bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allogeneic recognition and sex differentiation in chimeras of the freshwater sponge Ephydatia muelleri
Authors: Mukai Hideo 
Published: June 2005

AbstractAllogeneic recognition and sex differentiation in Ephydatia muelleri were studied with two types of chimeric sponges, mixed and unmixed. Using gemmules of nine original sponges (stocks) collected in a pond, chimeras were prepared in the laboratory. Subsequently, the chimeric sponges were transferred to and cultured in the pond of their origin. They were observed macroscopically and histologically. The unmixed chimeras consisted of halves of different stocks. All unmixed chimeras grew as a continuous sheet for more than 10 days. Then, some of them showed a demarcation line at the boundary of the paired partners. Histologically, the demarcation line of a grown chimera was detected as a gap, on either side of which a narrow zone of tissue was more or less disorganized, containing no sexual elements. The combinations of stocks showing a demarcation line in unmixed chimeras are called incompatible, and those with no demarcation line compatible. Five histocompatibility strains were distinguished among the nine stocks used. Some interstrain combinations were compatible. In the chimeric individuals, the putative male region contained spermatic cysts, and the putative female region contained oocytes and embryos. In compatible heterosexual chimeras, male and female sexual elements were sometimes more or less separated but often were intermingled in the boundary zone. Gender seems to be genetically determined. The mixed chimeras were produced from randomly mixed gemmules of different stocks. Mixed chimeras of heterosexual combinations gave the following results. Many chimeras of the incompatible combinations showed a few to several irregular demarcation lines and contained both male and female sexual elements. Some incompatible mixed chimeras, however, did not show a demarcation line and contained only male sexual elements. Some compatible mixed chimeras contained both male and female sexual elements, but the male area was usually larger than the female area. Moreover, some compatible mixed chimeras contained only male sexual elements. Thus, a dominance of the male over the female was revealed in the mixed chimeras. A replacement of female tissues by male tissues during a short period following gemmule hatching is assumed. This may be considered an example of somatic cell parasitism. © 1992 Wiley‐Liss, Inc.
Effect of air exposure on nitrogen metabolism in the crab Cancer pagurus
Authors: Regnault Michèle 
Published: June 2005

AbstractIn C. pagurus exposed to air for 18h, blood ammonia content decreased within the 2 first hours, then increased at a relatively constant rate (25 μM/h); blood urate content increased at a lower rate (10 μM/h) and a classical blood acidosis was observed. In the cheliped muscle, a transient 22% decrease in GDH activity for ammonia formation and a 48% increase in GDH activity in the reverse reaction (glutamate synthesis) occurred following 6 and 12 h of emersion, respectively. Changes in LDH activity, used as an indicator of anaerobic potential of muscle, were not observed, except for an 18% increase in crabs exposed to air for 24 h.The increase in blood urate content, not known as a response to emersion in decapods, appeared to be different from that observed in response to hypoxia. The relatively low blood ammonia overload and the GDH increased activity for glutamate synthesis suggested that part of the produced ammonia was stored under a bound from in some tissues. The response of C. pagurus to air exposure is discussed on account of the Storey and Storey ('90) theory. © 1992 Wiley‐Liss, Inc.
Histochemical heterogeneity of fibers in the abdominal superficial flexor muscles of the Norway lobster, Nephrops norvegicus (L.)
Authors: Fowler William S. , Neil Douglas M. 
Published: June 2005

AbstractThe superficial flexor muscle in the abdomen of the Norway lobster Nephrops norvegicus (L.), comprises medial and lateral bundles with distinct fiber type composition. Fibers of the medial bundle have long sarcomeres (>9 μm) and a thick fringe of subsarcolemmal mitochondria. In histochemical tests they have a low total myofibrillar ATPase activity, a pH‐stable isoform of myosin ATPase, and a high level of oxidative enzyme activity. A few fibers of the lateral bundle also display these morphological and histochemical properties. However, the majority of lateral fibers have shorter sarcomeres (<8 μm), no subsarcolemmal mitochondria, but a well‐developed tubular system. They also have a higher total myofibrillar ATPase activity, a pH‐labile isoform of myosin ATPase, and a low level of oxidative enzyme activity. The heterogeneous pattern of different fiber types in the lateral bundle of this muscle is similar but not identical in the different abdominal segments and in different individuals. © 1992 Wiley‐Liss, Inc.
Cryopreservation of Atlantic croaker spermatozoa: Evaluation of morphological changes
Authors: Gwo Jin‐Chywan , Arnold Connie R. 
Published: June 2005

