To detect transcripts encoding the interleukin-6 receptor (IL-6R) molecule lacking the transmembrane (TM) domain, in various cell lines and peripheral blood mononuclear cells (PBMC), we used the polymerase chain reaction (PCR) with primer pairs that flank the TM domain and which were selected to generate a 398-bp fragment. We detected 398-bp and 304-bp DNA molecules in the PCR products of the U1, J22HL60, MT-2, MT-4, U937 and HL60 cell lines and of PBMC isolated from several individuals. The sequencing analysis of both DNA molecules showed that a 94-bp region consisting of the TM domain of IL-6R was deleted in the 304-bp molecule. Moreover, we detected a soluble (s) IL-6R protein of 45 kDa in culture supernatants of the MT-2, MT-4 and U937 cell lines by radioimmunoprecipitation using specific antibodies against sIL-6R. Our results indicate that active deletion of the TM domain by alternative splicing of mRNA represents one mechanism for release of sIL-6R into the culture supernatants of cells, or into serum or urine.

This study was conducted to investigate effects of disodium fumarate (DF) on fermentation characteristics and microbial populations in the rumen of Hu sheep fed on high-forage diets. Two complementary feeding trials were conducted. In Trial 1, six Hu sheep fitted with ruminal cannulae were randomly allocated to a 2 3 2 cross-over design involving dietary treatments of either 0 or 20 g DF daily. Total DNA was extracted from the fluid-and solid-associated rumen microbes, respectively. Numbers of 16S rDNA gene copies associated with rumen methanogens and bacteria, and 18S rDNA gene copies associated with rumen protozoa and fungi were measured using real-time PCR, and expressed as proportion of total rumen bacteria 16S rDNA. Ruminal pH decreased in the DF group compared with the control (P , 0.05). Total volatile fatty acids increased (P , 0.001), but butyrate decreased (P , 0.01). Addition of DF inhibited the growth of methanogens, protozoa, fungi and Ruminococcus flavefaciens in fluid samples. Both Ruminococcus albus and Butyrivibrio fibrisolvens populations increased (P , 0.001) in particle-associated samples. Trial 2 was conducted to investigate the adaptive response of rumen microbes to DF. Three cannulated sheep were fed on basal diet for 2 weeks and continuously for 4 weeks with supplementation of DF at a level of 20 g/day. Ruminal samples were collected every week to analyze fermentation parameters and microbial populations. No effects of DF were observed on pH, acetate and butyrate (P . 0.05). Populations of methanogens and R. flavefaciens decreased in the fluid samples (P , 0.001), whereas addition of DF stimulated the population of solid-associated Fibrobacter succinogenes. Population of R. albus increased in the 2nd to 4th week in fluid-associated samples and was threefold higher in the 4th week than control week in solid samples. Analysis of denaturing gradient gel electrophoresis fingerprints revealed that there were significant changes in rumen microbiota after adding DF. Ten of 15 clone sequences from cut-out bands appearing in both the 2nd and the 4th week were 94% to 100% similar to Prevotella-like bacteria, and four sequences showed 95% to 98% similarity to Selenomonas dianae. Another 15 sequences were obtained from bands, which appeared in the 4th week only. Thirteen of these 15 sequences showed 95% to 99% similarity to Clostridium sp., and the other two showed 95% and 100% similarity to Ruminococcus sp. In summary, the microorganisms positively responding to DF addition were the cellulolytic bacteria, R. albus, F. succinogenes and B. fibrisolvens as well as proteolytic bacteria, B. fibrisolvens, P. ruminicola and Clostridium sp.

Abstract.To study the effects of heat stress (HS) on the growth and reproductive performance of chicks, 1-day-old male Wenchang chicks were randomly selected and divided into control (CK) and HS groups. The two groups of birds were fed according to a routine. The chicks in the HS group were placed under HS for 2 h day −1 (temperature, 40 ± 0.5 • ; humidity, 63.0-80.0 %) until the sixth week. At the end of each week, six chicks were randomly selected from each group and dissected for pituitary and testicular tissues, which were then weighed and sectioned onto slides to observe the histological changes in pituitary and testis under a microscope. Our results indicated that compared with the CK group, with the increase in age, HS significantly reduced the feed conversion rate (FCR) and weight gain per week, and these changes were positively correlated. The pituitary and testicular weights and volumes of chicks in the HS group were significantly lower than those in the CK group (P < 0.05). For 3-week old chicks, the cross-sectional area of seminiferous tubule in chicks of the HS group was extremely significantly lower than that of the CK group (P < 0.01). Compared with the CK group, the seminiferous epithelium was thinner in the HS group, the arrangement of spermatogenic cells became loose and irregular, and the integrity of the histological structure of testicular tissues was also damaged. Therefore, the above results indicated that HS significantly impeded the growth and development of pituitary and testis in chicks.

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SUMMARYA polymerase chain reaction (PCR) method was used to detect the interleukin-2 receptor a-chain (IL-2Ra) chain which lacks the conventional transmembrane ( TM) domain in mRNA from human T-cell leukaemia virus type-I ( HTLV-I ) -infected cell lines or peripheral blood mononuclear cells (PBMC ) isolated from adult T-cell leukaemia (ATL) patients. Primer pairs encompassing the TM domain were selected to generate a 357-base pair (bp) fragment. A 146-bp PCR product was observed consistently in addition to the target 357-bp PCR product in mRNA from HTLV-I-infected cell lines, such as MT-1, MT-2, MT-4 and in PBMC isolated from ATL patients. However, this 146-bp PCR product was undetectable in HTLV-I-negative cell lines. The product was also detected in PBMC from normal individuals if activated in vitro with phytohaemagglutinin but not without stimulation. DNA sequence analyses revealed that exons from 5 to 7, which define a 211-bp region containing the conventional TM domain, were deleted in the 146-bp PCR product. The C-terminal amino acid sequence starting from Gly174 of the 211-bp-deleted molecule was distinct from that of conventional IL-2Ra as a result of an altered reading frame. We identified a 45 000 MW peptide generated from IL-2Ra mRNA through this exon skip in cell lysate of MT-1 and MT-2 by Western blot analyses using an antibody raised against the peptides specific to an altered IL-2Ra. Our results indicate that an altered IL-2Ra chain is expressed in HTLV-I-infected T lymphocytic cell lines and in ATL patients.