Injection of mitochondria into oocytes and fertilized eggs]

The suspension of mitochondria isolated from the loach embryos or the frog heart were injected in the oocytes or fertilized eggs of the loach, newt, toad and frog in the amount roughly equivalent to the content of mitochondria in the egg. After the injection the oocytes did not differ during several days from the normal ones and the fertilized eggs of the loach, newt and South Afican clawed toad developed normally. The activity of cytochrome oxidase in the injected oocytes was kept at a somewhat higher level (1.4 to 1.9 vs 1.0 in the control) during several days. In the developing eggs the activity of cytochrome oxidase began to decrease from the blastula stage and attained rapidly the control level. The decrease of the enzyme activity is due to non-specific degradation of excessive mitochondria or to compensatory inactivation of the enzyme ensuring the maintenance of its normal activity during the development.     

Gamma-glutamyltransferase activity in the developing brain of the rat and the pika Ochotona pusilla

The activity of gamma-glutamyl transferase (GGTF, EC 2.3.2.2) has been investigated in different brain structures (hemispheres, cerebellum, hippocamp, brain stem) of newborn, 3-8-, 15-, 21-30-day and adult rats and piping hare. In both animals, the activity of this enzyme in all the structures investigated increases during ontogenesis. Interspecific differences were found in the increase of the enzymic activity in different brain structures during ontogenesis as well as in the level of the activity in different structures in mature animals.     

The presence of a correlation between erythrocyte acetylcholinesterase activity and body mass in small rodents

Studies have been made on the activity of erythrocyte acetylcholinesterase in 18 species of wild and laboratory rodents. Significant differences in the enzymic activity unrelated to taxonomic position of rodents were revealed. Negative correlation was found between the enzymic activity and body mass in rodents. The relationship between these parameters for wild rodents is approximated by an allometric equation Y = 1.1 . X-0.73, for laboratory species--Y = 1.5 . X-0.41. It is suggested that the revealed relationship indicates the existence of a connection between the activity of erythrocyte acetylcholinesterase and the intensity of metabolism in small rodents.     

Comparative study of superoxide dismutase and glutathione peroxidase activity in embryos and skeletal muscles of adult fish

The activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in loach and sturgeon embryogenesis as well as in red and white skeletal muscles of loach was studied. The specific activity of cytoplasmic and mitochondrial forms of superoxide dismutase in developing sturgeon embryos was higher than in loach embryos, which may be due to oxygen conditions under which these species develop in nature. A similar dependence was also observed for the activity of glutathione peroxidase in embryos of these fish species. A comparative study of specific superoxide dismutase activity in loach and sturgeon embryos and in loach skeletal muscles showed that the activity of cytoplasmic superoxide dismutase is maximum in red and white muscles and minimum in loach embryos, whereas the activity of the mitochondrial form of this enzyme is maximum in red skeletal muscles.     

Indirect positive effects of agricultural modernization on the abundance of Japanese tree frog tadpoles in rice fields through the release from predators

In Japan, the density of Japanese tree frogs (Hyla japonica) may not be necessary high in traditional rice fields compared to modern fields because the modernization of drainage systems from shallow earthen ditches to deep concrete-line ones reduces the abundance of predators/competitors for tadpoles, such as dojo loach (Misgurnus anguillicaudatus). This hypothesis was tested using two approaches. First, laboratory experiments revealed that the presence of the loach significantly reduced the survival of tree frog eggs and tadpoles. Second, observational studies in rice fields showed that the direct effect of modernization on tadpoles was not significant but the indirect (and thus total) effects were weakly positive due to the reduction in the density of dojo loach. Our study suggests that recent agricultural intensification in rice fields does not negatively impact all aquatic species but that some species may not be affected or can even flourish by having tolerance for the changes and release from potential predators or competitors.     

