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A. ROSS, SHEILA CHRISTIE and M. G. KERR

Summary.

A 38-year-old male with a history of 11 years' involuntary infertility was investigated at a subfertility clinic. Seminal analysis showed a sperm density of 40 to 50 × 106 spermatozoa/ml and 1 to 2% motility. He had a normal male complement of 46 chromosomes and meiotic analysis showed 23 normal bivalents. The testes appeared normal histologically, but in the biopsy specimen abnormal spermatozoa were detected in the seminiferous tubules by electron microscopy. Electron microscope examination showed that 97% of ejaculated spermatozoa were structurally abnormal, with elongation of the mid-piece, absence of an outer sheath on the main-piece and extra axial fibres.

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A. ROSS, SHEILA CHRISTIE and P. EDMOND

Summary.

Similar ultrastructural defects were found in the spermatozoa of two oligospermic men attending a subfertility clinic.

The majority of spermatozoa had a mid-piece of grossly abnormal morphology and the diameter of the tail was increased, due to an excess of outer-sheath fibres. Extra, as well as missing, axial-filament fibres were also seen. In both cases, only a very small proportion of the spermatozoa were motile.

A testicular biopsy was performed on each man and although the histological appearance was normal, abnormal spermatozoa were seen in thin sections examined by electron microscopy.

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D. A. Ross, H. S. Dhadwal and J. A. Foulkes

Summary. An objective method of assessing bull sperm motility by specifying the mean swimming speed and number of motile spermatozoa in a sample is described. Laser light was conducted into diluted semen samples using a fibre-optic Doppler anemometer (FODA). The signal correlation of the back-scattered laser light was modelled using least squares computer curve fitting of the resulting data. Agreement was found between the mean swimming speeds obtained and those measured using time lapse photography.

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Christine Gosden, A. Ross, A. McGovern and W. Reid

Summary. Of the 8 pregnancies studied, 2 were of small gestational sacs with blighted ova and were associated with devices in which the copper wire had very high detectable X-ray emissions for copper (>90%). In 2 other pregnancies intrauterine deaths had occurred by the time of termination at 13 and 17 weeks and copper levels in the products of conception were variable. There was no abnormality of the fetus in the term pregnancy but it seems possible that copper can affect the early growth and development of the embryo. On only 1 of the 8 devices was any great amount of calcium deposited and it is therefore considered unlikely that calcium deposition increases the risk of pregnancy by preventing the release of copper.

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Andrew L Siebel, Ross A D Bathgate and Laura J Parry

Mesotocin, an oxytocin-like peptide, is released in highest concentrations during parturition in macropodid marsupials. In late pregnant wallabies, uterine sensitivity to mesotocin increases markedly in the myometrium of the gravid uterus. This coincides with a significant increase in myometrial mesotocin receptor concentrations 3–4 days before term. To date, there is no information on mesotocin receptor gene expression in female wallaby reproductive tissues. This study aimed to examine mesotocin receptor gene expression in the uterus and ovaries of pregnant tammar wallabies, and to localise mesotocin receptors within the uterus. An RT-PCR strategy produced a consensus nucleotide sequence of 834 bp, which encoded 278 amino acids of transmembrane domains I to VI. This protein sequence has approximately 80% homology with the bovine and rat oxytocin receptor exon 2 region. Only one mesotocin receptor was detected in the tammar genome. The myometrium and mammary gland both expressed a 4.1 kb mesotocin receptor gene transcript. Myometrial mesotocin receptor gene expression increased on day 22 of the 26-day gestation and was significantly higher in the gravid than the non-gravid uterus in late pregnancy. This pattern of mesotocin receptor gene expression paralleled mesotocin receptor concentrations. Mesotocin binding sites were localised only to the myometrium, the highest densities being observed in the gravid uterus. Finally, this study showed high expression of mesotocin receptors in the corpus luteum. The pattern of luteal mesotocin receptor expression differed from the myometrium, with a decrease in mesotocin receptors occurring on the day of expected births.

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S. G. Hillier, A. J. Zeleznik, R. A. Knazek and G. T. Ross

Summary. Oestrogen-priming of the hypophysectomized immature female rat promotes preantral follicle development in the absence of endogenous gonadotrophins and such an animal is useful for study of the intraovarian glyco-protein—steroidal hormone interactions which underlie morphological and functional development of the ovarian follicle. The present report identifies in vitro the functional characteristics (gonadotrophin binding and steroidogenesis) of granulosa cells harvested at different stages of follicular maturity following treatment with exogenous hormones in vivo. Preovulatory follicle maturation, induced by FSH, has been studied up until antrum formation and the acquisition by granulosa cells of the ability to respond directly to LH or hCG. Before the increases in available granulosa cell membrane LH/hCG receptors associated with the formation of follicular antra, effects of hCG or other hormones with interstitial cell stimulating activity are mediated via interactions with cells outside the lamina basalis. In-vivo studies with oestrogen-primed hypophysectomized immature rats indicate that androgens secreted by LH/hCG-stimulated thecal and/or interstitial cells may act directly on the preantral follicle to promote atresia. However, in-vitro studies have shown a stimulatory effect of androgen on FSH-responsive progesterone secretion by granulosa cells isolated from preantral follicles. These effects, if shown to operate within the ovary during the normal cycle, need not be mutually exclusive because FSH stimulation of granulosa cells in vivo may be a major determinant of follicular responses to androgen. The increase in follicle size and antrum formation accompanying FSH treatment in vivo are associated with (i) increases in the steroidogenic potential of isolated granulosa cells; (ii) the induction of granulosa cell LH/hCG receptors and of steroidogenic responsivity to hCG; and (iii) stimulation of granulosa cell aromatase activity. These observations highlight the critical role of FSH in the organization of preovulatory follicular morphology and function.

