摘要:

AbstractSeasonal changes in blood composition (plasma osmolality, total plasma protein, hematocrit) in two free‐living populations of fence lizards,Sceloporus occidentalis, one living in a very arid environment (Pearblossom, CA) and another in a milder desert (Bend, OR), were analyzed. In this analysis, two features of reptilian physiology and ecology were incorporated: ontogenetic variation in blood composition and seasonal variation in body‐size distribution. The population living in the arid environment, but not the mild environment, exhibited significant seasonal changes in blood composition: mean plasma osmolality increased (345 ± 4 to 356 ± 3 mOsmol/kg) and mean plasma protein (4.19 ± 0.20 to 3.34 ± 0.14 g/dl) and hematocrit decreased (43.8 ± 0.3 to 31.6 ± 0.4) from April to August. These changes suggested that the physiological condition of the California population was affected by seasonal changes in the external environment. However, among individuals, a significant portion of the variation in blood composition was associated with an internal factor, body size. Larger lizards had higher osmolality, total protein, and hematocrit than smaller lizards in all seasons. In addition, the mean body size of active lizards decreased from April to August in California, but not Oregon. Because the body‐size distribution of active lizards in California shifted between seasons, changes in mean population values of these blood parameters probably do not accurately reflect changes that occur within individuals and therefore may be misleading in assessing the physiological consequences of drought. © 1995 Wil

ISSN:0022-104X    

DOI:10.1002/jez.1402720202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractIsolated plumes and vestimenta of the tubewormRiftia pachyptilawere perfused to determine the form in which carbon is transported to the animal's symbionts via the circulatory system. Catheters supplying colored saline were inserted into an afferent blood vessel while samples were collected from the efferent vessel. During perfusion, the plumes were immersed in sea water containing radiolabeled CO2. The effluent showed radioactivity in inorganic carbonate (∑ CO2, sum of all forms), malate, and succinate. When isolated vestimenta were perfused with saline containing labeled CO2, labeled malate and succinate could be detected in the effluent. Carbon transport in the blood as ∑ CO2is estimated to be of similar importance to that transported after incorporation into organic carbon. The significance for the establishment of the carbon isotope ratio of tubeworms is discussed. © 1995 Wiley‐Lis

ISSN:0022-104X    

DOI:10.1002/jez.1402720203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe causes of the differential sensitivity of auditory receptor cells of two tettigoniid species to low‐frequency airborne sound were investigated with neurophysiological, neuroanatomical, and bioacoustic methods. The experiments employed adult males of the Chinese speciesGampsocleis gratiosa(Decticinae) and the Australian speciesMygalopsis marki(Conocephalinae).G. gratiosaemits very broad‐band songs with a fundamental frequency component at 3.8 kHz, extremely low for a bushcricket; in contrast, the songs ofM. markihave a narrow‐band frequency spectrum, from 9 to 25 kHz. Accordingly, the threshold of the auditory organ as a whole is low in the low‐frequency range in the case ofG. gratiosa, whereasM. markiis similarly sensitive only at frequencies above 5 kHz.The experiments were designed to reveal the origin of this sensitivity difference. One possibility considered was that low‐frequency receptors of a particularly sensitive type are present inG. gratiosaand not inM. marki; alternatively, with a similar complement of receptor cells the whole‐organ threshold curve might be expanded or restricted as a result of differences in the lower cutoff frequency of the sound‐conducting system.The results confirm the latter interpretation. The proximal crista acustica and the distal intermediate organ comprise the same numbers and types of cells in the two species, and the difference in threshold of the low‐frequency receptors is produced by a shift of the frequency range in which the acoustic trachea has an amplifying effect. © 1995

