No abstract

Annexin 5, a unique calcium- and phospholipid-binding protein, has been investigated for its specific distribution in rat endocrine organs by immunocytochemistry with a specific antiserum to recombinant rat annexin 5. Follicular epithelial cells and parafollicular cells of the thyroid gland, adrenocortical cells of the zona fasciculata and zona reticularis, luteal cells, testicular interstitial cells, and Sertoli cells were shown to contain annexin 5. To examine whether the synthesis of annexin 5 would be affected by a change in humoral signal, the distribution of annexin 5 in the anterior pituitary was examined three weeks after ovariectomy. The withdrawal of ovarian hormones induced huge castration cells in the anterior pituitary gland, which contained abundant annexin 5. Annexin 5 was not detected in the pineal gland, the parathyroid gland, the islet of Langerhans, the adrenal medulla, zona glomerulosa cells, and granulosa cells. Since annexin 5 was shown to exist in many of the endocrine tissues examined, to be localized in specific cell types, and to be abundant in castration cells, it is suggested that annexin 5 contributes to secretory cell functions, which may be common to endocrine cells secreting chemically different hormones.

No abstract

Effects of NH3 concentration in sea water and pH of sea water on the motility of spermatozoa obtained from testes were examined in the Japanese pearl oyster. Percent motility at 30 s after dilution increased with increasing NH3 concentration in sea water from 0.75-2.0 mM. When spermatozoa were diluted with sea water containing 0.75 mM NH3, which is widely used as the insemination fluid in the hatchery of this species, the percent motility increased with time elapsed after dilution, and peaked at 5 min. For spermatozoa diluted with sea water containing 2.0 mM NH3, the percent motility increased rapidly and peaked at 30 s. The pH of sea water increased with increasing NH3 concentration from 8.2 (0 mM NH3) to 9.9 (5.0 mM NH3). When spermatozoa were diluted with artificial sea water at various pH (buffered without NH3 at 6.0-10.0), only spermatozoa diluted with artificial sea water of pH 10.0 were motile, and the percent was considerably lower than those in ammonical sea water. These results indicate that sea water containing 2.0 mM NH3 is a suitable solution for evaluating sperm motility, and that NH3 and/or ammonium ions may activate sperm motility in this species.KEY WORDS: ammonical seawater, artificial fertilization, Japanese pearl oyster, sperm motility.

The effects of feeding liquid brewer's yeast (LBY) on growth, carcass characteristics, and meat quality of finishing pigs were investigated. The LBY diet was prepared by replacing soybean meal (control diet) with LBY (experimental diet). A total of 12 crossbred pigs (Large White×Landrace× Duroc, six barrows and six gilts) were housed at a density of two pigs (one barrow and one gilt of similar weight) per pigpen, and three pigpens were assigned to each of the control and LBY diet groups. Pigs were supplied either the control or LBY diet when their weight reached approximately 80 kg, and feeding was stopped when their weight reached approximately 115 kg. The experimental diet contained sufficient crude protein (CP) and total digestible nutrients (TDN), with dry weights of 15% and 75%, respectively, which were diluted with water to obtain a final dry weight of 22%. Growth performance, carcass characteristics, and sensory evaluation of the longissimus dorsi muscle were not significantly different between the groups. The fatty acid composition in the LBY group showed a significant decrease in C18 : 2 and C18 : 3 content and a high fat melting point. These results indicate that LBY may be a useful protein source for swine.

