Roles of guanylyl cyclase system in adaptation to the environment

研究人员发现，与哺乳动物共激活物“PC4”同源的17 kDa蛋白与OIGC6基因5'侧区90 -81之间的核苷酸（AGACCTTTGC）结合，是medaka鱼肠中OlGC6基因转录所必需的。在欧洲鳗鲡中，研究表明，将黄色淡水驯化的鳗鲡转移到海水中后，肠中GC-C2转录物的表达增加了100%，而将成年medaka鱼个体转移到500/0的海水中，未观察到OlGC9的表达变化。研究了含或不含各基因反义寡核苷酸的medaka鱼胚胎发生过程中神经元NO合成酶基因（nNOS）、可溶性GC 3个不同亚基基因（OlGCS-α_1、OlGCS-α_2和OlGCS-β_1）和PKG 3个基因（PKG 1α、PKG 1β和PKG II）的表达。nNOS和OlGCS-β_1通过母体表达，OlGCS-α_1、OlGCS-α_2、PKG I和PKG II通过合子表达。第19期检测到OlGCS-α_1的合子表达，第16期检测到OlGCS-a2的合子表达。香港medaka鱼Oryzias curvinotus表达9个膜GC基因（OcGC1-OcGC8和OcGC-R2）和3个可溶性GC亚基基因（OcGCS-_1、OcGCS-_2和OcGCS-_1）。无论杂交方向如何，弯叶菊都能与宽叶菊产生杂交后代，杂交后代对母体和母体可溶性GC亚基基因的表达几乎相同，表明杂交后代可能形成嵌合异源二聚体。

We demonstrated that binding of a protein with 17 kDa, which is a medaka fish homologue of mammalian co-activator "PC4", to the nucleotides (AGACCTTTGC) between-90 and -81 in the 5'-flanking region of the OIGC6 gene are essential for transcription of the OlGC6 gene in medaka fish intestine. In European eel, it has been demonstrated that expression of the GC-C2 transcript in the intestine was increased by 100% following the transfer of yellow fresh water-acclimated eels to sea water, while no changes in expression of OlGC9 were seen when adult medaka fish individuals were transferred to 500/0 sea water. Expression of neuronal NO synthase gene (nNOS), three different subunit genes (OlGCS-α_1, OlGCS-α_2, and OlGCS-β_1) of soluble GC, and three PKG genes (PKG 1α ; PKG 1β, and PKG II) were examined during embryogenesis of medaka fish with or without morpholino antisense oligonucleotide of respective gene. nNOS and OlGCS-β_1 were expressed matemally and OlGCS-α_1, OlGCS-α_2, PKG I, and PKG II were expressed zygotically. The zygotic expression of OlGCS-α_1 was detected at stage 19, while that of OlGCS-a2 was detected at stage 16. The Hong Kong-originated medaka fish Oryzias curvinotus expresses nine genes (OcGC1-OcGC8 and OcGC-R2) for membrane GCs and three genes (OcGCS-_1 OcGCS-_2, and OcGCS-_1) for soluble GC subunits. O. curvinotus was able to produce the hybrids with O. latipes irrespective of the direction of crossing and the resulting hybrids expressed both the matemal and patemal soluble GC subunit genes almost equally, suggesting the possibility of the formation of chimeric heterodimer in the hybrids.