bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct detection of two cross‐reactive antigens between porcine and rabbit zonae pellucidae by radioimmunoassay and immunoelectrophoresis
Authors: Wood David M. , Dunbar Bonnie S.
Published: June 2005

Zonae pellucidae were isolated from oocytes obtained from rabbit and porcine ovaries. Antisera were prepared in rabbits against heat‐solubilized porcine zonae and in guinea pigs against intact and heat‐solubilized rabbit zonae and against purified rabbit zona proteins isolated from two‐dimensional electro‐phoresis gels. These antisera were used in radioimmunoassay studies to show cross‐reactivity between porcine and rabbit zona antigens. Immunoelectrophoresis studies also demonstrated the immunochemical cross‐reactivity between two distinct antigens of rabbit and porcine zonae. These two rabbit zona antigens were demonstrated to be immunochemically identical to porcine zona antigens by crossed‐line immunoelectrophoresis.
Specificity of H‐2 antigens expressed on mouse blastocysts
Authors: Cozad Karen M. , Warner Carol M.
Published: June 2005

A highly sensitive cytotoxicity assay was used to detect H‐2 antigens on mouse blastocyst stage embryos of the b, a, k, and d haplotypes. The assay was based on the principle that live embryos incorporate 3H‐thymidine into DNA whereas embryos killed with antiserum and complement do not. The use of specific alloantisera showed that blastocysts of different haplotypes express different H‐2 antigens. Thus, positive evidence was obtained for the expression of Kd and Dk molecules and negative evidence for the expression of Db, Kk, and Dd molecules. Evidence was also obtained that blatocysts express different H‐2 antigens than those found on adult lymphocytes. Unexpected cross‐reactions were found when some of the alloantisera were tested on blastocysts of different haplotypes. It is proposed that the aberrant expression of H‐2 antigens on embryos might facilitate their escape from surveillance by the maternal immune system.
Studies on the female sterile mutant Rudimentary of Drosophila melanogaster. IV. The activities of de novo and salvage pathway enzymes for pyrimidine biosynthesis during oogenesis, embryonic and postembryonic development of wild‐type flies
Authors: Fausto‐Sterling Anne
Published: June 2005

In order to gain a better understanding of how a defect in pyrimidine biosynthesis leads to the specific set of morphological aberrations seen in Drosophila bearing the mutant allele of rudimentary, we made the following measurements of enzyme activity in wild type flies: (1) during ovarian development – the first three enzymes of the de novo pathway for pyrimidine biosynthesis (aspartate transcarbamylase, dihydroorotase, and carbamyl phosphate synthetase) and two enzymes in the salvage pathway for pyrimidine biosynthesis – uridine kinase and uridine phosphorylase; (2) during embryonic development – uridine kinase and uridine phosphorylase in embryos taken at hourly intervals; and (3) during postembryonic development – uridine kinase and uridine phosphorylase.

Our results suggest: (1) that the de novo pyrimidine enzymes are synthesized during the early stages of oogenesis, while the pattern for the salvage pathway enzymes is somewhat different; (2) that a lowering of uridine kinase activity at 13 hours of embryonic development may be responsible for bringing on the developmental crisis in r embryos; and (3) that the postembryonic pattern of activity for salvage pathway enzymes, with one exception, is quite similar to that for the de novo pathway enzymes.
Induction of malformed zooids and determination of polarity in palleal buds of the polystyelid ascidian, Polyandrocarpa misakiensis
Authors: Oda Takaharu , Watanabe Hiroshi
Published: June 2005

The development of malformations was studied in palleal buds of the polystyelid ascidian, Polyandrocarpa misakiensis. Various malformations were induced by transection of protruding buds. Three types could be distinguished: zooids with reversed bilateral asymmetry, zooids with double malformations, and zooids with three apertures. During the early developmental stages of transected proximal pieces, when depigmentation occurred in the distal area, the pieces produced zooids with reversed bilateral asymmetry. When depigmentation occurred in the distal and proximal areas, the pieces induced either zooids with double malformations or zooids with three apertures. In the former, the two depigmented areas were about the same size, whereas in the latter the two areas were very different in size. The individuals occurring from the depigmented proximal area had the same polarity as the parent. Individuals derived from the depigmented distal area displayed either reversal of the left‐right (L‐R) axis (reversed laterality) or reversal of the L‐R and anteroposterior (A‐P) axes (normal laterality). The malformed zooid with reversed L‐R axis produced buds with reversed laterality. We examined the frequency of induction of these malformed zooids in relation to the following four points: 1) the position of the parent body at which buds are produced, 2) the different developmental stages of blastogenesis, 3) the different levels along the maximum protruding bud, and 4) the different transecting times of the maximum protruding bud. The results are discussed in relation to the mechanism of the expression of polarity in the normal development of the palleal bud.
Fertile life of acrosome‐reacted guinea pig spermatozoa
Authors: Fleming Alan D. , Yanagimachi Ryuzo
Published: June 2005

