bluuebunny/crossref_metadata_2025 huggingface dataset:
The compensatory regeneration of the operculum of Hydroides norvegica: Identification of the inhibiting substance
Authors: Puccia Egidio , Durante Maria
Published: June 2005

In the polychete Hydroides norvegica there are two opercula with different degrees of organization: one is completely developed and functional, the other, present only in rudimentary outline. The latter only begins to develop when the functional operculum is removed. It was observed that in the whole body of the Hydroides, but particularly in the functional operculum, there is a substance which inhibits the development of the rudimental operculum. This substance was purified in order to determine its chemical nature.

From preparation of opercular homogenates we chemically separated numerous fractions, each of which was tested for inhibitory activity and chemical and physical properties. The inhibitor under study proved to be soluble in aqueous solutions, heat resistant, of low molecular weight, of an organic nature, anionic and aromatic. Finally it was chromatographically identified as 5′ adenosine monophosphate.
A new fate map for Salmo gairdneri
Authors: Ballard William W.
Published: June 2005

Chalk granules implanted among the cells of the stage 7 blasto‐disc are carried along with the cells to final location in the differentiating tissues and organs. The results, more often than not, are inconsistent with predictions suggested by an earlier fate map for Salmo (Pasteels, (36). Granules vertically thrust into a given spot on the blastodisc are usually carried to various levels of the trunk and to a variety of organs, presumably because cells at different depths of one spot and at different distances from the center are moving at different rates. Data from hundreds of such implants are assembled into charts showing the areas from which cells are drawn, to contribute to formation of the endoderm, notochord, five separate zones of the central nervous system, the head mesoderm, anterior and posterior trunk somites, tail somites, lateral plate, and heart. Using evidence of the overlapping and intergradation of these areas, as well as evidence from vital dyes when allowed to penetrate to various depths of the pregastrular blastodisc, a three‐dimensional fate map is synthesized for Salmo gairdneri, which is very different from the earlier map, but consistent with the previously reported patterns of morphogenetic movements in this species (Ballard, (73b). In contrast with the gastrulation of amphibia and birds, Salmo germ layers arise without any invagination, and there is at no time an anterior mesoderm‐free area. Previous efforts to generalize upon vertebrate gastrulation and its evolution within the phylum seem to have been premature.
Effect of hypophysectomy, isletectomy and ACTH on glycemia and hematocrit in the bullhead, Ictalurus melas
Authors: Chidambaram S. , Meyer R. K. , Hasler A. D.
Published: June 2005

Effect of hypophysectomy, isletectomy and ACTH on glycemia and hematocrit in Ictalurus melas were studied. The mean blood glucose (BG) and hematocrit in intact untreated fish were found to be 69.65 mg/100 ml and 33.7% respectively. Following hypophysectomy there was a 73.1% decrease in BG and a 50% decrease in the hematocrit. Changes in sham‐operated controls were insignificant.

Eight IU of porcine ACTH administered in two injections on days 6 and 8 post‐hypophysectomy increased the BG to pre‐hypophysectomy level and the hematocrit to 70% of its initial value on day 9, whereas in vehicle injected controls BG and hematocrit values remained at their post‐hypophysectomy level.

Isletectomy caused hyperglycemia in all the experimental animals. It induced a net increase of 142.3% over the pretreatment BG compared to 5.2% increase in sham‐operated controls. Isletectomy unlike hypophysectomy did not produce any significant change in the hematocrit.
Studies on eye regeneration in a snail, Helix aspersa
Authors: Eakin Richard M. , Ferlatte Millie Miller
Published: June 2005

Part I is a study of the fine structure of the regenerating optic tentacle of a pulmonate snail, Helix aspersa. Electron microscopy demonstrates marked similarity between regeneration and embryonic development of the eye and its photoreceptoral microvilli, lens‐forming secretory droplets, clear photic vesicles, neurites, pigment granules, and bundles of tonofilaments. A cell type, heretofore undescribed, prominent in the regeneration of the tentacle, is a pigmented interstitial cell. This cell is characterized, and its presumed role in the tentacle is discussed. Part II is an attempt to test the importance of nerve fibers in the induction of a regenerating eye in the newly formed epithelium of the outer tentacular sheath. Ligatures were placed around the inner tentacular sheath above the stumps of severed optic and tentacular nerves. No eye regenerated in snails with the ties in place, some as late as 90 days postoperative. The results suggest that nerve fibers exert an influence on the regeneration of the eye in Helix aspersa.
Enzyme patterns in mitochondria of mouse liver and heart muscle
Authors: Kistler Andreas , Weber Rudolf
Published: June 2005

The content of membrane‐bound (COX, SDH) and matrix enzymes (MDH, GOT, GDH) in mitochondria of heart muscle and liver of the mouse has been compared. Ageing of osmotically lysed liver mitochondria has little effect on enzyme stability, except for GDH the activity of which drops by 40%. Purification of liver mitochondria by sucrose density‐gradient centrifugation results in a loss of COX‐activity of 70%, but has no effect on cytochrome aa3 content. Heart muscle mitochondria are characterized by higher activities (per unit mitochondrial protein) of SDH, MDH, GOT and cytochrome aa3 content, but lower levels of GDH activity as compared to liver mitochondria. When referred to cytochrome aa3 content “constant activity proportions” are noted for SDH, MDH and GOT, whilst “specific activity proportions” are characteristic of GDH. The enzyme patterns are compared to the ultrastructure of these mitochondria.
An analysis of urodelian retinal regeneration: III. Degradation of extruded melanin granules in Notophthalmus viridescens
Authors: Keefe J. Richard
Published: June 2005