AbstractThe spermatozoon of the Atlantic croaker (Micropogonias undulatus) is a primitive type in that it lacks an acrosome. The kidney‐shaped head has a diameter of about 1.5 μm and is occupied by a granular and electron‐dense nucleus. The short midpiece contains 3 spherical mitochondria and encircles the basal body of the flagellum but is separated from it. The flagellum consists of the typical 9 + 2 axoneme and surrounding plasma membrane but lacks a lateral ridge. Spermatozoa of Atlantic croaker diluted in either NaCl or sodium citrate solutions with or without DMSO were examined with the electron microscope before freezing in liquid nitrogen and after thawing. Damage following cryopreservation appeared to be greater to the mitochondria, plasma membrane, and 9 + 2 axoneme than to the nucleus. The incidence of postthaw damage in spermatozoa diluted with NaCl solutions containing DMSO was remarkably lower than that with either pure NaCl solutions, pure sodium citrate solutions, or sodium citrate solutions containing DMSO. © 1992 Wiley‐Liss, Inc.
Arginine vasotocin concentrations in the supraoptic nucleus of the lizard Anolis carolinensis are associated with reproductive state but not oviposition
Authors: Propper Catherine R. , Jones Richard E. , Dores Robert M. , Lopez Kristin H. 
Published: June 2005

AbstractArginine vasotocin (AVT) is a neuropeptide involved in reproductive function in many nonmammalian vertebrates. We determined brain and plasma AVT concentrations during the estrous cycle and oviposition in the lizard Anolis carolinensis. There were no differences in AVT concentrations in the plasma or any brain region during the ovipositional sequence. However, we found that females with an egg in each oviduct and a large pre‐ovulatory follicle (diameter > 4.5 mm) in oneovary had significantly higher AVT concentrations in the supraoptic nucleus (SON) of the hypothalamus than did females with small pre‐ovulatory follicles in both ovaries. In a second study, females with an egg in each oviduct and a large pre‐ovulatory follicle had significantly greater AVT concentrations in the SON than females with only one oviductal egg and a large pre‐ovulatory follicle or females with an egg in each oviduct and a small pre‐ovulatory follicle in each ovary. Concentrations of AVT in other brain regions and in the plasma did not differ among these groups. Changes in steroid profiles during estrous and/or direct neural communication between the uterus, ovary, and brain may account for the changes in AVT concentrations seen in the supraoptic nucleus during the estrous cycle of Anolis carolinensis. © 1992 Wiley‐Liss, Inc.
Lack of coupling between onset of giant transformation and genome endoreduplication in the mural trophectoderm of the mouse blastocyst
Authors: Gardner R. L. , Davies T. J. 
Published: June 2005

AbstractProminent among the various types of cell that differentiate from the trophectoderm of the mouse blastocyst are trophoblastic giant cells. Repeated endoreduplication of the genome accompanies the growth of these cells, which have been shown to be polytene rather than polyploid. Early stages in giant transformation have been examined, mainly in the mural trophectoderm of the implanting blastocyst which gives rise to the primary trophoblastic giant cells. One confusing issue is whether these early stages include the onset of endoreduplication of the genome. This issue has been addressed in the present study by comparing the DNA content of nuclei in isolated trophectoderm and ICM tissue rather than, as previously, by relating measurements on air‐dry preparations of entire blastocysts to those of adult liver. The results, particularly those from delayed and reactivated blastocysts, show that genome endoreduplication is not an obligatory early event in the transformation of mural trophectoderm cells. © 1993 Wiley‐Liss, Inc.
Production and characterization of monoclonal antibodies specific for bovine oviductal glycoproteins
Authors: Abe Hiroyuki , Numazawa Chikako , Abe Miki , Hoshi Hiroyoshi , Oikawa Taneaki 
Published: June 2005

