bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation and distribution of annulate lamellae in growing oocytes in the newt, Cynops pyrrhogaster
Authors: Imoh Hiroshi , Terahara Tomoko
Published: June 2005

Stages of oocyte development in Cynops pyrrogaster are defined, and changes of annulate lamellae in their fine structure, number, sizes and locations during oogenesis are described. The results show that two different types of annulate lamellae occur during oogenesis. One type differentiates in or at the periphery of vesicle‐rich cytoplasm at the early stages of vitellogenesis and increases in number and size. The maximum number of about 40 stacks per median section of oocyte is reached at the stage of complete differentiation of the animal and the vegetal hemispheres. In these growing oocytes, all the stacks show elongate appearances and tetragonal arrangements of annuli as common characteristics. A second type of stacks of annulate lamellae is added anew in full‐grown oocytes, increasing the number of stacks per median section of the oocyte to about 90. The new stacks occur in close contact with electron‐dense bodies in the cytoplasm and have a massive appearance and hexagonal array of annuli. It is suggested that they appear coincidentally with the onset of oocyte maturation. The possible significance of the observed results is discussed.
Electron microscopic observations on sperm entry and pronuclear formation in naked eggs of the rose bitterling in polyspermic fertilization
Authors: Ohta Tadayuki
Published: June 2005

Unfertilized eggs of the rose bitterling (Rhodeus ocellatus ocellatus) were squeezed out of females that had an elongated ovipositor and were dechorionated mechanically with fine forceps in physiological saline. The dechorionated eggs were transferred into fresh water then inseminated at once by spermatozoa of the same species. A large number of spermatozoa was found on the surface of eggs that had not yet had cortical reaction following insemination. The surface of the naked eggs responded by formation of many small cytoplasmic protrusions (viz., fertilization cones) at sperm attachment sites. The formed fertilization cones were rosettelike structures formed by the aggregation of some bleblike swellings devoid of microvilli and microplicae. About 10 min after insemination, the fertilization cones retracted, but marks of their presence characterized by less microvilli and microplicae remained in the eggs 15 min after insemination. Many spermatozoa penetrated into the cytoplasm of each naked egg. The sperm nuclear envelope disappeared by means of vesiculation resulting from fusion of the inner and outer membranes. The sperm nucleus decondensed and developed into a larger male pronucleus. Smooth‐surfaced vesicles surrounded the decondensing sperm nucleus and formed the new male pronuclear envelope. Sperm mitochondria and flagella were found in the egg 15 min after insemination. The response of the egg surface to sperm entry and pronucleus formation are discussed.
Cotical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores
Authors: Stapleton Connie L. , Mills Lora L. , Chandler Douglas E.
Published: June 2005

In sea urchin eggs fertilization is accompanied by cortical granule exocytosis, a secretory event thought to be initiated by release of intracellularly sequestered calcium. We have examined the effect of two drugs on this process: chlortetracycline (CTC), a known chelator of intracellular calcium, and 8‐(N,N‐diethylamino)octyl‐3,4,5‐trimethoxybenzoate (TMB‐8), an antagonist of intracellular calcium release in both skeletal and smooth muscle. Preincubation of eggs for 10 min with either CTC or TMB‐8 blocked sperm entry, inhibited the burst of 45Ca2+ efflux normally seen postinsemination, and prevented fertilization envelope elevation. Half‐maximal inhibition occurred with 200 μM CTC and 60 μM TMB‐8. Electron microscopy confirmed that cortical granule exocytosis had been blocked, although inhibition was not due to a direct effect on exocytosis. CTC and TMB‐8 had no effect on Ca2+‐stimulated granule fusion in isolated egg cortices. Rather, these drugs block the early events in egg activation: sperm incorporation and triggering of exocytosis. These two effects appear to be independent since addition of either drugs just before insemination permits sperm entry but inhibits calcium release and cortical granule exocytosis.
Thermoregulatory responses to photoperiod by kangaroo rats (Dipodomys ordii): Influence of night lighting on nonshivering thermogenesis and resting metabolism
Authors: Gettinger Ronald D. , Ralph Charles L.
Published: June 2005

The influence of photoperiod on resting oxygen consumption and nonshivering thermogenesis of winter‐acclimatized kangaroo rats was determined by exposing freshly captured animals to 10‐week controlled photoperiod treatments. Three treatments were employed: (1) long days (LD) = 16L:8D, (2) short days (SD) = 8L:16D, and (3) short days interrupted with 15 min light at midnight (SDL). Thermoneutral oxygen consumption was uninfluenced by treatment, and posttreatment values were not different from pretreatment values. Below thermoneutrality, mean values for oxygen consumption and norepinephrine(NE)‐induced thermogenesis each were significantly greater in the SD group than they were in either the LD or SDL groups. Furthermore, oxygen consumption of LD and SDL groups, and NE‐induced thermogenesis of LD and SDL groups were indistinguishable. Posttreatment oxygen consumption and NE‐induced thermogenesis of the SD group were not different from pretreatment values. These results indicate that thermogenic capacities of kangaroo rats are strongly influenced by photoperiod. The similarities of responses by the LD and SDL groups indicate that the length of the dark period is of importance, and indirectly support suggestions that the pineal gland, through its nocturnal secretion of melatonin, may be involved in the transduction of photic information.
Enzymatic activities during evolution of the cement gland in Xenopus tadpoles
Authors: Weets J. , Picard J. J.
Published: June 2005