The fine structural features of a retinal: melanophage, observed in degenerating retinae of Notophthalmus viridescens is described. The melanophage, believed to originate from the vascular supply, serves for the stepwise degradation of extruded single melanin granules from cellular elements of the pigment epithelium which are forming the regenerated retina.
Daily variations in the effects of handling on fat storage and testicular weights in several vertebrates
Authors: Meier Albert H. , Trobec Terry N. , Haymaker Holley G. , MacGregor Robert , Russo Albert C.
Published: June 2005

Handling disturbances alone repeated daily for ten days caused marked changes in the fat stores of a fish, Fundulus chrysotus, a lizard, Anolis carolinensis, a quail, Coturnix c. japonica, and a mouse, Mus musculus. Repeated handling also caused changes in the weights of the male reproductive organs in the lizard and mouse. Whether the effects of handling were stimulatory, inhibitory, or of no effect depended on the time of the disturbance with respect to a daily 16‐hour photoperiod. The results should serve as a warning to investigators in many areas in which experimental subjects are handled in one way or another at the same time each day.
Insulin content and B cell morphology of the pancreas after chronic insulin treatment in a lizard
Authors: Rhoten William B.
Published: June 2005

Daily intraperitoneal injections of insulin into the lizard Anolis carolinensis leads to a reduced immunoreactive insulin (IRI) content of the splenic lobe of the pancreas. This reduction correlates with the observed morphologic changes. On the sixteenth day of injection the IRI content is reduced by more than 50% of the control value. At this time, the aldehyde fuchsin‐reactivity of the B cells is markedly diminished and the diameter of the B cell secretory granules, as determined by electron microscopy, is reduced by approximately 125 nm. Since the number of secretory granules after 16 daily injections of insulin does not appear to be diminished, the reduced size and stainability suggest that the remaining intragranular component is predominantly a non‐insulin matrix material. These observations indicate the existence of a quantitative relationship between the size of the B granules and the insulin content of the pancreas.
Protein incorporation by isolated amphibian oocytes III. Optimum incubation conditions
Authors: Wallace R. A. , Jared D. W. , Dumont J. N. , Sega Marsha W.
Published: June 2005

Available evidence indicates that protein incorporation by amphibian oocytes is mediated through a process of micropinocytosis. Oocytes incubated under our standard conditions sequester protein at a constant rate for at least 24 hours and appear to maintain approximately the same level of micropinocytosis as that observed in situ. Protein uptake is markedly sensitive to temperature and the ionic composition of the medium, with calcium being a particularly important component. Magnesium, phosphate, and additional energy sources are of only minor significance. Based on these observations, several slightly improved reformulations of the standard incubation medium are provided.
Basal body addition in ciliary rows of Tetrahymena pyriformis
Authors: Perlman Bruce S.
Published: June 2005

Naked basal bodies in the Tetrahymena cortex are distributed as would be expected if they represent nascent ciliary units. They tend to be spaced alternately with ciliated basal bodies and are distributed throughout the length of the ciliary rows in the regions examined.
The post‐hatching transition of erythrocytes from larval to adult type in the rainbow trout, Salmo gairdnerii irideus
Authors: Iuchi Ichiro
Published: June 2005

In addition to typical, round disc‐like larval type erythrocytes (erythrocyte L) in pre‐hatching embryos as well as just‐hatched larva and the typical elliptic disc‐like adult type erythrocytes (erythrocyte A) in two‐year‐old fish, a third type of erythrocytes has been observed to appear in the peripheral blood of rainbow trout larvae during a short period (a few weeks) of erythrocyte transition from L to A. Analyses of the erythrocyte population at various stages of the transition have suggested that the third type erythrocytes may not be derived from erythrocyte L, but may be an independent population which will develop into erythrocyte A in the blood and therefore have been referred to as immature type erythrocyte A (erythrocyte ImA). Dynamics of erythrocyte replacement from one to the others during post‐hatching development is characterized by the rapid decrease in erythrocyte L and the compensatory appearance of erythrocyte ImA, which then will develop into the mature erythrocyte A in the peripheral blood.

The three types of erythrocytes differ with respect to sensitivity to osmotic shock. A difference has also been observed between erythrocyte L and erythrocyte A including A concerning reactivity with concanavalin A and wheat germ agglutinin.
Effect of adiposectomy and feeding level on FSH‐induced testicular growth in male lizards Anolis carolinensis (Reptilia: Iguanidae)
Authors: Cuellar Hector S.
Published: June 2005

Experiment 1. At 32°C and with a plentiful food supply the testes of Anolis carolinensis injected with 25 μg FSH for 11 days grow in the absence of fat bodies. The same dosage of FSH did not influence fat body weight in the sham‐operated animals.

