Transcriptome analysis showed differences of two purebred cattle and their crossbreds

The consequences of a cattle crossbreeding programme on the genes expression, signalling and metabolic pathways, molecular networks, and biological functions is still indistinctive. In this study differences of five cattle populations in a crossbreeding programme were studied using high throughput sequencing technology to characterise their transcriptome. Holstein (Bos Taurus origin) and Taleshi (Bos indicus origin) as purebred cattle were compared with their crossbreds including 50% sire Taleshi and dam Holstein (50CSN), 50% sire Holstein and dam Taleshi (50CSH) and 75% Holstein (75C). Differentially expressed genes (DEGs) and their related enriched metabolic pathways, transcription up-stream regulators and biological functions were studied by bioinformatics tools of transcriptome analysis. Total expressed transcripts in all populations were 72,812 with 22,627 annotated genes. We found 2262 DEGs in which 251 genes were uniquely expressed in purebreds or crossbreds. Functional analysis of DEGs showed that the immune and inflammatory responses were the most highly-impacted pathways and functions. Among all significantly enriched pathways, eukaryotic translation initiation factor-2 signalling had the highest activation Z-score (5.3) in crossbred compared to purebred cattle. The majority of up-stream regulators of genes including transcription regulators and cytokines were differentially expressed among populations in which their activation Z-score in purebred was more than crossbred cattle. Crossing of Holstein with Taleshi breed resulted lower activity of pathways related to immunity and inflammatory responses. The analysis revealed that the most important differences between studied genotypes, especially between purebred and crossbred cattle, were related to immune function

2,4-Thiazolidinedione in Well-Fed Lactating Dairy Goats: I. Effect on Adiposity and Milk Fat Synthesis

Background: In a prior experiment, treatment of goats with the putative PPARγ agonist 2,4-thiazolidinedione (2,4-TZD) did not affect milk fat or expression of milk-fat related genes. The lack of response was possibly due to deficiency of vitamin A and/or a poor body condition of the animals. In the present experiment, we tested the hypothesis that PPARγ activation affects milk fat synthesis in goats with a good body condition and receiving adequate levels of vitamin A. Methods: Lactating goats receiving a diet that met NRC requirements, including vitamin A, were injected with 8 mg/kg BW of 2,4-TZD (n = 6) or saline (n = 6; CTR) daily for 26 days. Blood metabolic profiling and milk yield and components were measured including fatty acid profile. Expression of genes related to glucose and lipid metabolism was measured in adipose tissue and in mammary epithelial cells (MEC). Size of adipocytes was assessed by histological analysis. Results: NEFA, BHBA, and fatty acids available in plasma decreased while glucose increased in 2,4-TZD vs. CTR. Size of cells and expression of insulin signaling and glucose metabolism-related genes were larger in 2,4-TZD vs. CTR in adipose tissue. In MEC, expression of SCD1 and desaturation of stearate was lower in 2,4-TZD vs. CTR. Conclusions: Overall data revealed a lack of PPARγ activation by 2,4-TZD and no effect on milk fat synthesis despite a strong anti-lipolysis effect on adipose tissue