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R. J. Aitken, M. J. Hulme, C. J. Henderson, T. B. Hargreave and A. Ross

Summary. Washed ejaculated human spermatozoa were surface labelled with 125I, using solid phase (iodogen) or enzymic (lactoperoxidase) methods, while membrane components possessing terminal galactose or galactosamine residues were labelled with the galactose oxidase–sodium [3H]borohydride technique. All three procedures revealed the presence of 2 major labelled surface components. The first comprised a broad band of radioactivity migrating just behind the ion front on SDS-PAGE, which could be extracted with chloroform and methanol, suggesting a lipid-like composition. The second fraction exhibited properties consistent with a major glycoprotein component of the human sperm plasma membrane, giving a peak of radioactivity with M r = 20 000, within which a discrete doublet of bands (M r = 17 000 and 19 000) could be resolved by autoradiography. A more detailed analysis of the labelled protein fraction after TCA precipitation revealed a number of other surface components, the major ones of which exhibited M r values of 30 000, 45 000, 66 000, 115 000 000 and 160 000.

Western blot analysis was then used to determine whether any of the surface components described above interacted with the γ-globulin fraction of antisera obtained from patients exhibiting idiopathic autoimmunity against sperm antigens. Using a purified membrane preparation as the target, antibodies were detected against numerous high molecular weight bands with M r values similar to the major components of the human sperm surface (35 000, 45 000, 66 000, 90 000 and 150 000). The nature of the antigens targeted by these antisera did not correlate with the ability of the latter to stimulate or suppress sperm–oocyte fusion.

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K L Bidne, M J Dickson, J W Ross, L H Baumgard and A F Keating

Endotoxemia can be caused by obesity, environmental chemical exposure, abiotic stressors and bacterial infection. Circumstances that deleteriously impact intestinal barrier integrity can induce endotoxemia, and controlled experiments have identified negative impacts of lipopolysaccharide (LPS; an endotoxin mimetic) on folliculogenesis, puberty onset, estrus behavior, ovulation, meiotic competence, luteal function and ovarian steroidogenesis. In addition, neonatal LPS exposures have transgenerational female reproductive impacts, raising concern about early life contacts to this endogenous reproductive toxicant. Aims of this review are to identify physiological stressors causing endotoxemia, to highlight potential mechanism(s) by which LPS compromises female reproduction and identify knowledge gaps regarding how acute and/or metabolic endotoxemia influence(s) female reproduction.

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M. X. ZARROW, A. FAROOQ, V. H. DENENBERG, P. B. SAWIN and S. ROSS

Summary.

Experiments have been conducted on maternal-nest building and factors affecting its occurrence in the rabbit. Females deprived of nesting material built a nest out of their own body hair and were as successful in rearing young as does which used both body hair and straw; females deprived of body hair (by shaving) and nesting material showed defective maternal behaviour. Interrupting pregnancy by spaying or foetectomy resulted in maternal-nest building. Nest building was induced in spayed females by the withdrawal of progesterone after injections of progesterone and oestradiol for several weeks. Similar regimes did not induce nest building by castrated males. Further experiments strongly suggest that the onset of nest building is governed by the change in the ratio of progesterone to oestrogen.

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Y. Zhao, L. M. Williams, L. T. Hannah, A. W. Ross, W. A. C. McKelvey and J. J. Robinson

Immunocytochemistry was used to detect the presence of oestrogen and progesterone receptors in the cervices of prepubertal lambs, seasonally anoestrous ewes, cyclic ewes, and pregnant ewes of known gestational stages, to define the roles of gonadal steroids in cervical function. The presence of the immediate early gene product, c-Fos, a marker for cellular activation, was also investigated using immunocytochemistry and in situ hybridization. Oestrogen receptor immunoreactivity was restricted to the endometrium on days 0–3 of the oestrous cycle (day 0 = oestrus). In immature animals, very few scattered nuclei in the endometrium were immunoreactive. Oestrogen receptor immunoreactivity was not apparent in the endometrium during the remainder of the oestrous cycle or in this region in anoestrous animals. In pregnant ewes, oestrogen receptor immunostaining appeared as relatively few isolated nuclei in the connective tissue stroma. Progesterone receptor immunoreactivity was found in the endometrium at days 0–3 of the oestrous cycle and also in the luminal epithelium, the myometrium and the blood vessels. Progesterone receptor immunoreactivity was also found in these regions, with the exception of the endometrium, at all other stages examined. Immunostaining for c-Fos was present in the endometrium at days 0–3 of the oestrous cycle, and some scattered immunopositive nuclei were present in prepubertal animals. c-Fos immunoreactivity was also found in the myometrium and in blood vessels at all other stages examined. Visualization of c-fos gene expression by in situ hybridization showed that it occurred in the luminal epithelium and blood vessels at oestrus, but was restricted to the blood vessels in all other samples examined.