Carcass weight, meat quality and muscle components are important traits economically and they underpin most of the commercial return to goat producers. In this study, the
muscle tissues were ...collected from five Liaoning cashmere (LC) goats and five Ziwuling black (ZB) goats with phenotypic difference in carcass weight, some meat quality traits and muscle components. The histological quantitative of collagen fibers and the transcriptome profiles in the
muscle tissues were investigated using Masson-trichrome staining and RNA-Seq, respectively. The percentage of total collagen fibers in the
muscle tissues from ZB goats was less than those from LC goats, suggesting that these ZB goats had more tender meat. An average of 15,919 and 15,582 genes were found to be expressed in
muscle tissues from LC and ZB goats, respectively. Compared to LC goats, the expression levels of 78 genes were up-regulated in ZB goats, while 133 genes were down-regulated. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the differentially expressed genes (DEGs) were significantly enriched in GO terms related to the muscle growth and development and the deposition of intramuscular fat and lipid metabolism, hippo signaling pathway and Jak-STAT signaling pathway. The results provide an improved understanding of the genetic mechanisms regulating meat production performance in goats, and will help us improve the accuracy of selection for meat traits in goats using marker-assisted selection based on these differentially expressed genes obtained.
Tibetan sheep is one of the dominant livestock at Qinghai-Tibet Plateau, which is the main food source of local people. In order to investigate the effect of slaughter age on meat quality, fatty acid ...profile and expression of myosin heavy chain (MyHC) isoform genes were analyzed in Tibetan sheep. A total of 24 Tibetan sheep including 4 months old (4 m), 1.5 years old (1.5 y), 3.5 years old (3.5 y), and 6 years old (6 y) were randomly selected. The results indicated that the MyHC IIx and MyHC IIb mRNAs increased with age, whereas MyHC IIa mRNA decreased. MyHC I mRNA was highest at 3.5 y. There were differences in the muscle fiber types of Tibetan sheep at different ages. Intramuscular fat (IMF) was highest at 1.5 y, the pH
45min
and pH
24h
value of 6 y sheep were lower than the other groups, the shear force increased with age (
p
< 0.05), and drip loss increased with age (
p
< 0.01). Tibetan sheep at 1.5 y had lower saturated fatty acid (SFA) contents and higher monounsaturated fatty acid (MUFA) contents (
p
< 0.05). Different muscle fiber types influence the meat quality and fatty acid composition of Tibetan sheep with increasing age. These results demonstrated the effect of age on meat quality of Tibetan sheep through regulation of expression of the MyHC isoforms which changed the myofiber types, and 1.5 y Tibetan sheep meat was more suitable for a healthy human diet.
Tomato yield prediction plays an important role in agricultural production planning and management, market supply and demand balance, and agricultural risk management. To solve the problems of low ...accuracy and high uncertainty of tomato yield prediction methods in solar greenhouses, based on experimental data for water and fertilizer consumption by greenhouse tomatoes in different regions over many years, this paper investigated the prediction models of greenhouse tomato yields under three different soil fertility conditions (low, medium, and high). Under these three different soil fertility conditions, greenhouse tomato yields were predicted using the neural network prediction model (NN), the neural network prediction model based on particle swarm optimization (PSO–NN), the neural network prediction model based on an adaptive inertia weight particle swarm optimization algorithm (AIWPSO–NN), and the neural network prediction model based on the improved particle swarm optimization algorithm (IPSO–NN). The experimental results demonstrate that the evaluation indexes (mean square error, mean absolute error, and R2) of the IPSO–NN prediction model proposed in this paper were superior to the other three prediction models (i.e., NN prediction model, AIWPSO–NN prediction model, and IPSO–NN prediction model) under three different soil fertility conditions. Among them, compared with the NN prediction model, the MSE of the other three prediction models under high soil fertility decreased to 0.0082, 0.0041, and 0.0036; MAE decreased to 0.0759, 0.0511, and 0.0489; R2 decreased to 0.8641, 0.9323, and 0.9408. These results indicated that the IPSO–NN prediction model had a higher predictive ability for greenhouse tomato yields under three different soil fertility conditions. In view of the important role of tomato yield prediction in greenhouses, this technology may be beneficial to agricultural management and decision support.
