bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spermatogenesis in XO,Sxr mice: Role of the Y chromosome
Authors: Kot Mary C. , Handel Mary Ann 
Published: June 2005

AbstractThe goal of this investigation was to evaluate the role of the Y chromosome in spermatogenesis by a quantitative and qualitative analysis of spermatogenesis as it occurs in the absence of a significant portion of the Y chromosome, i.e., in XO,Sxr male mice. Although these mice have the testis‐determining portion of the Y chromosome on their single X chromosome, they lack most of the Y chromosome. Since it was found that all sperm‐specific structures were assembled in a normal spatial and temporal pattern in spermatids of XO,Sxr mice, the genes controlling these structures cannot be located on the Y chromosome outside of the Sxr region, and are more likely to be on autosomes or on the X chromosome. In spite of the assembly of the correct sperm‐specific structures, spermatogenesis was not quantitatively normal in XO,Sxr mice and significantly reduced numbers of spermatids were found in the seminiferous tubules of these mice. Furthermore, two size classes of spermatids were found in the testes of XO,Sxr mice, normal and twice‐normal size. These findings are suggestive of abnormalities of meiosis in XO,Sxr spermatocytes, which lack one of the two sex chromosomes, and may not implicate function of specific genes on the Y chromosome. Morphological abnormalities of spermatids, which were not unique to XO,Sxr mice, were observed and these may be due to either a defective testicular environment because of reduced numbers of germ cells or to the lack of critical Y chromosome‐encoded products. Since pachytene spermatocytes of XO,Sxr mice exhibited a sex vesicle, it can be concluded that the assembly of this structure does not depend on the presence of either a complete Y chromosome or the pairing partner for the X chromosome.
Electrophoretic characterization of proteins in oviduct fluid of cows during the estrous cycle
Authors: Gerena R. L. , Killian G. J. 
Published: June 2005

AbstractThis study was undertaken to examine the in vivo protein composition of the bovine oviduct during the estrous cycle. Oviduct fluid was collected daily from four oviductcannulated dairy cows for a total of four complete estrous cycles. Fluid secretion followed a definite cyclic pattern, with maximum secretion occurring at estrus in all cycles. Protein concentration fluctuated during the cycle and varied among animals. In general, protein concentration was lower at the time of estrus. Total protein in oviduct fluid, however, was higher around estrus, indicating increased transudation or secretion by the oviduct. One‐dimensional SDS‐PAGE separation revealed the protein pattern of oviduct fluid to be generally similar to that of blood serum and follicular fluid. Two proteins appeared to be oviduct‐specific. The first, a protein of approximately 47 kDa, was evident in oviduct fluid throughout the estrous cycle. The second protein, evident as a broad diffuse staining band above albumin, appeared for only 3–4 days at or near ovulation. This protein had a molecular weight of 80–95 kDa and stained positive for carbohydrate with periodic acid‐Schiff reagent. These studies indicate that the in vivo protein composition of oviduct fluid varies with the estrous cycle, and that around estrus, an oviduct‐specific glycoprotein is present.
Calcium ion in chromatic nerve transmission and melanophore movements in teleosts
Authors: Miyashita Yoko , Moriya Tsuneo 
Published: June 2005

Abstract
Ca‐ionophore A23187 was examined for its action on innervated and denervated melanophores of the guppy Lebistes reticulatus and the Siamese fighting fish, Betta splendens.
This Ca‐ionophore (5 × 10−6 M) induced melanin aggregation in innervated melanophores of both species. This aggregating response disappeared in the presence of an alpha‐adrenolytic agent, phentolamine.
However, in denervated skin melanophores of these fish, A23187 failed to aggregate melanosomes.
An inhibitor for intracellular calcium release, 8‐(N,N‐diethylamino)octyl 3,4,5‐trimethoxybenzoate hydrochloride (TMB‐8), inhibited the melanophore‐aggregating responses induced by A23187 and by electrical stimulation of nerves.
In the presence of TMB‐8 (less than 10−4 M), the melanin aggregation response to norepinephrine (NE) commenced normally and both the rate and degree of aggregation were identical to those in saline solution alone. However, the time course of re‐dispersion from the aggregated state after NE treatment clearly shortened with TMB‐8. This action of TMB‐8 on the response to NE was enhanced in calcium‐free saline solution.
We discuss the possible roles and origin of calcium ions in chromatic nerve transmission and melanophore movements in teleost fish.
Sperm histones and chromatin structure of the “primitive” sea urchin Eucidaris tribuloides
Authors: Vodicka M. , Green G. R. , Poccia D. L. 
Published: June 2005