ISSN:0022-104X    

DOI:10.1002/jez.1402720204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractFemale reproductive properties, early embryonic development, and serum estradiol and progesterone levels of the senescence‐accelerated mouse (SAM)‐prone (SAM‐P) strain were compared with those of a SAM‐resistant (SAM‐R) strain. The reproductive life span of SAM‐P (from 11.4 to 25.0 weeks old) was shorter than that of SAM‐R (11.1 to 41.6 weeks old), and the total number of SAM‐P pups was 41.7% less than from SAM‐R. The reproductive senescence of SAM‐P is more accelerated than that of SAM‐R. At 15 weeks old, the maximum litter size of SAM‐P was noted and was 33.7% smaller than that of SAM‐R. Although no differences in the numbers of ovulated and fertilized ova were observed between two strains, the number of implants in SAM‐P was 21.6% less than in SAM‐R. Cell cleavage was delayed in embryos of SAM‐P (8% morula, at day 2 of pregnancy) compared to SAM‐R (48%). At day 3 of pregnancy, 9% and 33% of the embryos were blastocysts in SAM‐P and SAM‐R, respectively. At day 1 of pregnancy, serum estradiol level in SAM‐P was 18.2% higher than in SAM‐R, whereas the serum progesterone level in SAM‐P was 46.2% lower than in SAM‐R. The unbalance of estradiol and progesterone levels in SAM‐P was considered to be the cause of the delay in early embryonic development, and then the decrease of implantation an

ISSN:0022-104X    

DOI:10.1002/jez.1402720205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractA major regulatory site for species specificity of fertilization in mammals lies at the level of sperm binding to the zona pellucida. This implies a high degree of complementarity between gamete and receptor molecules. These molecules support species‐specific interactions between sperm and oocyte that lead to gamete fusion (fertilization). We identified a rat sperm head surface antigen using an IgG1 monoclonal antibody (HD1) against rat sperm of epididymis cauda. By electron microscopy the antigen was shown to be present on the plasma membrane surface of the sperm dorsal head. One‐ and two‐dimensional immunoblotting analysis of sperm proteins demonstrated that HD1 reacted only with a 52 K molecule with a pI ranging from 6.6 to 7.2. The 52 K protein was first detected in situ by indirect immunofluorescence and showed to be underlining few elongated spermatids in testis. However, when the sperm reached the epididymis caput, the antigen was seen to be expressed on the dorsal surface of spermatozoa head. A similar fluorescence reaction was detected on sperms in the epididymis corpus and cauda. The specific spermato‐zoa‐zona pellucida interaction was inhibited in the presence of monoclonal antibody HD1 in a sperm binding assay of in vitro fertilization. © 1995 Wiley

ISSN:0022-104X    

DOI:10.1002/jez.1402720206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe present study was designed to investigate the possibility that the goat oviduct produces specific substance(s) similar to the oviductal glycoprotein (BOGP) of the bovine oviduct. Oviductal flushings obtained from goats at the follicular and luteal phases of the estrous cycle were examined by immunoblotting for the presence of material that cross‐reacted with monoclonal antibodies (MAbs) specific for BOGP. The MAbs immunoreacted with a broad band with a molecular mass of protein of about 97 kDa in the flushings of goat oviducts after fractionation of proteins by electrophoresis under reducing conditions. The antigen was present in flushings obtained from the ampullar segments of oviducts from goats at the follicular stage, but this antigen could hardly be detected in the flushings from the ampulla at the luteal phase and or the flushings from the isthmus at either the follicular or the luteal phase. This antigen was not detected in uterine flushings, follicular fluid, or serum. An immunohistochemical study demonstrated that the MAbs reacted specifically with the epithelial cells of the goat oviduct. Intense labeling was observed in the ampullar and fimbrial epithelia of goat oviducts at the follicular phase, but the immunohistochemical reaction was very weak at the luteal phase. In the isthmus, the reaction was faint during both the follicular and the luteal phase. No specific immunohistochemical reactivity with the MAbs was observed with other tissues from the reproductive tract or with nonre‐productive tissues. Immunofluorescent staining showed that the antigen was associated with the zona pellucida of goat ovarian eggs that had been incubated with ampullar flushings from goats at the follicular stage. These results indicate that the oviductal epithelial cells of the goat produce an oviduct‐specific antigen that is immunologically and biologically similar to BOGP. © 1995 Wiley‐L

