Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.
Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI 48824, USA.
Sci Adv. 2023 Sep;9(35):eadg0328. doi: 10.1126/sciadv.adg0328. Epub 2023 Aug 30.
Traits that allow species to survive in extreme environments such as hot-arid deserts have independently evolved in multiple taxa. However, the genetic and evolutionary mechanisms underlying these traits have thus far not been elucidated. Here, we show that , a desert-adapted fruit fly species, has evolved high desiccation resistance by producing long-chain methyl-branched cuticular hydrocarbons (mbCHCs) that contribute to a cuticular lipid layer reducing water loss. We show that the ability to synthesize these longer mbCHCs is due to evolutionary changes in a fatty acyl-CoA elongase (). knockout in led to loss of longer mbCHCs and reduction of desiccation resistance at high temperatures but did not affect mortality at either high temperatures or desiccating conditions individually. Phylogenetic analysis showed that is a -specific gene, suggesting that while the physiological mechanisms underlying desert adaptation may be similar between species, the genes involved in these mechanisms may be species or lineage specific.
能够使物种在炎热干旱的沙漠等极端环境中生存的特征已经在多个分类群中独立进化。然而，这些特征背后的遗传和进化机制迄今尚未阐明。在这里，我们表明，一种适应沙漠的果蝇物种，通过产生长链甲基支链的角质层烃（mbCHC）来进化出高的抗干燥能力，这些 mbCHC 有助于形成一层角质层脂质，减少水分流失。我们表明，这种合成更长 mbCHC 的能力是由于脂肪酸酰基辅酶 A 延长酶（）的进化变化所致。 在 中敲除导致更长 mbCHC 的丧失和高温下干燥抗性的降低，但单独在高温或干燥条件下均不影响死亡率。系统发育分析表明 是一个 -特异性基因，这表明尽管物种间沙漠适应的生理机制可能相似，但参与这些机制的基因可能是物种或谱系特异性的。