AbstractThe “primitive” sea urchin Eucidaris tribuloides resembles the advanced sea urchins (euechinoids) in many respects, yet some features of its biochemistry and morphogenesis are more similar to other echinoderms such as starfish or sea cucumbers. Two unique characteristics of the sperm chromatin of all known euechinoids are an extremely long average nucleosomal repeat length and the presence of two male germ‐line‐specific histone variants, Sp H1 and Sp H2B. Histone composition and nucleosomal repeat length of the sperm chromatin of Eucidaris were compared to those of several euechinoids and a starfish. Eucidaris sperm chromatin contained large H1 and H2B histone variants typical of euechinoids. The H1 was about nine amino acids smaller than Sp H1 of the advanced urchin Strongylocentrotus purpuratus. Its Sp H2B molecules were the same size as in the euechinoids. Peptide maps showed that N‐terminal regions of Sp H1 and Sp H2B contained repeating basic amino acid motifs characteristic of euechinoids. The smaller size of Eucidaris H1 is accounted for by a smaller C‐terminal region. The repeat length of Eucidaris sperm chromatin was slightly shorter than that of two euechinoids, but significantly larger than starfish, which lacks a large H2B. The Sp H2B gene of Eucidaris was expressed during spermatogenesis in the same cell types as for S. purpuratus. Thus Sp histone subtype expression and chromatin structure in this distantly related echinoid closely resemble the euechinoids. The presence of an Sp H2B and a very long repeat length appear to be characteristic of the echinoids only.
Influence of intracellular pH on reduction of energy metabolism during hypoxia in the lugworm Arenicola marina
Authors: Juretschke Hans‐Paul , Kamp Günter 
Published: June 2005

AbstractThe influence of intracellular pH (pHi) on the energy metabolism during hypoxia was studied in the lugworm Arenicola marina using in vivo 31P nuclear magnetic resonance (NMR) spectroscopy and biochemical analysis of the metabolic end products during hypoxia. By addition of phenylphosphonic acid (PPA) to the incubation medium to increase the extracellular H+ buffering capacity, different degrees of intracellular acidosis during hypoxia could be attained.At low extracellular PPA concentrations pHi dropped within 12 h of hypoxia from 7.3 to 6.7. High extracellular PPA concentrations (50 mM) kept pH1 stable at 7.2. Glycogenolysis was enhanced during hypoxia at high pHi, as shown by the measured amounts of accumulated end products. ATP production at high pHi was 31 μmol/g h vs. 15 at low pHi‐ The mobilisation of the phosphagen phosphotaurocyamine (PTC) was, in contrast, decreased at high pHi: the ratio PTC/β‐ATP dropped from 4.8 (normoxia) to 2.8 at high vs. 1.3 at low pHi. The reduction of the metabolic rate during hypoxia hence depends on intracellular acidosis: the rate of the Embden‐Meyerhof‐Parnas pathway at high pHi was 4.5 μmol/g h vs. 1.9 at low pHi.
Heat shock protein 70 gene expression in intact salamanders (Eurycea bislineata) in response to calibrated heat shocks and to high temperatures encountered in the field
Authors: Near Joseph C. , Easton Douglas P. , Rutledge Paul S. , Dickinson Douglas P. , Spotila James R. 
Published: June 2005