ISSN:0022-104X    

DOI:10.1002/jez.1402720207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractWe have developed a simple direct method, requiring minimal manipulation, to measure beat frequencies of the cilia on the external surface of hamster oviducal infundibula in vitro. Two perfusion chambers (closed and open) were used; both can be hand‐made in a few minutes and discarded after use. Ciliary beat frequencies were determined by measuring variations in light intensity with time in a single pixel positioned over a video image of the beating cilia. Data files were collected using Image 1 software and later transferred to PSI Plot or Lotus 123 spreadsheets for analysis by counting the number of brightness peaks recorded per second or by subjecting the data to Fourier transformation with or without smoothing. These methods of analysis gave similar results. To verify that Image 1 data files contain accurate representations of CBF, videotapes of beating cilia were made and subjected to frame‐by‐frame analysis. Image 1 interfaced with a standard video camera was found to collect reliable data over a beat frequency range of 0‐‐15 cycles/sec. In some Fourier transforms, secondary peaks were observed and were shown to represent cilia beating at more than one frequency in a sampled region. Coefficients of variation for repeated measurements taken on the same region varied from 4.1% to 9.0%. Small but significant differences were found between beat frequencies at different regions of the same oviduct. When chambers were perfused discontinuously and measurements of beat frequency were made at least 5 min after each perfusion, no effect of perfusion on frequencies was observed. However, during continual perfusion of the open chamber, a slight but significant increase in beat frequency was observed after perfusion was initiated. Muscle contraction, which sometimes occurs in the open chamber, did not affect beat frequency measurements. Infundibula could be stored at 4°C overnight without any negative effect on beat frequencies. Cold storage also reduced muscle contraction. Placement of a small coverslip on infundibula in the open chambers was also found to reduce muscle contraction and facilitate beat frequency measurements. Coverslipping did not affect beat frequencies. This method of beat frequency analysis will be valuable for analyzing factors that regulate or influence cilia in mammalian oviducts. © 1995 Wile

ISSN:0022-104X    

DOI:10.1002/jez.1402720208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractBiomineralization in invertebrates, such as land snails, may serve as an excellent experimental model for understanding processes of skeletal calcification in higher organisms, the vertebrates. In the present study, the influence of nutrient and light restrictions on the calcification of the shell in land snails was investigated. It was found that nutrient and light restrictions led to an increase in weight and mineral content of shells. These events were accompanied by changes in the metabolism of vitamin D. The molluscan metabolite E was found to accelerate transfer of45Ca from mantle to shell. On the basis of these findings it is suggested that in land snails adaptation to environmental changes such as light and nutritional restrictions is mediated by the vitamin D endocrine system. © 1995 Wiley‐Liss, I

ISSN:0022-104X    

DOI:10.1002/jez.1402720209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe present study was carried out using dot‐blot Western analysis with pp39mos‐specific polyclonal antibodies to examine the quantitative and qualitative changes of c‐mosproto‐oncogene product, Mos, during bovine oocyte maturation in vitro. Mos is present throughout meiotic maturation, is produced from around the onset of meiotic resumption, and is phosphorylated on germinal vesicle breakdown. These results indicate for the first time that the synthesis and phosphorylation of Mos during maturation culture play a key role in the accomplishment of meiosis in bovine oocytes. © 1995 Wiley

ISSN:0022-104X    

DOI:10.1002/jez.1402720210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractParturition in the freshwater fingernail clamSphaerium (=Musculium) transversum(Say) was induced by external application of both 10−4and 10−3M serotonin [5‐hy‐droxytryptamine (5‐HT)]. 5‐HT induced release of viable juveniles within 30–60 min of application. Parturitions in 5‐HT (10−3M) occurred sooner and more often than in 5‐HT (10−5or 10−4M) or in artificial pond water. The numbers of juveniles per parturition in 5‐HT varied from one to nine. The parturition response to 5‐HT was completely blocked by 10−4M methiothepin (a vertebrate 5‐HT1/5‐HT2receptor antagonist) known to bind with high affinity to gastropod 5‐HT receptors and to block 5‐HT‐induced spawning in other freshwater bivalves. However, parturition was not induced by 8‐OH‐DPAT (8‐hydroxy‐dipropylaminotetralin HBr, a vertebrate 5‐HT1Areceptor agonist), a potent inducer of spawning in freshwater bivalves. Thus, the pharmacological profile of the 5‐HT receptor(s) mediating parturition inS. transversummay be unlike that mediating spawning in other bivalves. This is the first report of 5‐HT‐induced part

ISSN:0022-104X    

DOI:10.1002/jez.1402720211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY