Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2‐11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low‐marbled and high‐marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2‐11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker‐assisted selection to increase the levels of marbling in Japanese Black beef cattle.     

黑麦草与羊茅属间杂种研究进展

黑麦草属(Lolium L.)与羊茅属(Festuca L.)是世界范围内重要的禾本科牧草和草坪草。黑麦草与羊茅杂交能综合黑麦草优良营养品质与羊茅抗逆性强的优点,可培育出优质抗逆的黑麦草羊茅杂种。同时黑麦草羊茅杂种是研究禾本科牧草遗传机制的优质试材,倍受世界各国育种工作者关注。本文总结了黑麦草羊茅杂种高产、优质、抗性强的优势;分析了杂种染色体配型特点;重点介绍了通过基因渗入、雄核发育和转基因手段改良牧草的方法;对黑麦草羊茅杂种基因组原位杂交、分子标记和遗传图谱建立、数量性状位点分析等分子遗传学的最新研究进展进行了综述。     

高丹草品种主要农艺性状的比较研究

在日本北海道气候条件下,对6个高丹草品种的生长适应性及主要农艺特性进行了研究.田间观察6个品种生长势强,均能适应当地气候条件,但在生物学及生产性能方面品种间存在差异.发育前期及后期生长速度快的品种为Mnqsi No.1和Mnqsi No.2,最慢的品种为Greensorgo和Raceysorgo,品种Grenn-A在发育后期生长较快,Sudancums次之.Greensorgo和Raceysorgo为早熟型品种,Mnqsi No.1、Mnqsi No.2和Green-A均为晚熟型品种,Sudancums为中熟型品种.株高、鲜草产量顺次为:Mnqsi No.1＞Green-A＞Mnqsi No.2＞Sudancums＞Greensorgo＞Raceysorgo;茎粗、茎叶比顺次为:Green-A＞Sudancums＞Greensorgo Mnqsi No.2＞Raceysorgo＞Mnqsi No.1;分蘖能力顺次为:Mnqsi No.2＞Mnqsi No.1＞Sudancums＞Raceysorgo＞Green-A Greensorgo.穗型及叶片特征品种间有一定差异.     

The influence of fig proteases on the inhibition of angiotensin I‐converting and GABA formation in meat

The purposes of this research were to use fig protease for texture tenderizing, and to inhibit angiotensin I‐converting enzyme (ACE) action and γ‐aminobutyric acid (GABA) formation of meat. Liberated peptides by the enzymatic action of fig protease in processing meat and free amino acids were determined and ACE inhibitory activity was assayed. Meat treated with fig protease became tender as indicated by shear force value (SFV) which was half of those of non‐fig treated meat during storage even at 5°C. Liberated peptides, free amino acids and GABA increased while extremely low levels of Glu were detected after storage. The optimal temperature of fig protease against meat was 80°C. However, the activity of fig protease decreased after pre‐heating more than 40°C. High ACE inhibitory activity of a mixture of fig and meat was found around 80°C, and the value corresponded to the amount of liberated peptide. A lot of liberated peptides were found at 60–80°C and pasterization of meat product becomes convenient to produce peptides. Production of ACE inhibitory peptides and GABA can be expected as the healthy functional meat product such as antihypertensive activity and improve brain function.     

Sex differences in cervical spinal cord and spinal canal development in Thoroughbred horses

Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex differences in the development of cervical spinal cord and spinal canal in Thoroughbred horses. A total of 29 Thoroughbred horses underwent computed tomographic myelography. Thereafter, the volumes of cervical spinal cord and spinal canal were calculated. Accordingly, male horses had significantly lager cervical spinal cord volume and cervical spinal cord-to-spinal canal volume ratio than those of female horses (P<0.05). Sex differences in the cervical spinal cord-to-spinal canal volume ratio gradually decreased until around 1,400 days of age. Younger male horses have narrower interspace between the cervical spinal cord and spinal canal than younger female horses, suggesting that an imbalanced cervical spinal cord and spinal canal growth is one of the causes of CVSM.     

New strategies of boar sperm cryopreservation: Development of novel freezing and thawing methods with a focus on the roles of seminal plasma

Cryopreservation of boar spermatozoa offers an effective means of long‐term storage of important genetic material. Many researchers have investigated how to improve reproductive performance by artificial insemination (AI) using cryopreserved boar spermatozoa. Recently, we and other groups reported that high conception rates (70–80%) can be achieved by AI with frozen‐thawed boar spermatozoa using a modified temperature program during freezing, or a novel cryopreservation extender to improve sperm quality (including sperm survivability, motility, membrane status and fertilization ability) after thawing, or a novel sperm infusion method, deep intra uterine insemination. However, these techniques have not yet been used for commercial pig production. The variation in sperm freezability among boars or among ejaculations in an identical boar is one of the main reasons for this problem. In our previous study, it was revealed that some components of seminal plasma have a negative effect on the freezability of boar sperm. One of these factors is bacteria‐released endotoxin (lipopolysaccharide: LPS). LPS binds to Toll‐like receptor‐4 (TLR‐4) expressed on the sperm surface, resulting in induction of apoptosis. On the other hand, seminal plasma suppresses cryo‐capacitation induced by thawing stress. On the basis of these findings, we designed a novel protocol of AI using frozen‐thawed boar sperm.     

Detection of anti-ebolavirus antibodies in Ghanaian pigs

Some filoviruses such as ebolaviruses and marburgviruses, cause hemorrhagic fever in humans and nonhuman primates. Pigs are suggested to play a potential role in the filovirus ecology. We investigated the seroprevalence of filovirus infection in pigs in Ghana. Using a viral glycoprotein (GP)-based enzyme-linked immunosorbent assay, we detected filovirus-specific immunoglobulin G antibodies in 5 of 139 samples. These positive sera showed specificities to four different filovirus species. Particularly, two of the positive sera reacted to GPs of two African ebolaviruses (i.e., Ebola virus and Taï Forest virus) in Western blotting. Our results suggest that these Ghanaian pigs were exposed to multiple filoviruses and emphasize the importance of continuous monitoring of filovirus infection in pig populations in West African countries.     

Expression of podoplanin in various types of feline tumor tissues

Podoplanin is expressed in various human tumors where it promotes tumor progression, epithelial-mesenchymal transition, and distant metastasis. Podoplanin is also expressed in cancer-associated fibroblasts and induces tumor malignancy. The objective of this study was to evaluate podoplanin expression in various types of feline tumor tissues. Immunohistochemical analysis revealed that podoplanin was expressed in cells of 13/15 (87%) squamous cell carcinomas and 5/19 (26%) fibrosarcomas. Moreover, cancer-associated fibroblasts expressed podoplanin in most tumor types, including 18/21 (86%) mammary adenocarcinoma tissues. Our findings demonstrate that various types of feline tumor tissues expressed podoplanin, indicating the importance of the comparative aspects of podoplanin expression, which may be used as a novel research model for podoplanin biology.