AbstractSynthesis of heat shock proteins (hsps) is a universal response of cells to heat shock. Recent evidence suggests that hsps are involved in the repair of damage caused by heat or other protein‐denaturing insults. We have determined kinetics of induction for the 70 kD heat shock protein (hsp 70) and hsp 70 mRNA in adult salamanders, Eyrycea bislineata. We demonstrate that the extent of expression of the hsp protein and mRNA is proportional to the heat dose but differs with respect to tissue. Hsp 70 synthesis was shown to be controlled primarily at the level of mRNA transcription. Hsp 70 mRNA accumulation is prolonged in the adult animal when compared to cultured cells from other vertebrate ectotherms given similar heat shocks. Additionally, we show that the hottest of four animals captured in the field on a hot summer day had synthesized hsp 70 mRNA in its tissues. These findings are discussed relative to the thermal biology of vertebrate ectotherms.
Metabolic implications of Ldh‐B genotype during early development in Fundulus heteroclitus
Authors: Paynter Kennedy T. , DiMichele Leonard , Hand Steven C. , Powers Dennis A. 
Published: June 2005

AbstractThe metabolic rates of different Ldh‐B genotypes of developing Fundulus heteroclitus embryos were examined. Within 24 hours after fertilization, eggs homozygous for the southern (Ldh‐Ba) allele began to exhibit significantly higher oxygen consumption than eggs homozygous for the northern (Ldh‐Bb) allele. No significant differences existed between genotypes with respect to total LDH‐B4 activity or ontogeny throughout development. Lactate concentrations were significantly different in the oocytes between genotypes (Ldh‐Ba = 48 mM; Ldh‐Bb = 40 mM). Furthermore, lactate was utilized at a high rate during early development. Lactate utilization was approximately 100 times higher than apparent glucose utilization, and both rates were significantly different between genotypes. Within 24 hours after fertilization, half of the lactate present in the oocyte was utilized in both genotypes. Oxygen consumption and heat dissipation measurements demonstrated that the Ldh‐Ba homozygotes increased their metabolic rate dramatically between 10 and 15 hours after fertilization and that the Ldh‐Bb homozygotes did not. It is suggested that lactate is a source of intermediates important for early development and that LDH‐B4 may mediate the accumulation of that lactate in the oocyte and the utilization of lactate in the early development of the embryo. This metabolic role may lead to environmentally induced selection at the Ldh‐B locus.
Timing in the movement of jaws, tongue, and hyoid during feeding in the hyrax, Procavia syriacus
Authors: German Rebecca Z. , Franks Herschel A. 
Published: June 2005

AbstractThe anatomical structures used during mammalian feeding are morphologically linked by their connecting musculature, suggesting a predictable timing relationship among their movements. Cine‐x‐ray (100 frames per second) was used to record feeding behavior in four adult hyraxes (Procavia syriacus), herbivores. Movement of jaws, tongue, and hyoid bone was cyclic, and prior to the first swallow cycle, cycle duration was constant through time for all structures. Minimum gape, beginning of forward movement of the tongue and hyoid, and beginning of intrinsic tongue expansion occurred simultaneously over a large number of cycles. However, maximum gape, maximum protrusion of hyoid, and maximum forward position of the tongue happened at statistically different points in time. After the first swallow, cycle duration increased. Most of the variation in cycle duration can be explained by variation in the opening or forward phase of movement; the closing and return phases are constant in duration. These results are a quantitative description of the coordination that exists during different feeding behaviors (ingestion, intraoral transport, mastication, and swallowing) in normal, freely functioning hyraxes. The patterns of phase duration differ from some results obtained by using anesthetized animals.
Effects of 20‐hydroxyecdysone on protein synthesis in tissues of the land crab Gecarcinus lateralis
Authors: Paulson Charles R. , Skinner Dorothy M. 
Published: June 2005