To study the fertile life of acrosome‐reacted guinea pig spermatozoa, spermatozoa were induced to undergo a synchronous acrosome reaction after which vigorously motile acrosome‐reacted spermatozoa were isolated from acrosome‐intact ones. Acrosome‐reacted spermatozoa thus prepared were incubated in vitro for various periods of time before they were mixed with zona‐intact and zona‐free eggs. Such spermatozoa retained their ability to fertilize zona‐intact eggs for at least 2 hours after the acrosome reaction; thereafter they rapidly lost this ability. There was a close correlation between the decline and loss of the ability to penetrate the zona and the loss of hyperactivated motility by spermatozoa, indicating the importance of vigorous motility in passing through the zona. The ability of acrosome‐reacted spermatozoa to fertilize zona‐free eggs was maintained for many hours even after the spermatozoa had completely lost their capacity to fertilize zona‐intact eggs. As long as acrosome‐reacted spermatozoa are “alive,” they seem to retain the capacity to fuse with the egg plasma membrane regardless of the quality of their motility.
rRNA accumulation and protein synthetic patterns in growing mouse oocytes
Authors: Kaplan Gail , Abreu Sergio L. , Bachvarova Rosemary
Published: June 2005

The rRNA contents of mouse primordial oocytes, three stages of growing oocytes, full‐grown oocytes, and ovulated ova have been measured by hybridization of RNA samples to excess 3H‐DNA complementary to rRNA. Since it was known from previous work that rRNA is stable, the results when plotted against days of oocyte growth indicated that rRNA was synthesized at a constant rate over the first 9 days of growth and about 1.5 times faster in the last 5 days. The maximum value of 0.3 ng per oocyte was attained by about 14 days of growth in oocytes 59 μm in diameter, well below the maximum diameter of 77 μm for full‐grown oocytes.

The stability of proteins synthesized in mid‐growth phase oocytes was measured by labeling for 5 h with 35S‐methionine and then following the decline of incorporated label during a 48h chase; 40% of the label decayed with a half‐life of 11 h, and 60% was apparently stable. The two‐dimensional electrophoretic patterns of labeled proteins synthesized by growing and full‐grown oocytes were compared. The principal change was the appearance or great increase in intensity of several spots in full‐grown oocytes as compared to growing oocytes. Egg proteins separated on a two‐dimensional gel were visualized by silver staining. The cytoskeletal proteins actin, tubulin, and putative intermediate filament protein, as well as putative lactate dehydrogenase, were synthesized in growing and full‐grown oocytes, and accumulated to form a significant portion of bulk egg protein.
Hyperosmoticity of the mantle fluid in the freshwater bivalve, Anodonta woodiana
Authors: Matsushima Osamu , Kado Yoichi
Published: June 2005

Osmotic and ionic (Na, K, and Cl) concentrations in the mantle fluid, pericardial fluid, and blood of Anodonta woodiana were determined. The mantle fluid was extremely hyperosmotic (34 mOsm) to the external medium and the sum of Na and Cl accounted for 62% of the osmotic concentration. The osmotic and ionic concentrations in the blood were significantly higher than those in the mantle fluid. The mantle fluid seems to have a balancing effect in the osmotic relationship between the blood and the external medium.
Regulation of glyceraldehyde‐3‐phosphate dehydrogenase: Inheritance and biochemistry of a low‐activity genetic variant in the platyfish, Xiphophorus maculatus
Authors: Morizot Donald C. , Wright David A. , Siciliano Michael J.
Published: June 2005

Analysis of an electrophoretic variant coded by the glyceraldehyde‐3‐phosphate dehydrogenase‐2 (GAPD2) locus of the playtfish (Xiphophorus maculatus) revealed that the variant allele produced a defective subunit. As a homotetramer (from tissue extracts of homozygotes), the variant enzyme had only 12% the activity of homotetramers specified by the normal allele. In heterozygotes the defective subunits aggregated with the normal subunits to produce hybrid tetramers in the amounts expected for equal production of the two subunits by the two alleles but with the activity reduction expected according to the subunit composition. The total activities of muscle extracts in heterozygotes were reduced to about 55% of normal, consistent with that expected if neither compensatory synthesis of allelic products of the GAPD2 locus nor the GAPDl locus took place. This result implies that regulation of the production of this enzyme is constitutive (produced at maximal rate) or depends on a mechanism which does not recognize the functional activity of the gene products. The absence of detectable segregation distortion suggests that the variant has no significant effect on viability, and thus may be selectively neutral, though producing in several tissues an activity deficiency of 88% in homozygotes.
Horseshoe crab phylogeny based on amino acid sequences of the fibrino‐peptide‐like peptide C
Authors: Shishikura Fumio , Nakamura Shin , Takahashi Kenji , Sekiguchi Koichi
Published: June 2005

Phylogenetic relationships of recent horseshoe crabs including two subfamilies, i.e., Limulinae (Limulus polyphemus), and Tachypleinae (Tachypleus tridentatus, Tachypleus gigas, and Carcinoscorpius rotundicauda), were investigated by amino acid sequence analysis of the 28 amino acid peptide C released from each coagulogen during gel formation. Our results support the phylogenetic separation of the two subfamilies, whereas the relations among Tachypleinae do not match the accepted generic classification. Thus, T. tridentatus appears to be more closely related to C. rotundicauda than it is to T. gigas. Divergence times among Tachypleinae are estimated to be 106 million years ago between T. gigas and two other species'and 53 million years ago between T. tridentatus and C. rotundicauda.
Biosynthesis of the sesquiterpenoid skeleton of juvenile hormone 3 by Dysdercus fasciatus corpora allata in vitro
Authors: Feldlaufer Mark F. , Bowers William S. , Soderlund David M. , Evans Philip H.
Published: June 2005

In an effort to determine the nature of the juvenile hormone of a hemipteran insect, we have analyzed the in vitro biosynthetic products of cultured corpora aleata using thin layer chromatography and normal and reverse phase high performance liquid chromatography. We now report that the corpora aleata of Dysdercus fasciatus (Hemiptera: Pyrrochoridae) synthesize in vitro methyl 3,7,11‐trimethyl‐2E, 6E, 10‐dodecatrienoate, the methyl ester precursor of juvenile hormone 3.
Uptake of ferritin by the mosaic egg surface of Brachydanio
Authors: Donovan Michael , Hart Nathan H.
Published: June 2005

The internalization of membrane from the mosaic egg surface of the zebra fish, Brachydanio, was investigated using anionic ferritin and transmission electron microscopy.

