Long non-coding RNAs (lncRNAs) are a kind of non-coding RNA being >200 nucleotides in length, and they are found to participate in hair follicle growth and development and wool fiber traits ...regulation. However, there are limited studies reporting the role of lncRNAs in cashmere fiber production in cashmere goats. In this study, Liaoning cashmere (LC) goats (
= 6) and Ziwuling black (ZB) goats (
= 6) with remarkable divergences in cashmere yield, cashmere fiber diameter, and cashmere color were selected for the construction of expression profiles of lncRNAs in skin tissue using RNA sequencing (RNA-seq). According to our previous report about the expression profiles of mRNAs originated from the same skin tissue as those used in the study, the
and
target genes of differentially expressed lncRNAs between the two caprine breeds were screened, resulting in a lncRNA-mRNA network. A total of 129 lncRNAs were differentially expressed in caprine skin tissue samples between LC goats and ZB goats. The presence of 2
target genes and 48
target genes for the differentially expressed lncRNAs resulted in 2 lncRNA-
target gene pairs and 93 lncRNA-
target gene pairs. The target genes concentrated on signaling pathways that were related to fiber follicle development, cashmere fiber diameter, and cashmere fiber color, including PPAR signaling pathway, metabolic pathways, fatty acid metabolism, fatty acid biosynthesis, tyrosine metabolism, and melanogenesis. A lncRNA-mRNA network revealed 22 lncRNA-
target gene pairs for seven differentially expressed lncRNAs selected, of which 13
target genes contributed to regulation of cashmere fiber diameter, while nine
target genes were responsible for cashmere fiber color. This study brings a clear explanation about the influences of lncRNAs over cashmere fiber traits in cashmere goats.
Wool and hair fibres consist of a variety of proteins, including the keratin-associated proteins (KAPs). In this study, a putative ovine homologue of the human KAP21-2 gene (
) was identified. It was ...located on chromosome 1 as a 201-bp open reading frame (ORF) in the ovine genome assembly from a Texel sheep (v.4 NC_019458.2: nt122932727 to 122932927). A polymerase chain reaction- single strand conformation polymorphism (PCR-SSCP) analysis of this ORF, and subsequent DNA sequencing, identified five sequences (named
-
). The putative amino acid sequences that would be produced, shared some identity with each other and with other KAPs, but they were most similar to ovine KAP21-1, and phylogenetically related to human KAP21-2. The location of the ovine
sequence was consistent with the location of human
and this suggests they represent different variant forms of ovine
-2. Variation in this gene was investigated in 389 Merino (sire) × Southdown-cross (ewe) lambs. These were derived from four independent sire-lines. The sequence variation was found to be associated with variation in five wool traits: including mean staple length (MSL), mean fibre diameter (MFD), fibre diameter standard deviation (FDSD), prickle factor (PF), and greasy fleece weight (GFW). The most persistent effect of
variation was with variation in MSL; with the MSL of sheep of genotype
being 12.5% greater than those of genotype
. A similar effect was observed from individual variant absence/presence models. This suggests that
should be further investigated as a possible gene-marker for improving MSL.
Tibetan sheep are mainly distributed in the Qinghai–Tibet Plateau. Its meat is not only essential for the local people but also preferred by the non-inhabitant of this plateau also. To investigate ...the salient development features and molecular mechanism of the meat difference of LT muscle caused by different growth stages in Tibetan sheep, the carcass performance, meat quality, and comparative transcriptome analysis were performed for investigating the potential molecular mechanism of the meat quality difference of the LT muscle caused by four growth stages 4-months old (4 months), 1.5-years old (1.5 years), 3.5-years old (3.5 years), and 6-years old (6 years) in the Tibetan sheep. The shear force increased with the increase of age (
p
< 0.05) while the intramuscular fat (IMF) was the highest at 1.5 y. The AMPK signaling pathway was significantly enriched in the four comparative groups. The weighted gene co-expression network analysis (WGCNA) results showed that the hub genes
P4HA2, FBXL4
, and
PPARA
were identified to regulate the meat quality. In summary, 1.5 years was found to be the most suitable slaughter age of the Tibetan sheep which ensured better meat tenderness and higher IMF content. Moreover, the genes
LIPE, LEP, ADIPOQ, SCD
, and
FASN
may regulate the transformation of the muscle fiber types through the AMPK signaling pathway, further affecting the meat quality.