AbstractThe endocrine regulation of molting was investigated in the crab Gecarcinus lateralis by treating tissues from anecdysial (intermolt) animals with the arthropod molting hormone 20‐hydroxyecdysone (20HE) in vitro and observing changes in the incorporation of [35S]‐methionine into proteins. Although total protein synthesis was not affected by levels of 20HE ranging from 10−9 to 10−5 M, synthesis of five out of 30 protein bands was significantly stimulated at hormone concentrations of 10−9−10−7 M, the latter characteristic of proecdysis. Increases were as large as eightfold. Synthesis was not significantly inhibited for any of the integumentary proteins. Treatment of integumentary tissues with 10−5 M 20HE (approx. 100 times greater than the highest endogenous concentration) had less effect than physiological concentrations. The dose response varied substantially among integumentary proteins. In some instances, the effects were similar to changes in synthesis that occur in vivo during specific stages of proecdysis (Stringfellow and Skinner, Dev. Biol., 128: 97–110, '88). Midgut gland (hepatopancreas) was also treated with 20HE in vitro. Treatment with 20HE significantly inhibited total protein synthesis in tissue from males, but not in that from females. This treatment inhibited the synthesis of a number of the 32 protein bands examined in both sexes. Synthesis of six protein bands was significantly inhibited in males, while synthesis of three different bands was significantly inhibited in females. This inhibitory action of 20HE is consistent with the atrophy of the midgut gland that occurs during proecdysis (Gibson and Barker, Oceanogr. Mar. Biol. Annu. Rev., 17: 285–346, 79).
Ontogenetic changes in fusibility in the colonial hydroid Hydractinia symbiolongicarpus
Authors: Shenk M. Andrew , Buss Leo W. 
Published: June 2005

AbstractInvertebrate fusion and rejection responses are typically assumed to be mutually exclusive and temporally stable states. We here describe a segregant class appearing in an F1 cross of the colonial hydroid, Hydractinia symbiolongicarpus, that displays an ontogenetic change in fusibility. Reproductively immature offspring fuse to parental strains and have been observed to remain continuously fused for up to 76 days. By contrast, reproductively mature offspring initially fused with parental strains, only to separate into distinct colonies after a period of 3–21 days postfusion. Experimental manipulations demonstrate that (1) ontogenetic changes in fusibility cannot be removed by resetting a colony to a reproductively immature state, and (2) secondary contact does not result in an accelerated response.
Selective growth and serial passage of mouse melanocytes from Neonatal epidermis in a medium supplemented with bovine pituitary extract
Authors: Hirobe Tomohisa 
Published: June 2005

AbstractSuspensions of disaggregated epidermal cells from skins of newborn C57BL/10JHir mice were plated in a growth medium that consisted of Ham's F‐10 plus bovine pituitary extract (BPE), insulin, and transferrin. Fetal bovine serum (FBS) was added to the culture medium at a concentration of 4% at the time of plating. On the second day of culture, a small number of melanocytes was randomly distributed among large sheets of keratinocytes. From the third day onward, FBS was excluded from the culture medium to prevent the proliferation of keratinocytes and fibroblasts. The melanocytes began to grow preferentially, and after 12 days pure and enriched populations of melanocytes could be harvested. In the absence of the proliferation of keratinocytes and fibroblasts, melanocytes could be serially passaged in the growth medium supplemented with a conditioned medium (CM) prepared from keratinocyte‐enriched cultures, namely, those at the early stages of the primary culture. FBS was added at a concentration of 1% for the first day. These results suggest that both BPE and keratinocyte CM contain growth factors required for proliferation of melanocytes.
Production of identical twin and triplet mice by nuclear transplantation
Authors: Kono T. , Tsunoda Y. , Nakahara T. 
Published: June 2005

AbstractTransplantation of a single nucleus from two‐ or four‐cell embryos into one of the enucleated blastomeres of a two‐cell embryo resulted in successful production of identical triplet and twin mice. The proportion of reconstituted embryos that developed in blastocysts was 71% (84/118) when four‐cell embryos were used as donors of nuclei; 10 sets of quadruplet and nine sets each of triplet and twin blastocysts were obtained by this technique. After transfer to recipients, 30% (18/61) developed to term, and one set of identical triplet and four sets of identical twin mice were obtained. When two‐cell embryos were used as donors of nuclei, 79 (95%) sets of twin embryos developed to blastocysts. Of 38 twin blastocysts transferred to recipients, 21 sets (55%) developed to term as identical twin mice. These results demonstrate that the enucleated two‐cell embryo develops in vitro after transfer of a nucleus from a two‐ or four‐cell embryo and the resultant blastocyst has high potential for development to term after transfer to a recipient.
Effects of lamellolysin from a parasitoid wasp on Drosophila blood cells in vitro
Authors: Rizki R. M. , Rizki T. M. 
Published: June 2005