The activities of the hydrolases, α‐L‐fucosidase, N‐acetyl‐β‐D‐glucosaminidase (NAG), and zpacoumase appear to be involved in the regression of the cement gland in Xenopus laevis. The involution of the gland is marked by an important rise of the total as well as the specific activities of α‐L‐fucosidase and zpacoumase. The specific activity of α‐L‐fucosidase and of zpacoumase increases about five‐fold and eight‐fold, respectively, after 12 days of development. Although total activity of NAG decreases during involution, its specific activity undergoes an increase of 93% after 12 days. In contrast, there is a dramatic loss in the total and specific activity of aldolase, used as a control enzyme.

The behaviour of these four enzymes is strikingly different in the epidermal tissue adjacent to the gland. Their activity remains stable during the developmental period considered. These observations demonstrate that possible contamination of the explanted gland by surrounding tissue is not responsible for the observed increase in hydrolytic activity in the gland.
Demonstration of sperm chemotaxis in Echinodermata: Asteroidea, Holothuroidea, Ophiuroidea
Authors: Miller Richard L.
Published: June 2005

The sperm of starfish (Asteroidea), sea cucumbers (Holothuroidea), and brittle stars (Ophiuroidea) are chemotactically attracted to the tip of a micropipette releasing very small volumes of egg water or seawater solution of an alcoholic extract of ovaries or spawned eggs. The sperm are unresponsive to injections of seawater or a weak solution of ammonium chloride in seawater. No other echinoderm tissue tested yields an extract with sperm‐attracting activity. A complex set of species‐specificities has been demonstrated between many of the genera and species used in these experiments. Plotting of the paths of chemotactic sperm reveals that they approach the tip of the pipette along a path consisting of small loops alternating with straight segments orientated directly up the gradient. This is similar to the chemotactic behavior previously reported for the sperm of hydrozoans, molluscs, and urochordates. Sperm velocity does not change in response to the sperm attractant. Attracted sperm remain motile long after they have been attracted and do not agglutinate. In at least some cases the attraction response is reversible. This is the first direct evidence of sperm chemotaxis in echinoderms.
X‐ray micro analyses of cations (Na, K, Ca) and anions (S, P, Cl) in uterine secretions during blastocyst implantation in the rat
Authors: Nilsson B. Ove , Ljung Leif
Published: June 2005

The mass changes of sodium, potassium, and calcium ions in the rat uterine secretion at blastocyst delay, activation, and attachment have been estimated with X‐ray microanalyses of samples of uterine secretions absorbed by small Sephadex beads. A quantification of the ions was attempted by using a standardized coat of gold on the beads as a reference element for normalization of the ion peaks and by fitting the normalized values into corresponding linear regression equations obtained from measurements of step‐wise dilutions of a control rat serum.

The concentrations of sodium observed at delay, activation, and attachment were 117, 201, and 203 mEq/l, respectively, and those of potassium were 6, 18, and 19 mEq/l, respectively. Calcium values were about 2 mEq/l and decreased at attachment. Among the anions, only the chloride concentration increased at activation and attachment.
Effects of redox agents on glucose‐6‐phosphate dehydrogenase isozymes and enzyme activity in sea urchin eggs and zygotes
Authors: Sparling (Barber) Mary Lee , Killeen Timothy , Sinisgallo Yolanda , Yabuta Craig
Published: June 2005

Glucose‐6‐phosphate dehydrogenase (G6PD) is present in different mixtures of interchangeable states of aggregation in each of the supernatant and pellet fractions of unfertilized and fertilized sea urchin eggs. These states are each altered differently by redox agents, as shown by changed electrophoretic isozyme patterns and altered filtration retention following treatment by diamide, oxidized glutathione, reduced glutathione, ascorbate, or dithiothreitol. Activity levels of G6PD are altered by redox agents, probably as a result of change in aggregation state or change in association with inhibitory associated molecules. This suggests that there are control mechanisms for G6PD that are in different conditions in unfertilized vs. fertilized stages and supernatant vs. pellet compartments, resulting in different states of G6PD in the isolates.
A metabolic test for the quantitative analysis of alarm behavior of honeybees (Apis mellifera L.)
Authors: Moritz Robin F. A. , Southwick Edward E. , Breh Michael
Published: June 2005

The reaction of a group of 40 worker honeybees to exposure to the major compound of the alarm pheromone Iso‐pentyl‐acetate (IPa) can be easily quantified by their metabolic response. A flow through system oxygen consumption of the bees shows a characteristic increase within 30 sec after the application of IPA. There are significant differences in response among colonies in the tested population; these were most extreme for 4‐day‐old workers. As there is a highly significant correlation between the colony defense in the field and the metabolic laboratory test, this technique may be usable as a routine in breeding programs for honeybees with low defensive behavior.
Electrophoretic patterns of hemoglobin and oxygen binding properties of blood of Anostomidae fishes from Parana‐Pardo‐Grande hydrographic basin (São Paulo State, Brazil)
Authors: de Almeida‐Val Vera Maria Fonseca , Schwantes Arno Rudi , Val Adalberto Luis
Published: June 2005

