bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of the progression of squamation and the formation of ctenii in the Japanese flounder, Paralichthys olivaceus
Authors: Kikuchi Shin‐Ichi , Makino Naoshi 
Published: June 2005

AbstractThe progression of squamation and the formation of ctenii in developing juveniles of completely ambicolorate specimens of the Japanese flounder, Paralichthys olivaceus (Temmink et Schlegel), have been examined and compared with those of normally colored fish. The squamation developed with a similar pattern on both the ocular and blind sides of completely ambicolorate fish and of normal fish. In the normal fish, formation of ctenii occurred only on the ocular side and not on the blind side. In the completely ambicolorate fish, the formation of ctenii occurred on both the ocular and the blind side, but the formation of ctenii on the blind side differed from that on the ocular side in both normal and completely ambicolorate fish in terms of both mode and pattern. On the blind side of ambicolorate fish, the formation of ctenii progressed not from the lateral axis as is the case in the normal fish, but from the dorsal and ventral edges just after the formation of ctenii reached the edges on the ocular side, suggesting the diffusion of an unknown factor(s) through the dermal tissue.
Protection of rabbit embryos against fracture damage from freezing and thawing by encapsulation in calcium alginate gel
Authors: Kojima T. , Hashimoto K. , Ito S. , Hori Y. , Tomizuka T. , Oguri N. 
Published: June 2005

AbstractAvoidance of fracture damage to the zona pellucida during freezing and thawing is essential for the successful freezing of rabbit embryos. The aim of this study was to examine the effects of encapsulation of rabbit embryos in calcium alginate gel, prior to freezing, on damage to the non‐cellular components (zona and mucin coat) caused by freezing and thawing, and on the survival of embryos after thawing in vivo as well as in vitro. Morulae immersed in 2% sodium alginate in Ringer solution were aspirated into a Pasteur pipette. The contents of the pipette were then ejected into a 110 mM solution of calcium chloride. After 30 min, 1‐ to 2‐mm long semi‐solid cylinders, each including one embryo, were cut off with a surgical blade. In the presence of 11% dimethyl sulfoxide, the encapsulated embryos were cooled by the standard method and stored in liquid nitrogen. After rapid thawing, the alginate gel was mechanically removed from around the embryos, and the embryos were morphologically evaluated and allocated to different groups for examination of their development in vitro or in vivo. The percentage of embryos with an intact zona was higher in the encapsulated group than in the non‐encapsulated group (95.3% vs. 76.5%, P < 0.001). The encapsulation markedly reduced the occurrence of damage to the mucin coat (from 43.1% to 8.5%, P < 0.001). The frozen and thawed embryos that were released from alginate gel developed normally in vitro (86.3%) and in vivo (54.2%). The results suggest that encapsulation of rabbit embryos in alginate gel prior to freezing improves the percentage of transferable embryos after thawing and increases the number of offspring that originate from frozen and thawed embryos.
Comparative kinematic analysis of prey capture in Anolis carolinensis (iguania) and Lacerta viridis (scleroglossa)
Authors: Bels Vincent L. , Goosse Veronique 
Published: June 2005

AbstractThe kinematic profiles of jaw movements are described for Anolis carolinensis and Lacerta viridis feeding on the same prey item (maggot). A. carolinensis is an iguanian (typified by lingual prey capture) and L. viridis is a scleroglossan (typified by prey capture using jaws alone). A. carolinensis, however, catches maggots by using only the jaws. In so doing, it exhibits the four stages of gape profile considered typical for lizards (slow open, fast open, fast close, slow close). Gape cycle in L. viridis shows a hyperbolic curve (no slow open). Two hypotheses concerning the relationship between the two gape cycles are discussed.
Mobilization of lipid and protein by embryonic snapping turtles in wet and dry environments
Authors: Janzen Fredric J. , Packard Gary C. , Packard Mary J. , Boardman Thomas J. , Zumbrunnen James R. 
Published: June 2005