The cortical cytoplasm of the 5‐min activated egg showed numerous membrane‐bound vesicles not found in the unactivated egg cortex. Two types of vesicles were identified: uncoated (smooth) and coated. Coated vesicles measured about 0.7 to 0.9 μm in diameter. Coated pits, considered to be precursors to the formation of coated vesicles, were frequently observed at the base of membrane‐lined cortical granule crypts. Anionic ferritin was localized over coated pits and in both smooth and coated vesicles. The absence of any morphological evidence of a surface origin for smooth vesicles suggested these ferritin‐labeled organelles might be formed by coated vesicle fusion.

Our results indicate that the plasma membrane redundancy created by the exocytosis of cortical granules in Brachydanio appears to be resolved in part by the internalization of membrane through endocytosis.
The use of chlorotetracycline to localize calcium in neural crest cells
Authors: Moran Denis
Published: June 2005

Cultured amphibian neural crest cells in the early phases of migration (1–2 days) extend broad, clear cytoplasmic processes known as lobopodia. These regions exhibit rapid changes in the contraction‐relaxation cycle and in substratum adhesion. Because of the putative role of Ca2+ in both cytoskeletal function and cell attachment, its distribution in these cells was studied. Chlorotetracycline (CTC), the Ca2+‐chelating fluorescent probe, was used to investigate whether there is a temporal and spatial localization of Ca2+ in cell regions concerned with movement and attachment. Differentiated neural crest cells (7 days), which contain an abundance of actin stress fibers, were also studied to determine whether these cytoskeletal elements were associated with Ca2+. The results with CTC indicate that in early migratory cells regions of membrane extension and protrusion contain higher levels of Ca2+ and that the actin stress fiber system of differentiating neural crest cells (7 days) is associated with Ca2 +. It was determined that using the CTC in the fixative produced the same labeling profile as when live cells were labeled with the CTC. Use of CTC in the fixative is a decided advantage over treatment of cells with CTC while alive since it avoids the photooxidative damage which normally accompanies fluorescent observations of CTC on living cells.
Immunocytochemical localization of acrosin in boar spermatozoa
Authors: Castellani‐Ceresa Lucia , Berruti Giovanna , Colombo Roberto
Published: June 2005

Acrosin was localized on the acrosomal membranes of boar sperm by immunofluorescence and immunoelectron microscopy. Indirect labeling of sperm head sections was performed with an Imposil (iron‐dextran) antibody conjugate. The results of electron microscopy indicated a preferential deposition of the antiacrosin antibodies on the outer acrosomal membrane, although a lesser deposition was also found on the inner acrosomal membrane. No labeling was detected in the acrosomal content when such material was still present.
Studies on mouse germ cells inside and outside the gonad
Authors: McLaren Anne
Published: June 2005

Soon after entering the genital ridge, mouse primordial germ cells take either a male or a female pathway of development. Which direction they follow, and how successful their subsequent gametogenesis turns out to be, depends on various factors, including their own genotype and the phenotype of the gonad they inhabit. Experimental situations that have helped to throw light on this problem include XX⟷XY chimeras, XO females, and mice carrying the sex‐reversed gene (Sxr). Further information can be obtained by studying germ cells that fail to enter the genital ridge, as well as culturing isolated germ cells.
A Diffusional route of transport of horseradish peroxidase through the midgut of a fleshfly
Authors: Fishman Lena , Zlotkin Eliahu
Published: June 2005

Horseradish peroxidase (HRP) was orally introduced to Sarcophaga falculata flies (0.03–0.3 mg per insect), and its morphological route of transport across the midgut was followed with the aid of light and electron microscopy. During a period of about 30 min HRP was shown to penetrate the peritrophic membrane, to enter the epithelial gut cells through the microvilli, and to spread progressively throughout its cytoplasm and finally across the entire gut wall via the inner plasma membrane, basal membrane, and the outer envelope of muscles. The progressive movement of HRP in the present system was diffusional and continuous, and it did not reveal any cytological characteristics of the well‐known pinocytotic uptake and vesicular transport typical for HRP and other macromolecules in digestive and other biological systems.
Human pancreatic growth hormone‐releasing factor (hpGRF) stimulates growth hormone release in goldfish
Authors: Peter Richard E. , Nahorniak Carol S. , Vale Wylie W. , Rivier Jean E.
Published: June 2005

Synthetic human pancreatic growth hormone‐releasing factor (hpGRF) was injected intraperitoneally in different dosages, either as one injection or two injections 3 hours apart, into goldfish. Serum GH levels were increased by certain dosages of hpGRF under both treatments. This is the first demonstration of GH‐releasing activity of hpGRF in a teleost fish.
Trophectoderm cell subpopulations in the periimplantation mouse blastocyst
Authors: Chávez Daniel J. , Enders Allen C. , Schlafke Sandra
Published: June 2005