The electrophoretic patterns of hemoglobin (Hb) and the functional properties of blood of seven migratory fish species, in two different kinds of habitat during both the rainy and dry seasons, were studied. All species showed multiple hemoglobins and very similar electrophoretic patterns except for Schizodon nasutus, which showed two cathodal components. The functional properties of blood reflect those electrophoretic patterns, since all species showed very little or no Bohr effect during each situation studied. Data on Leporinus obtusidens blood (during the rainy season), from both lotic and lentic environments, showed a normal Bohr effect (ϕ = −0.073). Similarly, Schizodon nasutus and Leporinus friderici from a lotic environment during the dry season were compared and showed a reverse Bohr effect (ϕ=0.042). In the other 14 situations, only Leporinus elongatus from a lentic environment during the rainy season showed a statistically significant difference in log P50 values from the other fishes.
Escape reflex development during posterior regeneration in the earthworm, Eisenia foetida
Authors: Welch Margaret F. , Drewes Charles D.
Published: June 2005

Morphological and electrophysiological correlates of giant nerve fiber development were examined during posterior segmental regeneration in the earthworm, Eisenia foetida. Seven days after amputation of the last 40 segments a small undifferentiated tail bud was evident. Tactile stimulation of this bud evoked all‐or‐none lateral giant fiber (LGF) spikes in original (substrate) segments adjacent to the bud, suggesting an early expansion of the LGF sensory field into the bud. This idea was further supported by experiments involving selective cutting of (and electrical recording from) ventral nerve cord and segmental nerves in the substrate segment immediately adjacent to the bud. By 12–16 days after amputation, segmental delineation of the bud was completed, lateral and medial giant fibers were evident in cross sections of the bud, and all‐or‐none giant fiber spikes were detected in surface recordings from the bud. LGF spikes, evoked by touching any of the bud segments, were readily conducted (velocity ≅ 1.0 m/s) along the bud and into substrate segments. During the next few weeks, giant fiber conduction velocities increased gradually in the bud and eventually were comparable to those in normal posterior segments. The patterns of conduction velocity increases during posterior segmental regeneration closely paralleled those of normal post‐embryonic development in posterior segments.
Accumulation of RNA in blastocysts during embryonic diapause and the periimplantation period in the western spotted skunk
Authors: Mead Rodney A. , Rourke A. W.
Published: June 2005

The in vivo incorporation of 3H‐uridine into RNA was studied in delayed implanting and activated blastocysts obtained from 33 western spotted skunks. 3H‐uridine was incorporated into RNA by all blastocysts; however, significantly more label was incorporated as blastocyst diameter increased. Activated blastocysts with diameters of 1.6 mm or greater on average incorporated 65 times more 3H‐precursor in 5 hr than diapausing blastocysts with diameters of 1.1 mm or less. Polyadenylated RNA was likewise synthesized by delayed implanting and activated skunk blastocysts; however, the proportion of polyadenylated RNA synthesized by the former was greater than in the latter (43.9% vs. 27.5%). Our data suggest that the transition from embryonic diapause to fully activated blastocysts first occurs gradually for several days before entering a 1–2‐day period of rapid development characterized by an abrupt increase in RNA accumulation.
Electrical activity at metamorphosis in larvae of the sea urchin Lytechinus pictus (Echinoidea: Echinodermata)
Authors: Satterlie Richard A. , Andrew Cameron R.
Published: June 2005

Two types of electrical potentials were recorded from competent echinopluteus larvae of Lytechinus pictus. The first was associated with reversal of cilia that line the ridges of larval epaulettes. Ciliary reversal potentials were recorded from all parts of the larvae and from isolated body parts. Estimated conduction velocity of ciliary reversal potentials was 10–20 cm/s. The second type of potential was largest when the electrode was placed over the urchin rudiment. Rudiment potentials could not be recorded from isolated epaulettes and could not be correlated with any obvious behavior of the larva.

Both potentials increased in frequency when a larva was brought in contact with a “conditioned” substrate. Ciliary reversal potential frequency increased six‐ to seven fold within a minute or two of contact and remained elevated until the point of partial tissue collapse during metamorphosis. Rudiment potential frequency also increased, but only three‐ to five fold and with a longer latency (3–6 min to peak frequency). Rudiment potentials maintained an elevated level of firing through total tissue collapse, at which time the larvae were electrically silent. Attempts to record from juvenile urchins, to determine the fate of the rudiment potential system in the final stage of metamorphosis, were unsuccessful.
C pigment locus mutants of the fowl produce enzymatically inactive tyrosinase‐like molecules
Authors: Oetting W. S. , Churilla A. M. , Yamamoto H. , Brumbaugh J. A.
Published: June 2005

