Male parental assistance in embryo hatching of barred-chin blenny Rhabdoblennius nitidus
Male parental assistance in embryo hatching of barred-chin blenny Rhabdoblennius nitidus
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雄性亲本协助条纹鲢鱼胚胎孵化
DOI：
10.1002/jez.b.22854
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M.
中科院分区：
文献类型：
--
作者：
Sano;K.;Yokoyama;R.;Kitano;T.;Takegaki;T.;Kitazawa;N.;Kaneko;T.;Nishino;Y.;Yasumasu;S.;Kawaguchi;M.
大多数硬骨胚胎在没有亲代帮助的情况下发育和孵化，尽管有些接受亲代照顾。我们关注的是一种父系抚育物种，即横颚白蛉（Rhabdoblennius nitidus[g<s:1> nther, 1861]）。随着孵化的临近，雄性父母的扇风行为急剧增加，然后胚胎孵化。在没有父本的情况下，大多数胚胎都无法孵化。然而，通过引入人工水流，孵化率大大提高，这表明胚胎成功孵化需要除曝气以外的父系辅助。接下来，我们分析了成功克隆出的条形颚鱼的孵化酶和卵包膜蛋白基因，发现其表达模式与其他真鱼动物不同。一般来说，高绒毛膜溶解酶使完整的卵包膜肿胀，低绒毛膜溶解酶使肿胀的卵包膜溶解。这两种酶的表达水平，尤其是后者，在大多数其他卵生物种中都很低。此外，横颚鱼的卵包膜主要成分为ChgHm和ChgL，而其他真核鱼类的卵包膜主要成分为ChgH和ChgL。由于观察到草后卵囊肿胀但未被溶解，这些在横下巴的混合会导致卵囊消化无效。雄性亲代通过扇扇直到孵化可以弥补这一不足。我们的研究举例说明了建立在一种新型关系上的亲本-胚胎相互作用的进化：孵化酶/卵包膜消化系统的降解，伴随着雄性亲本的孵化协助。
Most teleostean embryos develop and hatch without parental assistance, though some receive parental care. We focused on a paternal brood‐care species, the barred‐chin blenny (Rhabdoblennius nitidus[Günther, 1861]). As hatching approached, fanning behavior by the male parent drastically increased and then embryos hatch. In the absence of the male parent, most embryos failed to hatch. However, the hatching rate was greatly assisted by introducing an artificial water current, suggesting that paternal assistance other than for aeration is required for successful embryo hatching. Next, we analyzed genes for the hatching enzyme and egg‐envelope protein, which were successfully cloned from barred‐chin blenny, and found the expression patterns differed from those of other euteleosts. Generally, high choriolytic enzyme swells the intact egg envelope, and then low choriolytic enzyme solubilizes the swollen envelope. The expression levels of both the enzymes, but especially the latter, were much lower in barred‐chin blenny that is known in most other oviparous species. In addition, the main component of the egg envelope was changed into ChgHm and choriogenin L (ChgL) in barred‐chin blenny, whereas ChgH and ChgL for other euteleosts. These in barred‐chin blenny would result in ineffective egg‐envelope digestion because the posthatching egg envelopes were observed to be swollen but not solubilized. Male parental assistance by fanning until hatching may compensate for this insufficiency. Our study illustrates an example of the evolution of parent‐embryo interaction built on a novel relationship: Degradation of the hatching enzyme/egg‐envelope digestion system, accompanied by male parental hatching assistance.