Trophectoderm of the preimplantation mouse blastocyst is composed of two cell subpopulations relative to their proximity to the inner cell mass. The polar trophectoderm overlying the inner cell mass proliferates to form the ectoplacental cone, and the mural trophectoderm endoreplicates and gives rise to giant cells. We examined specific differences in the two trophectoderm cell populations using a lectin (Dolichos biflorus) to detect cell surface characteristics and a simple sugar (D‐Gal) to detect differences in incorporation. During the first day of delayed implantation, the mural trophectoderm presented twice as many lectin binding sites as did the polar trophectoderm. The mural trophectoderm of both nondelaying and delayed implantation blastocysts showed a greater rate of incorporation of the tritiated sugar by presenting more reduced silver grains in radioautograms. These results indicate that the mural trophectoderm and polar trophectoderm are two distinct cell types in the periimplantation blastocyst.
Cell cycle timing in colchicine‐treated sea urchin eggs: Persistent coordination between the nuclear cycles and the rhythm of cortical stiffness
Authors: Yoneda Mitsuki , Schroeder Thomas E.
Published: June 2005

Cyclic changes in cortical stiffness, condensation‐decondensation of chromosomes, and breakdown‐reformation of the nuclear envelope were found to continue in eggs of Dendraster excentricus treated with colchicine even though mitosis and cleavage were suppressed. Furthermore, a consistent and precise synchronization persisted between these cyclic phenomena; each rise and fall of cortical stiffness coincided with the breakdown and reformation, respectively, of the nuclear envelope. The overall cycle length was prolonged relative to controls because of an extended intermitotic phase, indicating that assembled mitotic microtubules do not influence cell cycle timing in this species. In colchicine‐treated eggs of Strongylocentrotus purpuratus, however, the cortex and the nucleus became arrested in conditions equivalent to metaphase, as if the mitotic phase was indefinitely prolonged. The cortex was stabilized in a state of high stiffness, the chromosomes remained condensed, and the nuclear envelopes remained broken down. In this species, even in the absence of rhythmic change, a strict correlation between the cortical status and the nuclear condition was still consistently observed. The persistence of coordination, in spite of diverse species‐specific responses to colchicine, suggests the existence of a common control mechanism between the cytoplasm and nucleus in normal eggs that is important in cell cycle timing. The insensitivity to colchicine indicates that the mechanism of coordination is independent of microtubules.
Application of recombinant DNA technologies to studies on chicken growth hormone
Authors: Souza Lawrence M. , Boone Thomas C. , Murdock Doug , Langley Keith , Wypych Jette , Fenton Dennis , Johnson Steven , Lai Por H. , Everett Richard , Hsu Rou‐Yin , Bosselman Robert
Published: June 2005

Messenger RNA isolated from chicken pituitaries was used to construct a chicken pituitary cDNA library. A chicken growth hormone cDNA clone was isolated using 32P‐labeled mammalian growth hormone cDNA probes. The amino acid sequence (derived from the DNA sequence) of the mature form of chicken growth hormone shows 77% homology with that of bovine growth hormone. The chicken growth hormone cDNA clone was used to generate a vector capable of producing chicken growth hormone in Escherichia coli. The recombinant E. coli‐derived chicken growth hormone was similar to pituitary chicken growth hormone in several biochemical and immunological properties. The recombinant‐derived hormone has been used to establish a sensitive radioimmunoassay for growth hormone determinations made from chicken sera. The chicken growth hormone gene has also been introduced into a retroviral vector capable of establishing productive infections of chicken cells both in in vitro and in vivo. The resulting infections are accompanied by the production of radioimmunoassay‐detecable growth hormone. The concentrations of growth hormone in sera of Leghorn chickens infected with the recombinant retrovirus are three‐ to tenfold higher than in control animals.
Chondrogenesis and skeletal morphogenesis occur despite intervening adipocytes in regenerating newt limbs
Authors: Aulthouse Amy Lynn , Neufeld Daniel A.
Published: June 2005

The interface between bone and blastemal tissues of regenerating newt limbs was examined to determine the nature of “tissue spaces” described earlier. Regenerating limbs were prepared either by aldehyde fixation/osmium postfixation and plastic embedding or by Bouin's fixation and paraffin embedding. The osmium‐stained tissues revealed that the interruptions are predominately adipocytes. They are adjacent to the marrow cavity and apparently originate from it. The adipocytes frequently are present in the midst of aggregating prechondrogenic cells and mature chondrocytes. Paraffin embedded tissues revealed that adipocytes distal to bone may be present at all stages of skeletogenesis. Adipocytes apparently do not hinder prechondrogenic aggregation, chondrogenesis or skeletal pattern formation.
Light flashes of different durations (0.063–3.33 msec) phase shift the circadian flight activity of a bat
Authors: Joshi D. , Chandrashekaran M. K.
Published: June 2005