Patterns of activity and body temperature of Aldabra giant tortoises in relation to environmental temperature

We studied the temperature relations of wild and zoo Aldabra giant tortoises (Aldabrachelys gigantea) focusing on (1) the relationship between environmental temperature and tortoise activity patterns (n = 8 wild individuals) and (2) on tortoise body temperature fluctuations, including how their core and external body temperatures vary in relation to different environmental temperature ranges (seasons; n = 4 wild and n = 5 zoo individuals). In addition, we surveyed the literature to review the effect of body mass on core body temperature range in relation to environmental temperature in the Testudinidae. Diurnal activity of tortoises was bimodally distributed and influenced by environmental temperature and season. The mean air temperature at which activity is maximized was 27.9°C, with a range of 25.8–31.7°C. Furthermore, air temperature explained changes in the core body temperature better than did mass, and only during the coldest trial, did tortoises with higher mass show more stable temperatures. Our results, together with the overall Testudinidae overview, suggest that, once variation in environmental temperature has been taken into account, there is little effect of mass on the temperature stability of tortoises. Moreover, the presence of thermal inertia in an individual tortoise depends on the environmental temperatures, and we found no evidence for inertial homeothermy. Finally, patterns of core and external body temperatures in comparison with environmental temperatures suggest that Aldabra giant tortoises act as mixed conformer–regulators. Our study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change.     

Phylogenesis of the general structure of immunoglobulins.

The study of the general structure of macroglobulins and 7S (IgG) immunoglobulins of frog and tortoise by relaxation methods shows the rotational correlation time of 7S immunoglobulins to be 67–68 nsec whereas that of macroglobulins of frog is 135 nsec and of tortoise is 103 nsec. Experimental values of rotational correlation time for 7S immunoglobulins are close to those calculated for the model of this molecule approximated by the rigid rotational ellipsoid and lower than those estimated for macroglobulins. This indicates that frog and tortoise 7S immunoglobulins have a fairly compact general structure with no marked intramolecular rotational freedom for high-molecular fragments, whereas macroglobulins possess it to a limited extent. It is seen from our evidence on the rigidity of 7S immunoglobulins and the limited flexibility of macroglobulins in amphibia and reptiles, as compared to previous data on the limited flexibility of carp macroglobulins and on the pronounced flexibility of IgG and IgM of mammals, that the general structure becomes more flexible on passing from lower vertebrates to representatives of a more recent class of mammals. The reported increased flexibility of immunoglobulins accompanied by the progressive evolution of species is likely to provide one of the first indications of the possible directed selection in the course of molecular evolution.     

Plasmalogen distribution in the subcellular fractions of the vertebrate brain

Studies have been made on plasmalogen and diacylic forms of phospholipids, i. e. phosphatidylethanolamine and phosphatidylcholine (their relative content and ratio), in subcellular fractions isolated from the brain of the trout Salmo trideus, frog Rana temporaria, pigeon Columba livia, tortoise Testudo horsfieldi, and rabbit. Investigation was carried out on 5 subcellular fractions (myelin, nuclei, microsomes, mitochondria, synaptosomes) as well as on brain homogenates. In all the fractions, relative content of plasmalogens is the lowest in the trout, increasing in parallel with the increase in the complexity of the nervous system and reaching the highest values in pigeons and rabbits.     

Sleep--wakefulness cycle of cold-blooded vertebrates according to the results of continuous contact-free recording of the heart rate and motor activity

Using continuous non-contact registration of the heart rate and motor activity, separate states were revealed in awakefulness--sleep cycle of various poikilotherms (the catfish Ictalurus nebulosus, frog Rana temporaria, tortoise Emys orbicularis). The method employed allowed also to classify motor automatic activity which was observed in earlier experiments at the background of sleep-like forms of the resting state. Two basic types of these automaticities were distinguished. Comparison of the data obtained on poikilothermic animals with those obtained on homoiothermic ones (the ground squirrel Citellus parryi) indicates the validity of using the heart rate and motor activity for detection of the awakefulness-sleep cycle.     

Phylo- and ontogenic characteristics of lipid peroxidation in the retina of vertebrates

Phylo- and ontogenetic aspects of lipid peroxidation and antioxidative enzyme system in the retina of vertebrates were studied. It was established that both the intensity of lipid peroxidation and the activity of glutathione peroxidase in the retina of different vertebrate animals (carp, frog, tortoise, pigeon, rabbit) considerably diminished with evolution. The differences in the intensity of lipid peroxidation and the activity of glutathione peroxidase between dark- and light-adapted retinas also decreased depending on the level of the development. The activity of glutathione peroxidase in the retina of chick embryos was found only at the end of the incubation period.     

Serologic and molecular evidence for Testudinid herpesvirus 2 infection in wild Agassiz's desert tortoises, Gopherus agassizii

Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.     

Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management

The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.     

Does caloric restriction extend life in wild mice?

