Early adipose deposits in sheep: comparative analysis of the perirenal fat transcriptome of Assaf and Churra suckling lambs

Abstract

Adipose deposits influence the quality of ruminant carcasses, and in suckling lambs, internal types of adipose deposits represent a notable proportion of total fat. The aim of this study was to perform a comparative analysis of the perirenal fat transcriptomes of suckling lambs from two breeds with different growth and carcass characteristics. The perirenal fat tissue from 14 suckling lambs (Assaf, n = 8; Churra, n = 6) was used for the RNA-seq analysis. The functional enrichment analysis of the 670 highly expressed genes (>150 fragments per kilobase of exon per million fragments mapped) in the perirenal fat transcriptome of both breeds revealed that the majority of these genes were involved in energy processes. The expression of the UCP1 gene, a classical biomarker of brown fat, and the presence of multilocular adipocytes in the two breeds supported the presence of brown fat at the transition stage towards white fat tissue. The differential expression analysis performed identified 373 differentially expressed genes (DEGs) between the two compared breeds. Brown/white fat gene biomarkers were not included in the list of DEGs. In Assaf lambs, DEGs were enriched in Gene Ontology (GO) biological processes related to fatty-acid oxidation, whereas in Churra lambs, the majority of the significantly enriched GO terms were related to cholesterol synthesis, which suggests that upregulated DEGs in Assaf lambs are implicated in fat burning, whereas the Churra upregulated DEGs are linked to fat accumulation. These results can help to increase knowledge of the genes controlling early fat deposition in ruminants and shed light on fundamental aspects of adipose tissue growth.

Adipose gene expression profiles reveal novel insights into the adaptation of northern Eurasian semi-domestic reindeer (Rangifer tarandus)

“…The majority of adipose transcriptome studies using high-throughput RNA sequencing (RNA-Seq) have been limited to mice [20,21], sheep [22][23][24], pigs [25][26][27], and humans [28][29][30]. Adipose transcriptomes are affected by the type of adipose, as well as by the sex and age of the animal [31].…”

RNAseq Analysis of Brown Adipose Tissue and Thyroid of Newborn Lambs Subjected to Short-Term Cold Exposure Reveals Signs of Early Whitening of Adipose Tissue

“…Furthermore, results from an RNAseq study on perirenal BAT of six-month-old lambs subjected to cold conditions for 25 days reported an expression of UCP1 [ 65 ]. Another study using the same tissue from suckling lambs reported an expression of UCP1 through RNAseq at 19−35 days of age [ 66 ]. Yuan et al [ 67 ] reported different levels of expression of this gene from 2 to 12 months of age, where lower levels were found in superficial fat, and higher levels were seen in deep fat deposits.…”

GROWTH AND DEVELOPMENT SYMPOSIUM: STEM AND PROGENITOR CELLS IN ANIMAL GROWTH: Long noncoding RNAs in adipogenesis and adipose development of meat animals12

“…Coexpression networks of the differentially expressed genes indicated TCONS_00372767, TCONS_00171926, TCONS_00054953, and TCONS_00373007 might play important roles in tail fat deposition (Ma et al, 2018). In addition, by using RNA-seq, perirenal fat transcriptomes of Assaf and Churra suckling lambs with different early-life fattening patterns were analyzed (Suárez-Vega et al, 2018). It was shown that 23 lncRNAs were robustly expressed in all samples.…”

“…It was shown that 23 lncRNAs were robustly expressed in all samples. Among them, ENSOARG00000025723 and ENSOARG00000026925 were shown positionally linked to genes related to fat and adipose tissue, which might play a role in early adipose deposits in sheep (Suárez-Vega et al, 2018). Overall, studies on the lncRNAs in farm animals are just starting and a surge of literature in lncRNAs in adipogenic regulation of farm animals is expected in the following years.…”