Istituto di Nematologia Agraria, via Amendola 165/ A, 70126 Bari, Italy.
Tissue Cell. 1993 Jun;25(3):363-74. doi: 10.1016/0040-8166(93)90078-y.
The ultrastructure of the formation of the egg shell in the longidorid nematode Xiphinema diversicaudatum is described. Upon fertilization a vitelline membrane, which constitutes the vitelline layer of the egg shell, is formed. The chitinous layer is secreted in the perivitelline space, between the vitelline layer and the egg cell membrane. On completion of the chitinous layer, the material of the lipid layer is extruded from the egg cytoplasm to the outer surface, through finger-like projections. Both chitinous and lipid layers are secreted by granules in the egg cytoplasm that disappear as the layers are completed. Chitinous and lipid layers are formed during the passage of the egg through the oviduct. The vitelline layer is enriched with secretions produced by the oviduct cells and then by phospholipids secreted by the cells of the pars dilatata oviductus. The inner uterine layer is also formed by deposition of secretory products apposed on the egg shell in the distal uterine region and Z-differentiation. In the proximal part of the uterus, the egg has a discontinuous electron-dense layer, the external uterine layer. Tangential sections between chitinous and uterine layers revealed the presence of holes, possibly egg pores, delimited by the two uterine layers.
描述了长针线虫属线虫 Xiphinema diversicaudatum 卵壳形成的超微结构。受精后，形成卵黄膜，它构成卵壳的卵黄层。几丁质层在卵黄层和卵细胞膜之间的卵周腔中分泌。几丁质层完成后，脂质层的物质通过指状突起从卵细胞质挤出到外表面。几丁质层和脂质层都是由卵细胞质中的颗粒分泌的，随着层的形成而消失。卵在通过输卵管的过程中形成卵黄层、几丁质层和脂质层。卵黄层富含由输卵管细胞产生的分泌物，然后由输卵管扩张部细胞分泌的磷脂组成。内层子宫层也是通过在远端子宫区域与 Z 分化相对应的紧贴卵壳的分泌物沉积形成的。在子宫的近端部分，卵有一个不连续的电子致密层，即外子宫层。几丁质层和子宫层之间的切线切片显示存在可能是卵孔的孔，由两个子宫层限定。