AbstractFemale parasitoid Leptopilina heterotoma inject a factor, lamellolysin, along with their eggs into the host hemocoel to destroy selectively host hemocytes that encapsulate foreign objects. In parasitized Drosophila melanogaster larvae, these hemocytes (lamellocytes) change from discoidal cells to bipolar cells that no longer adhere to each other to form capsules. To study the effects of lamellolysin on Drosophila lamellocytes in vitro, a giant strain of D. melanogaster was constructed to yield hemolymph with an abundance of lamellocytes. The effect of lamellolysin on the adhesivity of lamellocytes in vitro was demonstrated when the cells were gently rotated in the culture medium. Under these conditions, the bipolar shape of the affected lamellocytes resembled that of lamellocytes in parasitized hosts. When lamellocytes were exposed to lamellolysin in stationary culture medium, the elongation of the bipolar cells continued until they became threadlike. Lamellocytes fragmented in both stationary and rotating culture medium in the presence of lamellolysin, although loss of cellular material was more pronounced in the latter. This study demonstrates that lamellolysin acts directly and destructively on lamellocytes.
Protamines in prosobranchian gastropods (mollusca) vary with different modes of reproduction
Authors: Daban Montserrat , Chiva Manel , Rosenberg Ellen , Kasinsky Harold E. , Subirana Juan A. 
Published: June 2005

AbstractWe have studied the protamines from different families of prosobranch gastropods. In those with external fertilization we find a simple pattern of sperm nuclear basic proteins, consisting of one major protamine. This protamine has between 75 and 105 amino acid residues in the ten species of the order Archaeogastropoda that we have examined. In six species of the order Patellogastropoda (Kozloff, Marine Invertebrates of the Pacific Northwest, Univ. of Wash. Press, Seattle, pp. 193–232, 1987), the protamine‐like component contains 220 ± 10 amino acid residues. However, the protamines from the archaeogastropod Monodonta turbinata and the patellogastropod Patella cerulea show a very similar amino acid composition. Cytochemically, four species of archaeogastropods and three species of patellogastropods show intermediate type 3 sperm basic proteins in the classification scheme of Bloch (Genetics 61:93–111, 1969; Handbook of Genetics, Plenum, New York, pp. 136–167, 1976). The sperm basic protein profile in six internally fertilizing species of the orders Mesogastropoda and Neogastropoda is more complex since several protamine bands are found. In all cases the major protamines have high electrophoretic mobilities and the number of amino acid residues is estimated to be from 40 to 60. The combined set of major protamines in the mesogastropod Littorina neritoides and the neogastropod Murex brandaris display a similar amino acid composition that differs significantly from that in the externally fertilizing gastropods. In one mesogastropod and three neogastropod species cytochemical staining indicates the possible presence of type 2 stable protamines. Protamines from a neogastropod have a capacity for compacting DNA that is similar to that of an externally fertilizing archaeogastropod. We propose that changes in protamine features amongst different prosobranch gastropods are correlated with changes in nuclear condensation patterns and the fertilization biology of these mollusks.
Isolation of highly acidic and vanadium‐containing blood cells from among several types of blood cell from ascidiidae species by density‐gradient centrifugation
Authors: Michibata Hitoshi , Iwata Yukinari , Hirata Junko 
Published: June 2005

AbstractThe reported pH values of ascidian blood cells vary considerably. It is likely that one or two of several different types of blood cell must have a highly acidic solution within their vacuoles, in which vanadium ions would be present in a reduced state. Thus, one of the reasons for the variation in reported pH values may be that measurements of pH were made without fractionation of the total population of cells. In the present experiments, the combination of fractionation of whole cells by density‐gradient centrifugation, use of a microelectrode that allows measurements of pH under anaerobic conditions, and atomic absorption spectrometry for determinations of vanadium revealed that the contents of signet ring cells, recently identified as vanadocytes, of three ascidian species, Ascidia gemmata, A. ahodori, and A. sydneiensis samea, had low pH values of 2.4, 2.7, and 4.2, respectively. Results obtained by ESR (electron spin resonance) spectrometry confirmed the values of pH obtained with the microelectrode.