The phase‐response curve (PRC) for the circadian rhythm in the flight activity of a cave‐dwelling bat, Hipposideros speoris, constructed with 0.063‐msec light flashes, reported here is the first of its kind for any circadian system and is unlike any other phase‐response curves constructed for other nocturnal animals. The phase responding with maximal advances (90°) and the phase responding with maximal delays (0°) of this PRC were exposed to light flashes of systematically varying durations from 0.083 to 3.33‐msec. For 0° phase, the flashes of 0.063‐3.33 msec effected delay phase shifts of comparable magnitude. For 90° phase, the flashes of 0.063‐1.0 msec effected advance phase shifts, whereas 3.33‐msec flashes effected unmistakable delay phase shifts with advancing transients. Phase shifts evoked with such light flashes are further compared with phase shifts evoked with pulses of longer durations (15 min to 2.8 hr) for H. speoris.
Production of pyruvate by isolated mouse cumulus cells
Authors: Leese Henry J. , Barton Alison M.
Published: June 2005

Cumulus cells were isolated by hyaluronidase treatment of whole cumulus masses from superovulated, non‐mated mice. The cells, in groups of approximately 200, were incubated for up to 4 h in 50 nl medium M2 at 37°C, and serial 3‐nl samples assayed for pyruvate using an ultramicrofluorescence technique. With 5.55 mM glucose, 23.3 mM lactate, or a mixture of the two substrates, the cumulus cells formed pyruvate at rates of 10.2, 9.6, and 8.9 fmol/cell/h, respectively. The concentrations of glucose, pyruvate, and lactate, as measured in 3‐nl aliquots of rabbit oviduct fluid were 1.5 mM, 0.3 mM, and 3.7 mM, respectively. When incubated with 1 mM glucose and 3 mM lactate, mouse cumulus cells formed 7.5 fmol pyruvate/cell/h. The mean number of cumulus cells per ovum within a cumulus mass was 2,060. Intact cumulus masses from mated and non‐mated superovulated mice, incubated with 1 mM glucose and 3 mM lactate, formed 22.6 and 23.3 pmol pyruvate/ovum/h, respectively. The results suggest that pyruvate production by cumulus cells may be important in supporting the nutrition of unfertilized and fertilized ova, and of spermatozoa, within the oviduct lumen.
Somatic and germ cell chimerism in chimeric mice between strains of high litter size and regular litter size
Authors: Watanabe Tomomasa
Published: June 2005

CFO is an inbred strain of mice showing a high litter size. The high fertility of CFO is due mainly to a very low embryonic death rate during uterine development. C57BL and 129 strains are characterized by regular litter size. Crosses were made and CFO ↔ C57BL and CFO ↔ 129 chimeras were produced. In CFO ↔ C57BL mice, coat color of the C57BL predominated over that of CFO; internal chimerism except for that of the gonads was observed to be in the same proportion as the two genotypes, but the genotypic component of the gonads was almost entirely CFO. Germ cells undergoing gametogenesis in the CFO ↔ C57BL mice were almost all derived from the CFO genotype, and the chimeric females showed high fertility just as did the CFO females. In the CFO ↔ 129 mice no obvious skewing toward one genotype was observed in the coat color, but the germ cells undergoing oogenesis in the two types of chimeric females were recognizable as nearly all of the 129 genotype but with the females showing the same high fertility as do the CFO females. This fact suggests that the genotypes of germ cells in the ovary or in developing embryos do not influence fertility, but rather that the litter size is controlled mainly by the uterine environment.
Proportioning and regeneration in fissioned and unfissioned individuals of the planarian Dugesia tigrina
Authors: Mead Robert W.
Published: June 2005

Regeneration was examined in fissioned and unfissioned planarians (Dugesia tigrina) in terms of regenerative success and body proportioning. Regenerative success was determined in terms of percent of abnormal regenerates and number of abnormalities per abnormal regenerate. Sections from unfissioned animals were less successful at regeneration than were those from fissioned animals, and body regions located immediately behind the pharynx represented those segments which formed fewer abnormal regenerates as a result of fissioning. Body proportioning was measured as a function of size of head and prepharygeal region to overall body length. A direct correlation was seen in the proportional size of these two parameters, which varied significantly among regenerates. Results suggest that body proportioning is not constant from one excised piece to another but is predictable and dependent on several variables including interval between fission and sectioning, region from which the segment was obtained, and/or original length of the segment.
Pyruvate dehydrogenase complex from ribbed mussel gill mitochondria
Authors: Paynter Kennedy T. , Karam George A. , Ellis Lehman L. , Bishop Stephen H.
Published: June 2005

The pyruvate dehydrogenase complex has been demonstrated in high speed pellet preparations from sonicated ribbed mussel gill mitochondria. The activity of the complex is inhibited by low chloride (< 100 mM) concentrations, EDTA (1 mM), succinate, ATP, and NAD/NADH ratios below 4. Inhibition by EDTA is relieved by addition of 10 mM MgCl2‐1 mM CaCl2. ATP inhibition was enhanced by NaF and reversed by high Mg+ + concentrations in the absence of NaF. Pyruvate and thiamine pyrophosphate inhibited the inactivation by ATP. The nonhydrolyzable ATP analog AMP‐PNP caused inhibition of the overall catalytic activity that was identical to ATP. Factors involved in the ATP inhibition and Mg+ + reversal are lost with freezing or cold storage. Preliminary results using γ‐32P‐ATP indicate that a protein kinase that phosphorylates the α subunit of E1 (pyruvate dehydrogenase) from the mammalian PDC is associated with the gill PDC. The activity of the complex may be regulated by a phosphorylation/dephosphorylation mechanism and by the relative levels of substrates, products, and other metabolites in the mitochondria.
Individual variation in maximum aerobic capacity: Cardiovascular and enzymatic correlates in Rana catesbeiana
Authors: Walsberg Glenn E. , Lea Malcolm S. , Hillman Stanley S.
Published: June 2005

