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Morphological Aspects of In Vivo Cleavage in Myocastor coypus (coypu)
Author(s) -
Felipe A. E.,
Teruel M. T.,
Cabodevila J. A.,
Callejas S. S.
Publication year - 2004
Publication title -
anatomia, histologia, embryologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.34
H-Index - 35
eISSN - 1439-0264
pISSN - 0340-2096
DOI - 10.1046/j.1439-0264.2003.00516.x
Subject(s) - blastomere , zona pellucida , cleavage (geology) , embryo , anatomy , biology , oviduct , embryogenesis , andrology , oocyte , microbiology and biotechnology , medicine , endocrinology , paleontology , fracture (geology)
Summary The objective of the present work was to characterize the in vivo cleavage stage of Myocastor coypus embryos. For this purpose a colpocytological follow‐up and controlled mating of 18 females were performed. Specimens from the beginning of the first cleavage to the acquisition of a morula appearance were considered to be in cleavage stage. Embryos in cleavage were collected between days 3 and 6 post‐coitus. Of the collected embryos, 80% presented an even number of blastomeres and the remaining 20% an odd number. Embryos from 3 to 7 cells were blastomere associations in a spherical disposition within the zona pellucida. Blastomeres were spherical or ovoid, presenting slight flattening in areas contacting with other blastomeres. Embryos of 8 and 9 cells were as a group of blastomeres slightly elongated, surrounded by a spherical zona pellucida. The percentage of peri‐vitelline space occupied by the embryonic mass ranged from 74.1 to 95.8% for all the substages. The cleavage pattern, developed in the oviduct, was of a rotational holoblastic type and asynchronic.