AbstractEggs of common snapping turtles (Chelydra serpentina) were incubated at 26°C on substrates with water potentials of – 150 kPa (wet) and – 850 kPa (dry) to assess the effects on patterns of mobilization of nutrients from the yolk. Embryos developing at – 150 kPa mobilized and incorporated both lipid and protein more rapidly than did embryos developing at – 850 kPa. As a consequence, embryos developing in wet environments hatched at a larger size than did embryos developing in dry settings. This effect of moisture on embryonic metabolism and growth in snapping turtles differs from that found in birds in which embryonic growth apparently is unaffected by moisture.
Photomanipulation of sexual maturation and breeding cycle of the steppe polecat (Mustela eversmanni) and other techniques for more rapid propagation of the species
Authors: Mead Rodney A. , Neirinckx Sandra 
Published: June 2005

AbstractTwenty steppe polecats were divided into 2 groups, each consisting of 4 males and 6 females, and subjected to either a natural photoperiod (controls) or alternating periods of short (8 h light/16 hr dark for 8–9 weeks) and long days (16 h light/8 h dark for 16–20 weeks). The experimental photoperiod significantly accelerated sexual maturation in both sexes, with males developing maximal testis size within 57 days and females breeding after an average of 52 days exposure to 16L/8D. Males in the experimental group completed 2 1/2 testicular cycles and participated in mating during 3 successive breeding seasons during the 18 month period whereas males in the control group completed a single testicular cycle and only had an opportunity to mate during a single breeding season. Females in the experimental group produced 3 litters whereas females in the control group only gave birth to a single litter. Litter size averaged 6.9 ± 2.0 (n = 23) and did not significantly differ with age, parity, or treatment. Pseudopregnant females returned to estrus within 12 days after the expected date of parturition, were bred, and gave birth to kits. Polecats which were subjected to the experimental photoperiods completed more molting cycles and underwent more photoperiod‐induced changes in body weight than those in the control group.Death or removal of kits within 8 days after birth resulted in 12/12 females returning to estrus within 6–26 days. Eleven of these females were remated and gave birth to kits. Eight domestic ferrets readily accepted neonatal polecat kits and 5 successfully reared kits, although kit survivial was quite poor. These results clearly demonstrate the potential of these techniques for inducing precocious sexual maturation and production of multiple litters each year.
Conserved tissue‐restricted expression of HUC 1‐1 actin phenotype among eumetazoan organisms
Authors: Sawtell N. M. , Hartman A. L. , Lessard J. L. 
Published: June 2005

AbstractActin has evolved from a single protein into a family of more than six distinct isoforms in mammals. Based on amino acid sequence data, actins segregate into two major classes, the “cytoplasmic” or nonmuscle actins, present in all animals, and the “α‐” or muscle actins, a group restricted to vertebrate muscle. We have recently identified two unique actin isoforms in rat intestinal brush border which combine features of these two classes. The amino terminal regions of these actins indicate that they are of a cytoplasmic type and yet the carboxy terminal regions contain an epitope (defined by Mab HUC 1‐1) which, among mammalian actins, is restricted to the muscle isoforms. We report here that in addition to the rat, all species thus far examined which have an intestinal “brush border” express actins containing the HUC 1‐1 epitope in this region. Furthermore, we show that the actins present in the muscle tissue of nonvertebrate eumetazoans, which are all of the cytoplasmic type, also contain this epitope. Thus these findings suggest that the HUC 1‐1 epitope appeared early on a subset of cytoplasmic‐type actins and was retained among actins expressed in muscle tissue throughout the evolutionary divergence of these cytoplasmic‐type actins to the “α‐” muscle actins.
Effects of prolactin and bromocryptine on the regulation of testicular luteinizing hormone receptors in mice
Authors: Takase Minoru , Tsutsui Kazuyoshi , Kawashima Seiichiro 
Published: June 2005

