Immunogenic properties of Landrace pigs selected for resistance to mycoplasma pneumonia of swine

Mycoplasma pneumonia of swine (MPS) lung lesions and immunogenic properties were compared between a Landrace line that was genetically selected for reduced incidence of pulmonary MPS lesions, and a non‐selected Landrace line. The MPS‐selected Landrace line showed significantly lower degrees of pulmonary MPS lesions compared with the non‐selected Landrace line. When changes in immunity before and after vaccination were compared, the percentage of B cells in the peripheral blood of the MPS‐selected Landrace line was significantly lower than that of the non‐selected line. Furthermore, the concentration of growth hormone and the mitogen activity of peripheral blood mononuclear cells in the MPS‐selected Landrace line showed significantly (P < 0.05) lower increases after vaccination than the non‐selected line. Conversely, the concentration of peripheral blood interferon (IFN)‐γ and salivary immunoglobulin A (IgA) after Mycoplasma hyopneumoniae vaccination was significantly higher in the MPS‐selected Landrace line than in the non‐selected line. Gene expression of toll‐like receptor (TLR)2 and TLR4 was significantly higher in the MPS‐selected Landrace line in immune tissues, with the exception of the hilar lymph nodes. The present results suggest that peripheral blood IFN‐γ, salivary IgA TLR2, and TLR4 are important immunological factors influencing the development of MPS lesions.     

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions in Large White pigs selected for higher peripheral blood immune capacity

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions were compared between the immunity‐selected Large White line and the non‐selected Large White line. The selected Large White line showed a higher level of pulmonary MPS lesions compared with the non‐selected Large White line. Subsequent to vaccination, the percentage of natural killer cells and T cells (CD3⁺CD4⁺CD8^‐ and CD3⁺CD4^?CD8⁺ T cells) were significantly increased in the non‐selected line but remained unchanged in the immunity‐selected Large White line. Secretion of Mycoplasma hyopneumoniae vaccine‐specific immunoblogulin G and phagocyte activity in peripheral blood were significantly higher in the immunity‐selected Large White line than in the non‐selected line. Expression of interleukin (IL)‐4 and IL‐6 messenger RNA in hilar lymph nodes was significantly lower in the immunity‐selected Large White line than in the non‐selected line. However, expression of IL‐10 in all immune tissues was significantly higher in the immunity‐selected Large White line. These results suggest that the selection for high immunity was not effective in increasing resistance to MPS lung lesions.     

Mycoplasma pneumonia of swine (MPS) resistance and immune characteristics of pig lines generated by crossing an MPS pulmonary lesion selected Landrace line and a highly immune capacity selected Large White line

To understand the influence of crossbreeding on Mycoplasma pneumonia of swine (MPS) resistance and immune characteristics, two crossbred lines were characterized. One crossbred line, LaWa, was generated by crossing the MPS pulmonary lesion selected Landrace line (La) and the highly immune‐selected Large White line (Wa). The second crossbred line, LaWb, was generated by crossing the La line and the nonselected Large White line (Wb). The crossbred LbWb line (nonselected Landrace line × nonselected Large White line) and the La line were used as controls. The LaWa and LaWb lines had an intermediate level of MPS lung lesions between La and LbWb lines, although the difference was not statistically significant. After stimulation with sheep red blood cells (SRBCs), the LaWb and LaWa lines showed immune characteristics similar to that of the La line; the number of monocytes in peripheral blood increased, while B cells, T cells, secretion of SRBC‐specific immunoglobulin G, and interleukin (IL)‐13 decreased. Additionally, the number of natural killer (NK) cells and the expression of IL‐4 and IL‐17 were significantly higher in the LaWb and LaWa lines, respectively. These data suggested that crossbreeding of La and Wa lines resulted in the inheritance of some of the selected immune responses.     

Increased number of whistles of bottlenose dolphins, Tursiops truncatus, arising from interaction with people

The acoustic mode is the most reasonable means for social animals such as dolphins to maintain contact in the underwater habitat, and has been developed since they moved to the sea. This study investigates variations in dolphin vocalizations under the following conditions in a captive environment: 1) before feeding (Pre-feeding), 2) during feeding (Feeding), 3) during free time without the presence of people (Free), 4) during interaction with people located upon a float (Float), 5) during interaction with people in the water (Water). During the experiments, a total of 2642 whistles were extracted from sonogram data using a spectrogram. About 44% of the total whistles were observed during Pre-feeding (1171/2642), and the number recorded during Free, when people were absent, was the smallest. The acoustic contours of dolphin whistles differed in different situations: convex, wave, and trill whistles were made repeatedly during Pre-feeding, thereby being more common at this time than at other times. The situation of Feeding saw an increased number of Upsweeps, which might be related to the use of echolocation. The lower frequencies were recorded during Pre-feeding, reflecting the emotion related to the dolphin's hunger. The results of this study indicate that dolphins increase their vocalization during interaction with people, suggesting that interactions with dolphins provide an effective treatment for human health problems, which is discussed with a reference article in this study. Vocal data obtained during contact with humans might serve as an important index for the dolphin-assisted therapy.     

