Altered mitogen response of peripheral blood lymphocytes in different stages of feline immunodeficiency virus infection

To elucidate relationship between disease progress and immunologic alteration in feline immunodeficiency virus (FIV) infection, we classified naturally infected cats into clinical stage groups using the working criteria modified from those for human immunodeficiency virus (HIV) infection. Among the five distinct stages described for HIV infection, the three phases; asymptomatic carrier (AC), AIDS related complex (ARC), and acquired immunodeficiency syndrome (AIDS), were evaluated for concanavalin A (Con A)-induced lymphocyte blastogenic activities by using glucose consumption assay. There was a significant decrease of lymphocyte response in AC phase. The loss of response became marked as the disease progressed to ARC and AIDS, with an almost complete loss of mitogen response in AIDS phase. In addition to the loss of a lymphocyte function, AIDS in FIV infection was characterized by marked emaciation, anemia or pancytopenia, and postmortem evidences of opportunistic infections and lymphoid depletion.     

Analysis of the canine IgE-binding epitope on the major allergen (Cry j 1) of Japanese cedar pollen with anti-Cry j 1 monoclonal antibodies

In our previous study [Immunology 91 (1997) 161] using monoclonal antibodies (mAbs) specific to Cry j 1, a major allergen in Japanese cedar (Cryptomeria japonica) pollen, we identified five independent epitopes (EP-1-EP-5) on the molecule and found that EP-1 and EP-5 are the predominant allergic epitopes for humans and monkeys, respectively. In this study, we analyzed the epitopes recognized by IgE in the sera of 10 dogs sensitive to C. japonica pollen allergen using an IgE-ELISA inhibition method with these mAbs. The IgE reaction patterns varied among dogs. In eight of the 10 dogs, IgE recognized EP-5 which is a predominant allergic epitope for monkeys with the pollenosis. In four dogs, IgE recognized EP-1 which is a predominant allergic epitope for human patients with the pollenosis. In three dogs, IgE recognized EP-4 which is a heat-stable epitope. EP-5 is a predominant allergic epitope for dogs and some, but not all, dogs have IgE reaction patterns to the epitopes similar to those of humans.     

Immunohistochemical localization of carbonic anhydrase isoenzymes in salivary gland and intestine in adult and suckling pigs

Localizations of carbonic anhydrase isoenzymes (CA I, CA II and CA III) were investigated immunohistochemically in the salivary glands and intestine of mature and suckling pigs. Carbonic anhydrase isoenzymes were not detected in the salivary glands of sucklings, but were present in the adult. Bicarbonate ion in saliva might be important for the digestion of solid foods in mature pigs, but unnecessary for the digestion of milk in sucklings. Expressions of CA I and CA II were detected strongly in the large intestine of the adult and sucklings, and faintly only at duodenum in the small intestine. CA I and CA II isoenzymes in the large intestine may be involved, at least in part, in ion absorption and water metabolism during digestion and absorption of milk in suckling pigs. In addition, CA I and CA II expression in the duodenal villus enterocyte may support the process of bicarbonate absorption in the duodenum.     

Comparative lectin histochemical studies on taste buds in five orders of mammals

Although it has been reported that specific proteins are present to take charge in the gustation in the taste buds, there have been only a few reports on the distribution of glycoconjugates binding to glycoproteins on the cellular membranes of the taste cells. In the present study, therefore, binding patters of 24 biotinylated lectins were examined in the three types of lingual papillae in five species of mammals belonging to different orders: cow (artiodactyl), horse (perissodactyl), monkey (primate), dog (carnivore) and mouse (rodent). As the results, lectin binding patterns were different among circumvallate, foliate and fungiform papillae, among the cells of the taste buds, and among animal species. These findings suggest that the different binding patterns of the lectins in the taste papillae and taste bud cells may be involved in different sensitivities of taste among mammalian species.     

Phylogenic aspects of the amphibian dual olfactory system

The phylogenic significance of the subdivision of dual olfactory system is reviewed mainly on the basis of our findings by electron microscopy and lectin histochemistry in the three amphibian species. The dual olfactory system is present in common in these species and consists of the projection from the olfactory epithelium (OE) to the main olfactory bulb (MOB) and that from the vomeronasal epithelium (VNE) to the accessory olfactory bulb (AOB). The phylogenic significance of subdivisions in the dual olfactory system in the amphibian must differently be interpreted. The subdivision of the MOB into its dorsal region (D-MOB) and ventral region (V-MOB) in Xenopus laevis must be attributed to the primitive features in their olfactory receptors. The middle cavity epithelium lining the middle cavity of this frog possesses both ciliated sensory cells and microvillous sensory cells, reminding the OE in fish. The subdivision of the AOB into the rostral (R-AOB) and caudal part (C-AOB) in Bufo japonicus formosus must be regarded as an advanced characteristic. The lack of subdivisions in both MOB and AOB in Cynops pyrrhogaster may reflect their phylogenic primitiveness. Since our lectin histochemistry to detect glycoconjugates expressed in the olfactory pathway reveals the subdivisions in the dual olfactory system in the amphibian, the glycoconjugates may deeply participate in the organization and function of olfactory pathways in phylogeny.     