AbstractThe binding of luteinizing hormone (LH) to testicular homogenates increased gradually in mice from 15 to 60 days of age, while the level at 90 days was almost the same as that at 60 days. The plasma concentration of prolactin (PRL) increased significantly from 15 to 40 days and thereafter remained constant. In order to ascertain the influence of PRL on testicular receptors for LH, bromocryptine was injected subcutaneously for 10 days into immature (20‐day‐old) and adult (90‐day‐old) mice. In 20‐day‐old mice, treatment with bromocryptine significantly reduced the plasma levels of PRL but had no significant effects on the binding of LH to receptors in 30‐day‐old mice. However, in 90‐day‐old mice, treatment with bromocryptine led to a significant reduction in numbers of receptors for LH 10 days later. There was no difference in dissociation constants (Kd) between groups of oil‐injected (Kd = 6.5 × 10−10 M) and bromocryptine‐injected (Kd = 4.6 × 10−10 M) mice. The reduction in binding of LH per testis of 100‐day‐old mice after treatment with bromocryptine was eliminated by the simultaneous administration of ovine (o) PRL. The plasma level of follicle‐stimulating hormone (FSH) in 100‐day‐old mice, which tended to be decreased as a result of treatment with bromocryptine, was markedly increased by treatment with oPRL. There were no distinct changes in binding of FSH in any of the groups. These results suggest that, in immature mice, PRL is not the principal factor involved in the age‐related increase in numbers of receptors for LH while, in adult mice, PRL plays a stimulatory role in the increase in the number of these receptors.
Developmental potential of biopsied mouse blastocysts
Authors: Nijs Martine , Van Steirteghem André 
Published: June 2005

AbstractThe health of a preimplantation embryo can be diagnosed in one or more cells biopsied from the conceptus. Here, we tried to evaluate the impact of biopsy of some trophectoderm cells from hatching mouse blastocysts on their further in vitro implantation and early egg cylinder formation. Of 374 blastocysts evaluated 112 hours after hCG, 34% initiated hatching with a small number of mural, polar, or intermediate trophectoderm cells. Half of 59 embryos that underwent induction of hatching by zona puncturing herniated some cells through this opening. After removal of cells with a glass microneedle from spontaneously hatching blastocysts, viability assessed by vital FDA staining was impaired, as well as the in vitro zona pellucida shedding and implantation. When polar trophectoderm cells were biopsied, a significantly lower number of embryos reached the egg cylinder stage.
Role of body temperature in seasonal acclimatization: Photoperiod‐induced rhythms and heat production in Meriones crassus
Authors: Haim A. , Levi G. 
Published: June 2005

AbstractHeat production by means of nonshivering thermogenesis (NST) and food consumption were compared in individuals of the fat jird Meriones crassus, acclimated to 8L:16D and 16L:8D cycles at an ambient temperature of 28°C. Daily rhythms of body temperature were compared at the same time.A significant (P < 0.05 and P < 0.005) increase in NST and food consumption was noted in fat jirds acclimated to short photoperiod 8L:16D when compared with those acclimated to a long photoperiod 16L:8D. A clear difference in rhythms of body temperature was observed between the two groups.In light of these results it is reasonable to assume that seasonal acclimatization in the fat jird can be partly induced by the change of photoperiod. Rhythms of body temperature in the fat jird are entrained by photoperiod and appear to be adjusted to the different metabolic demands of summer and winter.
Action of 1,25‐dihydroxyvitamin D3 and parathyroid hormone on 45calcium uptake by the yolk sac membrane of chick embryos
Authors: Lee S. K. , Clark N. B. , Brown S. C. 
Published: June 2005

AbstractDuring development, the chick embryo mobilizes the calcium it needs from two extraembryonic sources, initially from the yolk and later from the eggshell. Calcium may be hormonally regulated during avian embryogenesis, but details of this regulation are lacking. We investigated the effects of 1,25‐dihydroxycholecalciferol [1,25(OH)2D3], bovine parathyroid hormone [bPTH], and vehicle [ethanol or saline] on blood calcium values and incorporation of 45Ca into the yolk sac membrane of 9, 12, and 15 day chick embryos. Control data were also collected from uninjected 6 day embryos. Solutions were injected directly into the yolk sac compartment 48 and 24 hours prior to the experiment. Exogenous 1,25(OH)2D3 induced hypercalcemia in all age groups examined, while exogenous PTH induced hypercalcemia in day 12 and 15 embryos. Small disks of yolk sac membrane were incubated in medium to which 45Ca was added and assayed for 45Ca content at various intervals after start of incubation. In control yolk sac tissue, the uptake of 45Ca was greatest in younger embryos with decreasing uptake at developmentally more advanced ages; 1,25(OH)2D3 treatment significantly enhanced the uptake of 45Ca into yolk sac tissue in all groups (9, 12, and 15 day embryos). PTH treatment caused a significant elevation in 45Ca uptake in the day 12 and 15 embryos.
Relative developmental abilities of hamster 2‐ and 8‐cell embryos cultured in hamster embryo culture medium‐1 and ‐2
Authors: Seshagiri Polani B. , Bavister Barry D. 
Published: June 2005