Direct effects of prolactin on adrenal steroid release in male Hatano high-avoidance (HAA) rats may be mediated through Janus kinase 2 (Jak2) activity

Prolactin (PRL) has been proposed to directly stimulate corticosterone release. However, the role of PRL on adrenocortical function in male HAA rats has not been fully clarified. The aim of this study was to investigate the effect of PRL on the secretion of corticosterone and progesterone using an in vitro cell culture system in male rats. Administration of PRL (10(-7) and 10(-6) M) resulted in dose-dependent increases in corticosterone and progesterone release. Cotreatment with PRL produced an increase in the stimulatory effects of ACTH-induced corticosterone and progesterone secretion. However, the PRL-induced corticosterone and progesterone releases were significantly reduced by treatment with AG490, a specific Janus kinase 2 (Jak2) inhibitor. In addition, administration of AG490 blunted the significant inhibition of ACTH-induced corticosterone and progesterone secretion by PRL. These results demonstrated that PRL could act directly on the adrenal gland to drive corticosterone and progesterone secretion in male rats. Additionally, the results emphasize that PRL stimulation of adrenal steroid release may be mediated through Jak2 activity.     

Effect of the squid viscera hydrolysate on growth performance and digestion in the red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis>

The improvement in feed efficiency is one of the most important subjects in fish culture. The development of feed, in terms of good intake, high growth performance, and high feed efficiency is needed. Squid viscera are one of the candidates for alternative material in improving feed efficiency in fish culture. In the present study, we described the dietary effect of the squid viscera hydrolysate (SVH) on the growth performance of the red sea bream. The addition of SVH to feed caused significant increases in feed intake, fork length, and body weight and produced a marked improvement in feed conversion after 4 weeks of feeding. Furthermore, the results of this feeding revealed that low dietary levels of SVH promote growth performance in the red sea bream. We physiologically analyzed digestion and appetite in fish fed diet containing SVH. SVH promoted the activity of hepatic trypsin and lipase, gene expression of stomach pepsin, hepatic lipase, and pyloric caeca trypsin, thereby improving the nutrient availability in red sea bream. Moreover, the mRNA expression of appetite regulating factor, such as brain NPY and stomach ghrelin was significantly improved by dietary SVH. Our current results indicate that dietary SVH as alternative material produced excellent effects on growth performance, which is dependent on the promoting effect on digestion and appetite in red sea bream.     

Fine structure and differentiation of the alimentary canal in captive-bred Japanese eel Anguilla japonica preleptocephali

ABSTRACT:   The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.     

Structure of the intratesticular duct system for sperm emission in the starspotted smooth-hound Mustelus manazo

We conducted histological observation of male germ cells and reproductive organs of the starspotted smooth-hound Mustelus manazo in Tokyo Bay to reveal any abnormality in male reproductive traits, as part of a study to elucidate the factors causing recent fluctuation in abundance of the population. Spermatogenesis proceeded in spermatocysts from the germinal zone in the ventral part of the testis to the degenerative zone in the dorsal part, where the spermatozoa were conveyed into the ciliated lumina of the attached terminal branches of the intratesticular ducts. The intratesticular ducts were classified from their terminal ends into branch, stem, and collecting tubules. The ducts formed in the germinal zone and grew as the spermatocysts developed. An opening formed through the wall of each of the most mature spermatocysts into a branch tubule; bundles of spermatozoa were evacuated through this opening into the branch and then the stem tubule and subsequently into the collecting tubules in the rete testis and the efferent duct connected to the epididymis. Spermatocysts that were unable to emit sperm because of failure of adhesion to the branch tubules were disorganized in situ, as were their spermatozoa. The collapsed spermatocysts seem to be cleared by hemophagocytosis with lymphocytes and leukocytes, which may have been recruited from the epigonal organ. There were no specific abnormalities in the spermatogenesis or the morphological structure of testes, which suggested that an abnormality of male reproductive traits was not the major cause of the recent fluctuation in the population abundance of this species. Details of the intratesticular duct system for sperm emission to the epididymis are the first findings in elasmobranchs worldwide.