Three albino mutants of the fowl were tested for tyrosinase activity. Two of these mutants (c and ca) are alleles at the autosomal C locus, while the third mutant (sal) is sex‐linked. Both the standard type, E, and sal are tyrosinase positive whereas the two C mutants are tyrosinase negative. Anti‐chicken tyrosinase mouse serum was produced and all four genotypes were found to have cross‐reacting material to this antiserum. Tyrosinase from the standard type was isolated and its location on denaturing two‐dimensional gels determined. A co‐migrating series of spots was found within the protein pattern of both the standard type and the tyrosinase positive albino, sal. The same pattern of spots was also observed for c and ca with no apparent change in either the pI or the molecular weight. Transmembrane blots also showed spots that reacted with anti‐tyrosinase serum in all four genotypes and that migrated to the same location as that of standard tyrosinase. It is proposed that both c and ca are CRM+ mutants which produce tyrosinase‐like molecules that are inactive due to a change that is electrophoretically and antigenically “silent”.
Calcium mobilization, water balance, and growth in embryos of the agamid lizard Amphibolurus barbatus
Authors: Packard Mary J. , Packard Gary C. , Miller Jeffrey D. , Jones Menna E. , Gutzke William H. N.
Published: June 2005

Embryos of the agamid lizard Amphibolurus barbatus are at developmental stage 29 of Dufaure and Hubert at the time of oviposition. Mobilization of calcium and other nutrients from the yolk proceeds slowly for the first half of incubation, during which time embryonic growth also proceeds slowly. During the second half of incubation, however, embryos withdraw calcium and other nutrients from the yolk very rapidly, and growth rates are correspondingly high. Approximately 60% of the calcium used by developing embryos is obtained from the yolk, but fully 40% of their requirement is met by calcium mobilized from the eggshell. Very little calcium remains in residual yolk of hatchlings, so this yolk must be used in maintenance metabolism rather than in growth of neonates. No dichotomy exists among oviparous, amniotic vertebrates with respect to sources of calcium used by developing embryos, but one does exist with respect to patterns of mobilization of this element. Whereas calcium is extracted from yolk of embryonic reptiles throughout incubation, it actually is deposited in yolk of embryonic birds after the midpoint in development.
Seasonal variations in hair pigmentation of white‐tailed deer and their relationship to sexual activity and plasma testosterone
Authors: Bubenik G. A. , Bubenik A. B.
Published: June 2005

Intensity of hair pigmentation of dorsal scrotum, nose, cheek and forehead areas of seven mature, male white‐tailed deer were determined from close‐up colour slides taken once a month during a 2‐year period. Blood samples and skin biopsies from forehead areas were taken at the same time as the photographs. Plasma testosterone (T) levels were measured by radioimmunoassay and T in the skin was investigated by immunohistology. Seasonal variations of hair pigmentation are most pronounced in the forehead region followed by the cheek, scrotum, and nose area. Peak blood levels of T (15.4 ng/ml) were detected in November. The highest correlation between T levels and pigmentation of the forehead area (R = 93%; R2 = 0.87), was established when pigmentation values were shifted two months ahead. Immunohistologically detectable T was localized in hair follicles, hair sheets and apocrine glands but not in the sebaceous glands. It is hypothesized that pigmentation of head regions might serve as a visual cue indicating the sexual status of an individual.
An α2‐macroglobulinlike activity in the blood of chelicerate and mandibulate arthropods
Authors: Armstrong Peter B. , Rossner Michael T. , Quigley James P.
Published: June 2005

The α2‐macroglobulins are large molecular weight proteinase‐binding proteins that inhibit the ability of proteinases to hydrolyze protein substrates without suppressing activity against amide or ester substrates. They are also able to protect the active site of bound proteinases from active site inhibitors of suitably high molecular weight. The ability to protect the amidolytic activity of trypsin from the macromolecular active site inhibitor, soybean trypsin inhibitor, was used to demonstrate an α2‐macroglobulinlike activity in the blood of the horseshoe crab, Limulus polyphemus and the crustaceans Libinia emarginata (the spider crab) and Cancer borealis (the Jonah crab). The α2‐macroglobulinlike activities of L. polyphemus and L. emarginata are sensitive to methylamine, but that of C. borealis is relatively insensitive. The molecular weights (mw) of the trypsin‐protecting proteins in L. emarginata and C. borealis, estimated from gelfiltration studies, are, respectively, 480 × 103 and 460 × 103, and are significantly smaller than that of L. polyphemus (Mr = 570 × 103).
Metabolic correlates of intracellular pH change during rapid contractile activity in a molluscan muscle
Authors: Chih C. P. , Ellington W. R.
Published: June 2005

Intracellular pH (pHi) changes during burst contractile activity in in vitro preparations of phasic adductor muscle of the bay scallop, Argopecten irradians concentricus, were monitored using phosphorus nuclear magnetic resonance (31P‐NMR) spectroscopy. A transient alkalinization (from pHi 7.06 to 7.15) was observed during the first period of contractions. The predominant mode of adenosine triphosphate (ATP) production during this period was by hydrolysis of arginine phosphate, a proton consuming process. Subsequent contractions of the muscle resulted in a gradual acidification, with pHi approaching 6.94. During these later stages of contraction, glycolytic production of octopine was a major source of ATP. The net proton yields of energy transformations were estimated, based on proton consumption by arginine phosphate utilization and proton yield of octopine production. The resulting predicted pattern of proton change was very similar to those of observed changes in pHi. Intracellular pH changes during contractile activity in A. irradians concentricus phasic adductor muscle are strongly correlated with the pattern of proton yield of metabolic energy transformations taking place in the tissue.
Changes in the rates of glycogenesis, glycogenolysis, lipogenesis, and lipolysis in selected tissues of the coho salmon (Oncorhynchus kisutch) associated with parr‐smolt transformation
Authors: Sheridan Mark A. , Woo Norman Y. S. , Bern Howard A.
Published: June 2005