AbstractThe relative developmental abilities of hamster 2‐ and 8‐cell embryos in culture were compared using two versions of hamster embryo culture medium (HECM). These media differed primarily in the number of amino acids present, i.e., 20 amino acids in HECM‐1 and four amino acids in HECM‐2. When 2‐cell embryos were cultured for 24 h, the percentages of ⩾4‐cell embryos obtained in both HECM‐1 and HECM‐2 were comparable (≃93%); at the end of 48 h, the proportion of ⩾8‐cell embryos obtained in HECM‐1 (82.5%) was significantly (P ⩽ 0.001) more than that obtained in HECM‐2 (67.9%). Interchange of media, after 24 h culture, did not enhance the ability of cultured 2‐cell embryos to become blastocysts. When 8‐cell embryos were cultured for 18 h in HECM‐1 and ‐2, there was no appreciable difference in the proportion of total blastocysts formed (89‐91%). However, there were significantly (P ⩽ 0.001) more late blastocysts in HECM‐2 than in HECM‐1 (68.2% vs. 38.4%). Embryo development from 2‐ and 8‐cell stages was compared in media that differed by the presence and absence of phenol red and penicillin‐G. There was no difference in embryo development when these compounds were present or absent. Similarly, the difference in pyruvate concentration between HECM‐1 and ‐2 (0.5 and 0.2 mM, respectively) did not affect embryo development. These results show that a) the presence of four amino acids (Phe, Ile, Met, and Gln as in HECM‐2) was not sufficient for 2‐cell embryo development in culture and additional amino acids (as in HECM‐1) were required; and b) the four amino acids were better than 20 amino acids for obtaining late blastocysts starting from the 8‐cell stage. The low percentage of late blastocysts obtained in HECM‐1 was attributed to the presence of inhibitory amino acids in this formulation. Hence, it is concluded that the optimum medium for development of hamster embryos would contain <4 and >20 amino acids.
Glutathione effects Ciona intestinalis larval tunic morphogenesis
Authors: Robinson W. E. , Michibata H. , Kustin K. , Doona C. J. 
Published: June 2005

AbstractDechorionated neurulae and early tail‐bud embryos of Ciona intestinalis (Linnaeus) develop into tadpole larvae without fully formed dorsal, ventral, or caudal fins, although other aspects of organ and tissue development appear normal. Groups of dechorionated neurulae treated with the reducing agent glutathione exhibit a 5‐8% enhancement in caudal fin length compared with dechorionated controls. Other reducing substances tested, namely, gallic acid, chlorogenic acid, cysteine, and dithiothreitol, had no effect on fin formation, possibly due either to their rapid oxidation in aerated seawater (chlorogenic and gallic acids) or to kinetic inertness (dithiothreitol and cysteine). These results imply that larval fin morphogenesis requires secretion of a specific reducing substance.
Limb regeneration in juveniles of the mud crab Rhithropanopeus harrisii following removal of developing limb buds
Authors: McConaugha John R. 
Published: June 2005

AbstractRegeneration of autotomized limbs by third crab stage Rhithropanoepus harrisii followed the all‐or‐none rule and was completed without significant alteration of the normal molt cycle. Loss of three to six primary limb buds during late intermolt or early premolt (D0, day 3) resulted in a delay of ecdysis while secondary limb buds were formed. The number of animals delaying ecdysis and producing secondary buds was stimulus dependent. While the number of animals initiating secondary regeneration increased with the number of primary buds lost, fewer animals in these groups were capable of regenerating all of the missing primary buds. Animals not initiating secondary regeneration or regenerating only some of the primary limb buds completed regeneration during the following molt cycle. The duration of the subsequent molt cycle was significantly shorter for all regenerating animals, including the regeneration control group. Partial regeneration and acceleration of subsequent molts appears to be the best allocation of available energy reserves.
Changes in the function of dermal fibroblasts in the tadpole tail during anuran metamorphosis
Authors: Kinoshita Tsutomu , Takahama Hideki , Sasaki Fumie 
Published: June 2005