To investigate whether mice genetically unaltered by many generations of laboratory selection exhibit similar hormonal and demographic responses to caloric restriction (CR) as laboratory rodents, we performed CR on cohorts of genetically heterogeneous male mice which were grandoffspring of wild-caught ancestors. Although hormonal changes, specifically an increase in corticosterone and decrease in testosterone, mimicked those seen in laboratory-adapted rodents, we found no difference in mean longevity between ad libitum (AL) and CR dietary groups, although a maximum likelihood fitted Gompertz mortality model indicated a significantly shallower slope and higher intercept for the CR group. This result was due to higher mortality in CR animals early in life, but lower mortality late in life. A subset of animals may have exhibited the standard demographic response to CR in that the longest-lived 8.1% of our animals were all from the CR group. Despite the lack of a robust mean longevity difference between groups, we did note a strong anticancer effect of CR as seen in laboratory rodents. Three plausible interpretations of our results are the following: (1) animals not selected under laboratory conditions do not show the typical CR effect; (2) because wild-derived animals eat less when fed AL, our restriction regime was too severe to see the CR effect; or (3) there is genetic variation for the CR effect in wild populations; variants that respond to CR with extended life are inadvertently selected for under conditions of laboratory domestication.     

Serological studies of haemorrhagic fever with renal syndrome (HFRS) in Poland. Preliminary report

Serological studies of Hantaan virus infections among--blood donors (control group)--patients: chronic dialysed, leptospirosis suspected, hospitalised for various diseases,--risk group population: farmers, laboratory staff (contact with laboratory animals), as well as laboratory and wild animals (rodents) were carried out. Surveys were done by the indirect immunofluorescent antibody (IFA) procedure with 5 Hantaan virus strains as antigens.     

Detection of hybridization between two loach species (<Emphasis Type="Italic">Paramisgurnus dabryanus</Emphasis> and <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis>) in wild populations

Artificial interspecific hybrids between large scale loach P. dabryanus and tetraploid pond loach M. anguillicaudatus (Cobitidae, Cypriniformes) are viable. To detect the occurrence of possible natural hybridization, genetic analyses by using microsatellite markers were performed for natural populations of large scale loach and pond loach, the reciprocal laboratory hybrids, and “supposed hybrids” with ambiguous morphology. The fertility of the artificial hybrids was also tested. At one diagnostic microsatellite (Mac50), one out of 20 “supposed hybrids” was identified to be F₁ hybrid between the two loach species because it had the same genotype as that of the laboratory hybrids. The triploid hybrids between the two species were confirmed to be female-sterile. The results show that rare hybridization has occurred between diploid large scale loach and tetraploid pond loach in nature although it may have little effect in genetic introgression. This study is helpful for fish conservation and encourages further investigation on natural hybridization and introgression of loaches.     

Species differences in epinephrine concentration and norepinephrine N-methyltransferase activity in hypothalamus and brain stem

1. The concentration of epinephrine, norepinephrine and dopamine, and the activity of norepinephrine N-methyltransferase, the epinephrine-forming enzyme, were determined in hypothalamus and brain stem in several species. 2. Epinephrine concentration in hypothalamus, a nerve terminal region, varied in the order frog greater than turtle greater than chicken greater than cat greater than dog greater than pigeon greater than rat greater than ferret greater than hamster greater than mouse, with concentrations being undetectable in rabbits, horses and guinea pigs. 3. Epinephrine concentration was lower than norepinephrine concentration in all species except the frog. 4. NMT activity was detected in all species except guinea pigs. 5. Epinephrine concentration was lower in brain stem, a cell body region, than in hypothalamus in all species. Only in the frog brain stem was there more epinephrine than norepinephrine. 6. No epinephrine or NMT activity was detected in either brain region in guinea-pigs.     

Effect of loach consumption on the reproduction of giant water bug Kirkaldyia deyrolli: dietary selection, reproductive performance, and nutritional evaluation