AbstractFour monoclonal antibodies (MAbs) were produced in rat cells against materials obtained from the bovine oviduct. The MAbs (1H10, 2A4, 2C5, and 1B12) reacted strongly with the oviductal epithelium of cows in the follicular phase. An immunohistochemical study demonstrated that each of the MAbs bound strongly to the supranuclear cytoplasm of epithelial cells of the oviduct, but not of the stromal cells. Antigens that reacted with the MAbs were characterized by immunoblotting analysis of proteins after fractionation by SDS‐PAGE under reducing conditions of oviductal flushings obtained from cows at estrus. All MAbs strongly stained a band of protein with a molecular weight (MW) of 85–97 kD. MAb 1H10 also reacted with the minor band of a 55‐kD protein. Similar antigens were not detected in uterine flushings, follicular fluid, and serum. No specific immunohistochemical reactivity with the MAbs was observed with other tissues from the reproductive tract and with nonreproductive tissues. The immunohistochemical reactions were completely eliminated by pretreatment of tissues with trypsin, but not with periodic acid, results that suggest that the antigenic determinants that react with the MAbs were proteinaceous rather than carbohydrate. We have thus established clones that produce 4 MAbs that are specific for oviduct‐specific glycoproteins of the cow. © 1993 Wiley‐Liss, Inc.
Retinoic acid, cortisone, or thyroxine suppresses the mutant phenotype of the eyelid development mutation, lgMI, in mice
Authors: Juriloff D. M. , Harris M. J. 
Published: June 2005

AbstractThe development of the mammalian eyelid is one of the last major morphogenetic events during prenatal development. The eyelids originate as outgrowths of epithelium and mesenchyme above and below the eye; they grow and flatten across the eyes, and meet and fuse firmly but temporarily until several days after birth in mice. In mouse lidgap mutants, eyelid development fails. Previously, we have shown that normal eyelid development can be induced in lidgap mutants by maternal treatment with cortisone or thyroxine. These hormones have been reported to interact with members of a receptor superfamily, and their response elements have been shown to induce transcription of hormone‐regulated genes; retinoic acid also interacts with members of this superfamily. The purposes of our study were to examine the joint effect of thyroxine and cortisone on induced eyelid development in lidgap‐Miller mutant fetuses (lgMI/lgM1), to test for synergism, and also to test whether retinoic acid also induces eyelid development in this mutant. We found that the combined effect of thyroxine and cortisone was significantly greater than that of either hormone alone, but that the dose‐response slopes (log dose, probit scale) for eyelid development induced by cortisone alone or by cortisone preceded by 0.1 mg thyroxine were parallel, suggesting that their action is additive, not synergistic. We found that retinoic acid administered on day 14 of gestation induced eyelid development in lgMI/lgM1 mutant fetuses, with a significant dose response and ED50 of 24 ± 6 mg/kg. The response was treatment‐time dependent, with optimal responses after day 14 or 11 treatment. We conclude that the overlapping genetic regulatory network that orchestrates eyelid development can utilize at least 3 of the hormones that interact with members of the steroid receptor superfamily and its response elements. © 1993 Wiley‐Liss, Inc.
Differences in chromatin condensation during spermiogenesis in two species of fish with distinct protamines
Authors: Saperas N. , Ribes E. , Buesa C. , García‐Hegart F. , Chiva M. 
Published: June 2005

AbstractThe sperm cells of Mullus surmuletus (family Mullidae, order Perciformes) and Dicentrarchus labrax (family Percichthyidae, order Perciformes) belong respectively to “type I” and “type II” spermiogenesis categorized by Mattei ('70). The protein content in their sperm nuclei consists of two histone‐like proteins (Mullus surmuletus) and one typical protamine (D. labrax). In order to correlate the molecular characteristics of these proteins with their function, we have analyzed the molecules in detail and studied at the ultrastructural level the condensation of chromatin during the spermiogenesis in both species. D. labrax has a true protamine of 34 amino acid residues and its sequence (PR4QASRPVR5TR2STAER5V2R4) contains four arginine clusters. The sperm proteins of M. surmuletus contain 110 and 115 amino acid residues and, by their composition (23–24% Lys, 21–22% Arg, 11–12% Ala), they are similar to protamine‐like molecules from sperm of molluscs. During the spermiogenesis of D. labrax, chromatin condensation progresses from small fibro‐granular structures (25 ± 5 nm in diameter), to larger granules (150 ± 50 nm diameter). M. surmuletus accumulates 25 ± 5 nm diameter structures in the basal pole of the nucleus; these structures grow till they reach a diameter of 50 ± 10 nm and finally go through a process of fusion that changes the condensation of chromatin in sperm nuclei, acquiring a homogeneous aspect.These observations show that during spermiogenesis in the studied types, the last stages of chromatin condensation are dependent on the type of nuclear proteins. © 1993 Wiley‐Liss, Inc.
Proteins Of crustacean exoskeleton II: Immunological evidence for their relatedness to cuticular proteins of two insects
Authors: Kumari S. Sindhu , Skinner Dorothy M. 
Published: June 2005

