Cyclical changes in the fine structure of bovine endometrial gland cells

Summary Cyclical changes in bovine endometrial gland cells were investigated in six heifers, three at estrus and three at day twelve of the estrous cycle in the luteal phase. The epithelium is generally low at estrus but high in the luteal phase. There are ciliated and non-ciliated cells. The ciliated cells are fewer and lighter and show inconspicuous cyclical changes.The secretory cells show more prominent changes. At estrus, their free border is flat with short microvilli. The conspicuous rough-surfaced endoplasmic reticulum may synthesize protein for later secretion. The Golgi complex seems inactive. The high number of cytosegresomes and dense bodies might express cell regression caused by endocrine changes.In the luteal phase, the cells are lighter with long microvilli. The Golgi apparatus shows vacuoles and immature secretory droplets. Secretory vacuoles with light contents occur in the apical cytoplasm. Some of them appear to discharge their contents into the lumen. This is interpreted as evidence of merocrine secretion. Accumulations of tubular, smooth-surfaced endoplasmic reticulum, masses of glycogen granules, and several fat droplets are present.Some lymphocytes and degranulated granulocytes are seen near the basement membrane, more frequently at estrus.Financial support for this study was received from Anslaget för främjande av medicinsk forskning vid Veterinärhögskolan.The authors express their gratitude to Prof. A. Bane and Dr. J.-E. E. Ringmar, Department of Obstetrics and Gynecology, for their help with the selection and clinical control of the animals and for keeping them in good condition.Post doctoral fellow, No. 43-KO-52 (1968) from the Educational Ministry of Japan.     

Some Eugregarines (Sporozoa, Apicomplexa) from the Stored Fruit Beetle, Oryzaephilus mercator Fauv. (Coleoptera) from India

Morphology and life history of 3 cephaline gregarines found in the gut of the pest of stored fruit, Oryzaephilus mercator. are described. Of these 3, 2 are new species. The 3 species are (1) Hirmocystis minuta (Ishii, 1914) (LP TL = 1:7 – 1:22, WP/WD = 1:1, 6–1:7); (2) Amsotobus indicus n. sp. (LP/TL = 1:3–1:6, WP/WD = 1:1 – 1:1.3); (3) Leidyana oryzaephili n. sp. (LP/TL = 1:2 – 1:12; WP/WD = 1:1–1:1.6).     

A method for studying vegetation dynamics when there are no obvious individuals: Virtual-population analysis applied to the tundra shrub Betula nana L.

A method is presented to study dynamics of plants that cannot be separated into individuals such as many grassland, salt marsh and tundra species. A virtual population is created by using a permanent transect line through the vegetation and individuals are defined as the branch segments distal to the intercept with the transect line. Addition and loss of individuals together with growth or shrinkage form the basis for constructing a size-structured transition matrix. A discrete-event simulation demonstrates that: 1) a virtual population of individuals grows at the same rate as the parent population; and, 2) size-structured transition matrices for a virtual population and parent vegetation have similar dominant and subdominant eigenvalues so a virtual population can be used to describe the dynamics of a parent vegetation.Dwarf birch, Betula nana L., was studied in the northern foothills of the Brooks Range, Alaska, by using photography to record branch intercepts along permanent transect lines. The distal branch segments constitute a virtual population of the parent vegetation. Transects were photographed in 1985 and again in 1986 and changes of branch segments were used to construct two transition matrices for shrubs with and without elevated fertilizer treatment. Analysis of the virtual populations suggests that although Betula nana may show increased branch growth with increased fertilizer, in the long run this shrub may decline in the tundra in response to such treatment.     

人胃癌不同周期细胞膜表面ConA受体的分布与侧向运动

本文研究了人胃低分化粘液性腺癌细胞MGC 80-3不同周期时相中ConA受体的分布与侧向运动。MGc 80-3细胞经同步化培养,用F-ConA标记。被标记细胞中G_1、S和G_2期呈不连续的分布,但它们之间又存在显著的差异。M期呈较均匀的强荧光分布(与其它时相细胞比较)。荧光漂白恢复方法测定ConA受体复合物侧向运动表明:各个周期时相之间不仅运动方式不同,而且运动速率也有显著差异。M期与G_1期主要表现出扩散型运动;而S期与G_2期表现为流动型运动。G_1期的扩散系数大干M期的;S期的流动速率大于G_2期的。但可动分子百分比以G_2期最高。这些结果表明了ConA受体的动力学性质。它受到细胞周期的调节。     

The reproductive biology of female Père David's deer (Elaphurus davidianus)

Data for this study came from breeding records of 27 Père David's (Elaphurus davidianus) hinds maintained in large pastures and from estrous records of four hand-reared nulliparous hinds. The mean estrous cycle length ranged from 17.5 to 19.6 days. Standing estrus resembled that of other cervids, except that a low, moaning vocalization was given in response to contact, and activity (as measured by pedometers) did not increase. Mean gestation length was 183.38 ± SD 6.11 days (n = 21), and nearly all females conceived in the second and third years. The median interbirth interval was 362 days. The median birth date was April 8, and 80% of the births occurred over a 9.5-week period. Multiparous hinds gave birth an average of 20.5 days earlier in the season than primiparous hinds. There was no dimorphism in birth weight. The results are discussed in light of comparative data for other species.     

