CERZOS   05458
CENTRO DE RECURSOS NATURALES RENOVABLES DE LA ZONA SEMIARIDA
Unidad Ejecutora - UE
artículos
Título:
Male gametogenesis ultrastructure of Codium fragile subsp. novae-zelandiae (Bryopsidophyceae, Chlorophyta).
Autor/es:
MIRAVALLES, A. B.; LEONARDI, P. I.; CÁCERES, E. J.
Revista:
PHYCOLOGIA
Editorial:
INT PHYCOLOGICAL SOC
Referencias:
Año: 2011 vol. 50 p. 370 - 378
ISSN:
0031-8884
Resumen:
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Male gametogenesis was studied by light and electron microscopy in the
dioecious siphonous green alga Codium
fragile subsp. novae-zelandiae.
Gametangia were formed on the sides of utricules. Initially,
gametangia showed vegetative interphase nuclei and chloroplasts already with a
mature structure with few thylakoid lamellae and a single starch granule. Then,
mitotic divisions occurred originating a proliferation of gametic nuclei. Features
of the gametangial mitosis were similar to vegetative mitoses of other
Bryopsidophyceae. The fusion of minute vesicles
clearly delimited uninucleate portions of protoplasm with a large mitochondrion
and chloroplasts. Ultimately, the gamete final shape was delimited and the
basal-flagellar apparatus developed. Mature gametes were liberated immersed in
a mucilaginous material throughout an apical opening. They were elongated-ovoid in shape and showed two flagella,
a hyaline anterior portion and a rear portion with 2 or 3 yellow-green
chloroplasts. The nucleus was anterior, with abundant condensed
chromatin and without nucleolus. A large inverted
-V-shaped mitochondrion was located in the anterior region of the gamete. Chloroplasts
had poorly developed lamellae and a large starch granule. The basal-flagellar
apparatus features were the typical for the class.