Differential expression analysis of meat tenderness governing genes in different skeletal muscles of bovines.

BACKGROUND: The aim of this study was to compare 12 different skeletal muscles of bovine (n = 15) with each other in terms of tenderness and meat-quality-related gene expressions. Tenderness values were evaluated by shear force, and ANK1, CAPN1, CAST, HSPB1, HSPA1A gene expressions were analyzed by using quantitative real-time polymerase chain reaction. RESULTS: ANK1 gene showed significant differences between tender and tough muscles (P < 0.001) and was found to be more closely related to meat quality than CAPN1. No difference was found for CAST, HSPB1, and HSPA1A gene expressions between different parts of skeletal muscles (P > 0.05). The results also showed that the most convenient skeletal muscle for the meat quality studies is musculus psoas major. Furthermore, comparative use of musculus longissimus thoracis and musculus extensor digitorum muscles may give the most accurate results, rather than using other muscle groups in comparative studies between tender and tough muscles. CONCLUSION: ANK1 gene is a preferable biomarker for the determination of meat quality, and CAPN1 needs further studies. However, CAST, HSPB1, and HSPA1A genes may not be suitable biomarkers for the determination of meat quality based on this study. © 2018 Society of Chemical Industry.

Identification of intestinal M cells in isolated lymphoid follicles and Peyer's patches of the Angora rabbit.

The presence, distribution, and localization of M cells in isolated lymphoid follicles (ILF) and in follicle-associated epithelia (FAE) covering Peyer's patches (PP) in Angora rabbits were investigated by immunohistochemistry and electron microscopy. Although PP could macroscopically be identified along the length of the mucosal and serosal surfaces of jejunum and ileum, the presence of ILF could only be located microscopically. Typical M cells in FAE were detected within the periphery of the dome regions of the PP, and immature columnar M cells in the FAE resided in the vicinity of the crypts. M cells in the FAE of both ILF and PP showed vimentin-positive reaction. M cells in the FAE of ILF were morphologically similar to the immature M cells found in the FAE of PP. Typical mature M cells were also observed in the FAE of a few ILF. In contrast to FAE of PP, numerous goblet cells were observed in the FAE of many ILF. Moreover, among intestinal villi, we noticed villi-like solitary lymphoid structures that showed abundant lymphocytes in their lamina propria and that were surrounded with vimentin-positive cells and goblet cells. Thus, the occurrence of copious immature M cells and goblet cells, in addition to the detection of villi-like solitary lymphoid structures full of lymphocytes in the FAE of many ILF, indicate that ILF do not complete their immunological maturation in contrast to PP. Various antigenic stimulations conceivably induce the formation and maturation of ILF along the length of the small intestine. The morphological resemblance between ILF M cells and PP M cells suggests that these two types of cells perform similar or the same immunological functions.