The rates of glycogenesis, glycogenolysis, lipogenesis and lipolysis were determined in selected tissues of the coho salmon, Oncorhynchus kisutch, during the period of parr‐smolt transformation between February 1983 and June 1983. Glycogen synthesis in the liver, measured by uridine diphosphate formation, decreased 54% from initial levels. Liver glycogen phosphorylase a activity increased by 66%. Neutral lipid (sterol) and fatty acid synthesis in the liver and mesenteric fat was measured by tritium incorporation. Fatty acid synthesis in the liver and mesenteric fat decreased by 88% and 81%, respectively, between late February (parrs) and early June (smolts). There was no significant change in the rate of tritium incorporation into liver or mesenteric fat neutral lipids during the sampling period. Lipolytic rates were assessed by measuring the release of 14C‐oleic acid from 14C‐triolein in the presence of partially purified triacylglycerol lipase enzyme preparations from the liver, dark muscle and mesenteric fat. Liver, dark muscle and mesenteric fat lipase activity increased by 86%, 146% and 289%, respectively, during the sampling period. Increased glycogen and lipid breakdown, and concomitant decreased glycogen and fatty acid synthesis would contribute to the lipid and glycogen depletion observed in salmonid species undergoing parr‐smolt transformation.
Fertilization potential and polyspermy prevention in the egg of the nemertean, Cerebratulus lacteus
Authors: Kline Douglas , Jaffe Laurinda A. , Tucker Richard P.
Published: June 2005

We investigated the electrical properties of the egg of the nemertean worm Cerebratulus, and found evidence that an electrically‐mediated polyspermy block operates for a period of about 1 hr after fertilization. At fertilization, in natural or artificial sea water, the membrane potential shifts from its resting level of about −66 mV to a peak of about +43 mV, and in most cases remains greater than 0 mV for more than 1 hr. The average potential during the first 30 min is +22 ± 8 mV (SD, n = 12). When the external Na+ concentration is reduced from 486 to 51 mM (choline substituted) the fertilization potential amplitude is reduced; the average potential during the first 30 min is −27 ± 21 mV (SD, n = 5). Eggs inseminated in 51 mM Na+ sea water become polyspermic, indicating that polyspermy prevention depends on an electrically‐mediated mechanism. The electrical block is required for about 60 min, since transfer to 51 mM Na+ sea water during this period results in polyspermy. During the first hour following fertilization, the egg is also developing a permanent, nonelectrical block; the degree of polyspermy which results upon transfer to low Na+ sea water decreases progressively with time. The permanent block appears to be at the level of the egg plasma membrane or glycocalyx, since the egg envelope is not a barrier to sperm penetration, nor does its removal induce polyspermy. Electron micrographs show no obvious changes in the morphology of the extracellular layers, plasma membrane or cortex of the egg after fertilization.
The morphology of the migrating epiblast edge in gastrulating quail embryos: An SEM study of the effects of tissue handling before fixation on the attachment side
Authors: Andries L. , Vakaet L.
Published: June 2005

The expansion of the quail extraembryonic epiblast is a useful system for the study of epithelial sheet locomotion. A band of cells at the epiblast edge, referred to as edge cells (EC), adheres to the vitelline membrane. The attachment side of the EC and the dorsal surface of the submarginal cells were examined with scanning electron microscopy (SEM) after different fixation procedures. Our results indicate that especially the number of the submarginal microvilli and the surface structures of the lamellipodia are affected by tissue handling before fixation. The attachment region consists of overlapping lamellipodia that are bordered by filopodia. Proximal edge cells have a smooth contour, and they are probably elongated and oriented perpendicularly to the direction of locomotion of the EC. Parts of the proximal edge are occupied by lamellipodia and threadlike extensions. The submarginal cells located nearest the EC are usually outlined by intercellular ridges and numerous blebs, whereas the more central cells are outlined by microvilli.
Testicular cell differentiation in fetal mouse ovaries following transplantation into adult male mice
Authors: Taketo‐Hosotani Teruko , Merchant‐Larios Horacio , Thau Rosemarie B. , Koide Samuel S.
Published: June 2005

Testicular development is a complicated process involving differentiation and arrangement of several cell types. To analyze the process of testicular organization we examined the sequence of the appearance of testicular structures induced in fetal ovaries following transplantation. Fetal mouse ovaries on the twelfth day of gestation were transplanted beneath the kidney capsules of adult male mice. They continued to develop morphologically as ovaries until the eleventh day after transplantation, when seminiferous cord formation and testosterone production began in addition to follicle development (ovotestes). Between the eleventh and fourteenth day after transplantation, ovarian grafts frequently contained transitional structures consisting of Sertoli cells, pregranulosa cells, a third type of cells which show intermediate characteristics between Sertoli and pregranulosa cells, and oocytes enclosed by common basal lamina. Leydig cells or peritubular myoid cells were not found in the transitional area, whereas these cells were present around seminiferous cords composed only of Sertoli cells. Oocytes were absent or degenerated in the well‐developed seminiferous cords. The present findings suggest that, in ovarian grafts, pregranulosa cells can differentiate into Sertoli cells, which are responsible for the organization of the seminiferous cords, degeneration of oocytes, and differentiation of other testicular somatic cell types.
Proteolysis of the zona pellucida by acrosin: The nature of the hydrolysis products
Authors: Urch Umbert A. , Wardrip Nathan J. , Hedrick Jerry L.
Published: June 2005