Keratin-related proteins (KAPs) are structural components of wool fibers and are thought to play a key role in regulating the physical and mechanical properties of fibers. Among all KAP genes (
),
...gene family (
,
,
,
, and
) is a very important member with high polymorphism and notable association with some wool traits. In this study, we used real-time fluorescence quantitative PCR (RT-qPCR) and in situ hybridization to investigate spatiotemporal expression of
. The results revealed that
family genes were significantly expressed during anagen compared to other stages (
< 0.05). And it was found the five genes were expressed predominantly in the dermal papillae, inner and outer root sheaths, and showed a distinct spatiotemporal expression pattern. Also, it was found that
and
mRNA expression was negatively correlated with wool mean fiber diameter (MFD) and mean staple strength (MSS) (
< 0.05). In summary, the
family genes share a similar spatiotemporal expression pattern. And
and
may regulate the MFD and MSS of Gansu Alpine fine-wool sheep wool by changing the expression.
Keratin-associated proteins (KAPs) are structural components of wool fibres. High-glycine/tyrosine (HGT)-KAPs are a subset of the KAP family, and their abundance in fibres varies. In this study, we ...report the discovery of an ovine HGT-KAP gene to which we assigned the name KRTAP36-2. Polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analyses revealed four variants of this gene in a screening population of 170 sheep from a variety of breeds. The DNA sequencing of the variants revealed four single-nucleotide polymorphisms (SNPs) and a dinucleotide deletion. Three of these SNPs were in the coding region, and one of these was non-synonymous and potentially led to the amino acid substitution p.Cys27Gly near the middle of the protein. The remaining SNP was located near the putative TATA box, and the di-nucleotide deletion was near the putative transcription initiation site. The effect of this variation in KRTAP36-2 was investigated in 274 Southdown × Merino lambs that were the progeny of five sires. Variation was only found to be associated with wool yield, that is, the proportion of the greasy fleece that remained as clean fleece upon scouring (expressed as a percentage). This may have some value in increasing wool production.
As an important ruminant on the Qinghai-Tibet Plateau, Tibetan sheep can maintain their population reproduction rate in the harsh high-altitude environment of low temperature and low oxygen, which ...relies on their special plateau adaptations mechanism that they have formed for a long time. Microbiomes (known as "second genomes") are closely related to the nutrient absorption, adaptability, and health of the host. In this study, rumen fermentation characteristics, the microbiota, and rumen epithelial gene expression of Tibetan sheep in various months were analyzed. The results show that the rumen fermentation characteristics of Tibetan sheep differed in different months. The total SCFAs (short-chain fatty acids), acetate, propionate, and butyrate concentrations were highest in October and lowest in June. The CL (cellulase) activity was highest in February, while the ACX (acid xylanase) activity was highest in April. In addition, the diversity and abundance of rumen microbes differed in different months. Bacteroidetes (53.4%) and Firmicutes (27.4%) were the dominant phyla.
and
were the dominant genera. The abundance of
was highest in June (27.8%) and lowest in December (17.8%). In addition, the expression of
(Claudin-4) and
(Zonula occludens 1) was significantly higher in April than in August and December, while the expression of
(Sodium glucose linked transporter 1) was highest in August. Correlation analysis showed that there were interactions among rumen fermentation characteristics, the microbiota, and host gene expression, mainly by adjusting the amino acid metabolism pathway and energy metabolism pathway to improve energy utilization. At the same time, we adjusted the balance of the rumen "core microbiota" to promote the development of rumen and maintain the homeostasis of rumen environment, which makes Tibetan sheep better able to adapt to the harsh environment in different periods of the Qinghai-Tibet Plateau.
The importance of sheep's wool in making textiles has inspired extensive research into its structure and the underlying genetics since the 1960s. Wool keratin-associated proteins (KAPs) are a key ...structural component of the wool fibre. The characterisation of the genes encoding these proteins has progressed rapidly with advances in the nucleotide and protein sequencing. This review describes our knowledge of ovine KAPs, their categorisation into families, polymorphism in the proteins and genes, the clustering and chromosomal location of the genes, some characteristics of gene expression and some potential effects of the KAPs on wool traits. The extent and nature of genetic variation in wool KAP genes and its association with fibre characteristics, provides an opportunity for the development of gene-markers for selective breeding of sheep to produce better wool with properties highly matched to specific end-uses.
