Oxygen deprivation is rapidly deleterious for most organisms. However,
Caenorhabditis elegans
has developed the ability to survive anoxia for at least 48 hours. Mutations in the DAF-2/DAF-16 insulin-like signaling pathway promote such survival. We describe a pathway involving the HYL-2 ceramide synthase that acts independently of DAF-2. Loss of the ceramide synthase gene
hyl-2
results in increased sensitivity of
C. elegans
to anoxia.
C. elegans
has two ceramide synthases,
hyl-1
and
hyl-2
, that participate in ceramide biogenesis and affect its ability to survive anoxic conditions. In contrast to
hyl-2(lf)
mutants,
hyl-1(lf)
mutants are more resistant to anoxia than normal animals. HYL-1 and HYL-2 have complementary specificities for fatty acyl chains. These data indicate that specific ceramides produced by HYL-2 confer resistance to anoxia.
缺氧对大多数
生物来说是迅速有害的。然而,秀丽隐杆线虫已经发展出至少48小时的无氧生存能力。
DAF-2 /
DAF-16
胰岛素样信号通路的突变促进了这种生存。我们描述了涉及独立于
DAF-2的HY
L-2鞘
磷脂合成酶的一条途径。鞘
磷脂合成酶
基因hy
L-2的缺失导致秀丽隐杆线虫对缺氧的敏感性增加。秀丽隐杆线虫有两种鞘
磷脂合成酶hyL-1和hy
L-2,它们参与鞘
磷脂的
生物合成并影响其在无氧条件下的生存能力。与hy
L-2(lf)突变体相比,hyL-1(lf)突变体比正常动物更能抵抗缺氧。HYL-1和HY
L-2对
脂肪酸基团具有互补的特异性。这些数据表明,由HY
L-2产生的特定鞘
磷脂使其对缺氧具有抗性。