Structural characterization of muscles and epithelial sheaths of the oviduct of Stomoxys calcitrans (Diptera: Muscidae).
Fine structure of both muscle and epithelial cells in the oviduct of Stomoxys calcitrans (L.) was characterized. Each tubular section of the oviduct consisted of an inner epithelial sheath enveloped by an outer network of muscle fibers that showed noticeable variation in cross-sectional thickness. Some regions consisted of a single cellular layer, whereas others were composed of two or more layers of cells. Moreover, a wide variation in muscle fiber orientation was observed, with some cells appearing circular and others appearing nearly longitudinal. The myofibrils of oviduct muscles were separated into sarcomeres of irregular alignment. The classical A (1 microns in length) and I bands of myofilaments were evident, but the Z disk consisted of discontinuous rows of dense bodies. In partially contracted muscle cells, some myofilaments of the A band passed between the dense bodies of the Z band. T-system tubules were evident and formed dyads with sarcoplasmic reticulum. The structural integrity of the oviduct was maintained by connective tissue strands between muscles and the epithelial sheath. Many of these strands consisted of basal lamina. Epithelial cells that line the inner sheath of the oviduct were cuboidal. In transection, these cells revealed a prominent apical microvillar region with large numbers of mitochondria and an extensive infolding of the basal plasma membrane.
Cook
B J
BJ
USDA-ARS, Food Animal Protection Research Laboratory, College Station, TX 77845, USA.
Pryor
N W
NW
D000818:Animals; D003238:Connective Tissue / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D009117:Muscidae / Q000648:ultrastructure*; D018485:Muscle Fibers, Skeletal / Q000648:ultrastructure*; D010057:Oviducts / Q000648:ultrastructure*