We quantified natural variation in maximum aerobic capacity (V̊02max) exhibited by a free‐living by a free‐living population of bullfrogs (Rana catesbeiana) and examined the degree to which such variation is associated with key parameters of the systemic oxygen transport apparatus and oxidative enzyme (citrate synthase) activity at the tissue level. Regression analysis of these data revealed that only ventricle mass and hemoglobin concentration accounted for significant fractions of the variation in V̊02max. Neither variation in maximum heart rate nor in citrate synthase activity were significantly correlated with individual variation in maximum aerobic capacity. These results support the contention that, in at least some taxa, maximum aerobic capacity is limited by the ability of the cardiovascular system to deliver oxygen to the tissues.
Biomineralization in the presence of calcium‐binding phosphoprotein particles
Authors: Marsh M. E.
Published: June 2005

The innermost shell lamella, which coats the inner surface of the shells in the estuarine clam Rangia cuneata, is a dynamic structure with a variable composition. In some populations the lamella is a phosphoprotein‐rich structure devoid of crystalline mineral, and in others it is a glucosamine‐rich structure often containing barite (BaSO4) inclusions. Mineral depositions was artificially stimulated in Rangia containing glucosamine‐rich lamellae by scratching the inner shell surface. After stimulation, the lamellae were transformed into phosphoprotein‐rich structures in which aragonite (CaCO3) was deposited. The mineral grew in spherulitic and dumbbell‐shaped clusters characteristic of aragonite precipitated from strictly inorganic solutions. This study demonstrates that phosphoprotein particles accumulate in the innermost shell lamella during stimulated biomineralization but neither inhibit mineral deposition nor influence the crystal habits. Since phosphoprotein particles are high capacity calcium‐binding proteins, they may be the source and transport vehicle for the calcium ions utilized in shell mineralization.
Lectin binding to newt epidermis: Fluorescent localization and effects on motility
Authors: Mahan James T. , Donaldson Donald J.
Published: June 2005

The ability of seven lectins to bind to newt epidermal cells and influence their motility was examined. Of the seven fluoresceinated lectins applied to frozen sections containing intact newt skin and migrating epidermis (wound epithelium), only Con A (concanavalin A), WGA (wheat germ agglutinin), and PNA (peanut agglutinin) produced detectable epidermal fluorescence. Con A and WGA each heavily labeled all layers of intact epidermis, but PNA bound only to the more superficial layers. In contrast to a single population of labeled cells in migrating epidermal sheets after treatment with Con A, there were both labeled and unlabeled cells after exposure to either WGA or PNA. The wound bed was labeled by both Con A and WGA, but not by PNA. DBA (Dolichos bifloris agglutinin), RCA I (Ricinus communis agglutinin), and UEA (Ulex europaeus agglutinin), did not produce significant fluorescence with either migrating or intact epidermis. In general, inhibitory effects on epidermal motility correlated with the binding studies. Thus, Con A, WGA, and PNA, the lectins which clearly bound to the epidermis, all produced a concentration‐dependent depression in the rate of epidermal wound closure. RCA was somewhat paradoxical in that it was moderately inhibitory despite showing essentially no binding. The effects of SBA and UEA were equivocal. DBA had no effect. These results indicate that the inhibition of motility produced by Con A that we have described previously is not peculiar to this mannose‐binding lectin, but is shared by at least one lectin with an affinity for D‐GlcNAc (WGA), and one with an affinity for B‐D‐Gal(1‐3)‐D‐GalNAc (PNA). The fact that PNA labeled some migrating cells and the superficial layers of intact epidermis suggests that wound epithelium is derived, in part, from cells in the outer layers of the epidermis, or that the cell surface of the deeper cells becomes more like superficial cells during migration.
Microfilaments appear in boar spermatozoa during capacitation in vitro
Authors: Saxena Neerja , Peterson R. N. , Saxena N. K. , Russell L. D.
Published: June 2005

Boar spermatozoa were in a capacitation medium and examined for the presence of filamentous actin by using the fluorescent probe NBD‐phallacidin. F‐actin was not observed in uncapacitated sperm, but developed in most regions of the cell during the capacitation period. Fluorescent staining was most intense in the flagellum. When fresh seminal plasma was added to capacitated sperm and the sperm was further incubated, F‐actin was no longer observed. In view of previous experiments which indicated that plasma membrane protein (PMPs), including a major integnal PMP, move out of the sperm head into the flagellum during capcitation and that this movement is inhibited by the microfilament poison cytochalasin D (Peterson, Saxena, Saxena, and Russell: Biol. Reprod., in press, '86), we suggest that actin‐PMP interactions play a major role in capacitating boar spermatozoa.
Ordered flow of secretion from accessory glands to specific layers of the spermatophore of mealworm beetles: Demonstration with a monoclonal antibody
Authors: Grimnes Karin A. , Bricker Connie S. , Happ George M.
Published: June 2005

Monoclonal antibodies were produced against the secretory product of the bean‐shaped accessory gland (BAG) of male mealworm beetles (Tenebrio molitor). Antibodies from one clone (PL 6.3) recognized a 9,600 dalton protein with a pI of 6.6 which was found in homogenates of the BAG. The PL 6.3 antigen was first detected on Western blots of BAG proteins from 2‐day adults, and amounts increased for the next 6 days until reproductive maturation was achieved. The antibody also recognized a polypeptide with a molecular weight (mw) of about 5,000 daltons which we believe to be derived from the larger 9,600 dalton antigen.

