The Spontaneously Diabetic ToriiLepr(SDT fatty) rat is a novel type 2 diabetic model wherein both male and female rats develop glucose and lipid abnormalities from a young age. In this study, we investigated gender differences in abnormalities and related complications in SDT fatty rats. Food intake was higher in males compared to female rats; however, body weight was not different between genders. Progression of diabetes, including increases in blood glucose and declines in blood insulin, was observed earlier in male rats than in females, and diabetic grade was more critical in male rats. Blood lipids tended to increase in female rats. Gonadal dysfunction was observed in both male and female rats with aging. Microangiopathies, such as nephropathy, retinopathy, neuropathy, and osteoporosis, were seen in both genders, and pathological grade and progression were more significant in males. Qualitative and quantitative changes were observed for metabolic disease gender differences in SDT fatty rats. The SDT fatty rat is a useful model for researching gender differences in metabolic disorders and related diseases in diabetes with obesity.
Marbling defined by the amount and distribution of intramuscular fat, so-called Shimofuri, is an economically important trait of beef cattle in Japan. Our previous study detected 3 single nucleotide polymorphisms (SNPs), g.231054C > T, g.3109537C > T and c.*188G > A, respectively, in the 5' flanking region of the titin (TTN), the 5' flanking region of the ribosomal protein L27a (RPL27A) and the 3' untranslated region of the akirin 2 genes (AKIRIN2), which have been considered as positional functional candidates for the genes responsible for marbling, and showed association of these SNPs with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the 3 SNPs among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Shorthorn, Holstein and Brown Swiss breeds.
The number of diabetic patients has recently been increasing worldwide, and numerous anti-diabetic drugs have been developed to induce good glycemic control. In particular, metformin, which exhibits glucose-lowering effects by suppressing gluconeogenesis in the liver, is widely used as a first line oral anti-diabetic drug for type 2 diabetes mellitus. In this study, the pharmacological effects of metformin were investigated using female and male Spontaneously Diabetic Torii (SDT) fatty rats, a new obese type 2 diabetic model. Two experiments were performed: an assessment of repeated treatment with metformin in female SDT fatty rats 5 to 13 weeks of age (experiment 1), and an assessment of repeated treatment with metformin in male SDT fatty rats 6 to 10 weeks of age (experiment 2). In female SDT fatty rats, metformin treatment led to good glycemic control, increases in sensory nerve conduction velocity, and improvements in pancreatic abnormalities such as irregular boundaries and vacuole form of islets. In male SDT fatty rats, metformin decreased blood glucose levels 4 weeks after treatment. Metformin treatment led to maintained good glycemic control and improved neuropathy and pancreatic lesions in female SDT fatty rats. The SDT fatty rat is useful for the development of novel anti-diabetic agents that show potential to improve glucose metabolic disorders in the liver.
Fatty acid (FA) composition has an important impact on the nutrition and flavor of meat, and on consumer health, and is receiving more attention in the sheep industry. This study aimed to evaluate the relationship between the expression levels of the CAST gene and the FA composition in the longissimus thoracis (LL) muscle, to identify novel variants of CAST, and to perform association analysis with the FA composition in grazing Sonid lambs. The correlation results showed that high expression levels of CAST are correlated with better FA compositions and classes in LL. For association studies, the results showed that c.1210C>T and c.1437G>A in LD-M, and c.2097C>T mutations are associated with some compositions and classes of FA in the LL of grazing Sonid sheep. Two missense c.646G>C (G216R) and c.1210C>T (R404C) mutations were predicted to influence the Calpain_inhib domains of CAST. Thus, the correlation results and associated mutations are expected to be genetic selection markers for the FA composition and meat quality of grazing Sonid lamb muscle and provide new insights into sheep meat quality traits influenced by the ovine CAST gene.
Fatty acids (FAs) are a group of organic compounds that are regulated by polygenic and environmental factors and affect the taste, nutritional value, and quality of meat. Lamb meat is rich in FAs required by the human body, which has directed more attention to sheep research and meat production. The fatty acid-binding protein 4 (FABP4) gene is considered a candidate gene that can affect FA composition in livestock. Therefore, the aim of this study was to screen for genetic polymorphisms of FABP4 and confirm the association between these polymorphisms and FAs, chemical composition, and carcass traits in Sonid lambs. The results of the association study showed that g.57764667T>C, g.57764436T>G, g.57764242G>A, and g.57757988A>G were associated with the composition of certain long-chain FAs, and g.57764242G>A, g.57764436T>G, and g.57758026G>A were associated with free amino acid levels. In addition, g.57764667T>C and g.57757988A>G were associated with carcass weight and live weight in Sonid lambs. Therefore, the polymorphisms of the FABP4 gene are expected to be a genetic selection marker for superior traits in Sonid sheep breeding, which also provides new insights into how the ovine FABP4 gene affects traits of lamb quality.