To clarify factors reducing the motility and fertility of cryopreserved spermatozoa of the Japanese pearl oyster Pinctada fucata martensii, the structure of spermatozoa before and after cryopreservation was observed by scanning electron microscopy. Testicular spermatozoa were diluted with cryopreservation diluent (10% methanol + 18% fetal bovine serum + 72% sea water), and dispensed into 0.25-mL straws. The straws were cooled at a rate of approximately -20°C/min to -50°C, and subsequently immersed in liquid nitrogen. Percentage motility of spermatozoa before cryopreservation was 69.9 Ϯ 4.2%, and that of cryopreserved spermatozoa was 24.0 Ϯ 1.8%, respectively. In cryopreserved spermatozoa, the percentage that lacked or had a deformed flagellum was 56.6 Ϯ 3.9%, while in fresh spermatozoa this was 8.7 Ϯ 2.0%. In cryopreserved spermatozoa, the percentage of deformed acrosomes was 76.6 Ϯ 5.2%, while in fresh spermatozoa this was only 0.9 Ϯ 0.3%. Cryopreserved spermatozoa with a normal acrosome and flagellum were only 15.4 Ϯ 3.5% of those in fresh spermatozoa. These results indicate that lesion of the flagellum and deformation of the acrosome occurred through the cryopreservation procedure, and both types of damage lead to loss of the motility and fertility in thawed spermatozoa.

To develop methods for large-scale cryopreservation of Japanese pearl oyster spermatozoa, post-thaw motility and fertility of spermatozoa cryopreserved in straw and in a ‰at-bottomed aluminum cup were compared. Spermatozoa diluted 1:19 with an extender comprising 10 methanol, 72 seawater, and 18 fetal bovine serum were placed in the straw (0.25, 1.0, and 2.0 mL) and in the cup (10 mL). The vessels were then cooled in LN vapor to -50°C at a cooling rate of -17.6 to -20.6°C/min, and immersed in LN. The percentages of motility of spermatozoa cryopreserved in 0.25 mL, 1.0 mL, 2 mL straws, and the cup were 35.2, 31.1, 23.2, and 31.8 , respectively, of the pre-cryopreserved spermatozoa. When 100 mL of semen (pre-cryopreserved or cryopreserved in the 3 kinds of straw) was introduced to 2.5 million eggs, the percentages of fertility were invariably high, but not signiˆcantly diŠerent from one another. When fresh spermatozoa with low motility were cryopreserved, thawed, and then introduced to eggs, the percentage of fertility increased in a time-dependent fashion, until 20 min after the commencement of insemination. There were no harmful eŠects on growth and feed intake ability of pearl oyster larvae when the contact time of gametes at fertilization had been prolonged from 5 min to 60 min.

Using female Chinese hamsters stimulated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG), we investigated the influence of hormonal stimulation upon meiotic segregation in oocytes. In 1,576 oocytes ovulated spontaneously from 197 non‐treated mature females, the number (percentage) of hyperhaploid oocytes with more than 12 (12–14) chromosomes was 16 (1.0%). These cells had no extra single chromatids, but all had extra chromosomes. Single chromatids were seen in 7 (0.4%) cells with a haploid chromosome set. On the other hand, a total of 1,329 and 1,198 second meiotic (MII) oocytes from 64 mature females and 61 immature females stimulated with PMSG and hCG, respectively, were subjected to chromosomal analysis. Single chromatids were seen in 34 (2.6%) and 62 (5.2%) of these oocytes, respectively. Since these chromatids were mostly paired and the sister chromatids existed near each other in many cells, they may have separated from some chromosomes of haploid cells. Compared with the non‐treated females, the frequency of cells with single chromatids was significantly greater in oocytes from both mature and immature females stimulated with PMSG and hCG. The number (percentage) of hyperhaploid cells from mature and immature PMSG‐hCG‐stimulated females, respectively, was 15 (1.1%) and 14 (1.2%), which was not significantly greater than that in non‐treated females. Most of these cells had extra whole chromosomes but one oocyte from mature females and one from immature females had an extra single chromatid. These findings indicate that such hormonal stimulation induces premature centromere separation in MII oocytes and precocious division at anaphase I, which can be assumed by the presence of MII cells with extra single chromatids. Considering that no or less hyperhaploid MII oocytes with an extra single chromatid were seen in oocytes from spontaneous ovulation and from artificial ovulation on hormonal stimulation, these findings suggest that the major mechanism of malsegregations at first meiotic (MI) division is not a precocious division but rather, errors such as nondisjunction of homologous chromosomes (dyads).