Effect of cryoprotectant composition on in vitro viability of in vitro fertilized and cloned bovine embryos following vitrification and in-straw dilution

In this study the efficacy of the combination of glycerol (GLY) and ethylene glycol (EG) as cryoprotectants in a vitrification method developed for direct embryo transfer was evaluated by in vitro development of in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos after vitrification. The IVF and SCNT blastocysts were vitrified in either 40% GLY, 30% GLY + 10% EG, or 20% GLY + 20% EG using French straws. After warming, the straws were held vertically for 1 min without shaking and were then placed horizontally for 5 min to dilute the cryoprotectants. After washing, the vitrified-warmed embryos were cultured in vitro for 72 h. There were no differences among the vitrification solutions with respect to the rates of vitrified-warmed IVF and SCNT embryos surviving and developing to the hatched blastocyst stage. However, the rates of development to the hatched blastocyst stage of the SCNT embryos vitrified with 40% GLY tended to be higher than those vitrified with 30% GLY + 10% EG or 20% GLY + 20% EG (26% vs. 7-8%, respectively). The development rates to the hatched blastocyst stage of the IVF and SCNT embryos vitrified with solution containing EG were significantly lower (P<0.05) than those of non-vitrified embryos. These results suggest that use of the combination of GLY and EG as cryoprotectants had no beneficial effect on the viability of embryos after in-straw dilution. However, this method is so simple that it can be used for practical direct transfer of vitrified embryos in the field.     

Inbreeding depression and heterosis in various quantitative traits of the guppy, Poecilia reticulata

The present study examines the effects of inbreeding and crossing on various quantitative traits in the guppy, Poecilia reticulata. Effects of inbreeding and crossing were examined in six quantitative traits; body length at birth, survival at day 120, undwarf rate at day 120, body length at day 120, salinity tolerance and high temperature tolerance. Full-sib matings revealed that the amount of inbreeding depression varied from −1.0% to 24.6% among the traits and a significant decrease in survival at day 120 and salinity tolerance was observed. This result indicates that inbreeding reduces the performance for some of the quantitative traits but not all. On the other hand, crosses between genetically different strains showed that the amount of heterosis varied from −1.3% to 42.2% among the six quantitative traits and a significant increase in survival at day 120 and salinity tolerance was observed. The relationship between the amount of inbreeding depression and heterosis supports the theory that the phenomenon of heterosis is the reverse of inbreeding depression, indicating that the traits which have decreased by inbreeding can be recovered by means of crossing.     

DNA markers for estimation of inbreeding depression and heterosis in the guppy Poecilia reticulata

Molecular markers have significant potential for use in precise breeding programmes in aquaculture. This paper reviews the use of DNA markers to estimate inbreeding depression and heterosis in the guppy Poecilia reticulata. Full‐sib matings revealed that inbreeding causes declines in survival and salinity tolerance, but not in undwarfism, growth and high water temperature tolerance, indicating the effects of inbreeding differ among fitness‐related traits. Salinity tolerance was used to quantify the level of inbreeding depression and heterosis because the trait is strongly sensitive to inbreeding and shows a linear decrease with an increase in inbreeding coefficient. A positive correlation was observed between heterozygosity at microsatellite loci and salinity tolerance among 17 guppy populations. This indicates that heterozygosity estimated from microsatellites is a useful indicator for the estimation of inbreeding depression, suggesting that overall heterozygosity is important for fitness‐related traits that show inbreeding depression. Use of DNA markers to estimate the amount of heterosis in various strain combinations was examined using diallele and reciprocal crosses among four domestic strains. The amount of heterosis differed among the strain combinations and correlated with Nei's genetic distance measured by microsatellites and also by dissimilarity using random amplified polymorphic DNA (RAPD) analysis. This indicates that microsatellite and RAPD markers are useful for estimating the amount of heterosis in various strain combinations, further suggesting that the amount of heterosis depends on the genetic differences between the strains. The present study showed that DNA markers are useful tools for estimating inbreeding depression and heterosis in guppy breeding.     

Genetic differences in some haematological traits of communally reared clonal ayu, Plecoglossus altivelis Temminck & Schlegel, under stressed and non-stressed conditions

Four clonal lines of ayu, Plecoglossus altivelis Temminck & Schlegel, were produced through gynogenesis, mixed before hatching and reared communally. After 10 months, a randomly taken sample was subjected to a standardized shallow-water stressor. Haematocrit, haemoglobin, red blood cells count (RBC) and mean corpuscular volume (MCV) were obtained from stressed and non-stressed fish. DNA fingerprinting was used to confirm the clonal nature of the organisms and to identify the clonal line to which each fish belonged. We observed significant differences between clonal lines mostly in the haematocrit and MCV measured under no-stress conditions. Such differences are suggested to represent mainly genetic variance, on account of the common environment provided to all the experimental groups. The stress response ratio was lower than expected, mainly due to some unexpectedly high non-stress values. Heritability values (h²) were medium to high for the no-stress measurements (mean 0.238) and very low or zero for the stressed groups’traits (excepting one high value of 0.484). We conclude that the use of communally reared clonal lines represents a good tool for the characterization of the physiological traits, thus allowing for their utilization as genetic selection criteria.     

Hot carrier-assisted intrinsic photoresponse in graphene

We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may offer a path to hot carrier-assisted thermoelectric technologies for efficient solar energy harvesting.