AbstractThe role of the fibroblast in the degeneration of the dermal collagen layers was examined in the tail skin of Rana japonica during metamorphosis. At the early stages of tail resorption, spindle‐shaped fibroblasts, which had been staying beneath a dermal collagen layer, began to put out numerous cytoplasmic processes and to invade the collagen layers. As degeneration of the tail progressed, invading cells within the dermis seemingly increased in number. However, quantitative data concerning cell density within the dermis showed that remarkable cell migration other than invasion of fibroblasts does not occur in the dermis until the final stage of metamorphosis. Ultrastructural analyses by staining with ruthenium red and cytochemical localization of acid phosphatase supported a possibility that dermal collagen fibers are intracellularly digested in the invading fibroblasts. In order to confirm the ultrastructural observation that phagocytes of collagen fibers are fibroblasts, constituent cells of tail skin were characterized with isolectin GS‐1, from Griffonia simplicifolia, directly labeled with colloidal gold. In normal tail skin, GS‐1 bound to the free surface of the epidermis, macrophages, and neutrophils, but not to dermal fibroblasts at all. Binding of GS‐1 was also not found on the collagen‐phagocytosing cells in the degenerating skin. Thus, analysis with GS‐1 lectin was consistent with ultrastructural results. These results suggest that phagocytes of collagen fibers in the degenerating tail are fibroblasts and/or fibroblast‐derived cells and that dermal fibroblasts in the tail change in function to become collagen‐phagocytosing cells during metamorphosis.
Reproduction, pregnancy, and circulating reproductive hormones in the lactating siberian hamster (Phodopus sungorus)
Authors: Parkening T. A. , Collins T. J. 
Published: June 2005

AbstractThe Siberian hamster (Phodopus sungorus) has a post‐partum estrus in which it may mate, ovulate, and become pregnant. The pregnancy proceeds as a normal pregnancy while suckling young. Delayed implantation does not exist in this species. If the female fails to become pregnant during the post‐partum estrus, at least one and possibly two other estrous cycles follow in which she may mate and become pregnant. Of 88 litters born after the first litter from 20 pairs of Siberian hamsters during their reproductive life span the days elapsing/mean number of young (± SEM) were as follows: 18–23 days (5.85 ± 0.3, n = 33), 24–29 (5.16 ± 0.4, n = 19), 30–35 (4.25 ± 0.6, n = 8), 40–49 (4.33 ± 0.4, n = 16), 50–52 (5.80 ± 1.0, n = 5), 62–65 (4.00 ± 1.2, n = 3), 70–78 (2.75 ± 0.6, n = 4). No correlation could be found between the number of young nursing and the number of days between litters.Circulating plasma levels of progesterone (P), prolactin (Prl), luteinizing hormone (LH), and follicle‐stimulating hormone (FSH) were radioimmunoassayed from lactating pregnant and non‐pregnant Siberian hamsters and from lactating Syrian and Chinese hamsters at 2, 5, 10, and 15 days post‐partum. At 5 days post‐partum, both pregnant and non‐pregnant Siberian hamsters exhibited significantly higher levels of P than Syrian or Chinese hamsters. Prl levels were significantly lower in Siberian hamsters at 2 and 5 days post‐partum when compared with those in Syrian hamsters. Selected rank‐order comparisons showed a strong negative correlation (P<.001) between P and Prl for pregnant lactating Siberian hamsters.
Effect of egg water from Bufo arenarum on the fertilizing capacity of homologous spermatozoa
Authors: Fontdevila Marina F. Díaz , Bloj Bernabé , Cabada Marcelo O. 
Published: June 2005

AbstractThe effect of egg water (EW) from oocytes' string of Bufo arenarum on the fertilizing capacity of homologous spermatozoa was studied. When Bufo arenarum spermatozoa were incubated in EW, a decrease in the fertilizing capacity of spermatozoa was observed. This effect depended on the osmolarity of the incubation medium. When the osmolarity was between 35 and 40 mOsm/kg water, inhibition of fertility was observed even in the presence of only 10% EW. When osmolarity was greater than 60 mOsm/kg water, even 90% EW had no effect. Control spermatozoa incubated in saline medium with osmolarity similar to that of EW did not show any decrease in fertility. These effects seem to be related to a component of the EW that can be extracted with agents used to extract lipids. The effect of such lipidic extracts of egg water (LEEW) in reducing the fertilizing capacity of a sperm suspension depends on the concentration of LEEW and the duration of incubation.