Circular RNA (circRNA) is a type of non-coding RNA generated from back-splicing the reactions of linear RNA. It plays an important role in various cellular and biological processes. However, there ...are few studies about the regulatory effect of circRNAs on cashmere fiber traits in cashmere goats. In this study, the expression profiles of circRNAs in skin tissue were compared between Liaoning cashmere (LC) goats and Ziwuling black (ZB) goats, with a significant difference in cashmere fiber yield, cashmere fiber diameter, and cashmere fiber color, using RNA-seq. A total of 11,613 circRNAs were expressed in the caprine skin tissue, and their type, chromosomal distribution, and length distribution were characterized. A total of 115 up-regulated circRNAs and 146 down-regulated circRNAs in LC goats were screened compared to ZB goats. The authenticity of 10 differentially expressed circRNAs was validated by detecting their expression levels and the head-to-tail splice junction using RT-PCR and DNA sequencing, respectively. The parent genes of differentially expressed circRNA were mainly enriched in some Gene Ontology (GO) terms and pathways related to cashmere fiber traits, such as the canonical Wnt signaling pathway, which is involved in the regulation of cell promotion, stem cell proliferation, Wnt signaling pathway regulation, epithelial morphogenesis, MAPK signaling pathway, and cell adhesion molecules pathway. Eight differentially expressed circRNAs were further selected to construct a circRNA-miRNA network, and some miRNAs that were previously reported as related to fiber traits were found in the network. This study provides a deep understanding of the roles of circRNAs in the regulation of cashmere fiber traits in cashmere goats and the involvement of differential splicing in phenotypic expression according to breed and region.
MicroRNAs (miRNAs) are crucial regulatory molecules in lipid deposition and metabolism. However, the effect of miR-200b on the regulation of proliferation and adipogenesis of ovine preadipocytes is ...unknown in the sheep (Ovis aries). In this study, the expression profiles of miR-200b were investigated in the seven tissues of Tibetan ewes and differentiated preadipocytes. The effect of miR-200b, as well as its target genes p27 and KLF9, on the proliferation of ovine preadipocytes and adipogenesis was also investigated, using cell viability analysis, EdU staining, Oil Red O staining and reverse transcription-quantitative PCR (RT-qRCR). The miR-200b was expressed in all the tissues investigated, and it was highly expressed in lung, liver, subcutaneous adipose and spleen tissues. The expression of miR-200b continuously decreased when the differentiation of ovine preadipocytes initiated. The miR-200b mimic dramatically accelerated the proliferation but inhibited differentiation of ovine preadipocytes. The miR-200b inhibitor resulted in an opposite effect on the proliferation and differentiation of ovine preadipocytes. The dual luciferase reporter assay results showed that miR-200b mimic significantly decreased the luciferase activity of p27 and KLF9 in HEK293 cells transfected with wild-type dual luciferase reporter vectors. This suggests that p27 and KLF9 are the target genes of miR-200b. In over-expressed-p27 preadipocytes, the number of EdU-labeled preadipocytes and the expression levels of proliferation marker genes CDK2, CDK4, CCND1 and PCNA significantly decreased. In addition, the transfection of over-expressed-KLF9 vector into adipocytes remarkably increased the accumulation of lipid droplets and the expression levels of differentiation marker genes aP2, PPARγ, LPL and GLUT4. These results suggest that miR-200b accelerated the proliferation but inhibited the adipogenic differentiation of ovine preadipocytes by targeting p27 and KLF9, respectively.
Keratins are the main structural protein components of wool fibres, and variation in them and their genes (KRTs) is thought to influence wool structure and characteristics. The PCR–single strand ...conformation polymorphism technique has been used previously to investigate genetic variation in selected coding and intron regions of the type II sheep keratin gene KRT81, but no variation was identified. In this study, we used the same technique to explore the 5′ untranslated region of KRT81 and detected three sequence variants (A, B and C) that contain four single nucleotide polymorphisms. Among the 389 Merino × Southdown cross sheep investigated, variant B was linked to a reduction in clean fleece weight, while C was associated with an increase in both greasy fleece weight and clean fleece weight. No discernible effects on staple length or mean-fibre-diameter-related traits were observed. These findings suggest that variation in ovine KRT81 might influence wool growth by changing the density of wool follicles in the skin, the density of individual fibres, or the area of the skin producing fibre, as opposed to changing the rate of extrusion of fibres or their diameter.
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