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INFLUENCE OF THE MULTILAYERED STRUCTURE ON THE MORPHOGENESIS OF MARCHANTIA SPERMATIDS
Author(s) -
Kreitner Gerald L.
Publication year - 1977
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1977.tb07605.x
Subject(s) - biology , nucleus , microtubule , spermatid , biophysics , anatomy , morphogenesis , marchantia polymorpha , elongation , microbiology and biotechnology , sperm , botany , materials science , gene , biochemistry , ultimate tensile strength , metallurgy
The multilayered structure (MLS) in a spermatid of Marchantia is the morphogenetic blueprint of the headpiece in a mature sperm. As the nucleus begins elongation, a curved, tapered nuclear projection follows the path of microtubules extending from the MLS and becomes inserted into an indented zone at the rear of the asymmetric organelle. The indented zone defines the most forward penetration of the nucleus into the sperm headpiece. Partial disorganization of MLS lower strata nearest the nuclear projection facilitates overlapping of the nucleus with the rearward part of the anterior mitochondrion. At the front of the nascent headpiece, the mitochondrion is stabilized against microtubules following total disorganization of intervening MLS strata. Penetration of the nuclear projection along the MLS and directed disorganization of MLS lower strata control ultimate disposition of headpiece components. The headpiece is isolated and molded into final shape by undercutting and constriction of the cell membrane.