Transgenerational plasticity as a mechanism of response to marine heatwaves in the purple sea urchin, Strongylocentrotus purpuratus
Transgenerational plasticity as a mechanism of response to marine heatwaves in the purple sea urchin, Strongylocentrotus purpuratus
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DOI：
10.3389/fmars.2023.1212781
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发表时间：
2023-07-21
影响因子：
3.7
通讯作者：
Hofmann, Gretchen E.
中科院分区：
文献类型：
--
作者：
Chamorro, Jannine D.;McDonald, Adriane M.;Hofmann, Gretchen E.
加利福尼亚海流系统的海带森林经历了长时间的海洋热浪（MHW）事件，这些事件与许多底栖海洋无脊椎动物的生活史事件（例如配子发生和产卵）的物候时间重叠。为了研究高温热胁迫对紫海胆配子体发育的影响，并进一步探讨高温热胁迫是否会诱导后代耐热性的跨代可塑性（TGP），在实验室对成体海胆进行了两种条件的驯化——高温热胁迫温度为18℃；非mhw温度为13℃。经过4个月的驯化期（10月至1月），在MHW（18℃）和非MHW（13℃）温度下培育成虫和后代，共创建4个胚胎处理组。为了评估四组中的每一组的跨代效应，我们在急性热耐受性试验中测量了孵化囊胚胚胎的热耐受性。与非高温驯化雌性的后代相比，高温驯化雌性的胚胎具有更高的耐热性和更高的LT50值。此外，雌性驯化状态对子代在胚胎发育的两个阶段（早期原肠和早期棘棘幼虫）的体大小也有影响。为了评估母体供给是否也会改变胚胎性能，我们通过测量卵的大小和生化组成来评估不同驯化雌性的配子性状。经mhw驯化的雌鱼的卵蛋白浓度较高，而卵的大小和脂质含量没有差异。我们的研究结果表明，TGP作为雌性热历史的函数，在改变后代的表现中起作用，特别是当热应激与配子体发生同时发生时。此外，产蛋数据表明，母性经验可以通过卵蛋白含量影响胚胎性状。虽然这是一项基于实验室的研究，但结果表明TGP可能在天然海带林环境下的紫癜菌早期的抗性和耐受性中发挥作用。
Kelp forests of the California Current System have experienced prolonged marine heatwave (MHW) events that overlap in time with the phenology of life history events (e.g., gametogenesis and spawning) of many benthic marine invertebrates. To study the effect of thermal stress from MHWs during gametogenesis in the purple sea urchin (Strongylocentrotus purpuratus) and further, whether MHWs might induce transgenerational plasticity (TGP) in thermal tolerance of progeny, adult urchins were acclimated to two conditions in the laboratory - a MHW temperature of 18 & DEG;C and a non-MHW temperature of 13 & DEG;C. Following a four-month long acclimation period (October-January), adults were spawned and offspring from each parental condition were reared at MHW (18 & DEG;C) and non-MHW temperatures (13 & DEG;C), creating a total of four embryo treatment groups. To assess transgenerational effects for each of the four groups, we measured thermal tolerance of hatched blastula embryos in acute thermal tolerance trials. Embryos from MHW-acclimated females were more thermally tolerant with higher LT50 values as compared to progeny from non-MHW-acclimated females. Additionally, there was an effect of female acclimation state on offspring body size at two stages of embryonic development - early gastrulae and prism, an early stage echinopluteus larvae. To assess maternal provisioning as means to also alter embryo performance, we assessed gamete traits from the differentially acclimated females, by measuring size and biochemical composition of eggs. MHW-acclimated females had eggs with higher protein concentrations, while egg size and lipid content showed no differences. Our results indicate that TGP plays a role in altering the performance of progeny as a function of the thermal history of the female, especially when thermal stress coincides with gametogenesis. In addition, the data on egg provisioning show that maternal experience can influence embryo traits via egg protein content. Although this is a laboratory-based study, the results suggest that TGP may play a role in the resistance and tolerance of S. purpuratus early stages in the natural kelp forest setting.