Experiment 2. Animals injected with FSH for 25 days and given either one mealworm/day, one worm every five days, or no food did not differ significantly in body weight from one another. The livers and fat bodies of those groups receiving one mealworm/day or one every five days were drastically reduced in size. The liver fat content was significantly greater in the adiposectomized group than in the sham‐operated group. The testes were greatly reduced in animals treated with saline and given one mealworm every five days or no food. The FSH‐treated groups had significantly larger testes than the saline‐treated groups and the initial control group. It is suggested that (1) in the absence of fat bodies the liver stores fat, (2) FSH may induce thirst or inhibit body water loss or both, and (3) conditions of insufficient diet may inhibit testes growth by shutting off or decreasing gonadotropin secretion.
Interactions between gametes and environment in the toad Xenopus laevis (Daudin) and their relationship to fertilization
Authors: Del Pino Eugenia M.
Published: June 2005

The Xenopus laevis egg jelly becomes swollen in different solutions: however; the degree of swelling of each of the three jelly layers and appearance vary depending on the medium. On eggs kept in a medium of low salt concentration, three sublayers of layer J‐3, the “J‐3 complex,” are visible. However, these sublayers cannot be distinguished in eggs hydrated in DeBoer's. Presence of the J‐3 complex is correlated with loss of egg fertilizability. Changes in the swelling of the jelly, disappearance of the J‐3 complex and regaining of egg fertilizability are brought about by brief exposures of the hydrated eggs to DeBoer's. The process that elicits these changes in the jelly was named “jelly reversal.” Jelly reversal is dependent on the solute concentration of the medium, is independent of pH and can be elicited by qualitatively different solutions. Non‐polar solutions act more slowly than those of polar solutes. Regaining of egg fertilizability is dependent on jelly reversal, nature of solute, solute concentration and pH. The phenomena of jelly reversal and regaining of egg fertilizability imply that specific ions of the jelly are needed for fertilization. Hydration of the jelly can form blocks to sperm entry, therefore, the block to polyspermy in Xenopus is not a single event.

Layer J‐1 stains metachromatically with toluidine blue and incorporates 35S‐sulfate during its formation. Failure of eggs to regain fertilizability after reversal at low pH is correlated with diminished toluidine blue metachromasia of J‐1. Retention of staining was dependent upon the salt concentration of the medium.
The lonic permeability of the Amphibian oocyte in the presence or absence of external calcium
Authors: Tupper Joseph T. , Maloff Bruce L.
Published: June 2005

The membrane potential of the Rana oocyte, as determined by intracellular microelectrodes, ranges from approximately −40 to −70 mV (inside negative). Upon removal of external Ca, a large, rapid depolarization in membrane potential occurs. The depolarization is reversible by both Ca and Mg. In the presence of Ca, the magnitude of the membrane potential is primarily dependent on the K distribution across the oocyte membrane with a lesser but significant Na dependence. Upon Ca removal, the Na dependence is greatly increased, indicating an increased Na permeability. Direct measurements of Na, K and Cl permeability by tracer‐flux analysis indicate the following. In the presence of Ca the permeabilities are approximately: Na (1.0 × 10−6 cm/sec); K (5.6 × 10−6 cm/sec); Cl (1.4 × 10−6 cm/sec). Upon Ca removal the K and Cl permeabilities are not significantly altered. However, there is an approximately four‐fold increase in Na permeability (4.5 × 10−6 cm/sec). This increase explains the observed depolarization in membrane potential upon Ca removal. It has been suggested previously that Ca may regulate the in vivo depolarization observed during transition from oocyte to ovulated egg in the amphibian. The present experiments indicate that, if Ca does play a role, its role is not analogous to the in vitro effect on the oocyte, since the ovulated egg has reduced Na as well as K permeability.
Metabolic sources of ammonia in the earthworm, Lumbricus terrestris L
Authors: MacDonnell Paul C. , Tillinghast Edward K.
Published: June 2005

The earthworm Lumbricus terrestris is ammonotelic while feeding but becomes ureotelic with fasting.

The metabolic sources of ammonia nitrogen in feeding worms have been examined. Two deaminating enzymes, L‐serine dehydratase and 5′‐AMP deaminase, have been observed to be present in high activity. The latter enzyme was an order of magnitude more active than the former.

The activity of L‐serine dehydratase was modified by theophylline but not by cyclic AMP.

5′‐AMP deaminase appears to be an allosteric enzyme with ATP functioning as a positive modulator. The positive allosteric effector increases the apparent affinity of 5′‐AMP deaminase for its substrate while having no effect on the maximum velocity of the reaction.

Both enzymes were located predominantly in the gut tissue.

While neither enzyme decreased in activity with fasting their possible role in ammonia production is discussed.
Effects of pinealectomy and melatonin injections at different seasons on ovarian activity in the lizard Anolis carolinensis
Authors: Levey Irwin L.
Published: June 2005

The short‐term effects of pinealectomy and melatonin treatment on ovarian activity in the lizard, Anolis carolinensis were examined at various times of the year. Animals were maintained under short photoperiod (6L:18D) at a constant temperature of 31 ± 1°C.

Destruction of the epiphysis by heat cautery in November and January caused significant follicular development within 14 days. Daily administration of 10 μg synthetic melatonin blocked ovarian stimulation resulting from pinealectomy. Ovarian sensitivity to pinealectomy decreased with the onset of seasonal reproductive activity and was absent at the end of the normal breeding season, i.e., September.