AbstractThe exoskeletons of crustaceans and cuticles of insects are characterized by an abundance of proteins with acidic pIs and Mrs 31 kDa or smaller. Immunochemical data described here further demonstrate the similarities of such proteins among representatives of these two major classes of Arthropoda. Proteins extracted from the four individual layers of the exoskeletons of Bermuda land crabs Gecarcinus lateralis at different stages of the intermolt cycle and from exuviae, the partially degraded old exoskeleton that is cast at ecdysis, were analyzed on Western blots with polyspecific polyclonal antibodies against either larval cuticular proteins (anti‐LCP) or pupal cuticular proteins (anti‐PCP) of the tobacco hornworm Manduca sexta, or against two pairs of larval cuticular proteins from third instar larvae (anti‐L3CPs) of Drosophila melanogaster. M. sexta anti‐LCP cross‐reacted with many of the crab proteins extracted at all stages of the intermolt cycle. It reacted with more high Mr proteins from late proecdysial exoskeleton and exuviae than with such proteins from anecdysial or early proecdysial exoskeletons, probably because the larger Mr proteins are enriched when the lower Mr proteins are degraded during proecdysis. M. sexta anti‐PCP cross‐reacted hardly at all with the crab proteins. Both D. melanogaster anti‐L3CPs cross‐reacted with crab epicuticular proteins at all stages of the intermolt cycle and from exuviae. Anti‐L3CP 3 + 4 reacted even more intensely and with many more proteins from the three inner layers of the exoskeleton than did anti‐L3CP 1+2. Controls included 2D gels with rabbit anti‐ovalbumin to detect glycoproteins containing mannose and N‐acetyl‐glucosamine; it cross‐reacted with only one protein in membranous layer of an anecdysial crab, while rabbit anti‐fluorescein reacted with none. By contrast, the intensity and specificity of the cross‐reactions of crab exoskeletal proteins with antibodies against cuticular proteins of members of two orders of insects suggest that at least some cuticular proteins in the two arthropod Classes, Crustacea and Insecta, are evolutionarily conserved. Published 1993 Wiley‐Liss, Inc.
Metabolic adaptations by the leech Nephelopsis obscura during long‐term anoxia and recovery
Authors: Reddy D. C. , Davies Ronald W. 
Published: June 2005

AbstractMetabolic adaptations to long‐term (40 day) anoxia were determined in two size groups (small and large) of the freshwater leech Nephelopsis obscura. Neither size group accumulated the lactic acid during anoxia; rather succinate and alanine were the major end products. Glycogen and amino acids were the primary energy reserves utilized with lipid also utilized by small N. obscura. After 40 days of anoxia glycolytic flux was reduced by 99.8% in small and 99.7% in large N. obscura. Cellular energy status adenosine triphosphate/adenosine diphosphate (ATP/ADP) also declined significantly in small (79%) and large (69%) leeches. After return to normoxia the energy charge in small N. obscura was restored within 6 hours and glycogen, malate, succinate, alanine, and aspartate restored within 24 hours. Large N. obscura utilized lower proportions of their energy reserves than small N. obscura. © 1993 Wiley‐Liss, Inc.
Mapping of the chicken N‐CAM gene and a myosin heavy chain gene: Avian microchromosomes are not genetically inert reserves of DNA
Authors: Dominguez‐Steglich Marina , Robbins Jeffrey , Schmid Michael 
Published: June 2005

AbstractPhysical mapping of the chicken neural cell adhesion molecule gene and of a chicken myosin fast‐white heavy chain gene via in situ hybridization has assigned both loci to different‐sized microchromosomes in this species. Two genomic cloned chicken DNA probes of 16 kb (λ cN6) and 15 kb (DCM 11), respectively, were biotin labeled for fluorescent detection of the genes. The implications derived from these results, together with further data just now beginning to accumulate regarding the genetic content of avian microchromosomes, confirm an unexpectedly active role for these minute chromosomes. © 1993 Wiley‐Liss, Inc.
The role of organic osmolytes in osmoregulation: From bacteria to mammals
Authors: Kinne Rolf K. H. 
Published: June 2005

