明该基因是正常雄性生殖行为所必需的。