These observations support the hypotheses that, under conditions of short photoperiod and high environmental temperature, (a) the pineal organ can modify ovarian activity in Anolis; (b) there exists a definite seasonal sensitivity to this influence; and (c) melatonin may be an active agent of pineal function.
Properties of rattlesnake shaker muscle
Authors: Martin James H. , Bagby Roland M.
Published: June 2005

The goals of this study were to learn something of the physiology of the rattlesnake's rattling mechanism and the mechanical properties of tension development. Using the rattlesnakes, Crotalus atrox and Crotalus scutulatus, it was found that the rattling motion is a complex oscillation rather than the simple back and forth motion often described. Rattling is accomplished by “doublet” contractions, i.e., if the shaker muscles on one side of the tail contract, then so do the muscles on the other side. The time interval between the two members of a doublet is temperature dependent and is the ultimate determinant of maximum rattling speed. The rattling is not produced by asynchronous type muscle such as found in insects. The isometric twitch is extremely fast at 18°C, and the contraction time is on the order of 8–10 msec. The rattlesnake shaker muscle at 18°C produces 0.3 kg/cm2 tension and has a twitch‐tetanus ratio of 0.19. The length‐tension curve for the active muscle is typical for skeletal muscle, but there is a larger passive resistance to stretch like that found in insect fibrillar flight muscle or cardiac muscle.
Maturation of spermatozoa in the rabbit epididymis: Effect of castration and testosterone replacement
Authors: Orgebin‐Crist M.‐C.
Published: June 2005

Rabbit epididymal spermatozoa gain their fertilizing ability upon reaching the distal corpus epididymidis. When prevented by ligatures from reaching this region, they become fertile in the proximal corpus after 24 hours in the intact male but not in the three‐day castrated male. Unilateral castration has no such effect. Testosterone propionate (2 mg/kg/day) prevents this effect of castration. Abnormalities in ova fertilized by spermatozoa from castrated males and castrated males receiving testosterone suggest that an adequate level of androgen is necessary not only for the spermatozoa to become fertile but, also, for support of the normal development of the ova.
Lactate dehydrogenase isozyme patterns of thirteen species of snakes
Authors: Schwantes Maria Luiza
Published: June 2005

Starch gel electrophoresis patterns of lactate dehydrogenase (LDH) from various tissues of 13 species of snakes belonging to three families are described. At least five LDH isozyme bands could be identified in the species analyzed. In Pseustes sulphureus sulphureus and Clelia clelia plumbea three bands were detected at the LDH‐5 site, suggesting the existence of an electro‐phoretic variant of the A subunit. Additional isozymes restricted to regions of the eye were also observed in some Bothrops insularis and B. jararaca. A population study of Boa constrictor amarali, Philodryas patagoniensis, Xenodon merremii, Bothrops insularis, and B. jararaca failed to detect any LDH polymorphism.
Effect of actinomycin D, mitomycin C, puromycin, and cycloheximide on desoxycorticosterone‐induced in vitro maturation in oocytes of the catfish, Heteropneustes fossilis (Bloch)
Authors: Goswami Shashi V. , Sundararaj Bangalore I.
Published: June 2005

Actinomycin D and mitomycin C, inhibitors of DNA‐dependent RNA synthesis, were ineffective in blocking desoxycorticosterone (DOC)‐induced in vitro maturation in oocytes of the catfish, Heteropneustes fossilis (Bloch). This suggests that a concurrent mRNA synthesis is not obligatory for DOC‐induced maturation. On the other hand, cycloheximide and puromycin, inhibitors of protein synthesis, effectively blocked DOC‐induced oocyte maturation; the former was effective at much lower concentrations than the latter. Further, cycloheximide or puromycin completely blocked oocyte maturation when introduced to the culture medium simultaneously with, or within the first three hours of addition of DOC. As the introduction of the inhibitors to the culture medium was delayed, a progressively larger number of oocytes completed the process of maturation. These results indicate that DOC‐induced maturation in the catfish oocytes is contingent upon protein synthesis which takes place within the first three to four hours of DOC stimulation.
Desmosomes and their components after cell dissociation and reaggregation in the presence of cytochalasin B
Authors: Overton Jane , Culver Naomi
Published: June 2005

Corneal epithelial cells of the chick, in a stage in which desmosomes are forming, have been dispersed and reassociated in the presence of cytochalasin B in order to assess the affects of the drug on desmosomes. Any affect on these adhesive structures or on normal cell apposition as determined by fine structure would provide morphological evidence for interference with cell adhesion. Dispersed cells in concentrations of cytochalasin B of 3 μg/ml or more showed stabilization of the cell membrane in that after desmosome disruption single plaques remained at the cell surface rather than entering the cytoplasm on vacuoles, as occurs in normal medium. Interference with cell surface apposition particularly at early stages of aggregation provided additional evidence for surface immobility. Despite these effects the presence of a stainable surface coat could be demonstrated early in reaggregation and by 24 hours of culture cell surfaces became closely apposed over wide areas and desmosomes formed between cells and in some cases between different parts of the same cell even in dosages of 10 μg/ml. Thus interference with cell adhesion in corneal cells as measured by these criteria appears to be related to immobility rather than to adhesive properties. These findings bear on studies of cell sorting in the presence of cytochalasin B.
Phenotypic variability of lactate dehydrogenase in Daphnia magna
Authors: Hebert Paul D. N.
Published: June 2005

Three zones of L( + ) lactate dehydrogenase (LDH) activity are apparent after electrophoresis of extracts prepared from well fed individuals of Daphnia magna. Phenotypes of individuals subjected to brief starvation are characterized by additional bands below each of the original zones of activity, while prolonged starvation results in the total disappearance of LDH activity in two of the three zones.

