Ultrastructure of the Midgut Epithelial Cells in the Mosquito Larvae, Anopheles sinensis Wiedemann

중국얼룩날개모기 유충내에 있는 중장 상피세포들의 미세구조

  • 류재혁 (인하대학교 이과대학 생명과학과)
  • Published : 2004.09.01

Abstract

The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

중국얼룩날개모기(Anopheles sinensis; Culicidae; Diptera)를 사육하여 종령 유충의 중장 상피를 구성하는 세포들에 대한 미세구조를 전자현미경으로 관찰하였다. 중장 상피조직은 원주상흡수세포, 재생세포 그리고 분비과립세포 등으로 구성된 단층 점막상피를 이루었다. 원주상흡수세포의 첨단부 원형질막은 미세융모로 변형되어 "brush border"를 형성하였다. 기저원형질막은 심하게 주름이 잡혀 "canaliculi"를 만들며 길게 발달한 사립체와 접해 있었다. 또한 원주상흡수세포는 세포질내에 과립소포체, 사립체 그리고 골지체 등이 고루 발달한 전형적인 물질 흡수세포의 형태이었다. 재생세포는 세포기관이 미분화된 상태이었고, 세포질의 전자밀도가 높아 검게 보였다. 작은 재생세포들은 1개 혹은 $2{\sim}3$개가 집단 (nidi)을 이루어 원주상흡수세포의 기저부 사이에 위치하였다. 직경이 약 $200{\sim}400$ nm 크기의 분비과립을 가지는 분비과립세포가 관찰되었는데 이 세포는 기저막상, 원주상세포의 기부 사이에 위치하여 원추형으로 관찰되었다. 기저막 바깥쪽에는 전형적인 골격근으로 분화된 환상근과 종주근 다발이 있었으며, 기저막과 근육층사이 결합조직인 점막하층에는 신경세포와 기관세지들이 관찰되었다.

Keywords

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