Boar sperm acrosin was previously shown to hydrolyze the porcine zona pellucida in a specific and limited fashion. The action of acrosin on its presumed physiological substrate was investigated further in terms of the hydrolysis products formed. Peptide mapping experiments of zona pellucida glycoprotein families using acrosin demonstrated the formation of several products 2–4K smaller than the original susceptible families. When zona pellucida hydrolysates were examined with gel filtration, the hydrolysis products were associated in large macromolecular aggregates. These observations suggest that zona pellucida solubilization by acrosin may not be a relevant criterion for assessing acrosin's role in sperm penetration of the zona pellucida.
Demonstration of the maternal inheritance of avian mitochondrial DNA in chicken‐quail hybrids
Authors: Watanabe T. , Mizutani M. , Wakana S. , Tomita T.
Published: June 2005

The mtDNAs of chicken and Japanese quail can be readily distinguished from each other following electrophoresis after digestion with the restriction endonucleases, Hind III and Sal I. In hybrids between female quail and male chicken, the cleavage patterns of mtDNA were the same as the quail restriction fragment patterns. These results indicate that the avian mtDNA is maternally inherited. On the other hand, isozyme analysis revealed that the nuclear encoded enzyme GPI was assembled from both paternal and maternal gene products.
The effect of hypoosmotic stress on glycine influx in isolated muscle cells of Cancer irroratus
Authors: Moran William M. , Pierce Sidney K.
Published: June 2005

When the rock crab Cancer irroratus is exposed to hypoosmotic artificial seawater (ASW) its muscle cell volume is regulated, in part, by a reduction of the intracellular glycine concentration. Therefore, the effect of reduced ASW osmolarity on the unidirectional glycine influx and efflux of isolated rock crab muscle cells was assessed to determine whether changes in these fluxes might contribute to the decreased intracellular glycine concentration. The glycine influx (extracellular glycine concentration = 1mM) into muscle cells exposed to 60% ASW decreased from 810 nmol/g dry wt × 8 min (100% ASW) to 470 nmole/g dry wt × 8 min, whereas the glycine efflux increased from 3,410 nmole/g dry wt × 8 min (100% ASW) to 5,930 nmole/g dry wt × 8 min. The decrease in influx was due to the reduced osmolarity rather than the reduced Na+ concentration of the 60% ASW. Further, even the total replacement of Na+ (Li+ and Tris substituted) reduced the glycine influx by only 34%. Thus Na+‐coupled glycine influx is not an important factor in adjusting the intracellular glycine concentration of muscle cells exposed to reduced ASW osmolarity. Since under isosmotic conditions glycine efflux exceeds influx by a factor of four, the hypoosmotically induced increase in glycine efflux is largely responsible for the decrease of the intracellular glycine concentration during the initial stages of hypoosmotic stress.
Convergent evolution of reticulate scales
Authors: Brush Alan H.
Published: June 2005

Structural proteins of scales with various morphologies were compared. Ventral reticulate scales have soluble proteins that differ from both dorsal reticulate scales and scutellate scales. Ventral reticulate scale proteins are more like those in reptilian scales, whereas both dorsal type scales have proteins of the ϕ‐keratin family found in beaks, claws, and feathers. The morphological similarity in avian reticulate scales is due to convergence as the result of functional requirements.
Light response of cultured melanophores of a teleost adult fish, Oryzias latipes
Authors: Negishi Sumiko
Published: June 2005

Melanophores of adult fish of Oryzias latipes in culture exhibited light‐sensitivity. They responded with pigment aggregation to darkness, and with dispersion to light. These responses, which could be repeated more than several times by changing the light intensity, were not affected by α‐ or β‐adrenergic blockers. These facts suggest that melanophores of Oryzias directly respond to light with pigment displacement. The degree of melanosome translocation was changed depending on the intensity of illumination. The most effective wavelength for the induction of melanosome dispersion was near 415 nm, and light with wavelength around 550 nm was scarcely effective. Theophylline (2mM) and cyclic AMP (50 μM) inhibited dark‐induced melanosome aggregation. Such inhibition suggests that light may act as a trigger to induce changes in the intracellular levels of cyclic AMP. Seasonal variation was observed in the light‐sensitivity of melanophores in culture; dark‐induced melanosome aggregation was less significant in winter. These facts suggest that a photoreceptive substance may play a role in the light‐sensitivity of melanophores as a trigger to induce the aggregation of melanosomes.
Changes in the amount of nonhaem iron in the plasma, whole body, and selected organs during the postlarval life of the lamprey Geotria australis
Authors: Smalley S. R. , Macey D. J. , Potter I. C.
Published: June 2005