Proteolysis of pre‐existing LDH molecules is responsible for the appearance of the more anodally migrating components after brief starvation, but the cause of the phenotypic changes after prolonged starvation is uncertain.

The possibility of the using LDH phenotypes to monitor changes in food availability within natural populations of D. magna is discussed.
Sperm‐egg interaction in immature hamster oocytes
Authors: Barros C. , Muñoz G.
Published: June 2005

Immature oocytes were recovered from ovarian follicles at 0, 2, 4, 6, 8 and 10 hours after an ovulating injection of HCG. The envelopes (cumulus, corona cells and zona pellucida) of these oocytes were removed by enzymic treatment. The naked oocytes were incubated in vitro with capacitated spermatozoa to study the rate of sperm entry.

A close correlation existed between the appearance of the ability of the oocyte to effectively interact with capacitated spermatozoa and the stage of nuclear maturation. The lowest percentage of sperm entry into zona‐free oocytes was observed at zero and two hours after the HCG injection. The nuclei of these oocytes were at the germinal vesicle stage and early first meiotic metaphase respectively. A significant increase in the rate of sperm entry was observed in oocytes recovered four hours after the HCG injection. The nuclei of these oocytes were still at the first meiotic metaphase. Percentages of sperm entry similar to controls were observed in oocytes recovered 6, 8 and 10 hours after the HCG injection.

Germinal vesicle breakdown and a delay period for nuclear and cytoplasmic materials to interact, seem to be two important factors before gamete fusion can take place.
DNA synthesis during differentiation of tadpole shank epidermis
Authors: Wright Sister Mary L.
Published: June 2005

DNA synthesis in the shank epidermis of tadpoles of Rana pipiens was studied by autoradiography with thymidine‐3H. Differentiation of the epidermis at late stages of spontaneous metamorphosis was found to correlate with a peak followed by a slow decline in labeling index in the inner layer, a rapid fall to complete absence of labeling in the outer layer, and a progressive restriction of labeling site to basal cells. Treatment of Stage X tadpoles with 30 μg/liter thryoxine for up to five days accelerated changes in labeling index and differentiation of the epidermis.

In three experiments, tadpoles at Stages III, XII and XVIII were treated with thyroxine for intervals of up to 82 hours, and DNA synthesis in the shank epidermis was compared with controls. Whereas at Stage III in the outer layer the labeling index remained the same as the controls except for a slight increase at 12 hours, at Stages XII and XVIII the index fell significantly below the controls by 24 hours. The inner layer labeling index rose significantly above the controls by 12 hours at Stage III, and by 36 hours at Stage XII. At Stage XVIII, the inner layer showed essentially no response to thyroxine. These results indicate an early effect of thyroxine at Stage III, stage‐specific changes in sensitivity of epidermis to thyroxone treatment, and a differential response of outer and inner layers.
The effect of testosterone on the development of the perianal glands of the guinea pig cavia porcellus (L)
Authors: Harmsen R. , Sittig N.
Published: June 2005

Daily injections into female and castrate guinea pigs resulted in an increase in size and scent production of the perianal glands. Before testosterone application the glands were significantly smaller than those of entire males. After 45 days of treatment the glands of castrates and females were indistinguishable from the glands of entire males.

The perianal glands must be considered secondary sexual characteristics. Social behaviour which is affected by exogenous testosterone may in some cases be affected via interference in the normal scent production.
Hatching, attachment, and outgrowth of mouse blastocysts in vitro: Fixed nitrogen requirements
Authors: Spindle Akiko I. , Pedersen Roger A.
Published: June 2005

Hatching, attachment and outgrowth of mouse blastocysts in vitro are dependent upon the presence of specific free amino acids in the medium. When grown in Eagle's Basal Medium (BME) containing 1% dialyzed fetal calf serum, 67% of blastocysts hatch. Omission of histidine, methionine, threonine, tryptophan, tyrosine, or valine from BME significantly reduces the incidence of hatching. For attachment to occur, cystine and lysine are also required, and for trophoblastic outgrowth, every essential amino acid except isoleucine is required. Omission of glutamine reduces the extent of outgrowth. Addition of higher (10X–20X BME) concentrations of cystine, histidine, or lysine increases the extent of outgrowth, but addition of 10−5–10−2 M concentrations of non‐essential amino acids does not stimulate either hatching, attachment, or outgrowth.

