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Early development in canine species follows a very specific pattern. Oocytes are ovulated at the germinal vesicle stage and meiotic resumption occurs in the oviduct. However, because of difficulties in the accurate determination of ovulation time and in the observation of oocyte nuclear stage by light microscopy, these early events have not been fully(More)
This study was designed to describe the follicular population present on the canine ovary (Canis familiaris) during the preovulatory period and essentially the changes in oocyte size, mucification, and chromatin configuration occurring from before the luteinizing hormone (LH) surge up to postovulation. In a first experiment, ovaries of beagle bitches were(More)
The aim of the present study was to describe the canine oocyte ultrastructural modifications during in vivo maturation, with precise reference to the timing of the LH surge and of ovulation. Twenty-five bitches were ovariectomized at specific stages between the onset of proestrus and the fifth day post-ovulation: 65 oocytes were observed by transmission(More)
The biology of the canine oocyte is unusual compared with that of other mammalian females. The present paper reviews both in vivo and in vitro specificities of canine oocytes. Final follicular growth in the bitch is characterised by an early appearance of LH binding sites in the granulosa, a high proportion of polyovular follicles and a preovulatory(More)
Reproductive physiology in dogs is quite unusual compared with that in other mammalian species. The peculiarities include the presence of numerous polyoocyte follicles, the ovulation of an immature oocyte (GV stage, non-fertilizable) and a peri-ovulatory period during which concentrations of circulating progesterone are particularly high. The aim of this(More)
Folliculogenesis covers the sequential steps in the development of a follicle, from primordial to preovulatory. Most of the time, one follicle contains a single oocyte, but some follicles are polyovular in that they contain several. These follicles were considered earlier as pathological, but they are, actually, fairly common in several species, from mice(More)
In the dog, oocyte maturation, fertilization, and early embryo development take place within the oviduct in the presence of increasing circulating progesterone (P4) levels. Expression of the oviduct-specific glycoprotein 1 (OVGP1), known in other species to be estrogen-dependent, was explored by real-time quantitative reverse-transcriptase PCR, Western(More)
In order to better understand the pituitary regulation of follicular growth in the domestic cat, follicle stimulating hormone (FSH) and luteinizing hormone (LH) receptors (R) were localized and quantified in relation to follicle diameter and atresia using in situ ligand binding on ovarian sections. Expression of FSHR was homogeneous and restricted to(More)
This study was designed to describe, both quantitatively (morphometry) and qualitatively (histological differentiation), follicle and oocyte growth in the feline ovary. The ovaries of 43 cats were collected and processed for histology. The diameters of 832 follicle/oocyte pairs were measured, with and without zona pellucida (ZP), and a special emphasis was(More)
The IGF system plays a crucial role in ovarian folliculogenesis, and changes in IGF-binding protein (IGFBP) levels modulate IGF bioavailability. Data from various mammalian models suggest a link between body size, IGF1 in serum and female reproduction parameters. Among the vertebrate species, the dog exhibits the widest span in body height. Height is known(More)