A comparison of chorions from eggs of northern and southern populations of Fundulus heteroclitus

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Copeia; (United States)

DOI:https://doi.org/10.2307/1444565· OSTI ID:5245408

Brummett, A R; Dumont, J N

A comparative study of the chorions of eggs of northern and southern populations of Fundulus heteroclitus by scanning and transmission electron microscopy reveals striking differences. Chorionic fibrils of eggs of the northern (Woods Hole) population are very long, approx. 1.5 ..mu.. in diameter, and very sparsely distributed; the chorionic surface between attached fibrils is dotted with small protuberances. Most of the fibrils of the eggs of a southern (South Carolina) population are shorter, approx. 0.5 ..mu.. in diameter, and very densely distributed. The South Carolina eggs have a few longer and thicker (approx. 1.0 ..mu..) fibrils in the vicinity of the micropyle. The fibrils of the Woods Hole eggs are club-shaped at their bases, surrounded by a collar of ''jelly'' at their attachment points, and are seated in an indentation in the chorion. Those of the South Carolina eggs show no such basal modifications and appear to extend from a small chorionic hillock. A surface coat of jelly is present on the ovulated eggs of both populations but appears to be thicker and denser on the eggs of southern origin. Scanning electron microscopy of freeze-fractured preparations of ovarian tissue from the two populations shows that the chorionic fibrils are present and attached to the developing chorion as soon as it is visible. Jelly is not present on the surface on the unovulated eggs. The data are discussed from the standpoint of considerations of the taxonomy and distribution of the species, and questions are raised concerning the possible significance of the structural differences observed.

• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5245408
• Journal Information: Copeia; (United States), Journal Name: Copeia; (United States) Vol. 3; ISSN COPAA
• Country of Publication: United States
• Language: English

Related Subjects

550300* -- Cytology
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AQUATIC ORGANISMS
COMPARATIVE EVALUATIONS
ELECTRON MICROSCOPY
FEDERAL REGION I
FEDERAL REGION IV
FETAL MEMBRANES
FISHES
GAMETES
GERM CELLS
MASSACHUSETTS
MEMBRANES
MICROSCOPY
NORTH AMERICA
OVA
POPULATIONS
SCANNING ELECTRON MICROSCOPY
SOUTH CAROLINA
TRANSMISSION ELECTRON MICROSCOPY
USA
VERTEBRATES