Circular RNAs (circRNAs) have a regulatory role in animal skeletal muscle development. In this study, RNA sequencing was performed to reveal the temporal regularity of circRNA expression and the ...effect of the circRNA-miRNA-mRNA ceRNA regulatory network on the meat quality of longissimus thoracis (LT) muscle in Tibetan sheep at different growth stages (4 months old, 4 m; 1.5 years old, 1.5 y; 3.5 years old, 3.5 y; 6 years old, 6 y). There were differences in the carcass performance and meat quality of Tibetan sheep at different ages. Especially, the meat tenderness significantly decreased (
< 0.05) with the increase of age. GO functional enrichment indicated that the source genes of the DE circRNAs were mainly involved in the protein binding, and myofibril and organelle assembly. Moreover, there was a significant KEGG enrichment in the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway, as well as the calcium signaling pathway, regulating the pluripotency of the stem cells. The circRNA-miRNA-mRNA ceRNA interaction network analysis indicated that circRNAs such as circ_000631, circ_000281, and circ_003400 combined with miR-29-3p and miR-185-5p regulate the expression of
, and
related to the transformation of muscle fiber types in the AMPK signaling pathway. The oxidized muscle fibers were transformed into the glycolytic muscle fibers with the increase of age, the content of intramuscular fat (IMF) was lowered, and the diameter of the muscle fiber was larger in the glycolytic muscle fibers, ultimately increasing the meat tenderness. The study revealed the role of the circRNAs in the transformation of skeletal muscle fiber types in Tibetan sheep and its influence on meat quality. It improves our understanding of the role of circRNAs in Tibetan sheep muscle development.
In order to investigate the effects of aging on the expression of Mic60 and OPA1 and mitochondrial morphology in plateau animals, the expression of Mic60 and OPA1 genes and proteins, and the ...morphology of mitochondria in the myocardium of adult and aged Tibetan sheep were investigated. The expression of Mic60 and OPA1 genes and OPA1 protein were higher (p < 0.05) in the myocardium of adult Tibetan sheep than in those of the aged ones. The number of mitochondrial cristae in the myocardium of adult was higher than that in aged (p < 0.05). The density of mitochondria in the myocardium of adult was higher than that in aged (p < 0.01). Compared with the adult Tibetan sheep, the mitochondrial crista of aged were relatively sparse, the crista membrane was wide, and the mitochondria were not closely linked, showing fragmentation. These results suggest that the myocardial mitochondria of the adult have better energy supply ability, indicating that aging can lead to the weakening of oxygen supply in the myocardial mitochondria of Tibetan sheep.
microRNAs (miRNAs) are involved in the regulation of biological phenomena by down-regulating the expression of mRNAs. In this study, Liaoning cashmere (LC) goats (
= 6) and Ziwuling black (ZB) goats ...(
= 6) with different cashmere fiber production performances were selected. We supposed that miRNAs are responsible for the cashmere fiber trait differences. To test the hypothesis, the expression profiles of miRNAs from the skin tissue of the two caprine breeds were compared using small RNA sequencing (RNA-seq). A total of 1293 miRNAs were expressed in the caprine skin samples, including 399 known caprine miRNAs, 691 known species-conserved miRNAs, and 203 novel miRNAs. Compared with ZB goats, 112 up-regulated miRNAs, and 32 down-regulated miRNAs were found in LC goats. The target genes of the differentially expressed miRNAs were remarkably concentrated on some terms and pathways associated with cashmere fiber performance, including binding, cell, cellular protein modification process, and Wnt, Notch, and MAPK signaling pathways. The miRNA-mRNA interaction network found that 14 miRNAs selected may contribute to cashmere fiber traits regulation by targeting functional genes associated with hair follicle activities. The results have reinforced others leading to a solid foundation for further investigation of the influences of individual miRNAs on cashmere fiber traits in cashmere goats.
Long noncoding RNA (lncRNA) plays an important regulatory role in mammalian adipogenesis and lipid metabolism. However, their function in the longissimus thoracis (LT) muscle of fatty acid metabolism ...of Tibetan sheep remains undefined. In this study, fatty acid and fat content in LT muscle of Tibetan sheep were determined, and RNA sequencing was performed to reveal the temporal regularity of lncRNA expression and the effect of lncRNA-miRNA-mRNA ceRNA regulatory network on lipid metabolism of LT muscle in Tibetan sheep at four growth stages (4-month-old, 4 m; 1.5-year-old, 1.5 y; 3.5-year-old, 3.5 y; 6-year-old, 6 y). The results indicated that the intramuscular fat (IMF) content was highest at 1.5 y. Moreover, the monounsaturated fatty acid (MUFA) content in 1.5 y of Tibetan sheep is significantly higher than those of the other groups (
< 0.05), and it was also rich in a variety of polyunsaturated fatty acids (PUFA). A total of 360 differentially expressed lncRNAs (DE lncRNAs) were identified from contiguous period transcriptome comparative groups of 4 m vs. 1.5 y, 1.5 y vs. 3.5 y, 3.5 y vs. 6 y, and 4 m vs. 6 y, respectively. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis found that the target genes in lncRNA trans-mRNA were significantly related to the protein digestion, absorption, and fatty acid biosynthesis pathways (
< 0.05), which demonstrated that DE lncRNA
-regulated the target genes, and further regulated the growth and development of the LT muscle and intramuscular fatty acid metabolism in Tibetan sheep. We further analyzed the role of the lncRNA-miRNA-mRNA regulatory network in the lipid metabolism of Tibetan sheep. Additionally,
(lipase E hormone-sensitive enzyme)
, and other mRNA related to fatty acid and lipid metabolism and the corresponding lncRNA-miRNA regulatory pairs were identified. The enrichment analysis of mRNA in the regulatory network found that the AMPK signaling pathway was the most significantly enriched (
= 0.0000112361). Comprehensive transcriptome analysis found that the
, and
that were regulated by lncRNA might change the formation of energy metabolism in Tibetan sheep muscle through the AMPK signaling pathway, and oxidized muscle fibers are transformed into glycolytic muscle fibers, reduced IMF content, and the fatty acid profile also changed.