When all essential amino acids are at optimal concentrations, nearly 100% hatching occurs in a chemically defined medium in the absence of a macromolecular fixed nitrogen source. Extensive trophoblastic outgrowth and inner cell mass growth occur at optimal amino acid concentrations, but only in the presence of serum. Under these conditions, a collagen substrate is not necessary for growth and differentiation of the inner cell mass into endoderm and ectoderm in vitro. These requirements indicate that during post‐blastocyst development in vitro the mouse embryo gradually becomes dependent upon specific exogenous fixed nitrogen sources, including essential amino acids and a non‐dialyzable component from serum.
Hypertrophy of the rat urinary bladder following reduction of its functional volume
Authors: Peterson Christine M. , Goss Richard J. , Atryzek Vladimir
Published: June 2005

If the functional volume of the rat urinary bladder is reduced by injecting varying quantities of a 50:50 melted mixture of paraffin and vaseline, the capacity of the bladder increases so as to provide the extra space needed to accommodate for the storage of urine. By four weeks, such bladders were found to have hypertrophied roughly in proportion to the size of the bolus of paraffin‐vaseline they contained.
In vitro fertilizability of rabbit ova from donors isoimmunized with sperm
Authors: Russo Irma , Metz Charles B.
Published: June 2005

Ovulated ova in cumulus masses were obtained from rabbits following isoimmunization with rabbit sperm. They were inseminated in vitro with capacitated sperm, cultured and examined for cleavage and cumulus dispersion. In five experiments only 11 of the 81 (13.6%) ova from the immunized females cleaved compared to 15 out of 41 (36.5%) from the inseminated control females. The cumulus masses of ova from immunized donors dispersed more slowly than controls following insemination.
Yolk proteins in Drosophila: Identification and site of synthesis
Authors: Gelti‐Douka H. , Gingeras T. R. , Kambysellis M. P.
Published: June 2005

The yolk proteins from several Drosophila species were identified and partially purified. One or two predominant proteins were found in the crude extracts of mature oocytes and in the hemolymph of mature females. They were absent or present in trace amounts in male and young female hemolymph. Fat body from mature D. silvestris cultured in Grace's insect culture medium, synthesized and released several proteins, two of which were precipitable by antibodies against silvestris crude yolk extract. Fat body from immature flies synthesized and released only one of these proteins.
Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species
Authors: Bedford J. M. , Calvin H. I.
Published: June 2005

Treatment of immature and mature epididymal spermatozoa with SDS and DTT reveals differences in the structural character of their respective tail organelles as a function of their maturity, which are not apparent in untreated spermatozoa. The response of mature sperm tails of rat, rabbit and other mammals to these reagents indicates that the segmented connecting pieces, the coarse outer fibers, the outer membrane of the mitochondrion and the fibrous sheath of the principal piece, as well as the relationships between these organelles, are stabilized highly by intermolecular SS crosslinks. The disruption of these structures by SDS alone in caput epididymal spermatozoa, however, implies their stabilization by disulfide bonds during sperm passage through the epididymis. Hence the pattern of flagellar beat seen typically in mature epididymal or ejaculated spermatozoa is probably determined by post‐spermiation changes in the structural as well as in the metabolic properties of the tail organelles.

In similar studies of a wide variety of sub‐mammalian species, the sperm tails fell into two broad classes. The “simple” tail, a plasma membrane enclosing only mitochondria and microtubule doublets (teleosts, frog, chicken and pigeon), disappeared immediately in SDS, though a partial SS dependent stability was inducible in the microtubules of teleost sperm tails. In the second class, the coarse fibers, arrayed as a nine‐membered ring (octopus, snake, lizard, turtle and sparrow) or otherwise (skate, newt), and the fibrous sheath (snake, lizard) also are stabilized by SS bonds, as is the undulating membrane of the urodele sperm tail.

Since the sperm mitochondria in all sub‐mammalian species were totally disrupted by SDS alone, an extreme SS dependent stability of the outer mitochondrial membrane may well be a feature unique to mammalian spermatozoa.
Pituitary regulation of appetite and growth in the turtles Pseudomys scripta elegans and Chelydra serpentina
Authors: Brown Patricia Stocking , Giuliano Ralph , Hough Gerard
Published: June 2005

Eleven weeks of treatment with growth hormone (20 μg 3 times/wk) and prolactin (20 μg 3 times/wk) increased the size of immature Pseudomys scripta elegans beyond controls. Food consumption was controlled so that all effects of the hormones were direct ones on growth and not due to hyperphagia. Hypophysectomy decreased growth, food consumption and liver protein in Chelydra serpentina. Growth hormone replacement (20 μg/2 days) in hypophysectomized animals increased growth, food consumption, liver protein, liver water and decreased liver lipid and liver glycogen compared to hypophysectomized animals. In intact Chelydra serpentina, growth hormone (5 and 50 μg/2 days) also increased appetite, growth, liver protein, liver water and decreased liver lipid and glycogen. Blood sugar was not altered by growth hormone treatment.
The effects of light and sympathetic innervation to the head on nidation in mink
Authors: Murphy Bruce D. , James Derek A.
Published: June 2005

Ninety primaparae female mink were bred on two consecutive days between March 11–15. Six days after first mating mink were subjected to one of the nine treatments, control (n = 21); sham superior cervical ganglionectomy (Sham SCGX) (n = 5); bilateral orbital enucleation (n = 10); bilateral orbital enucleation and constant light (n = 16); constant light (n = 19); an accelerated photoperiod of 15L, 9D + 5 min of light per day (cumulative) (n = 10); an accelerated photoperiod and SCGX (n = 6); SCGX and environmental light (n = 5); bilateral orbital enucleation and SCGX (n = 5). The interval between first mating and calculated date of nidation [copulation to implantation (CI) interval] was compared among groups. CI interval was significantly abbreviated in accelerated photoperiod treated animals, and significantly lengthened by constant light; blindness regardless of light regime; and SCGX with accelerated photoperiod. Nonsignificant variation in the CI interval was observed in the blinded or environmental light treated SCGX animals that underwent implantation. Reproductive failure, defined as either absence of embryos in necropsied animals or failure to whelp by females alive on June 1, occurred less frequently in accelerated photoperiod animals and with considerably greater frequency in blind, SCGX, or constant light treated intact animals. Observations in blinded animals suggest that this treatment and presumably SCGX and constant light extend the period of embryonic diapause to the point of blastocyst degeneration resulting in reproductive failure. The occurrence of nidation in some blinded, and constant light animals indicates that this event can occur independent of either retinal receptor or photoperiod. The effects of SCGX suggest that the pineal body is either not involved in nidation or has a facilitatory rather than inhibitory role.
A somatic cell approach to the genetic analysis of the laboratory mouse
Authors: Kozak Christine , Nichols Elizabeth A. , Ruddle Frank H.
Published: June 2005

