京都大学 大学院医学研究科 人間健康科学系専攻 病理学研究室（形態形成医療科学）

上野さんの修論がAnat Recに掲載されました。

Somite stagの胚（CS11-13, 28-33日, 21−35体節）における消化管由来原基の形態と分化のTimeLineを検討

• 消化管と派生した原基は、以下のTimelineに従って発生し、個人差が少ないことを示唆
  • 消化管は最初、卵黄嚢の狭小化によって形成される
  • 咽頭、肺、胃、肝臓、および背側膵臓原基； CS12-13 の間に分化
  • 咽頭嚢； 4 つのペアの分化は、すべての CS13 胚で完了
  • 呼吸原基； ≥ 26 体節胚で認められ、CS13 で気管分岐が形成、≥ 35 体節胚で気管伸長。
  • 胃； ≥ 34 体節胚で紡錘形
  • 肝芽は ≥ 27 体節胚で確認
  • 背側膵臓は、3 つを除くすべての CS13 胚で最終的な出芽
  • 原始腸ループ ≥ 35 体節の胚形成

今後、消化管関連の異常発生の検出等に有用と考えられます。

22. Ueno S, Yamada S, Uwabe C, Männer J, Shiraki N, Takakuwa T, The digestive tract and derived primordia differentiate by following a precise timeline in human embryos between Carnegie stages 11 and 13, Anatomical Rec 2016, 299(4), 439-449, DOI: 10.1002/ar.23314

ABSTRACT

The precise mechanisms through which the digestive tract develops during the somite stage remain undefined. In this study, we examined the morphology and precise timeline of differentiation of digestive tract-derived primordia in human somite-stage embryos. We selected 37 human embryos at Carnegie Stage (CS) 11–CS13 (28–33 days after fertilization) and three-dimensionally analyzed the morphology and positioning of the digestive tract and derived primordia in all samples, using images reconstructed from histological serial sections. The digestive tract was initially formed by a narrowing of the yolk sac, and then several derived primordia such as the pharynx, lung, stomach, liver, and dorsal pancreas primordia differentiated during CS12 (21–29 somites) and CS13 (≥ 30 somites). The differentiation of four pairs of pharyngeal pouches was complete in all CS13 embryos. The respiratory primordium was recognized in ≥ 26-somite embryos and it flattened and then branched at CS13. The trachea formed and then elongated in ≥ 35-somite embryos. The stomach adopted a spindle shape in all ≥ 34-somite embryos, and the liver bud was recognized in ≥ 27-somite embryos. The dorsal pancreas appeared as definitive buddings in all but three CS13 embryos, and around these buddings, the small intestine bent in ≥ 33-somite embryos. In ≥ 35-somite embryos, the small intestine rotated around the cranial-caudal axis and had begun to form a primitive intestinal loop, which led to umbilical herniation. These data indicate that the digestive tract and derived primordia differentiate by following a precise timeline and exhibit limited individual variations. 

尾関さんの修士論文のうち、ヒト外耳の形態形成に関する内容がCongenit Anom (日本先天異常学会誌）に受諾されました。500例以上の外耳観察の成果です。

• CS19-23 間の耳介の形成を検討
• 耳介をStreeter の基準に修正を加えて 11 stepに分類
• 各 CS の代表的なstepは、CS16-23 の間にstep 3 -11 に移行、
• いくつかのステップでは隣接する CS 間で重複
• CS19 と CS23 の間の耳介の観察は、Stagingを決定するために利用可能

21. Ozeki-Sato M, Yamada S, Uwabe C, Ishizu K, Takakuwa T, Correlation of external ear auricle formation with staging of human embryos, Congenit Anom (Kyoto) 56, 86-90, 2016, DOI: 10.1111/cga.12140, . (概要),

Abstract

The formation of auricles in human embryos was evaluated between Carnegie stage (CS)19 and CS23, and the findings were correlated across the stages. The auricle was categorized into 11 steps according to Streeter’s criteria with modifications. Mesenchyme cell condensation was observed at Step 7, and two layers of cartilage consisting of the auricle were recognized at Step11. The representative steps at each CS shifted from Step 3 to Step11 during CS16 and CS23, although several steps overlapped between adjacent CSs. These results indicate that observations of the auricle between CS19 and CS23 may be utilized for determining embryo staging as convincing supportive evidence of external features reflecting the internal histological structure, although other findings should also be taken into account.