Rice fields provide major habitats for lentic aquatic insects including the giant water bug Kirkaldyia (=Lethocerus) deyrolli (Heteroptera: Belostomatidae) in Japan. Previous researchers have emphasized that conserving populations of the frogs, Hyla japonicus and Rana nigromaculata, is very important for preserving K. deyrolli because these frogs were found to be a major component of the diet of K. deyrolli adults. However, these previous studies were carried out in rice fields with no loaches, Misgurnus anguillicaudatus, which were probably been inhabited by loaches in the past. A series of field surveys and laboratory experiments were conducted to determine the dietary preference of K. deyrolli adults for loaches, frogs, and aquatic insects; the reproductive effects of consuming these foods; and their protein content. In the rice fields, K. deyrolli adults ate loaches when they were available. When the three prey species (frog: R. nigromaculata, loach: M. anguillicaudatus, and dragonfly: Orthetrum albistylum speciosum) were supplied in laboratory conditions, K. deyrolli adults ate more loaches than frogs or dragonflies. In addition, K. deyrolli adults provided with loaches or frogs laid more egg masses within the limited breeding season than when provided with dragonflies. The edible parts of the loach bodies were the largest of the three prey types. It is possible that K. deyrolli adults have been forced to eat frogs due to reductions in the population density of loaches because modern rice cultivation obstructs loach migration routes and reduces their spawning grounds.     

Non-identical contributions of two membrane-bound cpSRP components, cpFtsY and Alb3, to thylakoid biogenesis

The insertion of light-harvesting chlorophyll proteins (LHCPs) into the thylakoid membrane of the chloroplast is cpSRP-dependent, and requires the stromal components cpSRP54 and cpSRP43, the membrane-bound SRP receptor cpFtsY and the integral membrane protein Alb3. Previous studies demonstrated that the Arabidopsis mutant lacking both cpSRP54 and cpSRP43 had pale yellow leaves, but was viable, whereas the mutants lacking Alb3 exhibit an albino phenotype that is more severe and seedling lethality. We previously showed that a maize mutant lacking cpFtsY had a pale yellow-green phenotype and was seedling lethal. To compare the in vivo requirements of cpFtsY and Alb3 in thylakoid biogenesis in greater detail, we isolated Arabidopsis null mutants of cpftsY, and performed biochemical comparisons with the Arabidopsis alb3 mutant. Both cpftsY and alb3 null mutants were seedling lethal on a synthetic medium lacking sucrose, whereas on a medium supplemented with sucrose, they were able to grow to later developmental stages, but were mostly infertile. cpftsY mutant plants had yellow leaves in which the levels of LHCPs were reduced to 10-33% compared with wild type. In contrast, alb3 had yellowish white leaves, and the LHCP levels were less than or equal to 10% of those of wild type. Intriguingly, whereas accumulation of the Sec and Tat machineries were normal in both mutants, the Sec pathway substrate Cyt f was more severely decreased in the cpftsY mutant than in alb3, which may indicate a functional link between cpFtsY and Sec translocation machinery. These results suggest that cpFtsY and Alb3 have essentially similar, but slightly distinct, contributions to thylakoid biogenesis.     

亚热带林区啮齿动物对樱桃种子捕食和搬运的作用格局

在都江堰林区,通过在原生林、次生林和灌丛3类生境释放野生和栽培樱桃(Cerasus pseudocerasus)的种子,研究了啮齿动物对樱桃种子的捕食及其对樱桃种群更新的作用。结果表明,啮齿动物对樱桃两类种子的搬运无显著差异,而啮齿动物对野生樱桃种子的收获则明显快于栽培樱桃种子,且在3类生境均有类似的趋势。这说明啮齿动物偏爱于收获具有较高收益(种仁重/种子重)的野生樱桃种子。啮齿动物在小于10 d的时间尺度收获了所有释放的樱桃种子,其中,70%以上为啮齿动物所搬运。春季食物的匮乏可能是导致啮齿动物对樱桃种子有较大捕食压力的主要原因,而生境类型间的差异较小。因此,啮齿动物是都江堰林区樱桃地表种子的主要捕食者,它们对野生樱桃种子的选择性捕食和搬运能影响樱桃种子/果实的进化及其种群更新。     

Inbreeding linked to amphibian survival in the wild but not in the laboratory

We examined the effects of inbreeding on the performance of wood frog (Rana sylvatica) larvae in the field and in the laboratory. We used microsatellite analysis to establish the parentage and degree of inbreeding of the larvae. Two different estimators of inbreeding were used. The first was based on average multilocus heterozygosity, and the second was based on a molecular relatedness estimator. The estimators were highly correlated, and both showed a significant negative relationship between inbreeding and survival in the wild. However, there was no evidence that inbreeding influenced growth or development in the wild. Neither was there any evidence that inbreeding affected survival, growth, or development in the laboratory. These results suggest that, for wood frogs, inbreeding has a bigger effect on fitness in the wild than in captivity and that measurements of survival are more sensitive than measures of growth or development.