MicroRNAs (miRNAs) have been found to be involved in lipid deposition and metabolism. However, there have been no reports on the roles of miR-148a in the proliferation and adipogenesis of ...preadipocytes in sheep. In this study, the expression of miR-148a was profiled in the eight tissues of Tibetan ewes and differentiated preadipocytes, and the role of miR-148a in differentiation and proliferation of ovine preadipocytes was investigated using Oil Red O staining, CCK-8, EdU staining, cell cycle detection, and RT-qPCR. The effect of
on the differentiation of ovine preadipocytes was also investigated. The miR-148a was widely expressed in the eight tissues investigated and had significantly increased expression in liver, spleen and subcutaneous adipose tissues, and the heart. The expression of miR-148a continued to increase with the differentiation of ovine preadipocytes. The over-expression of miR-148a significantly promoted differentiation but inhibited the proliferation of ovine preadipocytes. The inhibition of miR-148a had the opposite effect on the differentiation and proliferation of ovine preadipocytes with over-expressed miR-148a. The results from the dual luciferase reporter assays showed that miR-148a mimic significantly decreased the luciferase activity of
-3'UTR dual luciferase reporter vector, suggesting that
is a target gene of miR-148a. In over-expressed-
preadipocytes, the number of lipid droplets remarkably decreased, and the expression levels of adipogenesis marker genes
,
,
,
,
and
were also significantly down-regulated. These results suggest that miR-148a accelerated the adipogenic differentiation of ovine preadipocytes by inhibiting
expression, and also inhibited the proliferation of ovine preadipocytes.
Diacylglycerol acyltransferase-1 (DGAT1) has been recognised as one of the functional genes during fat deposition and closely related to meat quality. It is well known that yak meat has low ...intramuscular fat (IMF) and poor tenderness, influencing the purchase decision for consumers. In this study, the variations of DGAT1 gene were detected using polymerase chain reaction single-stranded conformational polymorphism (PCR-SSCP) analysis so as to ascertain the association of DGAT1 variation with yak carcase and meat quality traits. Two variants (A
1
and B
1
) in intron 1 - exon 2 and another three variants (A
2
to C
2
) in intron 15 - exon 17 were identified in the yaks investigated. Three sequence variations (c.192-117 G > A, c.1252-23 C > T and c.1339 C > T) were detected among these variants, with c.192-117 G > A located in intron 1, c.1252-23 C > T located in intron 15 and c.1339 C > T located in exon 17. The mutation c.1339 C > T resulted in an amino acid change (p. Arg 447 Cys). Variants A
1
and B
2
were associated with a decrease and increase in Warner-Bratzler shear force (WBSF) (p = 0.027 and p < 0.001), respectively. Variant C
2
was associated with a decrease in WBSF and hot carcase weights (HCW) (p = 0.001 and p = 0.037, respectively). The presence of haplotype H3 and absence of H5 were highly associated with a decrease in WBSF (p < 0.05). These finding suggested that the variations in DGAT1 could be potential targets for gene-assisted selection to improve meat tenderness in Gannan yak.
Highlights
Three SNPs were identified in the DGAT1 gene in Gannan yak.
Variants (A
1
, B
2
and C
2
) and haplotypes (H3 and H5) have a significant influence on Warner-Bratzler shear force (WBSF) in Gannan yak.
DGAT1 variations may have potential in selection for improving meat tenderness in Gannan yaks.
Keratin-associated proteins (KAPs) are structural components of wool and hair fibers. To date, eight high glycine/tyrosine KAP (HGT-KAP) families have been identified in humans, but only three have ...been identified in sheep. In this study, the putative ovine homolog of the human KAP22-1 gene (
) was amplified using primers designed based on a human
sequence. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) was used to screen for variation in
in 390 Merino × Southdown-cross lambs and 75 New Zealand (NZ) Romney sheep. Three PCR-SSCP banding patterns were detected and DNA sequencing revealed that the banding patterns represented three different nucleotide sequences (
). Two single nucleotide polymorphisms (SNPs) were identified in these sequences. Variant
was most common with a frequency of 81.3% in NZ Romney sheep, while in the Merino × Southdown-cross lambs,
was more common with a frequency of 51.8%. The presence of
was found to be associated with increased wool yield and decreased mean fiber curvature (MFC). Sheep of genotype
or
had a higher wool yield than those of genotype
. These results suggest that ovine
variation may be useful when developing breeding programs based on increasing wool yield, or decreasing wool curvature.
PDF
