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Producing oocytes.
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Producing oocytes (ova).
Synonym(s): ovigenetic, ovigenic.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
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(o?o-jen'e-sis) [? + genesis, generation, birth]
The developmental process by which the mature human ovum (the female reproductive cell) is formed. Formation begins during the first 3 months of female embryonic life with the development of ovarian follicles. Each follicle contains one oogonium which, through the process of mitosis, becomes a primary oocyte containing 46 chromosomes. The oocyte then undergoes the first meiotic reduction division, resulting in formation of a secondary oocyte and a polar body, each containing 22 autosomes (half the number of chromosomes that are found in nongerm cells) and one X heterosome. Further division is arrested in prophase until the female reaches puberty. The second meiotic division begins at ovulation and reaches metaphase where, once again, division is arrested until the ovum is fertilized. The second meiotic division is completed at fertilization, ending with formation of the mature haploid ovum and one polar body. Synonym: ovigenesis
See: illustration; meiosisoogenetic (-je-net'ik), adjective
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Effect of tramadol (TR) on oogenic processes (percentages metaphase I [MI], mature, and degenerated oocyte) a, different from single female control (SC) MI, p<0.01; b, different from SC Mature, p<0.01; c, different from single female sham (SSh) MI, p<0.01; d, different from SSh Mature, p<0.05; e, different from single neuropathic female (SNP)+TR MI, p<0.05; f, different from SNP+TR Mature, p<0.05; g, different from MC Mature, p<0.01; h, different from MSh Mature, p<0.01; i, different from neuropathic female housed with male (MNP)+TR Mature, p<0.01).
Synchronisation of molting and oogenic cycles in a continuously breeding population of the sand crab Emerita asiatica on the Madras coast, south India.
In individuals having a gonad predominated by oogenic tissue and various developmental stages of oocytes, a small region appearing identical to inactive (non-secreting) TG tissue was present in the caudal region of the gonad closest to the gonoduct.
Newts and other amphibians in temperate regions begin Ptellogenesis shortly after the end of the prePous opposition season (i.e., summer), whereas prePtellogenic phase overlaps with the late Ptellogenetic phase of the prePous oogenic cycle (Verrell et al., 1986; Gilbert, 2000).
The breeding season for broadcast spawning species is relatively short and discrete; each colony usually spawns only once per year on a seasonal cycle, with oogenic cycle typically ranging from 6 to 14 months [1, 3].
The significance of this study is owed to the fact that the results of this study regarding the oogenic cycle of T.
At the beginning of cytoplasmic growth, each oocyte had an egg stalk and was attached to the follicle walls of the oogenic follicle (Fig.
Second, it can be the consequence of the oogenic disturbances resulting in unviable zygotes (12).
Comparative studies that examine temporal changes in oogenic mechanisms among wild populations will help us to understand the relationship between egg size and maternal age.
Sexual reproduction in solitary corals: Overlapping oogenic and brooding cycles, and benthic planulas in Balanophyllia elegans.