AbstractCells of marine species are known to establish osmotic balance with their environment by adjusting the concentrations of organic osmolytes rather than inorganic osmolytes such as sodium, potassium, and chloride. These organic osmolytes fall into three classes: polyhydric alcohols such as sorbitol, amino acids and amino acid derivatives, and urea and trimethylamines. Substantial evidence is available for a central role of each of these classes in osmoregulation in marine species. In this chapter information on the importance of organic osmolytes is extended to a study of isolated mammalian kidney cells. The intracellular concentration of organic osmolytes in these cells responds dramatically to changes in the osmotic environment. The release of sorbitol following hypoosmotic exposure appears to be triggered by calcium, possibly via a mechanism involving membrane recycling. The summarized experiments provide a basis for further work in marine species. © 1993 Wiley‐Liss, Inc.
Cold shock damage is due to lipid phase transitions in cell membranes: A demonstration using sperm as a model
Authors: Drobnis Erma Z. , Crowe Lois M. , Berger Trish , Anchordoguy Thomas J. , Overstreet James W. , Crowe John H. 
Published: June 2005

AbstractWhen cells are cooled to temperatures above the freezing point of water at rates greater than a few degrees per minute, they sustain irreversible injury. Reduction of this “cold shock” damage could increase the survival of animals and plants at low environmental temperatures and improve the cryopreservation of plant and animal cells. Leakage of solutes across membranes, associated with thermotropic phase transitions in membrane lipids, is thought to be responsible, but this hypothesis has not been tested directly. Using Fourier transform infrared spectroscopy (FTIR), we measured the lipid phase transitions in intact, living sperm, the animal cell in which cold shock has been studied most extensively. A shift in the CH2 absorbance peaks indicates the transition from liquid‐crystalline to gel phase. The phase transition in sperm membranes occurred at a lower temperature for a marine shrimp than for the pig. In each case, potassium leakage, which is a hallmark of cold shock damage, increased abruptly near the end of the phase transition. Human sperm are quite resistant to cold shock, and an abrupt lipid phase transition was not detected. This phase behavior is typical of membranes containing a high proportion of cholesterol, and human sperm have an unusually high sterol content. High cholesterol levels are known to stabilize membranes during cooling. Overall, the lipid phase behavior was consistent with the temperature range over which cooling was damaging for pig and shrimp sperm, and the with the extent of damage produced in pig and human sperm. This is the first direct evidence that cold shock results from lipid phase transitions in cell membranes. © 1993 Wiley‐Liss, Inc.
Physiology and morphology of the cord stretch receptors of the crayfish Cherax destructor
Authors: Savati Fiona , Macmillan David L. 
Published: June 2005

AbstractThe axons of stretch‐sensitive units were located in the isolated nerve cord of the crayfish Cherax destructor. Their physiology and distribution closely resembled that of the tonic and phasic cord stretch receptor (CSR) units of Procambarus clarkii (Grobstein: J. Comp. Physiol., 86:331–348, 1973a), phasic units responding to stretch of the ganglionic cord, and tonic units to stretch of the interganglionic connectives. Removal of the connective tissue sheath did not abolish either response. Small bundles of nerves containing a CSR from the ganglion or connective adjacent to the recording site were backfilled with cobalt. Two common cell types stained, one associated with each physiological result, and we propose that these are the CSRs. Both have cell bodies anteroventrally in the ganglion adjacent to the stretch‐sensitive area and neurites in the same dorsoventral plane as their axons. The neurites of the tonic CSRs are oriented transversely in the neuropile and those of the phasic CSRs longitudinally. We propose that the CSRs are the site of primary stretch activation, that they are either primary sensory neurons with an interneuron‐like structure or interneurons that have acquired a sensitivity to stretch, and that they are activated by connections to cord structures such as those described by Cobb and Heitler (J. Neurocytol., 14:413–426, 1985). We searched for and found no CSRs in the thorax or in the last abdominal ganglion. © 1993 Wiley‐Liss, Inc.