The determination of gene linkage in the laboratory mouse was approached through somatic cell techniques. Cells of an established line of Chinese hamster lung fibroblasts, E‐36, were fused with a population of mouse macrophages obtained from the AHe/J inbred strain. A total of 62 primary and secondary clones were isolated in HAT selective medium and characterized for the segregation of 12 murine enzyme markers by starch gel electrophoresis. While all other enzymes segregated nonrandomly, GPI was generally retained. Twelve subclones were isolated in medium containing 8‐azaguanine to determine whether this retention was due to a syntenic relationship between GPI and the enzymes of the salvage pathway of purine biosynthesis necessary for growth in HAT, but were found to express murine GPI. Of the other enzymes examined, MOD and MPI were determined to be syntenic and the others segregated independently of each other.
Temperature and prolactin as control factors in newt forelimb regeneration
Authors: Schauble Muriel K. , Nentwig M. Ruth
Published: June 2005

Temperature and prolactin were studied as control factors in the process of newt forelimb regeneration. Temperature was varied in five steps from 10° to 30°C under otherwise constant environmental conditions. Longitudinal new growth and limb differentiation were observed. Temperature was found to have a profound effect upon both developmental processes. Maximal longitudinal new growth resulting from changes in temperature alone occurred at 25°C with maximal limb differentiation at 30°C. At each temperature studied, prolactin enhanced both new growth and limb differentiation. With prolactin, maximum new growth also occurred at 25°C, but maximum limb differentiation occurred at 20°C. For our purposes optimum limb development was defined as the greatest new growth commensurate with full normal development. This optimum was reached by prolactin treated animals at 20°C when the regenerating limbs studied achieved 100% maximum normal differentiation and 87% maximum new growth. It was possible by employing a combination of temperature changes and hormone administration to control newt forelimb regeneration and produce a whole spectrum of limb development.
Partial purification of the crowding factor from Carassius auratus and Cyprinus carpio
Authors: Pfuderer Peter , Williams Penney , Francis A. A.
Published: June 2005

Crowding factors are those substances released by fish, which, under crowded conditions, inhibit both their growth and reproduction and depress their heart rate. We have partially purified the crowding factor from goldfish and carp by following a heart‐rate‐depression assay. The heart‐rate‐depression activity eluted with the diglyceride fraction from both silicic acid and Sephedex LH‐20. A slightly different activity eluted with the free sterols. The peak activity associated with the diglycerides has a distinctive ultraviolet spectrum distinguishable from that of phthalic acid esters, which are also active in the assay sytem and are found in fish tissues and fish water.
Inhibitory effect of dibutyryl cAMP on mouse oocyte maturation in vitro
Authors: Cho Wan Kyoo , Stern Samuel , Biggers John D.
Published: June 2005

The effects of dibutyryl cyclic AMP on the maturation of the mouse oocyte in vitro were studied. It was found that concentrations of 100 μg/ml or greater prevented germinal vesicle breakdown in more than 95% of the treated oocytes. The inhibition of maturation was found to be a reversible phenomenon. When oocytes were exposed to the drug after the completion of germinal vesicle breakdown, no effect of the drug was noted. Thus, dibutyryl cyclic AMP appears to effect only the initial stages of meiotic maturation in the mouse oocyte.

Theophylline was also found to inhibit maturation, suggesting that increased levels of cyclic AMP in the oocyte may be the causative agent of the inhibition of maturation.
Caudal neurosecretory system: Possible role in pheromone production
Authors: Richards I. S.
Published: June 2005

Isolated brown bullhead catfish, Ictalurus nebulosus, were conditioned to discriminate between water samples from aquaria containing solitary conspecifics. Urine and extracts of urophyses, thoracic spinal cord, integument, gill and urinary bladder were then assayed to determine if they were active in effecting this discrimination. Urine and urophyseal extracts were consistently most active as sources of chemical information.
Analysis of chemotaxis in the nematode Caenorhabditis elegans by countercurrent separation
Authors: Dusenbery David B.
Published: June 2005

C. elegans responds to several common chemicals. Comparisons of pairs of ions at equivalent concentrations indicated orders of attractiveness of:

The least attractive pair of ions, calcium acetate, is attractive, indicating all these ions are attractive. The most attractive pair, sodium chloride, was attractive from a threshold of 0.1 mM to at least 50 mM. The response to NaCl was maximal throughout the temperature range 15 to 25°C and the pH range 3.0 to 9.0. Acid was avoided and base was attractive from concentrations of 0.1 to 1 mM. Dissolved CO2 in the concentration range 0.1 to 1 mM was attractive in 10 mM sodium borate buffer, pH 8.8, but avoided in 25 mM potassium phosphate, pH 6.0. All these responses are likely to affect the distribution of C. elegans in nature and they also provide a tool for promising studies in neurogenetics.
The quantities of venom injected into prey of different size by Vipera palaestinae in a single bite
Authors: Allon Nahum , Kochva Elazar
Published: June 2005

The quantity of venom injected by a snake is one of the most important factors determining the danger of the bite. The present study tests whether the amount injected is in correlation with the size of the prey.

