Electron microscopy of the intestine of the african lungfish, Protopterus aethiopicus

Authors

  • M. L. Purkerson,

    1. Department of Anatomy, College of Physicians and Surgeons of Columbia University, New York, New York 10032
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    • This work was supported in part by grants from the National Institutes of Health (GM-15289), (NS-07887), from the Association for the Aid of Crippled Children and by a Special Fellowship, United States Public Health Service (AM-50950).

  • J. U. M. Jarvis,

    1. Department of Anatomy, College of Physicians and Surgeons of Columbia University, New York, New York 10032
    Current affiliation:
    1. Department of Zoology, University of Cape Town, Rondebosch, Cape Province, South Africa
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  • S. A. Luse,

    1. Department of Anatomy, College of Physicians and Surgeons of Columbia University, New York, New York 10032
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    • Deceased, December 28, 1970.

  • E. W. Dempsey

    1. Department of Anatomy, College of Physicians and Surgeons of Columbia University, New York, New York 10032
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Abstract

Electron microscopic observations are reported on the intestine of the African lungfish, Protopterus aethiopicus. The lungfish has a spiral valve rather than a true stomach. Segments of mucosa from this area reveal, by transmission microscopy, that most cells have distinct striated borders with parallel microvilli. Fibrils within the core of the microvilli extend deeply into the cytoplasm. Microvilli on the surface of goblet cells are less regularly arranged than those of absorptive cells. Interspersed among the cells with striated borders are cells, similar in cytologic appearance except that they are covered with tufts of kinetocilia. By transmission electron microscopy, abnormal cilia having one complete complement of microtubules plus incomplete sets from other cilia which share some of the peripheral doublets of the complete cilium are enclosed by a single membrane. Cilia are usual in the intestine of many lower forms but ordinarily absent in higher vertebrates. Their functional significance in this primitive fish is unknown.

Ancillary