ISSN:
0002-9106
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
The normal bovine sperm tail consists of the classical 9 + 9 + 2 fiber pattern bound anteriorly by the mitochondrial helix and posteriorly by the fibrous helix except for the last 2 to 3 μ.The outer ring of nine coarse fibers originate as laminated columns, beginning from a common base which is located in a recess at the base of the head. The fibers taper posteriorly ending at different levels in the principal piece. Evidence is presented for the alternate contraction and expansion of the laminated segments of the coarse fibers in the neck - the probable mechanism for initiating the flagellar wave.The mitochondrial helix is composed of several mitochondrial strands of different length. Each strand consists of several elongated mitochondria positioned end to end. Apparently the strands of mitochondria may begin or end at various locations along the middle piece. The number of turns in the mitochondrial helix was found to vary from approximately 65 to 75 turns among cells. The helix binds the axial fiber bundle with a pitch of 20 to 25° over most of the middle piece. The mitochondria are double-walled and possess internal cristae that are vesicular or tubular in structure.The fibrous helix consists of dense, circumferential strands of variable thickness and shape with two longitudinal elements on opposite sides of the helix. Both the circumferential strands and the longitudinal elements become thinner as they progress posteriorly.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aja.1001150110