Abstract
Through posttranscriptional gene regulation, microRNA (miRNA) is linked to a wide variety of biological processes, including adipogenesis and lipid metabolism. Although miRNAs in mammalian adipogenesis have been worked on extensively, their study in chicken adipogenesis is still very limited. To find miRNAs potentially important for chicken preadipocyte development, we compared the preadipocyte miRNA expression profiles in two broiler lines divergently selected for abdominal fat content, by sequencing two small RNA libraries constructed for primary preadipocytes isolated from abdominal adipose tissues. After bioinformatics analyses, from chicken miRNAs deposited in miRBase 20.0, we identified 225 miRNAs to be expressed in preadipocytes, 185 in the lean line and 200 in the fat line (derived from 208 and 203 miRNA precursors, respectively), which corresponds to 114 miRNA families. The let-7 family miRNAs were the most abundant. Furthermore, we validated the sequencing results of 15 known miRNAs by qRT-PCR, and confirmed that the expression levels of most miRNAs correlated well with those of Solexa sequencing. A total of 33 miRNAs was significantly differentially expressed between the two chicken lines (P<0.05). Gene ontology analysis revealed that they could target genes enriched in the regulation of gene transcription and chromatin function, response to insulin stimulation, and IGF-1 signaling pathways, which could have important roles in preadipocyte development. Therefore, a valuable information and resource of miRNAs on chicken adipogenesis were provided in this study. Future functional investigations on these miRNAs could help explore related genes and molecular networks fundamental to preadipocyte development.
Highlights
As small non-coding RNA molecules, ~22 nucleotides in length, microRNAs can regulate their RNA targets by either direct degradation or translational inhibition through partial complementary sequence recognition and binding
A number of miRNAs have been demonstrated to target genes involved in adipogenesis and lipid metabolism, such as the regulation on the proliferation of adipose tissue-derived mesenchymal stem cells by miR-21 and miR-196a [4,5,6]; the enhancement of adipogenesis by miR-103, miR-224 and the miR-17–92 cluster [7,8,9]; the impairment of adipogenesis by the let-7 family, miR-448, miR-15a and miR-27 [10,11,12,13]; the regulation of adipocyte lipid metabolism by miR-27a and miR-143 [13,14,15]; and the important role of miR-33 on the repression of sterol transporters reported in numerous studies [16,17,18,19,20,21,22,23,24]
Two other studies were limited in the identification of miRNAs, one in muscle and adipose tissues [32], and the other in preadipocytes obtained from Arbor Acres (AA) broilers reported previously by our group [33]
Summary
As small non-coding RNA molecules, ~22 nucleotides in length, microRNAs (miRNAs) can regulate their RNA targets by either direct degradation or translational inhibition through partial complementary sequence recognition and binding. A number of miRNAs have been demonstrated to target genes involved in adipogenesis and lipid metabolism, such as the regulation on the proliferation of adipose tissue-derived mesenchymal stem cells by miR-21 and miR-196a [4,5,6]; the enhancement of adipogenesis by miR-103, miR-224 and the miR-17–92 cluster [7,8,9]; the impairment of adipogenesis by the let-7 family, miR-448, miR-15a and miR-27 [10,11,12,13]; the regulation of adipocyte lipid metabolism by miR-27a and miR-143 [13,14,15]; and the important role of miR-33 on the repression of sterol transporters reported in numerous studies [16,17,18,19,20,21,22,23,24]. Two other studies were limited in the identification of miRNAs, one in muscle and adipose tissues [32], and the other in preadipocytes obtained from Arbor Acres (AA) broilers reported previously by our group [33]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
