Morphological and functional development of the spiral intestine in cloudy catshark (Scyliorhinus torazame)
Morphological and functional development of the spiral intestine in cloudy catshark (Scyliorhinus torazame)
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DOI：
10.1242/jeb.225557
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发表时间：
2020-07-01
影响因子：
2.8
通讯作者：
Hyodo, Susumu
中科院分区：
文献类型：
--
作者：
Honda, Yuki;Takagi, Wataru;Hyodo, Susumu
软骨鱼有一个相对较短的肠道，称为螺旋肠，由螺旋状的肠粘膜组成。然而，螺旋肠的形态和功能发育尚未完全描述。与硬骨鱼不同，软骨鱼的特点是在卵内或子宫内的发育期非常长;例如，在卵生的云猫鲨（Scyliorhinus torazame）中，发育中的鱼在卵囊内长达6个月，这表明胚胎肠可能在孵化前就开始发挥功能。在本研究中，我们描述了螺旋肠的形态和功能的发展，在发育中的猫鲨胚胎。胚胎肠的螺旋形形成在第31阶段中期完成，在“孵化前”之前，这是一个发育事件，其特征是在发育的前三分之一结束时打开蛋壳。在48小时内的孵化前事件，蛋黄开始从外部卵黄囊流入胚胎肠通过卵黄柄。同时，肽转运蛋白pept 1和中性氨基酸转运蛋白slc 6a 19的mRNA表达迅速增加。次级褶皱的肠粘膜和顶膜上的微绒毛出现后，孵化前，进一步支持在这个时候在发育中的肠道营养吸收的开始。我们证明了在孵化前阶段的卵生板鳃鱼肠道营养吸收的收购。
Cartilaginous fish have a comparatively short intestine known as the spiral intestine that consists of a helical spiral of intestinal mucosa. However, morphological and functional development of the spiral intestine has not been fully described. Unlike teleosts, cartilaginous fish are characterized by an extremely long developmental period in ovo or in utero; for example, in the oviparous cloudy catshark (Scyliorhinus torazame), the developing fish remains inside the egg capsule for up to 6 months, suggesting that the embryonic intestine may become functional prior to hatching. In the present study, we describe the morphological and functional development of the spiral intestine in the developing catshark embryo. Spiral formation of embryonic intestine was completed at the middle of stage 31, prior to `pre-hatching', which is a developmental event characterized by the opening of the egg case at the end of the first third of development. Within 48 h of the pre-hatching event, egg yolk began to flow from the external yolk sac into the embryonic intestine via the yolk stalk. At the same time, there was a rapid increase in mRNA expression of the peptide transporter pept1 and neutral amino acid transporter slc6a19. Secondary folds in the intestinal mucosa and microvilli on the apical membrane appeared after pre-hatching, further supporting the onset of nutrient absorption in the developing intestine at this time. We demonstrate the acquisition of intestinal nutrient absorption at the pre-hatching stage of an oviparous elasmobranch.