Seven specimens of Vipera palaestinae injected with 14C‐amino acids in order to label the venom, were offered three pairs of one mouse and one rat each. The amounts of venom injected into either prey were variable, ranging from zero to more than 200 mg. In most cases 50 mg were injected, approximately 8% of the total venom available in the glands. In three snakes the average amount injected into rats was two to three times higher than that injected into mice; in two snakes the mice received three to ten times more than the rats, while in two snakes there was no difference between the amounts injected into either prey.

It is concluded that the size of the prey does not necessarily influence the amount of venom injected by the snake.
Supernumerary limb induction in the anura
Authors: Balinsky B. I.
Published: June 2005

Induction of supernumerary limbs in Bufo tadpoles was achieved by transplanting the transverse neural fold with adjoining tissue from neurulae into tail bud stage embryos. The graft differentiated into brain, eyes, noses and mouthparts. Induced limb rudiments were associated with either noses or mouthparts. The author rejects the suggestion made by Perri that the induction is due to release of products of cytolysis from the graft and suggests that limb induction is due to a disorganization or reduction of the subepidermal basement membrane (layer of collagen fibres) by certain grafts, and that as a result the potentially limb forming flank mesenchyme is allowed to interact with the epidermis — a precondition for limb development. In support of this view the author presents electronmicrographs in which it is shown that at the edge of the nostril, and on the mouthparts (lips, oral papillae), the basal membrane is attenuated and disorganised, allowing processes of mesenchyme cells to penetrate through the layer of collagen fibres and reach the inner surface of the epidermis.
Capacitation of boar spermatozoa: Synergism between uterine and tubal environments
Authors: Hunter R. H. F. , Hall J. P.
Published: June 2005

The influence of the site of semen deposition on the rate of sperm capacitation was studied in 36 oestrous gilts in which ovulation had been induced at a precise time. Aliquots of semen were instilled into the proximal uterine horn on one side of the tract and into the isthmus of the contralateral Fallopian tube in 24 animals. Eggs were recovered in vivo, and examined by phase‐contrast microscopy for the number of spermatozoa associated with the zona pellucida and the stage of fertilization.

A total of 420 eggs was examined. The mean number of spermatozoa per egg increased from 3.3 at four hours after uterine insemination to 27.9 at six hours, compared with 0.6 to 6.3 at corresponding intervals after tubal insemination (p<0.05). The mean proportion of fertilized eggs increased from 54.3% at four hours to 95.9% at six hours after uterine insemination, compared with 0.0 to 51.0% at these intervals after tubal insemination (p<0.001). The temporal advantage accruing from uterine insemination was also seen in the developmental stages of the penetrated eggs. In a further six animals in which seminal plasma was introduced into the isthmus at the time of uterine insemination, fertilization was retarded by approximately two hours, although when a similar volume of physiological medium was introduced into the isthmus as a control, no such delay was observed.

The advantage of uterine over tubal insemination was attributed to a synergistic effect of the uterus and Fallopian tubes on those spermatozoa that penetrated the eggs. The nature of the membrane‐related changes in the spermatozoon initiated during passage through the uterus and utero‐tubal junction that facilitate rapid capacitation remains unknown, but is thought to involve modification or removal of seminal plasma constituents from the sperm surface. It was inferred that seminal plasma does not enter the Fallopian tubes of oestrous pigs in significant amounts after mating.
Comparative studies of hemoglobins from the clouded tiger salamander before and after metamorphosis
Authors: Woody A‐Young , Justus J. T.
Published: June 2005

Some comparative biochemical studies on the hemoglobin from the clouded tiger salamander, Ambystoma tigrinum nebulosum, before and after metamorphosis indicate (1) there is no hemoglobin change with metamorphosis; (2) both hemoglobins show three major fractions (Fractions I, II, III) in ion exchange chromatography and two bands in gel electrophoresis; (3) these fractions possess identical chemical properties except for their electrophoretic mobilities, and peptide maps; (4) Under our experimental conditions, Fraction II can be formed by the appropriate recombination of subunits present in equilibrium with Fractions I and II.
Biosynthesis of lipovitellin by the crustacean ovary
Authors: Lui Chung W. , Sage Becky A. , O'Connor John D.
Published: June 2005

The in vitro incorporation of 3H‐amino acids into purified lipovitellin by cultured crustacean ovaries can be demonstrated using either density gradient centrifugation or preparative electrophoresis as a final purification step. In addition 3H‐glycerol is incorporated into the phosphatidyl choline moiety of the lipovitellin. This evidence strongly suggests that the ovary is capable of synthesizing both the lipid and the protein components of the lipovitellin and therefore may not incorporate such moieties intact from the circulating hemolymph.