The concentration of plasma nonhaem iron and the concentration and weight of all nonhaem iron in the whole body and selected organs, together with its partitioning into ferritin and haemosiderin iron, have been measured during the metamorphosis and upstream spawning migration of the Southern Hemisphere lamprey Geotria australis. Some nonhaem iron was lost from the animal during metamorphosis. However, the concentration and weight of nonhaem iron in the liver rose sharply at this time, following its release from important storage sites in adipose tissue and the degradation of larval haemoglobins. The nephric fold of larval and metamorphosing stages contained over 40% of all nonhaem iron in the body at the commencement of metamorphosis. This was predominantly in the form of haemosiderin. While the rise in liver iron during the transition from larva to adult primarily reflected an increase in the weight of ferritin iron, the amount of iron stored as haemosiderin rose conspicuously towards the end of metamorphosis. The rise in ferritin iron in the liver was accompanied by a decrease in ferritin iron in the plasma, which implies that changes in the liver during metamorphosis result in a greater filtering of circulating ferritin. Such a process would account for the very much lower plasma nonhaem iron concentrations which characterise later adult stages. The weight of nonhaem iron increased markedly in the liver and adult opisthonephros and in the whole animal during the nontrophic upstream spawning migration. This was primarily due to a marked rise in ferritin which in turn could be related to the degradation of adult haemoglobins. The concentration of nonhaem iron (54,700 μg/g) and of its ferritin component (52,300 μg/g) in the liver of animals approaching sexual maturity are apparently by far the highest yet recorded for any vertebrate.
Labelling of living mammalian spermatozoa with the fluorescent thiol alkylating agent, monobromobimane (MB): Immobilization upon exposure to ultraviolet light and analysis of acrosomal status
Authors: Cummins James M. , Fleming Alan D. , Crozet Nicole , Kuehl Thomas J. , Kosower Nechama S. , Yanagimachi Ryuzo
Published: June 2005

Living spermatozoa of seven mammalian species were treated with the thiol‐alkylating fluorescent labelling compound, monobromobimane (MBBR). MB‐labelling alone had no effect on sperm motility, nor on the time course or ability of golden hamster spermatozoa to undergo the acrosome reaction when capacitated in vitro. Exposure of MB‐labelled spermatozoa to ultraviolet (UV) light and excitation of the MB fluorochrome resulted in virtually immediate immobilization of the spermatozoa without affecting acrosomal status. UV exposure of unlabelled spermatozoa for up to 30 sec had no effect upon motility. Immobilization of MB‐labelled spermatozoa depended on the midpiece being irradiated, as irradiation of the head alone, or of the more distal parts of the principal piece, had little or no effect upon motility. Labelling with MB followed by immobilization of individually selected spermatozoa was most useful for detailing the course and site of occurrence of the acrosome reaction during penetration of the cumulus oophorus by golden hamster spermatozoa in vitro. In these often hyperactivated spermatozoa, precise determination of the acrosomal status could not often otherwise be made due to the difficulty in visualizing the acrosomal region of a vigorously thrashing, hyper‐activated spermatozoon. This technique should prove valuable in a variety of studies on sperm motility, capacitation and fertilization, and could also be extended to other cell systems.
Normal development of hamster and rabbit eggs fertilized by spermatozoa labelled with the fluorescent thiol alkylating agent, monobromobimane
Authors: Fleming Alan D. , Cummins James M. , Kuehl Thomas J. , Seidel George E. , Yanagimachi Ryuzo
Published: June 2005

Cauda epididymal spermatozoa of the golden hamster were labelled with the thiol‐alkylating reagent, monobromobimane (MB). Female hamsters underwent uterine insemination with labelled spermatozoa at laparotomy under metofane anesthesia. All 12 females examined between 5 and 54 h postinsemination yielded a total of 83/100 (83%) eggs in the process of fertilization or embryos. Under ultraviolet (UV) exposure all exhibited a fluorescent tail which, in the 4‐ and 8‐cell embryos, could be seen to be fraying or disintegrating. As cleavage progressed, labelled tail components came to be restricted among the blastomeres such that at the 4‐ and 8‐cell stage the tail could be seen in only one to three blastomeres. To study complete development and pregnancy another 12 females received uterine insemination. After recovery from anesthesia (≃ 4 h) these females were mated with a vasectomized male bearing a dominant genetic marker (black eyes) to allow unequivocal determination of paternity in the fetuses and young produced. Seven became pregnant with one female losing her pregnancy about Day 7 of gestation. Two females sacrificed on Day 13 produced 17 normal fetuses and one resorption. Four females delivered 16 young, all normal at birth and in subsequent growth and fertility. In addition, insemination of female rabbits with MB‐labelled spermatozoa yielded normal embryos (50/52 96%) from 3 does on Day 2 and (38/64 60%) from 4 does on Days 4 or 5. Two normal litters (9 bunnies) have delivered from 3 does allowed to carry to term. These results suggest MB‐labelling of the fertilizing spermatozoon does not compromise normal development and may provide a valuable tool to determine the role and fate of some sperm components (non‐nuclear) to the process of development, particularly in the preimplantation embryo.
Taurine transport by the flounder (Pseudopleuronectes americanus) intestine
Authors: King Patricia A. , Goldstein Susanne R. , Goldstein Jonathan M. , Goldstein Leon
Published: June 2005

Taurine transport by the flounder gut was characterized in isolated strips of intestine mounted between Ringer's solutions. Taurine was transported into the cell, against its concentration gradient, by a sodiumdependent system present in both the mucosal and serosal membranes. This system appears to be specific for β‐amino acids and is regulated by cyclic nucleotides (cGMP and cAMP). Kinetic analyses indicated that under physiological conditions the magnitudes of the bidirectional taurine uptake rates would favor net absorption of taurine from lumen to blood.
Insulin‐independent controlled physiological morphogenesis of chick muscle from fusion‐capable myoblasts
Authors: Ramírez Oscar , Alemán Victor
Published: June 2005