There are eight types of secretory cells in the BAG. By using light microscopic immunohistochemistry, we localized the antigens recognized by PL 6.3 in cell type 7 (intense staining) and cell type 5 (weak staining). Results from electron microscopic immunocytochemistry showed that antigen PL 6.3 was concentrated in the secretory granules characteristic of each of these two cell types and was absent in all other cell types.

PL 6.3 antigens were traced from the BAG into its secretory product and then into the prespermatophoric mass in the ejaculatory duct. The antigen was not randomly mixed with other secretory products of the accessory glands. As it flowed from the BAG and into the ejaculatory duct, it remained in a coherent, precisely localized mass. Within the definitive spermatophore, the PL 6.3 antigen was concentrated in discrete layers of material that line the lumen.
Non‐cross‐reactivity of antibodies to murine LDH‐C4 with LDH‐A4 and LDH‐B4
Authors: Liang Zhi‐Guo , Shelton Joyce A. , Goldberg Erwin
Published: June 2005

The induction of infertility by immunization with the sperm‐specific lactate dehydrogenase, LDH‐C4, suggests its use in a contraceptive vaccine. Development of an immunological contraceptive for human use, however, requires that there be no cross‐reactions with somatic tissues. We have demonstrated, using enzyme‐linked immunoabsorbence, solid‐phase radioimmunoassay, and competitive inhibition radioimmunoassay, that antisera to LDH‐C4 is specific and does not cross‐react with the somatic isozymes, LDH‐A4 and LDH‐B4.
Production of a “spawning female‐specific substance” in hepatic cells and its accumulation in the ascites of the estrogen‐treated adult fish, Oryzias latipes
Authors: Hamazaki Tatsuo S. , Iuchi Ichiro , Yamagami Kenjiro
Published: June 2005

A “spawning female‐specific substance” cross‐reactive with an anti‐chorion glycoprotein antibody is present not only in the ovary but also in the liver and blood plasma of the teleost, Oryzias latipes [Hamazaki et al. (19851, J. Exp. Zool., 235269‐279]. Upon the administration of estrogen, this substance was produced in hepatic cells of both a nonspawning adult female and an adult male. Moreover, a large amount of the substance was accumulated in the ascites fluid that was accumulated in the abdominal cavity of the estrogen fed (EF) fish. The ascites fluid as well as blood plasma of these fish contained also a considerable amount of “probable vitellogenin” (recently identified as real vitellogenin) that showed no cross‐reactivity with the anti‐body. Thus these two substances were major components of the ascites fluid. The antigenic substance, as well as vitellogenin, seems to remain in its native molecular state in the ascites fluid without undergoing enzymatic digestion. On electron microscopic observation of the hepatic cells of the estrogenized male and nonspawning female fish, an unusual formation of electron dense droplets was found among well developed rough‐surfaced endoplasmic reticuli (r‐ER). Immunocytochemical examination revealed that the antigenic substance was localized in the lumen of the r‐ER, Golgi apparatus, some transport vesicles. These results strongly suggest that this “spawning female‐specific substance” is normally produced in the liver under the influence of an estrogenic hormone.
Effects of calcium antagonists, calmodulin antagonists, and methylated xanthines on polar lobe formation and cytokinesis in fertilized eggs of Ilyanassa obsoleta
Authors: Conrad Gary W. , Glackin Paula V. , Hay Robyn A. , Patron Roberto R.
Published: June 2005

We have studied the ability of fertilized eggs of Ilyanassa obsoleta to undergo polar lobe formation and cytokinesis in the presence of Ca2+ antagonists (Ca2+ channel blockers, Ca2+ uptake inhibitors). Earlier work had suggested little need for exogenous Ca2+ during these cellular shape changes. Again it appears that exogenous Ca2+ probably is not required, based on cell ability to undergo the shape changes with no, or only minor, delay in the presence of 50 mM La3+ at pH 6.5, 10 mM concentrations of Ni2+ or Co2+, 1 mM Cd2+, and 100 μM concentrations of Mn2+, papaverine, verapamil, D600, or diltiazem. In nominally Ca2+ ‐free seawater (containing ∼ 10 μM Ca2+) (CFSW), there still is no effect of Cd2+ (up to 100 μM), Ni2+, Co2+, Mn2+, or diltiazem; however, papaverine, verapamil, and D600 in CFSW cause longer delays in the shape changes than they do in the presence of normal levels of Ca2+ (SW). In 10–50 μM nifedipine, shape changes are progressively delayed to the same extent in both SW and CFSW, but more so in CFSW at concentrations above 50 μM nifedipine.