Platelet activating factor (PAF) production by mouse embryos in vitro and its effect on embryonic metabolism

Factors affecting the production of platelet activating factor (PAF) by mouse embryos during culture in vitro were investigated. Detectable levels of embryo-derived PAF were produced within 1-4 hr with maximum PAF activity being observed after 6 hr of culture in vitro. The amount of PAF detected in media after 24 hr of culture of two-cell embryos was equivalent to 12.8 ng PAF/embryo. However, differences in activity were apparent with increased time in culture. Reduced synthesis of PAF during culture in vitro was supported by the observation that morulae stage embryos collected fresh from the reproductive tract displayed more PAF activity than morulae resulting from the 48 hr culture of two-cell embryos. In addition to determining production characteristics of PAF by embryos, we also show that the production of CO2 from carbon-1 position of lactate is positively correlated with the ability of embryos to develop during subsequent culture in vitro and therefore could be used as a measure of embryo viability. Furthermore, culture of embryos in media supplemented with PAF resulted in an increase in lactate utilization demonstrating a direct effect of PAF on the embryo. As PAF is produced by preimplantation embryos, an autocoid role of PAF in regulating embryo development is implicated. Therefore, the reduced production of PAF by embryos in vitro may explain the decreased viability of embryos commonly observed following their culture in vitro.     

Food preferences and nematode parasitism in mycophagousDrosophila

Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom onPleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of thequinaria species-group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, onlyD. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagousDrosophila. D. pirka, D. trivittata andD. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo. Bionomics of Drosophilidae (Diptera) in Hokkaido, IX.     

The reaction to c-banding of c-banded constituents during mitotic cycle ofCrepis capillaris

The reaction to C-banding was investigated throughout the mitotic cycle ofCrepis capillaris (2n=6): (1) 18–22 C-bodies or C-bands were found during mid telophase and interphase to prophase and metaphase, and also 12–14 at late anaphase to early telophase in the mitotic cycle. Fewer C-bands in late anaphase to early telophase were due to the absence of minute bands; (2) large and medium sized C-bands were strongly stained by Giemsa, while small and minute bands stained palely. It is suggested that inCrepis capillaris the difference of color in C-banded segments following Giemsa staining is referable to the amount of constitutive heterochromatin rather than to the difference in the condensation and decondensation; (3) the size of C-bodies changed during telophase to interphase and prophase. It is inferred that the extent of C-bodies is regulated by both the length of DNA sequences of constitutive heterochromatin and the amount of proteins combined with C-banded DNA. It was shown that the reaction to C-banding is neither due to the differential condensation of chromatin nor to a higher concentration of DNA in the C-banded regions, in the C-banding mechanism as has been suggested so far at least.     

Effect of retinoic acid on the proliferation and tumorigenicity of mouse mastocytoma cells

Retinoic acid (RA) inhibited the in vitro growth of the mouse mast cell tumor line P₈₁₅ in a dose- and time-dependent manner. The inhibition was accompanied by an increase in the amount of neutral intracellular mucopolysaccharides. Study of cell cycle kinetics showed that exposure to retinoic acid led to a slowing-down of the cell-cycle progression possibly related to a more differentiated cell population disclosed by microscopy with a lower proliferative capacity. In vivo, delays in both tumor appearance and mouse mortality were observed after injecting RA into mice bearing mastocytomas. These results suggest that RA could be of interest in the treatment of human malignant systemic mastocytosis with proliferation of immature mast cells.     

Differential Expression of mRNA and Protein Encoding Retinal and Pineal S-Antigen During the Light/Dark Cycle

S-Antigen is a soluble cell protein unique to the retina and pineal gland. In the former, it is a well-characterized molecule that participates in light-induced signal transduction in photoreceptor cells. In the latter, the functional role is presently not known. The expression of S-antigen and its mRNA was examined in the rat retina and pineal gland throughout the diurnal cycle and with light interruption of the dark cycle. A cDNA for rat S-antigen was isolated from a pineal gland library to examine the mRNAs. A 1.7-kb mRNA for S-antigen was observed in both the pineal gland and the retina. Retinal S-antigen mRNA was expressed throughout the diurnal cycle and increased with light interruption of the dark cycle. In contrast, pineal gland S-antigen mRNA levels were detectable only during the dark and were absent preceding and during light. The phenotypic expression of immunoreactive S-antigen, identified with two S-antigen monoclonal antibodies (MAbs), MAb A9C6 and MAb C10C10, was analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel (PAGE) and isoelectric focusing (IEF) electrophoresis. Immunoblot analysis of gels after SDS-PAGE revealed a single 46-kDa protein in retina. In contrast, two bands of approximately 43 and 46 kDa were identified in the pineal gland. Immunoblots of the retinal extracts separated by IEF electrophoresis revealed five S-antigen isomers, which vary quantitatively throughout the diurnal cycle and when light interrupted the dark cycle. Immunoblots of the pineal gland samples separated by IEF electrophoresis indicated that the pineal gland possesses four pineal gland-specific forms of S-antigen in addition to the five forms present in the retina. The differences observed in the mRNA and protein analyses suggest tissue-specific structural components for S-antigen in the retina and pineal gland that are not regulated in the same manner.