Thigh myogenic cells from 11–12‐day‐old chick embryos were cultured continuously in the presence of medium containing no chick embryo extract (CEE). It is known that CEE contains a muscle‐inducing protein of 35,000 daltons. In spite of the absence of embryo extract and provided that calcium, starting at a concentration as low as 3 × 10−4 M, was present in the tested media, typically aligned myotubes with 20 or more nuclei per fiber or abnormal myosymplasts were produced at will. In the first case, the result was systematically obtained when the media were unchanged. Consequently, the cell microenvironment remained undisturbed and therfore was autoconditioned throughout the 7 days of culture. In the second case, the result depended on the feeding schedules. Conversely, no myotubes were formed in cultures in embryo extract‐free medium without calcium, irrespective of the frequency of medium changes. Insulin, a serum factor believed to be involved in syncytium formation process in vitro, was present in all tested media. Undialyzed or dialyzed fetal calf serum (FCS), used for the preparation of the media, contained 11 μunits of insulin per milliliter. The insulin content in all tested media was diluted, however, to one tenth the physiological serum concentration. The hormone did not promote any kind of myoblast fusion in any experiment in which calcium was deleted as a component of the tested media, regardless of the feeding schedule followed. Contrary to former claims, the present results demonstrate that, as in the initial development of chick heart and skeletal muscle in vivo, insulin, which is not produced in significant amounts until day 12 of incubation, does not participate in the early differentiation of skeletal muscle in vitro. These results lend further support to the idea of the existence of an intrinsically ‘fusion‐capable’ myoblast.
Histophysiology of a primary immune response against Aeromonas hydrophila in carp (Cyprinus carpio L.)
Authors: Lamers Cor H. J.
Published: June 2005

Histological and immunological parameters were monitored in carp during the primary immune response against Aeromonas hydrophila. Localization of antigen in the spleen initially ocurred in the ellipsoids, whereas in the head and trunk kidney it was diffusely distributed. When antibody titers increased (from day 9 onwards), antigen accumulated in melano‐macrophage clusters in all three organs, and it was mainly bound to cell membranes. Tissue‐bound immunoglobulin was present on several structures in the lymphoid organs. As a consequence of immunization, the number of cells with cytoplasmic immunoglobulin and the amount of immunoglobulin associated with the reticular sheath of ellipsoids and membranes of melano‐macrophages increased. Pyroninophilia was limited, and occurred in the spleen associated with ellipsoids; in addition, clusters of cells appeared, displaying a small rim of pyroninophilic cytoplasm. In the kidney the reaction was not conspicuous. The number of antibody forming cells in the head kidney peaked at day 9 and the serum antibody response followed with a peak at day 15. When the antigen was emulsified in adjuvant, the antigen processing and the antibody responses were affected. Antigen processing was retarded and a second burst of antibody production occurred from day 15 onwards. The relationship of melano‐macrophage centers with immunological processes is considered. It is suggested that in fish these centers might be primitive analogues of the mammalian germinal centers.
Descriptive kinetics of spermatogenesis in four chromosomal species of the Spalax ehrenbergi superspecies in Israel
Authors: Redi C. A. , Garagna S. , Heth G. , Nevo E.
Published: June 2005

The descriptive kinetics of the spermatogenic process has been studied in the four chromosomal species of Spalax ehrenbergi between November and March, the active period of reproduction.

Spermatid development can be subdivided into 16 steps in which the acrosome formation is clearly distinguishable and the Golgi, cap and acrosomic phases are identifiable. The first 12 steps of spermiogenesis can be utilized for the definition of characteristic time‐dependent relationships among different germ cell associations (stages): twelve stages, I–XII, are clearly identifiable.

In this regard no differences exist among the four chromosomal species. In general, the spermatogenic process in this species has the same pattern as that of Mus domesticus. Two relevant points distinguish Spalax spermatogenesis from Mus spermatogenesis: 1) the presence, throughout the stages I–XII of the seminiferous epithelium cycle of a larger size, oval shaped spermatogonium type containing heterochromatic granulations; 2) the Sertoli cells show only one heterochromatic clump closely attached to the nucleolus; moreover, the Sertoli cell cytoplasm is more PAS‐positive than that of Mus.
Inhibition of fertilization of the rabbit ova in vitro by the antibody to the inner acrosomal membrane of rabbit spermatozoa
Authors: Srivastava P. N. , Sheikhnejad Reza G. , Fayrer‐Hosken R. , Malter H. , Brackett B. G.
Published: June 2005

The antibody to the rabbit sperm inner acrosomal membrane, raised in guinea pig, completely inhibited the fertilization of rabbit ova in vitro. The F(ab′)2 of the antibody was equally effective in inhibiting fertilization. The antibody appeared to exert its inhibitory effect by binding to the inner acrosomal membrane of acrosome‐reacted sperm. The antibody‐treated sperm did not attach to or penetrate the zona pellucida. Thus, anti‐IAM offers a great potential as a contraceptive agent.