Among calmodulin antagonists, trifluoperazine up to 100 μM was without effect, but chlorpromazine at 25–100 μM and calmidazolium at 50–100 μM caused substantial, concentration‐dependent delays in the starting times for the shape changes. Methylxanthines caused a substantial speed‐up in the starting times for both polar lobe formation and cytokinesis. The most effective of these, caffeine, at optimal concentrations of 0.7–10 mM in SW or CFSW caused shape changes to occur 12–15 min earlier than in controls undergoing a normal 50‐min cycle. Caffeine is known to cause release of Ca2+ from muscle sarcoplasmic reticulum. A putative antagonist of intracellular Ca2+ mobilization, TMB‐8, significantly inhibited the shape changes of the Ilyanassa cells, whereas a variety of inhibitors of exogenous Ca2+ uptake noted above did not inhibit. We conclude that Ca2+ may be necessary for polar lobe formation and cytokinesis in Ilyanassa cells, but that it may be released from intracellular, sequestered stores rather than derived from exogenous sources.
Muscles proximal to the fracture plane atrophy after limb autotomy in decapod crustaceans
Authors: Moffett Stacia
Published: June 2005

In crabs (Carcinus and Uca) and crayfish (Procambarus), autotomy of distal limb segments is followed by atrophy of all leg muscles proximal to the fracture plane. The extent of the reversible muscle degeneration was revealed in light micrographs and was quantified by extracting the muscles and weighing them. In the period between autotomy and the next molt, the muscles which move the limb stump shrink to approximately 50% of the weight of contralateral muscles proximal to an intact leg. The atrophied muscles appear wasted in situ and in cross section, but are still innervated and continue to be activated.
Neuraminidase induces capacitation and acrosome reaction in mammalian spermatozoa
Authors: Srivastava Prakash N. , Kumar Vijay M. , Arbtan Kaveh D.
Published: June 2005

The treatment of epididymal spermatozoa of guinea pig and ejaculated spermatozoa of rabbit with neuraminidase from Arthrobacter ureafaciens induced significant acrosome reaction while the neuraminidase from Cl. perfringens failed to do so. The addition of the neuraminidase inhibitors kept the enzyme induced acrosome reaction to the control level. The zona‐free hamster ova test showed that the treatment of spermatozoa with Arthrobacter neuraminidase rendered 82% of the guinea pig and 69% of the rabbit spermatozoa capable of fertilization. Thus, neuraminidase seems to enhance the rate of acrosome reaction by first capacitating spermatozoa in vitro.
Comparative studies of visual field sizes in Pteronemobius lineolatus (Gryllidae, Nemobiinae) and some other cricket species
Authors: Lambin Michel , Beugnon Guy
Published: June 2005

The pseudopupil is a virtual dark spot that can be seen beneath the corneal surface in the depth of the insect compound eye. Observation of this pseudopupil allowed determination of the shape of the visual field of the cricket Pteronemobius lineolatus, and of five other cricket species: Nemobius sylvestris, Gryllus bimaculatus, Gryllus campestris, Acheta domesticus, and Oecanthus pellucens. These visual fields are characterized by their large dorsal and lateral extents and by different binocular overlaps. These differences are linked more to the way of life of a particular species rather than to any phyletic relationship.
Bioengineered human growth hormone supports limb regeneration in the hypophysectomized newt Notophthalmus viridescens
Authors: Landesman Richard H. , Copeland Kenneth C.
Published: June 2005

It is well documented that growth hormone (GH) replacement therapy will restore normal limb regeneration to hypophysectomized adult newts. However, it is also known that the GH preparations used in previous reports were contaminated by other pituitary hormones shown to support regeneration when administered free of GH. The recent availability of bioengineered human GH was studied for its ability to restore the regenerative capacity to hypophysectomized newts.

Five days posthypophysectomy adult newts were subject to forelimb amputation distal to the elbow. Animals were divided into three groups (n > 20). Each received one of three GH preparations: pituitary‐derived bovine GH, pituitary‐derived human GH, or bioengineered human GH. GH was administered via intraperitoneal injection (0.029 IU/50 μl) on alternate days for either the first 5 days (total of 3 injections) or for 35 days (total of 18 injections). Pituitary‐intact and hypophysectomized control newts were subjected to forelimb amputation and injected with hormone diluent.

All newts that received GH demonstrated normal limb regeneration to the early digitiform stage by 35 days postamputation. None of the hypophysectomized control newts showed any evidene of regeneration. We conclude that GH alone can restore the ability to undergo normal limb regeneration to hypophysectomized newts.
Alterations in the cell cycle characteristics of granulosa cells during the periovulatory period: Evidence of ovarian and oviductal influences
Authors: Schuetz A. W. , Whittingham D. G. , Legg R. F.
Published: June 2005

Granulosa cells at different stages of differentiation were collected from ovarian follicles and oviducts during the periovulatory period, and their nuclear DNA content was monitored by flow cytometry to establish their cell cycle characteristics (G0 + G1, S, G2 + M). The proportion of cells in the three phases of the cell cycle varied in characteristics patterns depending upon the time they were collected, before or following ovulation. Granulosa (cumulus) cells recovered from ovulated oocytes were mitotically inactive as shown by the large proportion of cells with a 2C amount of DNA and the absence of cells in S phase. The proportion of granulosa cells in G2 + M decreased when recovery from the oviducts was delayed. In contrast, granulosa (cumulus and/or mural) cells recovered from preovulatory follicles prior to luteinizing hormone (LH) exposure contained a considerable population of cells undergoing DNA synthesis, and a decreased proportion of cells with a 2C DNA content. Our findings indicate that granulosa cells undergo dynamic and characteristics changes in all cell cycle phases during the periovulatory period, within follicular and oviductal environments. Intrafollicular events appear to play a major role in controlling DNA synthesis, proliferation, and related cell cycle events in the granulosa cells. Flow cytometric techniques provide objective and detailed information on the cell cycle characteristics of granulosa cell populations at different stages of differentiation. Elucidation of the mechanisms regulating cell cycle parameters of granulosa cells and their physiological significance thus seems feasible.